This machine has sooo much cool factor, it doesn’t need to be practical. Expecting anything more from her would be like expecting Lindsey Pelas to wash dishes 😂
Haha cheers mate! It’s very interesting to see how much we’ve forgotten when it comes to flying with modern design and technology. We’ve seen a number of folk want to fly it but simply don’t recognise that it will bite them in a completely new (old) way, resulting in a rebuild!
Something you might consider: the hole you made in the original firewall; imagine doing what you would if you were just going to make the opening larger by maybe 6 or 8 inches on all sides, but instead of removing the ‘flaps’ that you cut, leave them in place, but angle them backwards by say, 45 degrees. Maybe re-attach them with full-length ‘piano hinges’ and lock them at the desired angle with some little triangular blocks. This would create a flair extending slightly into the cavity between the 2 firewalls instead of just a blunt opening, and I think it would channel the increased airflow more efficiently from the cowl backwards toward the opening you made on the bottom of the fuselage, plus decrease the turbulence created when the air coming past the engine encounters the flat face of the original firewall while trying to find a way out. A small fairing or lip along the leading edge of that opening might speed up the flow of the slipstream enough to increase the Venturi effect and pull more air out of it. Another (and much easier) thing you might consider is to try to insulate that exhaust manifold. Everything in there is being baked by the tremendous heat coming off of it. I think there is a type of wrap that is composed of ceramic material and fiberglass or asbestos fabric that will prevent it from introducing so much heat through convection at least, into everything nearby, but it would have to include in its construction some type of foil, or metallic powder or something that would actually block the transfer of heat energy in the form of electromagnetic radiation, which can travel through even the vacuum of space, and thus isn’t really affected by airflow, so eliminating it as much as possible might really decrease the temperature of all the nearby accessories, fuel lines, connectors, wiring, hoses etc. etc. … This part of the equation is often neglected because heat radiation is invisible, and has to be dealt with in the same ways that one deals with radio signals for example. Even a thin sheet of foil can make a tremendous difference. I remember when Saddam Hussein set all the oil wells on fire in Iraq and celebrity Texas fire fighter ‘Red’ Adair’s crackshot crew could approach the flames much, much more closely (for a short time) by simply carrying by an attached wooden or leather handle or strap, or even by mounting it to the front of the cab of their bulldozer, a sheet of corrugated steel in front of them with a little slit cut in it so they could see. The conductive metal shield would become hot as hell, but it blocked the radiation. Anyway, sorry that went on so long, but maybe it will help. Good luck to you!
Thanks for the input mate. The options you describe were definitely on the table. It’s sort of a catch 22 type thing when trying to fix an issue like that. Do we make small/easier adjustments, or go all out and re do everything. Our issue was to fault find on the fly (pardon the pun) and there were multiple sources to the overall problem. So by going through the systems first we could eliminate that and then concentrate on airflow. As you say, there is a lot that can be done to improve the overall flow through the engine, firewall and exit. We concentrated on directing air to our problem areas first and then continued until we got to a point where we were happy with how it operated. As it is now we can taxi for over 10 minutes after landing with absolutely no problems at all. At this stage we are happy to leave it at that. The next step would be to shield the exhaust and then leave the directing airflow past the false firewall till a bit later. I was leaning towards making metal heat shields rather than wrapping the exhaust. Not sure exactly why. Might have been because I like to inspect the piping for any cracking and blow outs. Airflow is a funny thing, especially through an engine compartment. It’s very fascinating. Cheers
I say old fellow, one thing about Biggles is that the books are damm ably expensive, even now. If you want a good read about WW1 pilots read either “The Bandy Papers” ( about six books) or “Innocents at War” (again, about six books).
The issues you have with the blanked rudder etc on landing and elevator effectiveness dropping off in the three point attitude are certainly a characteristic of the plane. My father flew a pup for some time many years ago and had nearly the same comments!
I'd guess with that original rotary engine spinning, there wasn't much of a cooling problem. Imagine how much worse the right torque must have been with that thing spinning.
That’s the trouble with fitting a modern engine and keeping it scale. There’s not much room for cooling. You’re right, the torque on those rotarys would be would be a whole other level to deal with
Don, thanks for the perspective on airflow around the nose of these things. Actually I feel more like Snoopy when I fly my SE5 replica, enjoy that Pup.
The intention was to build an accurate replica as possible. Brakes became a thing when airfields became runways. It’s truly amazing to see how advanced designs have become since the start of aviation. Brakes being one of them!
Biggles Learns to Fly: Biggles started in FE2B 2-seaters then moved to Pups in 266 Sqn, which was re-equipped with Camels shortly after he transferred in.
A rally lovely build! But a very poo engine choice, not a matter of if the engine will fail, but when it will rail, just do not fly anywhere you cant put this wonderful aeroplane down in an engine emergency , blue skies!
Thanks mate. We have the engine running quite well. We put a lot of effort in to ducting cooling air among other things. We noticed a lot of these engines have been installed poorly with very little cooling airflow through the cylinders to the rear engine casing. Without good cooling, the engine quickly overheats and causes problems including vapour lock. We have very good oil temps and pressures. Even after landing with the engine heat soaked, we have no issues with the long taxi back to our hangar. Cheers mate
@@donwtsn I am glad to hear you got the engine installation sorted out, there are so many really catastrophic failures with this engine, this Pup build looks really nice, and not having a rotary engine must make a lot of difference to the handling. Stay safe! Chris B.
Thanks mate. Paddy put a lot of effort in to building it as accurately to the original as possible, less a rotary engine. It’s such an interesting aircraft huh
Another thought: The question of C.G. What I have sort of found out is that back then they did not use a C.G. envelope like we do today. In addition there is the question of finding the MAC on a biplane of that era. Many articles were written in "FLIGHT" (Flight Engineer) 1920 ish, giving different methods and theories on where the MAC would be. Quick question, is this a RAF 15? Absolutely love the little things to make it authentic, esp. the 5/17 compass. NICE work. By the way Kermit is not the first to loose the cowling. "Whats his foot, the con" lost one in Omaka. I was in the air so didi not see it, only the aftermath. How is the engine holding up? CHEERS,
Gday mate. I know Paddy spent a lot of effort researching all things related to the pup’s C.G. And about MAC. I think the biggest challenge he had was the engine and propeller are lighter than the original, and the gun is much lighter as it’s not real. As he wanted to build to as close to original specs as possible and not move the engine forward, the C.G. Was always going to be a challenge. Very early on in the build he was constantly conscious of weight in the tail. His efforts have been rewarded with level flight being achieved with the control stick close to neutral instead of stick forward like other pups. I’m not sure about RAF 15, but as he put so much effort in to producing an accurate replica I would believe it is. I think I mentioned Kermit’s cowling departure because that was the latest one to happen so seemed most relevant. The rotec engine is running great. We had a bit of tweaking to do to get it happy but I reckon we achieved that. Hope this helps
Dave Gillespie very cool mate! This is my friends pup, I’m just lucky enough to help out. Paddy used pup blueprints and detailed drawings from scaled rc models. He wanted to build a replica that is a tribute to those who flew them in the war. It has the same wing and is dimensionally accurate. He used modern fabric and timbers and the aft fuselage is monocoque to make it more user friendly instead of wires and turnbuckles. The engine has the same torque as the original. The aim was to have it accurate in dimensions as well as performance. Your camel sounds very cool and interesting
My Pup (Rosie)is built using original Sopwith drawings and aerofoil with some changes to be able to build it in a home work shop. I have used modern epoxy adhesive, and covered her with the Stitz Poly Fibre system. I have also used hoop pine instead of spruce, hoop is readily available here in Australia and the ply is of excellent quality. Rosie does not represent any particular Pup rather she honours all the unremembered pilots many of whom never returned. The red wheels are for the capes the nurses wore who cared for the broken pilots and her name is for the wives, girlfriends, sisters and mothers of those pilots. My friend Don Watson built the cowlings for her.
Thanks mate. Taxiing is definitely a challenge! There are no brakes, only a skid at the tail that digs in to the ground a little. The skid has limited steering, only a few degrees so for most taxis there are wing walkers that grab the wing to pull the aircraft around. Great exercise for the ground crew!
Gday mate, yes we know of some of the stories about this engine failing. If you look up any engine type, you’ll find failure stories about them too. As I mentioned in the video, many times, we put a lot of effort into directing cooling air to the aft part of the engine. Also moving the firewall back to get the volume of air through the engine compartment is very important. We still experienced issues with vapour lock and heat sink, but with a bit more tweaking we have no overheat or vapour lock issues. We can do long run ups and long taxis without any issues now. The Rotec seems to be a bit finicky to set up, but I reckon we’ve got it sorted. Every time I see someone having troubles with this engine, I notice there is usually not enough room in the engine compartment to allow air to flow properly. Air cooled engines need air to cool the engine. Sometimes when they replace the rotec with another air cooled engine, the problems continue. Like any engine, it needs to be matched to the airframe. Boy does it sound great!
About the taxi: I take it that the tail skid has 2 bungees that allow it to swivel 10-20 degrees in either direction, but not connected to the rudder bar. So, are you giving a little down elevator to lift the tail and gunning the engine or is the rudder enough? I can see the rudder moving but not quite the elevator. Wheel landing tail low???
There is a separate set of cables connecting the rudder bar and the tail skid giving only a little movement left and right. He does use down elevator to lighten the tail as well as engine power, but still can only turn in large circles unaided. Paddy tries to keep the tail high (wheel landing) as long as he can to keep some control. That period between tail up and tail skid digging in is a land of no control. So he tries to transit through there quickly having made sure he has used up as much forward energy and airspeed as possible before dropping the tail. Given any chance, it will swing during that no control period which makes each landing fun and entertaining!
@@donwtsn Thanks for the info on the extra control wires. I did something similar on the Bristol F2B, only had about 20 degrees in each direction but found it to make a big difference. I had small disc brakes which were only used for maneuvering near the fuel pumps. Nice work.
@@edstoro3883 cheers mate. Paddy stuck to the original design as closely as he could, hence the extra cables to the skid like the original. The skid shoe was modified to dig in more which helped control the swing as well. At the moment it doesn’t have brakes, but we have ideas on how to fit them and keep the original look. Brakes sure would help!
That's why they flew out of large square fields always into the wind.
Absolutely. If only we had that option around here
This machine has sooo much cool factor, it doesn’t need to be practical. Expecting anything more from her would be like expecting Lindsey Pelas to wash dishes 😂
Haha cheers mate! It’s very interesting to see how much we’ve forgotten when it comes to flying with modern design and technology. We’ve seen a number of folk want to fly it but simply don’t recognise that it will bite them in a completely new (old) way, resulting in a rebuild!
Stunning Stunning Stunning! Absolutely love it. Thank you for sharing her with those of us that obsess over these things of beauty.
Thanks mate, paddy has done an awesome job building her. I’m very thankful to be able to help him out with it
Such a clean looking designed aircraft..
Biggles flew other aircraft before the Camel (used to have all the WW1 books as a boy).
Your right. I believe he started off flying in a squadron of F.E 2’s. I still love reading Biggles books even now
Something you might consider: the hole you made in the original firewall; imagine doing what you would if you were just going to make the opening larger by maybe 6 or 8 inches on all sides, but instead of removing the ‘flaps’ that you cut, leave them in place, but angle them backwards by say, 45 degrees. Maybe re-attach them with full-length ‘piano hinges’ and lock them at the desired angle with some little triangular blocks. This would create a flair extending slightly into the cavity between the 2 firewalls instead of just a blunt opening, and I think it would channel the increased airflow more efficiently from the cowl backwards toward the opening you made on the bottom of the fuselage, plus decrease the turbulence created when the air coming past the engine encounters the flat face of the original firewall while trying to find a way out. A small fairing or lip along the leading edge of that opening might speed up the flow of the slipstream enough to increase the Venturi effect and pull more air out of it. Another (and much easier) thing you might consider is to try to insulate that exhaust manifold. Everything in there is being baked by the tremendous heat coming off of it. I think there is a type of wrap that is composed of ceramic material and fiberglass or asbestos fabric that will prevent it from introducing so much heat through convection at least, into everything nearby, but it would have to include in its construction some type of foil, or metallic powder or something that would actually block the transfer of heat energy in the form of electromagnetic radiation, which can travel through even the vacuum of space, and thus isn’t really affected by airflow, so eliminating it as much as possible might really decrease the temperature of all the nearby accessories, fuel lines, connectors, wiring, hoses etc. etc. … This part of the equation is often neglected because heat radiation is invisible, and has to be dealt with in the same ways that one deals with radio signals for example. Even a thin sheet of foil can make a tremendous difference. I remember when Saddam Hussein set all the oil wells on fire in Iraq and celebrity Texas fire fighter ‘Red’ Adair’s crackshot crew could approach the flames much, much more closely (for a short time) by simply carrying by an attached wooden or leather handle or strap, or even by mounting it to the front of the cab of their bulldozer, a sheet of corrugated steel in front of them with a little slit cut in it so they could see. The conductive metal shield would become hot as hell, but it blocked the radiation. Anyway, sorry that went on so long, but maybe it will help. Good luck to you!
Thanks for the input mate. The options you describe were definitely on the table. It’s sort of a catch 22 type thing when trying to fix an issue like that. Do we make small/easier adjustments, or go all out and re do everything. Our issue was to fault find on the fly (pardon the pun) and there were multiple sources to the overall problem. So by going through the systems first we could eliminate that and then concentrate on airflow. As you say, there is a lot that can be done to improve the overall flow through the engine, firewall and exit. We concentrated on directing air to our problem areas first and then continued until we got to a point where we were happy with how it operated. As it is now we can taxi for over 10 minutes after landing with absolutely no problems at all. At this stage we are happy to leave it at that. The next step would be to shield the exhaust and then leave the directing airflow past the false firewall till a bit later. I was leaning towards making metal heat shields rather than wrapping the exhaust. Not sure exactly why. Might have been because I like to inspect the piping for any cracking and blow outs. Airflow is a funny thing, especially through an engine compartment. It’s very fascinating. Cheers
I say old fellow, one thing about Biggles is that the books are damm ably expensive, even now. If you want a good read about WW1 pilots read either “The Bandy Papers” ( about six books) or “Innocents at War” (again, about six books).
Cheers mate, I’ll hunt those ones down. I love ww1 flying books
If you have 3D printing, depending on what materials you can print, you may want to think about ducting air to the hots spots
3D printing is very cool. We used aluminium tube and high temp Scat hose for the ducting which is able to resist heat a bit better
Great video Don.
Loved the footage and a good description of what’s going on “ under the cowl”
Can’t wait for the next one
FleaFlyer1 thanks mate. Its great fun helping out
The issues you have with the blanked rudder etc on landing and elevator effectiveness dropping off in the three point attitude are certainly a characteristic of the plane. My father flew a pup for some time many years ago and had nearly the same comments!
It’s so hard to find good info about the particular tricks about these type of aircraft. I bet the albatross would have its own particular tricks too!
I'd guess with that original rotary engine spinning, there wasn't much of a cooling problem. Imagine how much worse the right torque must have been with that thing spinning.
That’s the trouble with fitting a modern engine and keeping it scale. There’s not much room for cooling. You’re right, the torque on those rotarys would be would be a whole other level to deal with
Great video, Don! 🙂
Thanks mate
Don, thanks for the perspective on airflow around the nose of these things. Actually I feel more like Snoopy when I fly my SE5 replica, enjoy that Pup.
Haha good ol snoopy! I’ve got replicraft plans for the SE5. Sometime in the future I’ll build one
I would be looking into a set of brakes to control the surprises
The intention was to build an accurate replica as possible. Brakes became a thing when airfields became runways. It’s truly amazing to see how advanced designs have become since the start of aviation. Brakes being one of them!
Beautiful Bird - sad there's really nothng that can be done w/the feckless Rudder control and ground control ..except anticipating it -stay safe!
Thanks mate. It’s been a steep learning curve. But understanding the problems help deal with them. Fun times!
Just looked at the website and to be honest not as expensive as I thought, Could happen someday :)
Rosie the pup is a shining example of how possible it is
@@donwtsn I:) She is a beaut
Biggles Learns to Fly: Biggles started in FE2B 2-seaters then moved to Pups in 266 Sqn, which was re-equipped with Camels shortly after he transferred in.
John Angelico love biggles. Being a small part of this project has brought biggles to life in my mind
@@donwtsn The family has a large collection which goes around our various households, for regular reading.
JA from work
John Angelico I’ve got a decent collection myself
If ya dont know who Biggkles was...i dunno if we can be friends. Been using that priciple all my life... nice one.
Haha cheers mate!
266 squadorn
A rally lovely build! But a very poo engine choice, not a matter of if the engine will fail, but when it will rail, just do not fly anywhere you cant put this wonderful aeroplane down in an engine emergency , blue skies!
Thanks mate. We have the engine running quite well. We put a lot of effort in to ducting cooling air among other things. We noticed a lot of these engines have been installed poorly with very little cooling airflow through the cylinders to the rear engine casing. Without good cooling, the engine quickly overheats and causes problems including vapour lock. We have very good oil temps and pressures. Even after landing with the engine heat soaked, we have no issues with the long taxi back to our hangar. Cheers mate
@@donwtsn I am glad to hear you got the engine installation sorted out, there are so many really catastrophic failures with this engine, this Pup build looks really nice, and not having a rotary engine must make a lot of difference to the handling. Stay safe! Chris B.
Thanks mate. Paddy put a lot of effort in to building it as accurately to the original as possible, less a rotary engine. It’s such an interesting aircraft huh
Another thought: The question of C.G. What I have sort of found out is that back then they did not use a C.G. envelope like we do today. In addition there is the question of finding the MAC on a biplane of that era. Many articles were written in "FLIGHT" (Flight Engineer) 1920 ish, giving different methods and theories on where the MAC would be. Quick question, is this a RAF 15?
Absolutely love the little things to make it authentic, esp. the 5/17 compass. NICE work. By the way Kermit is not the first to loose the cowling. "Whats his foot, the con" lost one in Omaka.
I was in the air so didi not see it, only the aftermath. How is the engine holding up? CHEERS,
Gday mate. I know Paddy spent a lot of effort researching all things related to the pup’s C.G. And about MAC. I think the biggest challenge he had was the engine and propeller are lighter than the original, and the gun is much lighter as it’s not real. As he wanted to build to as close to original specs as possible and not move the engine forward, the C.G. Was always going to be a challenge. Very early on in the build he was constantly conscious of weight in the tail. His efforts have been rewarded with level flight being achieved with the control stick close to neutral instead of stick forward like other pups. I’m not sure about RAF 15, but as he put so much effort in to producing an accurate replica I would believe it is. I think I mentioned Kermit’s cowling departure because that was the latest one to happen so seemed most relevant. The rotec engine is running great. We had a bit of tweaking to do to get it happy but I reckon we achieved that. Hope this helps
Lovely machine! Would you consider installing brakes?
Thanks mate. Fitting brakes would be possible, but I think Paddy is wanting to keep it authentic….just to make things a bit fun!
Bigglesworth…!!!😂
Cool. I have a Camel with a Warner 165hp. Tell us more about the design and construction details of your Pup.
Dave Gillespie very cool mate! This is my friends pup, I’m just lucky enough to help out. Paddy used pup blueprints and detailed drawings from scaled rc models. He wanted to build a replica that is a tribute to those who flew them in the war. It has the same wing and is dimensionally accurate. He used modern fabric and timbers and the aft fuselage is monocoque to make it more user friendly instead of wires and turnbuckles. The engine has the same torque as the original. The aim was to have it accurate in dimensions as well as performance. Your camel sounds very cool and interesting
My Pup (Rosie)is built using original Sopwith drawings and aerofoil with some changes to be able to build it in a home work shop. I have used modern epoxy adhesive, and covered her with the Stitz Poly Fibre system. I have also used hoop pine instead of spruce, hoop is readily available here in Australia and the ply is of excellent quality.
Rosie does not represent any particular Pup rather she honours all the unremembered pilots many of whom never returned. The red wheels are for the capes the nurses wore who cared for the broken pilots and her name is for the wives, girlfriends, sisters and mothers of those pilots.
My friend Don Watson built the cowlings for her.
Love the video.
I wonder how one does steer these old aircraft on the ground. Does it have independent wheel brakes?
Thanks mate. Taxiing is definitely a challenge! There are no brakes, only a skid at the tail that digs in to the ground a little. The skid has limited steering, only a few degrees so for most taxis there are wing walkers that grab the wing to pull the aircraft around. Great exercise for the ground crew!
@@donwtsn i never knew about steering with the skid. Thanks for the answer! Good reason to stay friends with the ground crew :)
@@Robert-yk8tx the draw card is it’s a cool aircraft, and paddy is a top bloke. Mind you, I’m not as fit as I once was!
Please check out Rotec engine failures. There have been a LOT of them. Be careful.
Gday mate, yes we know of some of the stories about this engine failing. If you look up any engine type, you’ll find failure stories about them too. As I mentioned in the video, many times, we put a lot of effort into directing cooling air to the aft part of the engine. Also moving the firewall back to get the volume of air through the engine compartment is very important. We still experienced issues with vapour lock and heat sink, but with a bit more tweaking we have no overheat or vapour lock issues. We can do long run ups and long taxis without any issues now. The Rotec seems to be a bit finicky to set up, but I reckon we’ve got it sorted. Every time I see someone having troubles with this engine, I notice there is usually not enough room in the engine compartment to allow air to flow properly. Air cooled engines need air to cool the engine. Sometimes when they replace the rotec with another air cooled engine, the problems continue. Like any engine, it needs to be matched to the airframe. Boy does it sound great!
I wish somebody would make rotary engines again
There’s a mob in New Zealand making them. Just a bit outside of the budget
I wonder if there was Any possibility of fitting Pups with a Second machine gun?
I’m sure they tried it out. Too heavy maybe?
About the taxi: I take it that the tail skid has 2 bungees that allow it to swivel 10-20 degrees in either direction, but not connected to the rudder bar. So, are you giving a little down elevator to lift the tail and gunning the engine or is the rudder enough? I can see the rudder moving but not quite the elevator. Wheel landing tail low???
There is a separate set of cables connecting the rudder bar and the tail skid giving only a little movement left and right. He does use down elevator to lighten the tail as well as engine power, but still can only turn in large circles unaided. Paddy tries to keep the tail high (wheel landing) as long as he can to keep some control. That period between tail up and tail skid digging in is a land of no control. So he tries to transit through there quickly having made sure he has used up as much forward energy and airspeed as possible before dropping the tail. Given any chance, it will swing during that no control period which makes each landing fun and entertaining!
@@donwtsn Thanks for the info on the extra control wires. I did something similar on the Bristol F2B, only had about 20 degrees in each direction but found it to make a big difference. I had small disc brakes which were only used for maneuvering near the fuel pumps. Nice work.
@@edstoro3883 cheers mate. Paddy stuck to the original design as closely as he could, hence the extra cables to the skid like the original. The skid shoe was modified to dig in more which helped control the swing as well. At the moment it doesn’t have brakes, but we have ideas on how to fit them and keep the original look. Brakes sure would help!