I've been following Stepan's designs for a couple of years and this is a culmination of several ingenious improvements of the axial jet drive. The stator with it's abbreviated fins, the super-efficient single bladed dual stage impeller, and the innovative steering nozzle with simple trim adjustment are all vast improvements to conventional design. And the professional, well thought out displays and directions are second to none! Bravo, Stepan my hat is off to you!
You said it better than me! I agree. Somebody needs to pay this man and develop this thing for big boats! man that would be bad ass! Maybe the new Tesla Jet sprint? LOL
hey man, found your channel a couple of mounths ago on my way through 3D-Printing-UA-cam and seeing how you were able to get so significant improvements over your desings without changing much of the electrics really motivated me to desing and print my own rc jetboat and pump. i´m on my Version 3 (only counting those that actually survived more than 3 min) and it has been a lot of fun. I just wanted to say thank you for the inspiration. Greetings from Germany :)
@@1sqeeze1 Yes, I did some tests in ansys fluent. You can find some screenshots from it if you click on my channel, click community (the non-video content) and scroll all the way down
@@1sqeeze1 And I did huge amount of calculations of the pump based on experimental thrust measurement during the development process, I measured over 100 different design combinations and plotted all parameters in an excel sheet
So I finally made the M-Jet 30 work in my water gun and you go ahead and release the 35. But DUDE! It TOTALLY works! 9 meters without any optimisation or even an active water supply from the backpack! I've only tested the wand so far, so I am very optimistic about it.
I am just having a nice evening with the owner of this channel and i think, that all of you just have to buy his latest model of sprintboat, because it is just awesome
Scaling it up is difficult and comes with some problems, mostly because dimensions of all hardware scale up too. This can result in non-existing dimensions of bearings, etc. Motor mount becomes incompatible. With some effort, it is still possible to scale it up - especially if you use a nice number like 200%. You could also consider looking at the M-Jet 60, which comes with a STEP file: www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-60-3d-printable-jet-drive-for-electric-surfboards
Any cheaper options with this because this would work amazing on my jet boat I am making but can you jsut put on the end part and will it still work because my 3d printed jet boat already comes with a a hole in the bottom were it comes through
Thank you for your kind words:) The development of the M-Jet 35 took me little over one year. And yes! This is a cheaper option you might like to consider, my previous M-Jet 30: www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-3d-printable-jet-drive-for-rc-boats
@@baconbulldog5250 The M-Jet 30 is a good pump already, and when I was using it back then, I was very happy with it. But the M-Jet 35 brings everything to a new level, the amount of work that went into it makes it better in every way. The difference is captured in the price.
You can try to scale it to 200%, yeah. But keep in mind there are many problems coming with the scale-up: All tolerances will get changed, motor mount will be incompatible, and it might generate some non-existing hardware sizes, like bearings and seals. If you can solve these problems, it is possible.
Really a great drive. I installed two M-Jet 30 in my last boat and they run great. As it's a big boat and therefore heavier than small jet boats, I'm planning to use the M-Jet 35 for a future model. It is important to me that the boats can reverse. Would it be possible for you to develop a reverse plate for the jet?
Glad you are happy with the M-Jet 30! Unfortunately, so far I am not planning to develop any reverse bucket for the M-Jet 35. Reasons are: 1) I myself never found the need for a reverse bucket, because it is possible to just steer at high throttle and turn basically 180° in place 2) In the very few cases when reverse is necessary, it is possible to just spin the motor backwards, pumping water in the opposite direction. This is not optimal, but still works as a slow reverse. 3) Adding a reverse bucket for the M-Jet 35 would add quite some complexity of the assembly, which goes aganist the philosophy of the pump. I still understand that some people prefer the reversing bucket anyway - I might get to designing it in the future, but so far it's not on the list.
@@mjetdevelopment Thanks anyway. I will still look forward to build the drive. The M-Jet 30 is already powerful, so I can hardly wait to install the M-Jet 35.
Only thing missing is a reverse thrust bucket, all that speed and no brakes! Makes no difference, I;ll still be straight on to CG Trader as soon as this month's wages drop into the bank, can't wait to fit 2 of these to my SAAB CB-90
Hi, are you talking about the M-Jet Sprint boat? Unfortunately I dont have any "smart" fix for this. Some things you can do: Probably you will need to use a lighter battery and mount the ESC as far backwards as possible to push CG towards the rear. Also use the standard first stage with ride plate that does not have any additional lift.
@@zohrabmamedov5446 You could try scaling it to 200% or 300%. Then theoretically, performance might be sufficient. However there is so much trouble with the upscaling process: If you upscale it, all bearings, shafts, hardware will upscale too, possibly resulting in non existent hardware sizes. Imagine 300% M3 screws -> M9, pretty much doesn't exist. The mount for motor and servo will no longer be compatible with anything. Tolerances might get screwed up randomly. Overall - the upscaling process would require great effort. Then, trouble will come as you will need enermously powerful electronics to spin the upscaled pump. Torque scales with 4th power of size here. 2x size -> 16x torque. Power consumption scales with 3.5th power of size. 2x size -> 11x power input and motor wattage.
If you made the M jet-35 and the M Jet-60 the same size, using the same motor and battery, even while the M jet-60 uses dual jetdrive/2 impellors, wich one would provide more thrust?(Im thinking of making a electric surfboard and I want to know if I should scale the size of the M-jet 35, only if it is more powerful than the M-jet 60 (when they are the same size)), dang thats a lot of parentheses..., so wich one is more powferful while The M jet 60 uses dual jet drives/2 impellors and the M-Jet 35 uses one impellor?? another way is, having the same rpm the jet drives, while being the same sizes, what is the rpm to kg of thrust for each jet drive while being the same size?
The M-Jet 35 is newer and is designed better than the M-Jet 60 in every way. Even though I am not sure how exactly the M-Jet 35 would perform after the scale-up, it is very likely that the upscaled 35 would have better thrust, exit velocity, efficiency and lower power consumption. Regarding the impellers - yes the M-Jet 60 has two stages ~ two impellers. But the M-Jet 35 has two stages as well, it just integrates the two impellers into one part - the "two stage single blade impeller" as you can see in the animation. The problem is, upscaling the 35 from 35 to 60mm will generate weird bearing dimensions. Scaling the 35 to 200% to 70mm makes more sense, you will still run into some problems with sizing but probably solvable.
Yes, getting the impeller metal 3D printed is the best option. There is very detailed information about all of this in the manual: drive.google.com/file/d/1d3b9momWcgAeUAn5o1v0-QZcIMYy4U90/view?usp=sharing
@@mjetdevelopment thanks again for the information. How much did it cost you to build one jet drive in total and do you sell the hardware kits and if so how much would it cost? I've bought and built one of your earlier models and built the whole boat but I haven't had any time to finish it up and I'm doing a couple mods to the water cooling by adding a piece of cut up antenna in between the jet drive and the one the tubing goes to inside the boat because the nipples snap off very easy.
@@martinconley4489 I dont sell hardware kits, you need to self source the parts. The build price obviously depends on your location and everything. For me, parts for the whole unit cost under 80$. The metal impeller is the most expensive part. I am aware of the issue with the printed cooling nipples easily breaking. The M-Jet 35 has this issue solved.
@@mjetdevelopment how does a 3d printed at 100% infill impeller work as I'm sure you have tried it. Possibly in nylon or another high temperature filament that is strong enough to hold up.
@@martinconley4489 Yes I did most of the development with plastic printed impellers, PLA. There is also a plastic impeller STL in the files, which has thicker blades to hold up. It has worse performance and questionable durability, but it works.
I assume you are talking about the M-Jet Sprint: www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-sprint-3d-printable-rc-jetsprint-boat-model For the Sprint, you need minimum build volume of 185mm x 150mm build plate x 200mm height There is a lot more information in the manual: drive.google.com/file/d/1JXAqPCIegU0TW2XvNSiWBZ-T3o3yTSlP/view?usp=sharing
There are 3 non-plastic parts I used apart from basic homemade hardware like driveshafts: impeller, ride plate and intake grate. You can print these parts in plastic and it will work. There is also a separate impeller file for printing in plastic. But overall durability of these 3 parts will be worse. As printing material I used CFPC. Using PLA or ABS is possible, depends on you. Motor size from 3660 to 4092. There is a lot more information to all these questions in the full PDF manual, and also in the M-Jet 35 full build video - link for both of these is in the description.
@@OzAndyify Glad you like it! The M-Jet 35 might be too small for a manned boat though. It depends how fast you would like to go, but generally my older M-Jet 60 could suit this purpose better: www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-60-3d-printable-jet-drive-for-electric-surfboards Alternatively you could also try resizing the M-Jet 35 to 200% to 70mm, but this is not tested and I cannot predict the result.
@@mjetdevelopment Thanks! That one looks a tad simpler and it should scale up OK. (cheaper too). I've got a Turnigy Aquastar T20, 56mm diam motor that can put out nearly 5kw running 10s and 730 kv. Looks like I can make the mount work with min changes. I plan to make a very light foam stepped hull with low hull loading to get min planing speed. I'm not expecting much, but should be fun.
I havent designed any fully 3D printable hull for the M-Jet 35. The 4G hull in the video is carbon fiber, and there are free plans for it here: www.cgtrader.com/free-3d-print-models/hobby-diy/automotive/4g-sprint-hull-for-rc-boats-2022 If you wish to 3D print the whole hull, you can try searching for a compatible hull design yourself, or look at what the community has created. For example, there is this huge hull created by Jeff Jackson: www.thingiverse.com/thing:5569969
In this video I used Hobbystar 3670 1200kv: rcjuice.com/collections/boat-motors/products/hobbystar-3670-4-pole-brushless-sensorless-boat-motor-waterproof?variant=47585211089191
Awesome engineering!! I’m asking myself why you’re using this 4 path nozzle, is it to reduce the rotantion of the water stream cause by the props rotating, just like a stator would?
The function is exactly the same as a regular jet pump stator has, it removes most of the water rotation caused by the impeller. Also it reduces the flow area, which accelerates the stream. A conventional jet pump stator has vanes, which stabilise the water stream, and obviously, they divide the stream into multiple sections. Then, as the vanes end, the water streams are joined together again in the center to pass into the steering nozzle. My approach with the 4-path nozzle started as an idea, that there is no point of joining the streams after they are divided by the vanes. The advantages are following: 1) After passing the wide impeller hub, water is not forced to return back into the center, instead continues on its natural radial path. Less curves in the flow path, more efficiency. 2) This leads to the flow path being around 2* shorter than before, decreasing the friction on walls, increasing efficiency. 3) Paired with the new M-Jet steering system, the whole assembly is at least 30mm shorter, which improves durability and lowers weight.
@@mjetdevelopment that’s great, I have never seen something like this before and I like the thoughts you’re putting into your project. Buy how much did the efficiency increase compared to a normal nozzle with a stator? And would it be ok if I use this nozzle design for my Dive-Jet?
@@3dprintcnc164 Based on a number of measurements, the efficiency improvement is over 30%. Yes you can absolutely use the idea for your Dive-Jet! Though I won't mind if you give me a little credit:)
@@mjetdevelopment What is the secret to this perfect stream of water? I adapted the design to my application, but the stream isnt nearly as perfect. With my nozzle the area is reduced by 35% which could be not enough to guide the water..
Incredible jet 👍🏼👍🏼👍🏼👍🏼👍🏼 Hey, if this goes make a update file to print for proboat Jetstream! On this price I saw this m-35 round 50bugs are perfect and will make this incredible boat like super boat and people like ironclad rc will love ❤ you for!!!! It is only a idea 💡
I understand! Then the M-Jet 30 might be for you, it is cheaper and still a very good unit. www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-3d-printable-jet-drive-for-rc-boats Also if you want to print a whole boat, then look at the M-Jet Sprint: www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-sprint-3d-printable-rc-jetsprint-boat-model
@@АнтонПетров-к2ъ If you mean the 4G sprint boat in this video, yes! The M-Jet 30 will fit very well into it. The 4G sprint hull files are free and you can build it from fibreglass or carbon fiber: www.cgtrader.com/free-3d-print-models/hobby-diy/automotive/4g-sprint-hull-for-rc-boats-2022 The M-Jet Sprint I posted www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-sprint-3d-printable-rc-jetsprint-boat-model includes its own pump.
I am currently building a small jet boat for my son, and I bought your two stage 60mm stl files. I am using the SSS 56114, and I wonder if its better to just increase it to 80mm in the slicer since 60mm is a bit small for that motor - or am I wrong? Also, this M-Jet 35, since you mention it as more efficient. Will you release it in a larger size for us building eJet boards or eJet micro jet boats? I had to modify the stl file to make some crude steering, but this design seems way nicer. Cheers
Hello, I had a vacation last week, so thanks for your patience. 1) Despite the motor might look big compared to the pump at first glance, don't get confused by looks. The 60mm impeller requires great amount of torque already, and in this case torque scales with 4th power of size. A 80mm pump would require 3x more torque than a 60mm one. I suggest keeping the M-Jet 60 as it is. 2) The M-Jet 35 is way better than the M-Jet 60. The M-Jet 60 was developed quite some time ago, and since then I gained better understanding and found new ways to improve performance. However, currently I am not planning to release any new large size pump, because I have no way to test it and have no use for it myself. The M-Jet 60 was tested in a collaboration which no longer continues. What you could try as an experiment would be a 200% upscaled M-Jet 35. It would require a lot of additional work to make it all fit after the upscale, but the result would very likely provide better performance than the M-Jet 60.
@@mjetdevelopment thanks - hope you had a good vacation! I saw someone in the fb group that had scaled it up. Since you provide the files to import to cad, it's probably quite easy to make the 35 work at 70mm, but yeah my SSS 56114 with 500kv probably is a bit weak when it comes to torque. Maybe I should buy a second with 300kv since I'm running it at 10S battery configuration. Or make it 14S and get an even lower kV motor. If you see my last video, that will be RC controlled and in practice a huge RC boat 🚤🚤🚤
@@NavalTechTinkerer Lowering the KV will help a lot. Please note that the M-Jet 35 comes with a STEP file, which includes almost all parts but does not include the first and second stage (the main pump parts). I am not sharing those as STEP to protect the most unique M-Jet geometry from misuse and competition on the market. The M-Jet 35 STEP file does include the housing and motor mount, which are probably the most important when it comes to upscaling. I took a brief look at your latest video - good job with the laminating! I think a 200% M-Jet 35 would be a good size for your project.
Great. I already printed the house in to the box. If my modifications works out, could we share it later? So people has to buy the main parts from you but print the bolt on box. Not in the game to earn anything but it would be nice to have the 60 mm as a bolt on box outboard for anyone who buys the files from you. It literally makes the boat a huge RC boat that you can sit in.
See my latest two shorts with the bolt on design. The goal is to have the jet outside the boat so people like me don't have to saw a hole in their boats. Also the most common issue seems to be it leaking, since I print it in abs and will use acetone vapor smoothing, I'm hoping this will be fully water proof without any work on using epoxy or sikaflex.
Around 50$. And even less per one, if you order two of them. There is some more information about the impeller on page 8 in the manual: drive.google.com/file/d/1d3b9momWcgAeUAn5o1v0-QZcIMYy4U90/view?usp=sharing
I sell 3D printable files for it: www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-35-3d-printable-jet-pump-for-rc-boats You can 3D print the pump for yourself. Or if you do not have a 3D printer, there are plenty of companies that can 3D print the parts for you.
Yeah it would be awesome if this got an opportunity to be tested on something full scale. But things are a lot different at full scale, partly because water boundary layers don't scale up. For example the single blade impeller would probably make no sense there, but the 4-path nozzle could bring some advantages.
There is no option to buy it. But you can buy the files for the pump, 3D print it and build it for yourself. Then you can freely download all files necessary to build the hull. Links: www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-35-3d-printable-jet-pump-for-rc-boats www.cgtrader.com/free-3d-print-models/hobby-diy/automotive/4g-sprint-hull-for-rc-boats-2022
Hi Stephan, I am planning to give a list of links to my wife for the plans and components needed to build your M35 design as my Christmas present this year 😁. I saw where you posted a link somewhere to the motor you used. Could you please list links to the motor, cooling jacket, speed control and batteries you used all in one place so I can show her. There are so many choices. I would just like to get what you already know works well.
Hi, nice idea:) I bought the 3674 1200kv motor and cooling jacket from RCJuice: www.rcjuice.com/motor-esc/brushless-boat-motors/hobbystar-3670-4-pole-brushless-sensorless-boat-motor-waterproof.html www.rcjuice.com/motor-esc/motor-cooling-jackets/hobbystar-water-cooling-jacket-for-boat-motor-46-5x44mm.html The motor depends on hull choice though. If you build bigger hull than me (over 50cm), then a 4070 will be better. My particular 120A Turnigy ESC is from hobbyking and is not sold anymore, so I am posting two different links for choice: www.rcjuice.com/motor-esc/boat-esc/hobbystar-brushless-boat-esc-130a-3a-sbec.html hobbyking.com/en_us/turnigy-rc-boat-esc-120a.html?queryID=0dd8da8386b0f062416b48b4d37a7032&objectID=73854&indexName=hbk_live_products_analytics And I ordered my batteries from a local supplier, it will be better if you find a local store as well. I used 6S 2600mAh 70C graphene LiPos. For example these seem to be good packs, just make sure it will not be too heavy for your particular hull: www.rcjuice.com/lipo-batteries/6s-22-2v/hobbystar-3500mah-22-2v-6s-60c-lipo-battery.html hobbyking.com/en_us/graphene-3000mah-6s-75c.html?queryID=d3e50318fa9d2ca64f8fedcd660c0ce1&objectID=75684&indexName=hbk_live_products_analytics
pretty awesome how you have created this hobbygrade++++++ design that is the most innovative thing in this scene since sliced bread especially your 2stage single blade counter balanced pump design. But you still removed that hexnut with pliars XD like!!! whaT?
Actually you are not the first one making jokes on that😂 But these are my favourite pliers so I started to use them for everything! Thanks for your kind words man:)
Straighter stream is more efficient in theory. But price for consilidating the water cone is generally making the nozzle longer, or adding some kind of vanes. Both of there options add friction on walls. During the development, I measured many setups and found out, that none of these options are worth it. Thanks for your kind words:)
Celkem by mně zajímalo jak se bude měnit rychlost a síla výtrysku s narůstající rychlostí lodě. Rychlost výtrysku by mněla vzrůstat protože se zvyšuje rychlost kterou jde voda do sání, ale síla by mněla klesat protože se zmenšuje rozdíl mezi rychlostí výtrysku a rychlostí lodě.
Přesně tak. Síla (tah pumpy) lineárně klesá s rychlostí lodi, protože se zmenšuje rozdíl mezi rychlostí výtrysku a rychlostí vody v jezeře. Je logická také úvaha, že s narůstající rychlostí lodi bude narůstat průtok pumpou, ale experimentální data (já to neměřil, ale několik různých lidí ano) ukazují, že tento efekt je mnohem menší, než by se dalo čekat - zvýšení průtoku je pouze v rozsahu 0%-15%. Toto je pro mě překvapivé a stále se snažím tomu více porozumět. Každopádně, pro dosažení vyšší rychlosti lodi je naprosto zásadní rychlost výtrysku, a to i při statickém testu - a proto jsem jí v poslední verzi designu zvýšil až na 70 km/h, i když to bylo částečně na úkor statického tahu. Když bych ignoroval to zvýšení průtoku a rozepsal to: Předchozí verze M-Jet 35 měla 7.4kg statický tah a 58km/h výtrysk, nová verze 6.8kg statický tah a 70km/h výtrysk. Ale jakmile loď jede alespoň 20 km/h, tak se tah při jízdě srovná na 4.8kg a následně nová verze začne tu starou předhánět.
@@technicbuilder6410 Výkon je nejvyšší ve statickém stavu. Ale počítá se jako 1/2 * hmotnostní tok * rychlost na druhou v m/s, což je vlastně kinetická energie vody vystříklé za 1s, výsledek je 667 W.
WOW what a video really good editing. Defiantly going to make a M-Jet 35 one summer really got the jet to be the best of the best👍. i have a youtube channel with rc cars if you want to check it out its called Tomabon.
60 bucks for 5 years worth of R AND D, countless test prints, experiments with aluminum 3d printing and all while getting a college degree in engineering. Spend 10 bucks on his first design Mjet30 and you will be quite happy. That design was worth $30 easy.
Thanks, yeah! Either you can find me in the M-Jet Facebook group, my name is Štěpán Müller: facebook.com/groups/623045356071128 Or you can use private message / product support on CGTrader: www.cgtrader.com/m-jet-development
I've been following Stepan's designs for a couple of years and this is a culmination of several ingenious improvements of the axial jet drive. The stator with it's abbreviated fins, the super-efficient single bladed dual stage impeller, and the innovative steering nozzle with simple trim adjustment are all vast improvements to conventional design. And the professional, well thought out displays and directions are second to none! Bravo, Stepan my hat is off to you!
Thank you very much!
You said it better than me! I agree. Somebody needs to pay this man and develop this thing for big boats! man that would be bad ass! Maybe the new Tesla Jet sprint? LOL
@@JeffJackson86 Haha I would love to! Maybe one day:)
@@mjetdevelopment just make a 70mm version of it and there we go ;) I would buy the drawings for sure he he
@@NavalTechTinkerer You know it's not that simple, but if I ever decide to build a boat to sit in, don't worry I will share it
I knew that you can do RC boats really well but I didn't know just how good you are at filmmaking. Great editing!
Thanks! The video took a lot of work😅
That shot of the boat landing in the water then jumping right back out of the water is impressive!
You out did your self with this one, Štêpán! It was amazing to see some of your development up to this point!
Thanks a lot! I am very happy with it myself😊
Un truc de fou une puissance incroyable franchement bravo.
I dont know which to compliment first, your design or your video editing... I'll be building one this winter!! wow
Really good jet pump it keeps getting better and better.
hey man, found your channel a couple of mounths ago on my way through 3D-Printing-UA-cam and seeing how you were able to get so significant improvements over your desings without changing much of the electrics really motivated me to desing and print my own rc jetboat and pump. i´m on my Version 3 (only counting those that actually survived more than 3 min) and it has been a lot of fun. I just wanted to say thank you for the inspiration. Greetings from Germany :)
Nice!👍
@@mjetdevelopment And also i`m curious, did you do any CFD-Symulations or just experimenting (and maybe some calculations)?
@@1sqeeze1 Yes, I did some tests in ansys fluent. You can find some screenshots from it if you click on my channel, click community (the non-video content) and scroll all the way down
@@1sqeeze1 And I did huge amount of calculations of the pump based on experimental thrust measurement during the development process, I measured over 100 different design combinations and plotted all parameters in an excel sheet
@@mjetdevelopment aah, didnt see that yet, i assume you used a student license right? I`ll try that too then, when i worked the other bugs out
Fantastic work as usual Stepan!
So I finally made the M-Jet 30 work in my water gun and you go ahead and release the 35. But DUDE! It TOTALLY works! 9 meters without any optimisation or even an active water supply from the backpack! I've only tested the wand so far, so I am very optimistic about it.
Hey man you cant stop me😂 Sounds fantastic! I would be interested to see how you did it😀
I am just having a nice evening with the owner of this channel and i think, that all of you just have to buy his latest model of sprintboat, because it is just awesome
:D
Amazing boat! It's on my list! You are a good designer. What you did is very impressive!
Buy M-Jet 35 files:
www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-35-3d-printable-jet-pump-for-rc-boats
Hardware kit by RCPrinter:
rcprinter.com/products/m-jet-35-pump-build-kits
I need one.. the boat that is - some of us don't have printers and I want to know how can I order one straight from you?
Will you make a full size version of this? Could be very interesting and ground breaking!
Maybe one day:) though there are many things working very differently at full scale.
I'mma scale it up and put it on a kayak haha! Got a 72v ebike battery I can use. just need to get an ESC and motor
Maybe next you could make a new and better 3d printed hull with this jet pump build into it as a upgrade over the mjet sprint.
Yes! It is a good idea, and I might do it at some point. But I am not planning to do it yet😀My only plan right now is to take a bit of rest!
@@mjetdevelopment good idea you are pushing a lot of ideas out maybe some rest and then even better. (If it is poseble
Would it be possible to scale this up to be used on a jet kayak?
Scaling it up is difficult and comes with some problems, mostly because dimensions of all hardware scale up too. This can result in non-existing dimensions of bearings, etc. Motor mount becomes incompatible.
With some effort, it is still possible to scale it up - especially if you use a nice number like 200%.
You could also consider looking at the M-Jet 60, which comes with a STEP file:
www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-60-3d-printable-jet-drive-for-electric-surfboards
Any cheaper options with this because this would work amazing on my jet boat I am making but can you jsut put on the end part and will it still work because my 3d printed jet boat already comes with a a hole in the bottom were it comes through
It is a amazing design how long did you work on it ?
Thank you for your kind words:) The development of the M-Jet 35 took me little over one year. And yes! This is a cheaper option you might like to consider, my previous M-Jet 30: www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-3d-printable-jet-drive-for-rc-boats
Oh now I see why cost so much what is the difference between the 2 is this on better
@@baconbulldog5250 The M-Jet 30 is a good pump already, and when I was using it back then, I was very happy with it. But the M-Jet 35 brings everything to a new level, the amount of work that went into it makes it better in every way. The difference is captured in the price.
I am thinking of buying that one now plus would fit on my 1/8 scale jet boat ?
Hi I’ m planing to make an electric surf board, do you think it is possible to scale it up a lot ?
You can try to scale it to 200%, yeah.
But keep in mind there are many problems coming with the scale-up: All tolerances will get changed, motor mount will be incompatible, and it might generate some non-existing hardware sizes, like bearings and seals.
If you can solve these problems, it is possible.
Really a great drive. I installed two M-Jet 30 in my last boat and they run great. As it's a big boat and therefore heavier than small jet boats, I'm planning to use the M-Jet 35 for a future model. It is important to me that the boats can reverse. Would it be possible for you to develop a reverse plate for the jet?
Glad you are happy with the M-Jet 30!
Unfortunately, so far I am not planning to develop any reverse bucket for the M-Jet 35. Reasons are:
1) I myself never found the need for a reverse bucket, because it is possible to just steer at high throttle and turn basically 180° in place
2) In the very few cases when reverse is necessary, it is possible to just spin the motor backwards, pumping water in the opposite direction. This is not optimal, but still works as a slow reverse.
3) Adding a reverse bucket for the M-Jet 35 would add quite some complexity of the assembly, which goes aganist the philosophy of the pump.
I still understand that some people prefer the reversing bucket anyway - I might get to designing it in the future, but so far it's not on the list.
@@mjetdevelopment Thanks anyway. I will still look forward to build the drive. The M-Jet 30 is already powerful, so I can hardly wait to install the M-Jet 35.
Only thing missing is a reverse thrust bucket, all that speed and no brakes! Makes no difference, I;ll still be straight on to CG Trader as soon as this month's wages drop into the bank, can't wait to fit 2 of these to my SAAB CB-90
Hello, my boats nose is pushing in the water when i am using it how csn i fix this?
Is this in the mod folder.
Hi, are you talking about the M-Jet Sprint boat? Unfortunately I dont have any "smart" fix for this. Some things you can do: Probably you will need to use a lighter battery and mount the ESC as far backwards as possible to push CG towards the rear. Also use the standard first stage with ride plate that does not have any additional lift.
can i use it for 3metre boat?of course in other size
@@zohrabmamedov5446 You could try scaling it to 200% or 300%. Then theoretically, performance might be sufficient.
However there is so much trouble with the upscaling process:
If you upscale it, all bearings, shafts, hardware will upscale too, possibly resulting in non existent hardware sizes. Imagine 300% M3 screws -> M9, pretty much doesn't exist.
The mount for motor and servo will no longer be compatible with anything.
Tolerances might get screwed up randomly.
Overall - the upscaling process would require great effort.
Then, trouble will come as you will need enermously powerful electronics to spin the upscaled pump. Torque scales with 4th power of size here. 2x size -> 16x torque.
Power consumption scales with 3.5th power of size.
2x size -> 11x power input and motor wattage.
that video was excellent :)
If you made the M jet-35 and the M Jet-60 the same size, using the same motor and battery, even while the M jet-60 uses dual jetdrive/2 impellors, wich one would provide more thrust?(Im thinking of making a electric surfboard and I want to know if I should scale the size of the M-jet 35, only if it is more powerful than the M-jet 60 (when they are the same size)), dang thats a lot of parentheses..., so wich one is more powferful while The M jet 60 uses dual jet drives/2 impellors and the M-Jet 35 uses one impellor?? another way is, having the same rpm the jet drives, while being the same sizes, what is the rpm to kg of thrust for each jet drive while being the same size?
The M-Jet 35 is newer and is designed better than the M-Jet 60 in every way. Even though I am not sure how exactly the M-Jet 35 would perform after the scale-up, it is very likely that the upscaled 35 would have better thrust, exit velocity, efficiency and lower power consumption.
Regarding the impellers - yes the M-Jet 60 has two stages ~ two impellers. But the M-Jet 35 has two stages as well, it just integrates the two impellers into one part - the "two stage single blade impeller" as you can see in the animation.
The problem is, upscaling the 35 from 35 to 60mm will generate weird bearing dimensions. Scaling the 35 to 200% to 70mm makes more sense, you will still run into some problems with sizing but probably solvable.
Ok how do I get the parts needed to be 3d printed in metal since the prop is metal?
Yes, getting the impeller metal 3D printed is the best option. There is very detailed information about all of this in the manual:
drive.google.com/file/d/1d3b9momWcgAeUAn5o1v0-QZcIMYy4U90/view?usp=sharing
@@mjetdevelopment thanks again for the information. How much did it cost you to build one jet drive in total and do you sell the hardware kits and if so how much would it cost? I've bought and built one of your earlier models and built the whole boat but I haven't had any time to finish it up and I'm doing a couple mods to the water cooling by adding a piece of cut up antenna in between the jet drive and the one the tubing goes to inside the boat because the nipples snap off very easy.
@@martinconley4489 I dont sell hardware kits, you need to self source the parts. The build price obviously depends on your location and everything. For me, parts for the whole unit cost under 80$. The metal impeller is the most expensive part.
I am aware of the issue with the printed cooling nipples easily breaking. The M-Jet 35 has this issue solved.
@@mjetdevelopment how does a 3d printed at 100% infill impeller work as I'm sure you have tried it. Possibly in nylon or another high temperature filament that is strong enough to hold up.
@@martinconley4489 Yes I did most of the development with plastic printed impellers, PLA. There is also a plastic impeller STL in the files, which has thicker blades to hold up. It has worse performance and questionable durability, but it works.
I know this might seem a silly question but, how slow can it go?
As slow as you want, this is only limited by how slow your electric motor can turn
What size 3d printer do I need to print the jetboat?
I assume you are talking about the M-Jet Sprint:
www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-sprint-3d-printable-rc-jetsprint-boat-model
For the Sprint, you need minimum build volume of
185mm x 150mm build plate x 200mm height
There is a lot more information in the manual:
drive.google.com/file/d/1JXAqPCIegU0TW2XvNSiWBZ-T3o3yTSlP/view?usp=sharing
Can it all be printed in plastic, or are there metal bits (rotor) apart from skid plate and intake?
Best in ABS or PLA?
Also, motor diameter?
There are 3 non-plastic parts I used apart from basic homemade hardware like driveshafts: impeller, ride plate and intake grate. You can print these parts in plastic and it will work. There is also a separate impeller file for printing in plastic. But overall durability of these 3 parts will be worse.
As printing material I used CFPC. Using PLA or ABS is possible, depends on you.
Motor size from 3660 to 4092.
There is a lot more information to all these questions in the full PDF manual, and also in the M-Jet 35 full build video - link for both of these is in the description.
@@mjetdevelopment Thanks for that. Looks like a great design. I'm thinking about making two for a manned micro boat.
@@OzAndyify Glad you like it! The M-Jet 35 might be too small for a manned boat though. It depends how fast you would like to go, but generally my older M-Jet 60 could suit this purpose better:
www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-60-3d-printable-jet-drive-for-electric-surfboards
Alternatively you could also try resizing the M-Jet 35 to 200% to 70mm, but this is not tested and I cannot predict the result.
@@mjetdevelopment Thanks! That one looks a tad simpler and it should scale up OK. (cheaper too). I've got a Turnigy Aquastar T20, 56mm diam motor that can put out nearly 5kw running 10s and 730 kv. Looks like I can make the mount work with min changes.
I plan to make a very light foam stepped hull with low hull loading to get min planing speed. I'm not expecting much, but should be fun.
@@OzAndyify Yeah sounds good👍
Fantastic!.I need a 80 mm Version 😋
What printed hull does this fit on?
I havent designed any fully 3D printable hull for the M-Jet 35. The 4G hull in the video is carbon fiber, and there are free plans for it here:
www.cgtrader.com/free-3d-print-models/hobby-diy/automotive/4g-sprint-hull-for-rc-boats-2022
If you wish to 3D print the whole hull, you can try searching for a compatible hull design yourself, or look at what the community has created. For example, there is this huge hull created by Jeff Jackson:
www.thingiverse.com/thing:5569969
What motor specific you use?
In this video I used Hobbystar 3670 1200kv:
rcjuice.com/collections/boat-motors/products/hobbystar-3670-4-pole-brushless-sensorless-boat-motor-waterproof?variant=47585211089191
Awesome engineering!!
I’m asking myself why you’re using this 4 path nozzle, is it to reduce the rotantion of the water stream cause by the props rotating, just like a stator would?
The function is exactly the same as a regular jet pump stator has, it removes most of the water rotation caused by the impeller. Also it reduces the flow area, which accelerates the stream.
A conventional jet pump stator has vanes, which stabilise the water stream, and obviously, they divide the stream into multiple sections. Then, as the vanes end, the water streams are joined together again in the center to pass into the steering nozzle.
My approach with the 4-path nozzle started as an idea, that there is no point of joining the streams after they are divided by the vanes. The advantages are following:
1) After passing the wide impeller hub, water is not forced to return back into the center, instead continues on its natural radial path. Less curves in the flow path, more efficiency.
2) This leads to the flow path being around 2* shorter than before, decreasing the friction on walls, increasing efficiency.
3) Paired with the new M-Jet steering system, the whole assembly is at least 30mm shorter, which improves durability and lowers weight.
@@mjetdevelopment that’s great, I have never seen something like this before and I like the thoughts you’re putting into your project.
Buy how much did the efficiency increase compared to a normal nozzle with a stator?
And would it be ok if I use this nozzle design for my Dive-Jet?
@@3dprintcnc164 Based on a number of measurements, the efficiency improvement is over 30%. Yes you can absolutely use the idea for your Dive-Jet! Though I won't mind if you give me a little credit:)
@@mjetdevelopment thank you very much, of course I’ll give you credits👍🏼
@@mjetdevelopment What is the secret to this perfect stream of water? I adapted the design to my application, but the stream isnt nearly as perfect. With my nozzle the area is reduced by 35% which could be not enough to guide the water..
Incredible jet 👍🏼👍🏼👍🏼👍🏼👍🏼
Hey, if this goes make a update file to print for proboat Jetstream! On this price I saw this m-35 round 50bugs are perfect and will make this incredible boat like super boat and people like ironclad rc will love ❤ you for!!!!
It is only a idea 💡
Thanks! The M-Jet 35 Jetstream mod is in the works:)
Really good. I need a boat 500mm< but jet soooo expensive. Can you create some cheaper then that boat. If you need help we can do this.
I understand! Then the M-Jet 30 might be for you, it is cheaper and still a very good unit.
www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-3d-printable-jet-drive-for-rc-boats
Also if you want to print a whole boat, then look at the M-Jet Sprint:
www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-sprint-3d-printable-rc-jetsprint-boat-model
@@mjetdevelopment So I can use the m-jet30 pump for this boat?
@@АнтонПетров-к2ъ If you mean the 4G sprint boat in this video, yes!
The M-Jet 30 will fit very well into it. The 4G sprint hull files are free and you can build it from fibreglass or carbon fiber:
www.cgtrader.com/free-3d-print-models/hobby-diy/automotive/4g-sprint-hull-for-rc-boats-2022
The M-Jet Sprint I posted
www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-sprint-3d-printable-rc-jetsprint-boat-model
includes its own pump.
@@mjetdevelopment thanks. can I use the engine from M-jet Sprint?
@@АнтонПетров-к2ъ Yes if you have a 3660 size.
I am currently building a small jet boat for my son, and I bought your two stage 60mm stl files. I am using the SSS 56114, and I wonder if its better to just increase it to 80mm in the slicer since 60mm is a bit small for that motor - or am I wrong? Also, this M-Jet 35, since you mention it as more efficient. Will you release it in a larger size for us building eJet boards or eJet micro jet boats? I had to modify the stl file to make some crude steering, but this design seems way nicer. Cheers
Hello,
I had a vacation last week, so thanks for your patience.
1) Despite the motor might look big compared to the pump at first glance, don't get confused by looks. The 60mm impeller requires great amount of torque already, and in this case torque scales with 4th power of size. A 80mm pump would require 3x more torque than a 60mm one. I suggest keeping the M-Jet 60 as it is.
2) The M-Jet 35 is way better than the M-Jet 60. The M-Jet 60 was developed quite some time ago, and since then I gained better understanding and found new ways to improve performance. However, currently I am not planning to release any new large size pump, because I have no way to test it and have no use for it myself. The M-Jet 60 was tested in a collaboration which no longer continues.
What you could try as an experiment would be a 200% upscaled M-Jet 35. It would require a lot of additional work to make it all fit after the upscale, but the result would very likely provide better performance than the M-Jet 60.
@@mjetdevelopment thanks - hope you had a good vacation! I saw someone in the fb group that had scaled it up. Since you provide the files to import to cad, it's probably quite easy to make the 35 work at 70mm, but yeah my SSS 56114 with 500kv probably is a bit weak when it comes to torque. Maybe I should buy a second with 300kv since I'm running it at 10S battery configuration. Or make it 14S and get an even lower kV motor. If you see my last video, that will be RC controlled and in practice a huge RC boat 🚤🚤🚤
@@NavalTechTinkerer Lowering the KV will help a lot.
Please note that the M-Jet 35 comes with a STEP file, which includes almost all parts but does not include the first and second stage (the main pump parts). I am not sharing those as STEP to protect the most unique M-Jet geometry from misuse and competition on the market.
The M-Jet 35 STEP file does include the housing and motor mount, which are probably the most important when it comes to upscaling.
I took a brief look at your latest video - good job with the laminating! I think a 200% M-Jet 35 would be a good size for your project.
Great. I already printed the house in to the box. If my modifications works out, could we share it later? So people has to buy the main parts from you but print the bolt on box. Not in the game to earn anything but it would be nice to have the 60 mm as a bolt on box outboard for anyone who buys the files from you. It literally makes the boat a huge RC boat that you can sit in.
See my latest two shorts with the bolt on design. The goal is to have the jet outside the boat so people like me don't have to saw a hole in their boats. Also the most common issue seems to be it leaking, since I print it in abs and will use acetone vapor smoothing, I'm hoping this will be fully water proof without any work on using epoxy or sikaflex.
Nice transistion as :48 seconds!
Thanks:))
What was the cost to have the impeller 3d printed in aluminum?
Around 50$. And even less per one, if you order two of them. There is some more information about the impeller on page 8 in the manual: drive.google.com/file/d/1d3b9momWcgAeUAn5o1v0-QZcIMYy4U90/view?usp=sharing
@@mjetdevelopment Thank you for the quick reply. $50 is much cheaper than I expected.
Zlaté české ručičky👍🇨🇿
brother where can i get the jet pump
I sell 3D printable files for it:
www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-35-3d-printable-jet-pump-for-rc-boats
You can 3D print the pump for yourself. Or if you do not have a 3D printer, there are plenty of companies that can 3D print the parts for you.
killer video!!
I wanna see what happens if we put this kind of jet designs on a bigger scale I'm talking jet racing boats full size
Yeah it would be awesome if this got an opportunity to be tested on something full scale. But things are a lot different at full scale, partly because water boundary layers don't scale up. For example the single blade impeller would probably make no sense there, but the 4-path nozzle could bring some advantages.
bro you should make a 3d modeling course
Oh thanks. I do have some CAD skills but I am no expert, in fact I'd love to learn from people way better than me:)
Hallo can i buy such a boat ? Greets Andreas from Gemany
There is no option to buy it. But you can buy the files for the pump, 3D print it and build it for yourself. Then you can freely download all files necessary to build the hull.
Links:
www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-35-3d-printable-jet-pump-for-rc-boats
www.cgtrader.com/free-3d-print-models/hobby-diy/automotive/4g-sprint-hull-for-rc-boats-2022
Hi Stephan, I am planning to give a list of links to my wife for the plans and components needed to build your M35 design as my Christmas present this year 😁. I saw where you posted a link somewhere to the motor you used. Could you please list links to the motor, cooling jacket, speed control and batteries you used all in one place so I can show her. There are so many choices. I would just like to get what you already know works well.
Hi, nice idea:)
I bought the 3674 1200kv motor and cooling jacket from RCJuice:
www.rcjuice.com/motor-esc/brushless-boat-motors/hobbystar-3670-4-pole-brushless-sensorless-boat-motor-waterproof.html
www.rcjuice.com/motor-esc/motor-cooling-jackets/hobbystar-water-cooling-jacket-for-boat-motor-46-5x44mm.html
The motor depends on hull choice though. If you build bigger hull than me (over 50cm), then a 4070 will be better.
My particular 120A Turnigy ESC is from hobbyking and is not sold anymore, so I am posting two different links for choice:
www.rcjuice.com/motor-esc/boat-esc/hobbystar-brushless-boat-esc-130a-3a-sbec.html
hobbyking.com/en_us/turnigy-rc-boat-esc-120a.html?queryID=0dd8da8386b0f062416b48b4d37a7032&objectID=73854&indexName=hbk_live_products_analytics
And I ordered my batteries from a local supplier, it will be better if you find a local store as well. I used 6S 2600mAh 70C graphene LiPos.
For example these seem to be good packs, just make sure it will not be too heavy for your particular hull:
www.rcjuice.com/lipo-batteries/6s-22-2v/hobbystar-3500mah-22-2v-6s-60c-lipo-battery.html
hobbyking.com/en_us/graphene-3000mah-6s-75c.html?queryID=d3e50318fa9d2ca64f8fedcd660c0ce1&objectID=75684&indexName=hbk_live_products_analytics
Perfect ! I’m planning to build your hull too. Thanks for the fast reply, I’ll give her this list and patiently wait for Christmas morning 😁😁
pretty awesome how you have created this hobbygrade++++++ design that is the most innovative thing in this scene since sliced bread especially your 2stage single blade counter balanced pump design. But you still removed that hexnut with pliars XD like!!! whaT?
Actually you are not the first one making jokes on that😂 But these are my favourite pliers so I started to use them for everything! Thanks for your kind words man:)
Interesting design, you'd think a consolidated cone of water would have better results, obviously not great work brother in boats
Straighter stream is more efficient in theory. But price for consilidating the water cone is generally making the nozzle longer, or adding some kind of vanes. Both of there options add friction on walls. During the development, I measured many setups and found out, that none of these options are worth it. Thanks for your kind words:)
Celkem by mně zajímalo jak se bude měnit rychlost a síla výtrysku s narůstající rychlostí lodě. Rychlost výtrysku by mněla vzrůstat protože se zvyšuje rychlost kterou jde voda do sání, ale síla by mněla klesat protože se zmenšuje rozdíl mezi rychlostí výtrysku a rychlostí lodě.
Přesně tak. Síla (tah pumpy) lineárně klesá s rychlostí lodi, protože se zmenšuje rozdíl mezi rychlostí výtrysku a rychlostí vody v jezeře.
Je logická také úvaha, že s narůstající rychlostí lodi bude narůstat průtok pumpou, ale experimentální data (já to neměřil, ale několik různých lidí ano) ukazují, že tento efekt je mnohem menší, než by se dalo čekat - zvýšení průtoku je pouze v rozsahu 0%-15%. Toto je pro mě překvapivé a stále se snažím tomu více porozumět.
Každopádně, pro dosažení vyšší rychlosti lodi je naprosto zásadní rychlost výtrysku, a to i při statickém testu - a proto jsem jí v poslední verzi designu zvýšil až na 70 km/h, i když to bylo částečně na úkor statického tahu.
Když bych ignoroval to zvýšení průtoku a rozepsal to:
Předchozí verze M-Jet 35 měla 7.4kg statický tah a 58km/h výtrysk, nová verze 6.8kg statický tah a 70km/h výtrysk. Ale jakmile loď jede alespoň 20 km/h, tak se tah při jízdě srovná na 4.8kg a následně nová verze začne tu starou předhánět.
@@mjetdevelopment díky za vysvětlení, tryska má tedy největší výkon ve statickém stavu a počítám že by to mnělo být 1,3kw.
@@technicbuilder6410 Výkon je nejvyšší ve statickém stavu. Ale počítá se jako 1/2 * hmotnostní tok * rychlost na druhou v m/s, což je vlastně kinetická energie vody vystříklé za 1s, výsledek je 667 W.
@@mjetdevelopment jasně, díky za upřesnění
Are the 3D plane free?
For the pump, no. For the hull, yes.
i love this design and the boat but it just that it costs 35 dollars and i cant affort that sadly
WOW what a video really good editing. Defiantly going to make a M-Jet 35 one summer really got the jet to be the best of the best👍. i have a youtube channel with rc cars if you want to check it out its called Tomabon.
60 bucks for a 3d printing file 😅
60 bucks for 5 years worth of R AND D, countless test prints, experiments with aluminum 3d printing and all while getting a college degree in engineering.
Spend 10 bucks on his first design Mjet30 and you will be quite happy. That design was worth $30 easy.
I really liked the job you done which i also interested. Can i contact you ?
Thanks, yeah! Either you can find me in the M-Jet Facebook group, my name is Štěpán Müller:
facebook.com/groups/623045356071128
Or you can use private message / product support on CGTrader:
www.cgtrader.com/m-jet-development
Hello Stepan. Do you have a private email I can chat with you on? I have an important private question for you.
Hi, yes, please send me a private message on CGTrader. Link to my profile is in the description of this video.
Edit: I added you on facebook.