I have ALWAYS wanted to get some basic understanding of how the strange rotary engines of the WW1 era operated. This is an EXCEPTIONAL explanation. Many Thanks from the UK.
Thank you for you feedback and compliments. Note that Weight was an important issue during the early days of aviation. Rotary engines have no need for cooling liquid, pipes, water jackets, radiator or batteries. They provided excellent self-cooling. The rotating crankcase/cylinder assembly created its own cooling airflow, even with the aircraft at rest. Because of the rotating mass, no flywheel is needed. They provided and excellent power to weight ratio. Thanks for watching !!
Thank you for your compliments. Indeed all done without computers, CNC etc. Just pencil on paper and perhaps a "Faber Castell" slide ruler. Thanks for watching !
Thank you for your compliments. It's these kind of responses that keeps me creating these videos. If you want to see more, click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines. Thanks for watching !!!
Maybe some more details will help understanding how this engine works. The method used in the Gnome is different from the Clerget, Bentley or Le Rhone rotary engines . The Gnome doesn't have induction tubes. The petrol line is connected to the hollow (stationary) crank shaft (doesn't rotate. Through a petrol tube within the crank shaft, the petrol gets drawn into the crank case via the petrol nozzle on the front end of this tube. When a piston reaches its bottom position (BDC - inlet stroke), the petrol gets drawn into the appropriate cylinder though the 32 holes (ports) at the skirt of the cylinders. The petrol within the cylinders will mix with the air that was drawn into the cylinder during the inlet stroke, because the valve is open. (see 8:47 etc. video frames) Note that this valve handles both the inlet- and exhaust flows (single valve = monosoupape in French). Hope this helps and thanks for watching !!
Thank you so much for this great video. I went from somehow missing the complete existence of this engine to a great basic understanding of it in 10 minutes. Fantastic work.
Hi Pierre, just found this brilliant animation you’ve achieved here, well done you!! It has enabled my mind to travel back 57 years to when I was a 16 year old engineering apprentice and out of the blue a 7 cylinder Gnome le Rhône turned up in our yard..and I was told (as I did have a leaning to a challenge), that my job was to de rust and rebuild it with no manual whatsoever to help! My boss ,however was a very clever man, and with the help of the Shuttlesworth Trust at Biggleswade we rebuilt it to full running order, for a Bleriot, all smuggled out of Belgium I was told! This was by an ex Royal Navy pilot of considerable wealth! It was to be used as a back up aircraft for the film the Magnificent Men and their Flying Machines! We didn’t,unfortunately manage in time, and the philanthropist died soon after! I never did find out what happened to it all..I was very,very disheartened! Anyone out there know?
Thank you for your response and compliments . Besides the memories, I hope this video answered some of the issues that you where faced with way back then. Perhaps I should have published this video it 57 years ago ... but, like you, I was 16 then and no CAD nor the possibilities we have today. No one I know out there, no contacts from these memorable 'old' days. Wish I had, they could possibly would have answers to issues I bumped in when doing this project. However, visiting Tony Wytenbug (CAMS) in New Zealand was a fantastic experience, help and resource. He and his team have re-build (and sold) the Gnome. Thanks for you kind words and for watching !!
Thank you for your compliments. It's these kind of responses that keeps me creating these videos. If you want to see more, click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines. Thanks for watching !!!
Mr. Jansen, your work is comparable to that of the geniuses who designed this elegant engine a century ago. Watching your animation, I can almost hear the roar and smell the castor oil in the exhaust. Many thanks.
Thanks for your compliments, but no ... they where the geniuses. I just had to model (copy) and animate what they've invented and made reality (without computers) a century ago. Thanks for watching !!
Thank you for your compliments and I'm glad to hear the video helped to understand the engine's operation. Thanks for watching !! Cheers (and all the best for 2024)
Indeed, a 4 stroke, single valve with and the 9 cylinders rotating with the crankcase. The oil is pumped into the crankcase and through several channels to other parts of the engine. They used castor oil which doesn't mix with the petrol. Thank you for you compliments and thanks for watching
Thanks for this phantasic video. It's great fun to see how all those parts are coming together. Also the function principle is explained very understandable! If I will be asked next time how the mono works, I will point them to this video. This will save me a lot of words ;-) Looking forward to see your next vid. For me, the mono is still the most beautiful rotary. Followed by the Clerget.
Thank you for your compliments and thanks for watching !! There are some more videos on my UA-cam channel: ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html You can also walk around the various WW1 engines on my website: www.pjvision.nl Cheers, Pierre.
Thank you for your compliments. Indeed these engines are masterpieces. The craftmanship of the people that made these engines is truly amazing. No CNC. All was designed without computers, just pencil on paper and perhaps a Faber Castel slide ruler. Thanks for watching. Cheers (and best wishes for 2024)
Thank you for your compliments. It's these kind of responses that keeps me going !. Perhaps you want to see more. Click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines and as well as a 360 panorama view of the Sopwith Camel cockpit. Thanks for watching !!
@@pierrejansen2702 You are most welcome Pierre. I have had a brief look at your channel (like it all, love the VickersMovie) and subscribed, and will watch out for your work in the future. To be honest I think my initial comment was understated - your work is truly outstanding and deserves a much wider audience. Anyone who has even a passing interest in engineering, or how things are made to do what they do, will be captivated. Bravo, maestro!
Good to hear. Thank you for your compliments. As you may have seen, there are more WW1 engine videos on my channel: www.youtube.com/@pierrejansen2702 and related information on my website: www.pjvision.nl/ Cheers and thanks for watching !!.
Thank you for your compliments. It's these kind of responses that keeps me creating these videos. If you want to see more, click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines. Thanks for watching !!!
This is beautiful . . . . and I love it! The only point I would make, however, is that the 9-B2 (Monosoupape) has the suction operated intake valve in the top of the cylinder. It sucks in the fuel/air mixture (oil diluted) directly from the crankcase. Maybe I am mistaken about this . . . . let me know. If I am correct, it would be really elucidating to show that feature. According to Aircraft Engine Historical Society . . . . "The inlet valves, which are in the center of the piston heads, are made of steel and are extremely light. The valve is cone shaped and has a short hollow stem which slides in a cast iron bush in the center of the valve seating or cage. During the suction stroke, the pressure in the cylinder falls below that in the crankcase with the result that the valve opens, overcoming the springs, and admits a charge into the cylinder."
Thanks for your compliments! Regarding the intake valve, as you've noted the Gnome doesn't have induction tubes. The petrol line is connected to the hollow (stationary) crank shaft (doesn't rotate. Through a petrol tube within the crank shaft, the petrol gets drawn into the crank case via the petrol nozzle on the front end of this tube. When a piston reaches its bottom position (BDC - inlet stroke), the petrol gets drawn into the appropriate cylinder though the 32 holes (ports) at the skirt of the cylinders. The petrol within the cylinders will mix with the air that was drawn into the cylinder during the inlet stroke, because the valve is open. (see 8:47 etc. video frames) Note that this valve handles both the inlet- and exhaust flows (single valve = monosoupape in French). Hope this helps and thanks for watching !!
Thank you for your compliments. It's these kind of responses that keeps me creating these videos. If you want to see more, click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines. Thanks for watching !!!
As a project many years ago in college I made a drawing of a WW1 rotary using Autodesk Inventor. I also transfered the drawings to a 3d printer (the sand and super glue type) and made a physical model the next semester. This movie makes my project look primitive. Great job.
My grandfather, Sgt Fidelis S. Jackson USAAS, was a “crew chief” on the Nieuport 28 with the 94th in France with the Gnome 9N engine. Now I know why he could fix anything
I'm honored ! Thanks for your msg. Although your grandfather was a Crew chief, he was one of the USAAS 'Fly boys' stationed in France. Very special and besides technical skills, improvising was one of the main skills these man possessed. Indeed, special talents were required to fix these rotary engines and to keep the planes flying. Thanks for watching !!
Sehr gutes Video! Ich kann alle Arbeitsschritte zur Montage des Motors aus eigener Erfahrung sehr gut nachvollziehen. Ein genial simples Triebwerk, wunderbar anschaulich demonstriert! Chapeau den Schöpfer dieses Filmes!
i liked how you showed slowly with a few parts where to place them first then speed up for that part, instead of just instantly doing all of them at once
@@pierrejansen2702 That blushing stuff happens to me sometimes too. I just figure it is a bunch of blood running to my head to get me ready for the next big learning event! LOL I twisted some nobs on Blender, have a pretty good grip on SolidWorks and TurboCad, doing 3-d stuff mostly for engineering stuff or architectural stuff. I can make the things look right, and get my drawings stamped by engineers and architects as needed; but I have yet to figure out the animations and stuff that you do that makes it look so cool.
@@4n2earth22 Getting your drawings stamped by engineers and architects its probably more important (pays the bill). 3D visualizations and animations are very, very time consuming !! Fyi, for rendering the (thousands) of images for these videos, I'm using 3 systems in parallel (Distributed processing). Thanks for your comment and compliment !!
Fantástica producción y generación de ésta animación mecánica 3D. Si esto lo vieran aquellos precursores de la aviación, quedarían tan asombrados como nosotros al ver hasta donde hemos llegado.
Thank you for your compliments. Indeed, these aviation pioneers had very limited tools. Therefore it's still amazing to see what they designed. Thanks for watching !!
Thank you for your compliments. It's these kind of responses that keeps me creating these videos. If you want to see more, click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines. Thanks for watching !!!
Thank you for your compliments. It's these kind of responses that keeps me creating these videos. If you want to see more, click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines. Thanks for watching !!!
Here is the answer: "In 1913, Louis Seguin and his brother Laurent (engineers who founded the Société Des Moteurs Gnome [the Gnome motor company] in 1905) introduced the new Monosoupape series, which eliminated the inlet valve, replacing it with piston-controlled transfer ports similar to those found in a two-stroke engine."
Exactly. When a piston reaches its bottom position (BDC - inlet stroke), the petrol gets drawn into the appropriate cylinder though the 32 holes (ports) at the skirt of the cylinders. The petrol within the cylinders will mix with the air that was drawn into the cylinder during the inlet stroke, because the valve is open. (see 8:47 in the video) Thanks for watching !!
Indeed, these rotary engines designed in the early days of aviation, were real Masterpieces of engineering. No computer driven machinery (CNC). Thanks for watching !!
Thank you for your compliments. You can always consult CAMS in New Zealand ( cams.net.nz/ ). -;) They are building (and selling) the Gnome Monosoupape and just manufactured a 7 cyliner prototype version ! Thanks for watching !!
Looking back at these engines through modern eyes, they look like they were designed by Fred Flintstone. But, once you see how they work you realize that Fred Flintstone was a genius!
Thank you for your compliments and for watching !! Being near that thing isn't that bad ...... If you want you can see me behind the engine as to control air, petrol and oil, engine during a test run. See: ua-cam.com/video/5Y6PsDfeFJ4/v-deo.html It is very noisy though, and you'll get a castor oil shower ;-)
Рік тому+1
Sevdiğim bir film gibi; gidip tekrar geliyor ve yeniden izliyorum. Muhteşem.
Best explanation of the working principleI have come across - only thing I would add is that pressure of burned gasses is about equal to the rich mixture in crankcase by the time the ports are uncovered on the bottom part of the power stroke
Thanks for your compliments and for your comment Indeed, you're right. Same would apply to separate inlet and exhaust valves during the moment of overlapping. However, equal pressure would not be a real issue, provided they are almost equal. I'm sure there have been thoughts about this during the designing a single valve engine. Whatever, no one to ask and it did work. Thanks for watching. Cheers, Pierre
Great animation of an ingeniously simple engine. Throttling was only by flicking off and on the ignition and mabey some mixture adjustment. There were two row models as well,where as I remember you could shut off one then the other row for two power settings. But you had to keep flicking the switch on every few seconds as the plugs quickly fouled and mabey it didn't catch at all when you needed it again! Many of these early Areo engines used Castor bean oil as well as did alot of race cars, thats where "Castrol" comes from. because it was unsurpassed for many years as a high temp oil. (Yes, the same oil the pharmacy sold as a laxative!) These Radials consume gallons of oil per flight and emit it unburned in the exhaust. thats why many WW1 pilots had no windsheilds, goggles and a scarf! Grandpa told me about taking his first plane ride in the 1920's it was behind a Gnome radial. The passenger sets in front and grandpa was to macho for goggles or scarf. The pilot laughed, and took off. Grandpa's eyes were burning so bad even before talking off he saw virtually nothing, wasn't breathing thru a scarf, and so, had to stop several times on the way home afterwards to fertilize the ditchbank from diarrhea from all the swallowed oil! I wonder if the cylinder cams were ground the same lift and duration since the inner lifters will act "bigger" than the outer due to pushrod angles. Great work! Next time Fold the legs on cotter pins! (Ok, im being silly now)
Thank you for your compliments. Regarding the throttling, blipping the ignition switch was the only way to throttle the Gnome engines. Some experiments were conducted with a selector switch, allowing to switch OFF (disable) half of the spark plugs. As you may know, some other rotaries e.g. the Clerget and the Le Rhone engines used the Tampier throttling device along with the Tampier bloc-tube carburetor. Thanks for your comments and for watching !!
As an individual who has been lucky enough to work first hand in New Zealand on this very engine- strip down and total recording of an original for remanufacture, this must have taken you a very long time and you should be commended on how accurate you have this. A difference we found (memory going back about 10 years now!) Was that we assembled these things with the front of the engine facing up with the crakshaft already in its mounts, and with the pistons already assemble onto the master rod, used the back half of the crankcase to place a cylinder over each piston kinda one by one. The channels in the half case we're more than enough to keep the pistons from falling out in this 'half shell' kind of state.
Thanks for your compliments and feedback !! For the video, I closely followed the procedure as outlined in the Instruction Book #2, acquired from CAMS (Tony Wytenberg) and all other information I was able to find. However, I realize that in reality no one follows the book ;-) Thanks for watching !! Cheers
@@pierrejansen2702ah yes. I never met. Tony but we (TVAL) did ours at roughly the same time (2009? 10? 11?) And his work looked good- more targeted towards reliable runners I think. We were just trying to replicate the exacting design. Mismatched oil holes and all.
@@reanimate_xyz I visited TVAL in 2017 and had a tour through the workshop. Very interesting but I didn't get answers on the specific Clerget manufacturing questions I had. Next on our trip was a visit to CAMS, stayed a couple of days with Tony and family. I tried to persuade Tony to build a Clerget 9B too, but he felt that he'd better focus on his Gnome business (going quite well). Cheeers !
Have to say I admirer the sophistication of the design and engineering, then to have to manufacture all the parts. Unfortunately most of the population today is unaware they hop into their cars taking it for granted. The Aviation industries in 100 years look at the difference, jumbo jets that can fly without pilots( although not done, yet?). Excellent work Pierre. Hopefully I planted a seed for jet engines, fly by wire, DC3 hydraulics. Ok I'll stop.
Keep in mind that weight was an important issue during the early days of aviation. Rotary engines have no a need for cooling liquid, pipes, water jackets and the radiator. This provides excellent self-cooling, the rotating crankcase/cylinder assembly created its own cooling airflow, even with the aircraft at rest. Because of the rotating mass, no flywheel is needed. But, days have changed and jet engines offer the same, but much more sophisticated. Both designs offer and excellent power to weight ratio. Thanks for watching !!
Excellent Video ! .... I was Wondering how those old Airplane Rotary Engines worked ? ... And your Animation made its design and function easy to understand .... Cheers !
Thank you for your compliments. It's these kind of responses that keeps me creating these videos. If you want to see more, click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines. Cheers and thanks for watching !!!
Thank you for your compliments. It's these kind of responses that keeps me creating these videos. If you like to see more. Click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines. Thanks for watching !!
@@MSSakib-lz2gg Could do, there are so many interesting engines. For now, I'm trying to keep the history of the early days of aviation and aero engines alive. Thanks for your response !!.
Awesome animation,it surprises me that the ignition systems actually work with such exposure!! Good old fashioned hand machined and hand built engines...perfectly balanced!! One correction...Walthamstow is in East London, not Essex!! Thanks for posting and taking the time to make such brilliant content
Thanks for your compliments and for watching ! Regarding Walthamstow, I'm confused as it is listed as a major district in N-E London, historically in the county of Essex (and became part of Greater London in 1965) ????. Oh well, there's no way change the published youtube videos anyway.
Liked the pic showing the Alfred Herbert turret lathe at the beginning... I have a Herbert No 4 turret lathe from around WW1 era... Lineshaft driven... ☹🇬🇧
I didn't think about just animated assembly. it's a real technological wonder of the day. I'd liked to see actual footage of the construction or a build from a modeler's project, as there are radial piston and rotary engine kits out there. nice work tho
Thanks for your response. CAMS in New Zealand is building the engine in 1:1 scale ( cams.net.nz/ ) Not a modelers project but maybe worth looking at. Thanks for watching !!
All my pleasure!...Somewhere buried in my loft I believe I may have still,all the photos I took at the time?! If I locate them in the not too distant future I will contact you again! All the best for now, cheers ..Nigel
@@pierrejansen2702 had you considered doing one for the de Havilland Gypsy 6 as used on the DH.88? You have a real talent for this. Once again thank you.
@@smalcolmbrown Thanks again. There are many interesting planes and engines, but I'm trying to keep the early days of aviation (and engines) alive. Thanks for your response !!
@@pierrejansen2702 I had better declare an interest here. I volunteer at the de Havilland Aircraft Museum and helped restore a dh.88 replica that was used in the film the great air race. Half the fun is figuring out how they did it 100 years ago without the Benifit of modern machine tools and metalagergy. They were very skilled people back then
@@smalcolmbrown I see ! Restoring the DH88 must have been a great project (and challenge). It's a beautiful plane ! Was it the G-ACSS that you worked on ? Indeed, it's remarkable to see what these engineers achieved. No computers, CNC etc. and limited material choices ... just workmanship skills. They designed and produced engineering master pieces in those days ! Thanks for your response
sorry for the stupid question.. I saw radial engines where the cylinders doesn't rotate and others where cylinders rotate. In this video cylinders rotate, but what are the advanteges? SO much mass and weights rotating doesn't mean a loss of energy? Thanks
Weight was an important issue during the early days of aviation. Rotary engines have no need for cooling liquid, pipes, water jackets, radiator or batteries. They provided excellent self-cooling. The rotating crankcase/cylinder assembly created its own cooling airflow, even with the aircraft at rest. Because of the rotating mass, no flywheel is needed. No, no real loss of energy. Rotary engines provided and excellent power to weight ratio. Thanks for watching !!
I have ALWAYS wanted to get some basic understanding of how the strange rotary engines of the WW1 era operated. This is an EXCEPTIONAL explanation. Many Thanks from the UK.
Thank you for you feedback and compliments.
Note that Weight was an important issue during the early days of aviation. Rotary engines have no need for cooling liquid, pipes, water jackets, radiator or batteries. They provided excellent self-cooling. The rotating crankcase/cylinder assembly created its own cooling airflow, even with the aircraft at rest. Because of the rotating mass, no flywheel is needed. They provided and excellent power to weight ratio.
Thanks for watching !!
@@pierrejansen2702
Many thanks from Italy too.
@@tonykeith76 Thank you. You've made my day.
Ciao, saluti dall'Olanda !
Brilliant animation, and very high tech precision work from a hundred years ago.
Thank you for your compliments.
Indeed all done without computers, CNC etc. Just pencil on paper and perhaps a "Faber Castell" slide ruler.
Thanks for watching !
Incredible, the best technical animation I have ever watched so far
Thank you for your compliments. It's these kind of responses that keeps me creating these videos.
If you want to see more, click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html
Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines.
Thanks for watching !!!
Killer tune, brother. Actual "music", that enhanced the video, instead of ruining it! BRAVO! 👏👌❤🎉
Thank you, glad you liked it!
Thanks for watching (and listening). Cheers !
Even after seeing it being assembled and in action it still baffles me as to how this engine works. Quite amazing.
Maybe some more details will help understanding how this engine works.
The method used in the Gnome is different from the Clerget, Bentley or Le Rhone rotary engines . The Gnome doesn't have induction tubes. The petrol line is connected to the hollow (stationary) crank shaft (doesn't rotate. Through a petrol tube within the crank shaft, the petrol gets drawn into the crank case via the petrol nozzle on the front end of this tube. When a piston reaches its bottom position (BDC - inlet stroke), the petrol gets drawn into the appropriate cylinder though the 32 holes (ports) at the skirt of the cylinders. The petrol within the cylinders will mix with the air that was drawn into the cylinder during the inlet stroke, because the valve is open. (see 8:47 etc. video frames)
Note that this valve handles both the inlet- and exhaust flows (single valve = monosoupape in French).
Hope this helps and thanks for watching !!
Thank you so much for this great video. I went from somehow missing the complete existence of this engine to a great basic understanding of it in 10 minutes. Fantastic work.
Thank you for your compliments and for watching. Glad it helped !!
Fantastic animation, really impressive. One of the best I saw until now.
Glad you liked it!
Thank you for your compliments and thanks for watching !!
Hi Pierre, just found this brilliant animation you’ve achieved here, well done you!!
It has enabled my mind to travel back 57 years to when I was a 16 year old engineering apprentice and out of the blue a 7 cylinder Gnome le Rhône turned up in our yard..and I was told (as I did have a leaning to a challenge), that my job was to de rust and rebuild it with no manual whatsoever to help! My boss ,however was a very clever man, and with the help of the Shuttlesworth Trust at Biggleswade we rebuilt it to full running order, for a Bleriot, all smuggled out of Belgium I was told! This was by an ex Royal Navy pilot of considerable wealth! It was to be used as a back up aircraft for the film the Magnificent Men and their Flying Machines! We didn’t,unfortunately manage in time, and the philanthropist died soon after! I never did find out what happened to it all..I was very,very disheartened! Anyone out there know?
Thank you for your response and compliments . Besides the memories, I hope this video answered some of the issues that you where faced with way back then. Perhaps I should have published this video it 57 years ago ... but, like you, I was 16 then and no CAD nor the possibilities we have today. No one I know out there, no contacts from these memorable 'old' days. Wish I had, they could possibly would have answers to issues I bumped in when doing this project.
However, visiting Tony Wytenbug (CAMS) in New Zealand was a fantastic experience, help and resource. He and his team have re-build (and sold) the Gnome.
Thanks for you kind words and for watching !!
I finally got my head around it. thankyou for taking the time to make a detailed video.
Glad you liked it and thanks for watching
Best ever mechanical animation.
Thanks for your compliment and for watching !!
After watching the animation, I feel I can assemble an engine and get it up and running. Wow! Thank you so much.
Thank you for your compliments.
It's these kind of responses that keeps me creating these videos.
If you want to see more, click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html
Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines.
Thanks for watching !!!
Mr. Jansen, your work is comparable to that of the geniuses who designed this elegant engine a century ago. Watching your animation, I can almost hear the roar and smell the castor oil in the exhaust. Many thanks.
Thanks for your compliments, but no ... they where the geniuses. I just had to model (copy) and animate what they've invented and made reality (without computers) a century ago.
Thanks for watching !!
I knew I had seen a biplane with an engine that spun! I had wondered for years if I had imagined it. Thank you for this.
Thank you for your compliments and thanks for watching the video !!
Just loved this. Replayed a dozen times to understand the operation but got it in the end. Brilliant animation! Thanks so much.
Thank you for your compliments and I'm glad to hear the video helped to understand the engine's operation.
Thanks for watching !!
Cheers (and all the best for 2024)
Spectacular graphics. I've never seen anything like it before. WOW!
Thanks for your compliments and for watching !!
Excellent work. I finally see the details of how a Gnome works.
Thanks for your compliments and thanks for watching !!
Thank You for this beautiful presentation!
Thanks for your compliments and thank you for watching !!
*SO IT IS* a pressurised crankcase 4 stroke single valve rotating block 9 cylinder dry sump rotary engine - WOW
Brilliant video BTW - thank you!!!
Indeed, a 4 stroke, single valve with and the 9 cylinders rotating with the crankcase. The oil is pumped into the crankcase and through several channels to other parts of the engine.
They used castor oil which doesn't mix with the petrol.
Thank you for you compliments and thanks for watching
Isn’t this engine a two stroke?
Each cylinder fires every revolution, right?
@@davemilster no
Thanks for this phantasic video. It's great fun to see how all those parts are coming together. Also the function principle is explained very understandable! If I will be asked next time how the mono works, I will point them to this video. This will save me a lot of words ;-) Looking forward to see your next vid.
For me, the mono is still the most beautiful rotary. Followed by the Clerget.
Thanks for watching and thanks for your compliments !!!
Simply the best animation I've seen.
Thank you for your compliments and thanks for watching !!
There are some more videos on my UA-cam channel: ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html
You can also walk around the various WW1 engines on my website: www.pjvision.nl
Cheers, Pierre.
WOW, excellent animation. So cool to see such engineering from 110 years ago.....amazing to watch..!!!!
Thank you for your compliments and thanks for watching !!
Fabulous video, this engine is a work of art ,thank you for your effort
Thank you for your compliments. Indeed these engines are masterpieces. The craftmanship of the people that made these engines is truly amazing. No CNC. All was designed without computers, just pencil on paper and perhaps a Faber Castel slide ruler.
Thanks for watching.
Cheers (and best wishes for 2024)
Absolutely stunningly beautiful animation. Many thanks for posting!
Thank you for your compliments.
It's these kind of responses that keeps me going !.
Perhaps you want to see more. Click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html
Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines and as well as a 360 panorama view of the Sopwith Camel cockpit.
Thanks for watching !!
@@pierrejansen2702 You are most welcome Pierre. I have had a brief look at your channel (like it all, love the VickersMovie) and subscribed, and will watch out for your work in the future. To be honest I think my initial comment was understated - your work is truly outstanding and deserves a much wider audience. Anyone who has even a passing interest in engineering, or how things are made to do what they do, will be captivated. Bravo, maestro!
@@stephenmurray2335 Thanks a lot. You make me blush !!
It's going to be hard to TO TOP THIS! AND IT MAKES ME FEEL LIKE A GENIUS JUST BY UNDERSTANDING WHAT I JUST WACHED !
Good to hear. Thank you for your compliments.
As you may have seen, there are more WW1 engine videos on my channel: www.youtube.com/@pierrejansen2702
and related information on my website: www.pjvision.nl/
Cheers and thanks for watching !!.
That was incredible to watch. Thanks so much
Thank you for your compliments. It's these kind of responses that keeps me creating these videos.
If you want to see more, click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html
Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines.
Thanks for watching !!!
This is beautiful . . . . and I love it! The only point I would make, however, is that the 9-B2 (Monosoupape) has the suction operated intake valve in the top of the cylinder. It sucks in the fuel/air mixture (oil diluted) directly from the crankcase. Maybe I am mistaken about this . . . . let me know. If I am correct, it would be really elucidating to show that feature.
According to Aircraft Engine Historical Society . . . . "The inlet valves, which are in the center of the piston heads, are made of steel and are extremely light. The valve is cone shaped and has a short hollow stem which slides in a cast iron bush in the center of the valve seating or cage. During the suction stroke, the pressure in the cylinder falls below that in the crankcase with the result that the valve opens, overcoming the springs, and admits a charge into the cylinder."
Thanks for your compliments!
Regarding the intake valve, as you've noted the Gnome doesn't have induction tubes. The petrol line is connected to the hollow (stationary) crank shaft (doesn't rotate. Through a petrol tube within the crank shaft, the petrol gets drawn into the crank case via the petrol nozzle on the front end of this tube.
When a piston reaches its bottom position (BDC - inlet stroke), the petrol gets drawn into the appropriate cylinder though the 32 holes (ports) at the skirt of the cylinders. The petrol within the cylinders will mix with the air that was drawn into the cylinder during the inlet stroke, because the valve is open. (see 8:47 etc. video frames)
Note that this valve handles both the inlet- and exhaust flows (single valve = monosoupape in French).
Hope this helps and thanks for watching !!
Incredible animation, superbly well done.
Thank you for your compliments. It's these kind of responses that keeps me creating these videos.
If you want to see more, click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html
Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines.
Thanks for watching !!!
Amazing animation. Thank you very much for that.
You're very welcome!
Glad you liked it. Thanks for watching !!
Great animation - thank you very much!
Thanks your for your compliments and thanks for watching !!
Beautiful job of graphics and explanations... Now it makes sense...
Glad you liked it . Thanks for your compliments and for watching !
Thank you for this excellent video
You are very welcome and thanks for watching !!
As a project many years ago in college I made a drawing of a WW1 rotary using Autodesk Inventor. I also transfered the drawings to a 3d printer (the sand and super glue type) and made a physical model the next semester. This movie makes my project look primitive. Great job.
Thanks for your compliments.
I assume you've printed it on 1/3rd or 1/4th scale ?
Thank you for watching !!
My grandfather, Sgt Fidelis S. Jackson USAAS, was a “crew chief” on the Nieuport 28 with the 94th in France with the Gnome 9N engine. Now I know why he could fix anything
I'm honored ! Thanks for your msg. Although your grandfather was a Crew chief, he was one of the USAAS 'Fly boys' stationed in France.
Very special and besides technical skills, improvising was one of the main skills these man possessed. Indeed, special talents were required to fix these rotary engines and to keep the planes flying.
Thanks for watching !!
Sehr gutes Video! Ich kann alle Arbeitsschritte zur Montage des Motors aus eigener Erfahrung sehr gut nachvollziehen. Ein genial simples Triebwerk, wunderbar anschaulich demonstriert! Chapeau den Schöpfer dieses Filmes!
You make me blush ! Thank you for your compliments and thanks for watching !!
i liked how you showed slowly with a few parts where to place them first then speed up for that part, instead of just instantly doing all of them at once
Thank you for your feedback and compliments.
Good to hear that you liked the way I've put the animation together !
Thanks for watching
Cheers
Absolutely briilliant -- well done!
Thank you for your compliments and thanks for watching !!
Perfect, thanks for that education for these kind of motors, THX.
Thank you for your compliments. You make me blush !
Thanks for watching !!
@@pierrejansen2702 ;-)
Awesome video. Thanks for sharing.
Thank you for your compliments and thanks for watching !!!
Excellent production!!! Love the tunes and the 3D work, very nice presentation indeed!
Thank you for your compliments. You make me blush !!
Thanks for watching and for listening !!
@@pierrejansen2702 That blushing stuff happens to me sometimes too. I just figure it is a bunch of blood running to my head to get me ready for the next big learning event! LOL
I twisted some nobs on Blender, have a pretty good grip on SolidWorks and TurboCad, doing 3-d stuff mostly for engineering stuff or architectural stuff.
I can make the things look right, and get my drawings stamped by engineers and architects as needed; but I have yet to figure out the animations and stuff that you do that makes it look so cool.
@@4n2earth22 Getting your drawings stamped by engineers and architects its probably more important (pays the bill).
3D visualizations and animations are very, very time consuming !!
Fyi, for rendering the (thousands) of images for these videos, I'm using 3 systems in parallel (Distributed processing).
Thanks for your comment and compliment !!
Amount of work put into this animation had to be sky high... Very good job, sir. It will become a recommended vid soon
Yes, excellent job!
Indeed. Not a video that was created on a Sunday afternoon.
Thanks for your compliment and thanks for watching !!
Fantástica producción y generación de ésta animación mecánica 3D. Si esto lo vieran aquellos precursores de la aviación, quedarían tan asombrados como nosotros al ver hasta donde hemos llegado.
Thank you for your compliments. Indeed, these aviation pioneers had very limited tools. Therefore it's still amazing to see what they designed.
Thanks for watching !!
Incredible animaton. Brilliant
Thank you for your compliments You make me blush !!
Thanks for watching !
I really wanted to know how the spark plugs were wired and now I know. Thanks Pierre this animation is something beyond !!!
Thank you for your compliments. It's these kind of responses that keeps me creating these videos.
If you want to see more, click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html
Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines.
Thanks for watching !!!
Wonderful and interesting animated video. Great work.
Thank you for your compliments.
It's these kind of responses that keeps me creating these videos.
If you want to see more, click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html
Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines.
Thanks for watching !!!
I never get tired listening to this tune
Thank you for your compliment. Glad to hear you like my music !
Thanks for watching.
That was a amazing video!
Thank you and thanks for watching !!!
Nicely done !
Thank you for your compliment and for watching !!!
thanks a lot for the great job
You are welcome! Glad you liked it and thanks for watching !!
Here is the answer: "In 1913, Louis Seguin and his brother Laurent (engineers who founded the Société Des Moteurs Gnome [the Gnome motor company] in 1905) introduced the new Monosoupape series, which eliminated the inlet valve, replacing it with piston-controlled transfer ports similar to those found in a two-stroke engine."
Exactly. When a piston reaches its bottom position (BDC - inlet stroke), the petrol gets drawn into the appropriate cylinder though the 32 holes (ports) at the skirt of the cylinders. The petrol within the cylinders will mix with the air that was drawn into the cylinder during the inlet stroke, because the valve is open. (see 8:47 in the video)
Thanks for watching !!
Hats off to the old buggers that machined all those parts.
Indeed, these rotary engines designed in the early days of aviation, were real Masterpieces of engineering.
No computer driven machinery (CNC).
Thanks for watching !!
Maravilloso, un video genial y de gran calidad, lastima no haberlo tenido hace 50 Años, ;-)
Thanks for your compliments. Yes indeed. 50 years ago we did not have internet no 3D capabilities.
Thanks for watching !!
Thanks for the great video
Glad you enjoyed it.
Thanks for your compliment and thanks for watching !!
Thank you so much!!
Glad you liked it. Thanks for watching !!
Thanks for this tutorial. Now I can build a fully functioning Gnome Monosoupape with no problems.
Thank you for your compliments. You can always consult CAMS in New Zealand ( cams.net.nz/ ). -;)
They are building (and selling) the Gnome Monosoupape and just manufactured a 7 cyliner prototype version !
Thanks for watching !!
@@pierrejansen2702 I'll be sure to check them out.
Looking back at these engines through modern eyes, they look like they were designed by Fred Flintstone. But, once you see how they work you realize that Fred Flintstone was a genius!
Yes, Fred was the inventor of rotatt wheels. He used stones, but these where perhaps the base for rotary engines ;-)
😀@@pierrejansen2702
Simplement magnifique. Merci.
Thank you for your compliments and thanks for watching !!
vous avez réalisé un travail fantastique. Et ce moteur est génial.
Thanks for your compliments. Yes these French engineering companies produced some excellent engines e.g. Clerget and Le Rhone.
Thanks for watching !!
Pierre te felicito! Que video! Soy una persona que no tiene mucha educación y lo vi fácil dentro de lo complicado que es la ingeniería.
Thanks for your compliment and kind words.
Glad to hear it helped you. Thanks for watching !!
MARVELOUS - THANKS !
😎👍
Thank you for your compliments and thanks for watching !!
Magnifique vidéo en 3D!
Thanks for your compliments and thanks for watching !!
Wow! Awesome! Incredible!
Thanks a lot!
Thanks for watching !!
Brilliantly made video. Hate to be sitting near that thing in real life.
Thank you for your compliments and for watching !!
Being near that thing isn't that bad ...... If you want you can see me behind the engine as to control air, petrol and oil, engine during a test run.
See: ua-cam.com/video/5Y6PsDfeFJ4/v-deo.html
It is very noisy though, and you'll get a castor oil shower ;-)
Sevdiğim bir film gibi; gidip tekrar geliyor ve yeniden izliyorum. Muhteşem.
Thank you for your compliments and thanks for watching !!
There's more and also 360 degr. views of the engines on my web-site ( www.pjvision.nl/ )
@@pierrejansen2702 Web sitenizi de inceledim. Süper 👋👋👋
People were much more inventive when they didn't know how an engine was 'supposed' to be. Fascinating.
Yes indeed amazing, without computers. Just pencil, paper and slide rulers.
Thanks for watching !!
Famous engine. Thanks.
Thank you !!
Best explanation of the working principleI have come across - only thing I would add is that pressure of burned gasses is about equal to the rich mixture in crankcase by the time the ports are uncovered on the bottom part of the power stroke
Thanks for your compliments and for your comment
Indeed, you're right. Same would apply to separate inlet and exhaust valves during the moment of overlapping. However, equal pressure would not be a real issue, provided they are almost equal.
I'm sure there have been thoughts about this during the designing a single valve engine. Whatever, no one to ask and it did work.
Thanks for watching.
Cheers, Pierre
Great animation of an ingeniously simple engine. Throttling was only by flicking off and on the ignition and mabey some mixture adjustment. There were two row models as well,where as I remember you could shut off one then the other row for two power settings. But you had to keep flicking the switch on every few seconds as the plugs quickly fouled and mabey it didn't catch at all when you needed it again! Many of these early Areo engines used Castor bean oil as well as did alot of race cars, thats where "Castrol" comes from. because it was unsurpassed for many years as a high temp oil. (Yes, the same oil the pharmacy sold as a laxative!) These Radials consume gallons of oil per flight and emit it unburned in the exhaust. thats why many WW1 pilots had no windsheilds, goggles and a scarf! Grandpa told me about taking his first plane ride in the 1920's it was behind a Gnome radial. The passenger sets in front and grandpa was to macho for goggles or scarf. The pilot laughed, and took off. Grandpa's eyes were burning so bad even before talking off he saw virtually nothing, wasn't breathing thru a scarf, and so, had to stop several times on the way home afterwards to fertilize the ditchbank from diarrhea from all the swallowed oil! I wonder if the cylinder cams were ground the same lift and duration since the inner lifters will act "bigger" than the outer due to pushrod angles. Great work! Next time Fold the legs on cotter pins! (Ok, im being silly now)
Thank you for your compliments.
Regarding the throttling, blipping the ignition switch was the only way to throttle the Gnome engines.
Some experiments were conducted with a selector switch, allowing to switch OFF (disable) half of the spark plugs.
As you may know, some other rotaries e.g. the Clerget and the Le Rhone engines used the Tampier throttling device along with the Tampier bloc-tube carburetor.
Thanks for your comments and for watching !!
Excellent production, and wonderful for us old aeroplane nerds who grew up on comic strips like Don Nixon fighting WW1.
Thank you for your compliment and thanks for watching !!
@@pierrejansen2702 o
@@josesegovia754 ការ
Ingenious!
Yes. Tanks for watching the video !
Great Video
Glad you enjoyed it. Thanks for watching !!
As an individual who has been lucky enough to work first hand in New Zealand on this very engine- strip down and total recording of an original for remanufacture, this must have taken you a very long time and you should be commended on how accurate you have this. A difference we found (memory going back about 10 years now!) Was that we assembled these things with the front of the engine facing up with the crakshaft already in its mounts, and with the pistons already assemble onto the master rod, used the back half of the crankcase to place a cylinder over each piston kinda one by one. The channels in the half case we're more than enough to keep the pistons from falling out in this 'half shell' kind of state.
Thanks for your compliments and feedback !!
For the video, I closely followed the procedure as outlined in the Instruction Book #2, acquired from CAMS (Tony Wytenberg) and all other information I was able to find. However, I realize that in reality no one follows the book ;-)
Thanks for watching !!
Cheers
@@pierrejansen2702ah yes. I never met. Tony but we (TVAL) did ours at roughly the same time (2009? 10? 11?) And his work looked good- more targeted towards reliable runners I think. We were just trying to replicate the exacting design. Mismatched oil holes and all.
@@reanimate_xyz I visited TVAL in 2017 and had a tour through the workshop. Very interesting but I didn't get answers on the specific Clerget manufacturing questions I had.
Next on our trip was a visit to CAMS, stayed a couple of days with Tony and family. I tried to persuade Tony to build a Clerget 9B too, but he felt that he'd better focus on his Gnome business (going quite well).
Cheeers !
Simply phatastic :- ))) My english is not good enough to say what i feel .. just great
Knuth, thank you for your compliments and for watching the video !
Have to say I admirer the sophistication of the design and engineering, then to have to manufacture all the parts. Unfortunately most of the population today is unaware they hop into their cars taking it for granted. The Aviation industries in 100 years look at the difference, jumbo jets that can fly without pilots( although not done, yet?). Excellent work Pierre. Hopefully I planted a seed for jet engines, fly by wire, DC3 hydraulics. Ok I'll stop.
Keep in mind that weight was an important issue during the early days of aviation.
Rotary engines have no a need for cooling liquid, pipes, water jackets and the radiator.
This provides excellent self-cooling, the rotating crankcase/cylinder assembly created its own cooling airflow, even with the aircraft at rest. Because of the rotating mass, no flywheel is needed. But, days have changed and jet engines offer the same, but much more sophisticated.
Both designs offer and excellent power to weight ratio.
Thanks for watching !!
Amazing engineering
Indeed, a Masterpiece of engineering. Thanks for watching !!
Excelente. Un gran abrazo desde Argentina
Thanks for your compliment and thanks for watching !!
Excellent Video ! .... I was Wondering how those old Airplane Rotary Engines worked ? ... And your Animation made its design and function easy to understand .... Cheers !
Thank you for your compliments. It's these kind of responses that keeps me creating these videos.
If you want to see more, click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html
Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines.
Cheers and thanks for watching !!!
Thank you 😊
You're welcome 😊
Re 🙏🏽 beautiful video
Thanks you for your compliments and thanks for watching !!
А ведь у инженера, который это изобрел, весь этот мультик был в голове...
Indeed. Given the limited possibilities in those days, these engines were engineering masterpieces !
Thanks for watching !!
that's a great video!
Thank you for your compliments. It's these kind of responses that keeps me creating these videos.
If you like to see more. Click on my channel; ua-cam.com/channels/byGXbMxmWfH8XsXzmmddhQ.html
Also my web-site ( www.pjvision.nl ) now contains 360 degr. views of the various WW1 engines.
Thanks for watching !!
@@pierrejansen2702 sure..
please make videos on assembling different type of jet engines
@@MSSakib-lz2gg Could do, there are so many interesting engines.
For now, I'm trying to keep the history of the early days of aviation and aero engines alive.
Thanks for your response !!.
Way better than an actual engine with some English guy trying to explain it.
Thanks for your complements and thank you for watching !!
Awesome animation,it surprises me that the ignition systems actually work with such exposure!! Good old fashioned hand machined and hand built engines...perfectly balanced!! One correction...Walthamstow is in East London, not Essex!! Thanks for posting and taking the time to make such brilliant content
Thanks for your compliments and for watching ! Regarding Walthamstow, I'm confused as it is listed as a major district in N-E London, historically in the county of Essex (and became part of Greater London in 1965) ????. Oh well, there's no way change the published youtube videos anyway.
@@pierrejansen2702 I lived there for a few years and I disd not know that .
your videos show that you love engines !
Thank you .
Liked the pic showing the Alfred Herbert turret lathe at the beginning...
I have a Herbert No 4 turret lathe from around WW1 era...
Lineshaft driven...
☹🇬🇧
Amazing that you've spotted this Herbert lathe. Some people see more in my videos than what I put in !!
Thanks for your feedback and for watching !!
@@pierrejansen2702
I knew what it was caus I have a near identical one...
☹🇬🇧
@@glennmoreland6457 Wow !! It's BIG !!
WOW fantastic radial engine 😍😍😍
Thank you for your response and thanks for watching !!
It's a rotary. Radial engines don't spin.
I didn't think about just animated assembly. it's a real technological wonder of the day. I'd liked to see actual footage of the construction or a build from a modeler's project, as there are radial piston and rotary engine kits out there. nice work tho
Thanks for your response.
CAMS in New Zealand is building the engine in 1:1 scale ( cams.net.nz/ ) Not a modelers project but maybe worth looking at.
Thanks for watching !!
素晴らしい！！ Phantasic!!
Thank you for your compliments and thanks for watching !!
the grates who designed the engine , we loves you
Thanks and thanks for watching !!
Wow thanks really helped
Glad it did. Thanks for the Wow and thanks for watching !!
All my pleasure!...Somewhere buried in my loft I believe I may have still,all the photos I took at the time?! If I locate them in the not too distant future I will contact you again! All the best for now, cheers ..Nigel
Thanks. Hope you'll find them. Would be great !
You can contact me via my website ( www.pjvision.nl/ )
All the best and stay safe !
Cheers, Pierre
Love the music. Wish I’ll be that’s easy to assemble real time
Thanks. Glad you liked it and thanks for watching and listening !!
Fabuloso tirou todas minhas duvidas
Estou feliz que você gostou. Obrigado por assistir!
Genial !!! Incrível!!!
Thanks for your compliments and for watching !!
Woow, amazing
Thanks for your compliment and thanks for watching !!
Thank you so much for this.
Thank you. Glad you liked it and thanks for watching !!
@@pierrejansen2702 had you considered doing one for the de Havilland Gypsy 6 as used on the DH.88?
You have a real talent for this. Once again thank you.
@@smalcolmbrown Thanks again. There are many interesting planes and engines, but I'm trying to keep the early days of aviation (and engines) alive.
Thanks for your response !!
@@pierrejansen2702 I had better declare an interest here. I volunteer at the de Havilland Aircraft Museum and helped restore a dh.88 replica that was used in the film the great air race.
Half the fun is figuring out how they did it 100 years ago without the Benifit of modern machine tools and metalagergy. They were very skilled people back then
@@smalcolmbrown I see ! Restoring the DH88 must have been a great project (and challenge). It's a beautiful plane ! Was it the G-ACSS that you worked on ?
Indeed, it's remarkable to see what these engineers achieved. No computers, CNC etc. and limited material choices ... just workmanship skills. They designed and produced engineering master pieces in those days !
Thanks for your response
And they did all that without dropping any acid. Amazing!
Perhaps. I don't know ... I wasn't there.
Thanks for watching !!
wonderful
Thank you and thanks for watching !!!
Awesome..!
Thank you and thanks for watching !!!
Круто, молодцом!
Thank you for your compliment and thanks for watching !!
알기쉽게 잘 만들었다.
Thank you for your compliments and thanks for watching !!
sorry for the stupid question..
I saw radial engines where the cylinders doesn't rotate and others where cylinders rotate.
In this video cylinders rotate, but what are the advanteges? SO much mass and weights rotating doesn't mean a loss of energy?
Thanks
Weight was an important issue during the early days of aviation. Rotary engines have no need for cooling liquid, pipes, water jackets, radiator or batteries. They provided excellent self-cooling. The rotating crankcase/cylinder assembly created its own cooling airflow, even with the aircraft at rest. Because of the rotating mass, no flywheel is needed.
No, no real loss of energy. Rotary engines provided and excellent power to weight ratio.
Thanks for watching !!