Hi! I made a jet a while ago, here's a few of the things I learned. You need a variable blade angle on the impeller. The blade pitch is measured as how many inches it travels per rotation, and as the edge of the blade travels farther than the inside per rotation the angle gets shallower the farther out you go from the centre. This makes the blades appear twisted. Also, stator. The water from the impeller is spinning, the centrifugal force of which pushes on the nozzle and kills thrust. You can also extract extra energy from this spin by having vanes going all the way to the nozzle exit. Also use a greased bushing at the back rather than a bearing. Smaller and increases thrust, plus less submerged moving steel parts.
@@AndrewWorkshop let me know if you need any advice on the rc jet pump design 😁 I spent about 3 years working on this one. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-H074iZxeR8I.html
As a fellow tinkerer, I'm highly inspired. A few tips: on the final epoxy flow coat over the board after glassing, wait 10 minutes after spreading it out, then hit it with a blow torch to pop all of the bubbles. Also, have to tried printing with PETG? I'll never go back to PLA after using it. Higher Tg, less brittle, no smell when printing, no need for an enclosure, etc.
I plan to use the jet pump for a 6'4" plywood boat i built. I will use a trolling motor and put the battery up front. Thanks for the design. I hope there is not much modification needed.
Dear Andrew, Thank you for making your creative genius public on RU-vid. Using a 3d print scheme for the jet pumps was sweet indeed. It is when you shifted into welding an aluminum box for the jets that just blew my mind. We, as creators have to be capable/ talented at interdisciplinary skillsets. That you can fiberglass a board and then shift to make 3d printed parts and then machine these goods is awesome. I am thoroughly inspired to build out new projects. Will also take your advice and not build this jet powered surfboard. Vicarious thrills will suffice indeed.
Прекрасная работа. Радует четкость и продуманность до самых мельчайших деталей. Спасибо что делитесь своим опытом и спасибо за 3D модели. Когда что-либо сделаю, сообщу вам. Успехов вам в дальнейшей работе.
I've watched a few of the videos of that guy you mentioned at the beginning of this video, and he appears to be an engineer for all the things he has created. Never fear - You Are An Engineer. I sure would have liked to see you moving that board at speed, just to see how it planes-out. Great video. Thanks
Great work!! I think a lot of your speed problem is with the impeller design. You may want to look into any of the big three company’s impeller designs. None of them look like those flat bladed impellers you used. The flat blades just don’t have the grip on the water you need. I’d bet a hundred bucks it would go way better with different impellers.
I agree. And I would add to that to have look at your intakes: the leading edge needs to be smooth, where currently there is a step that prohibits proper flow of water into the jetdrive. Other than that great work!!!
@@hjl4004 I noticed that too the intake ports are way too small and there should be far more of a radius to the edge, letting water funnel in instead of making it all take a 90 degree turn just before entering the pump.
Yep I totally agree. You can't just eyeball an impeller design; he should copy the design of an expensive retail version. You can see the impeller is creating a TON of cavitation too, just throwing away energy he could be using to haul ass.
Yes you are right. Came to say the exact same thing. His impeller looks more like an impeller for a water pump to cool an engine (normally running in an inclosed space and made of rubber). When you look at jetski thrust impellers they have overlapping blades with less pitch compared to this one. More disc like impellers. But Those will be a pain to keep in one piece under load when 3d printed I think. And pump inlet indeed needs to be more smooth to guide the water instead of starting with a vertical ridge all around before starting to guide it back.
I would love to see the height of the box lowered so the top cover would be flush with the top surface of the board. Also some heavy duty lithium battery packs. A wrist band mounted wireless controller would be better too. You're on to great things with this board !
I caught my workshop on fire when trying to replicate a few projects when RClifeon said don't try this at home. I should have listened. You are one of those rare survivors that made it out alive like me. I wonder how many missing people or people who never came out of their workshops are out there from doing the same. lol. Good job, bro! Welcome to the survivors club. 😂
Awesome project. I agree with others that your jet pumps are holding you back. The flow of water out of them is very turbulent. Turns out jet pumps are fairly easy to get working, but optimizing them is an art form. There are a couple good videos from a few people making pumps for RC boats that are really good and I think their designs are open too.
That’s a hell of a lot of work and working out well done it’s brilliant...and for sharing all your work as well I don’t have a printer I don’t surfe or live buy the sea but I found your previous videos and really enjoyed your builds and your attention to detail all detail brilliant and thank you for sharing..I personally learnt a lot and so thank you..👍🏻🇬🇧
This is awesome and some real engineering skills on show there. So nearly there though! It's probably got the power and the board width is probably fine too. Worth spending on getting custom steel impellers built for it. I'm not sure 3D printing will ever let you make the blades thin enough- other than with very exotic printing media that won't be possible with your machine- a little bit of carefully designed stainless steel or bronze could transform things. The jetski racers use custom built impellers and they aren't that expensive. What you've done with the impeller is the marine equivalent of building a car but also insisting on moulding your own tires for it- there are certain things where you just have to admit that relying on other folks decades of experience in a very niche technical field is just way more efficient than insisting that you build every bit of it yourself! There's being inventive and resourceful, and then there's just being stubborn! I know because I do it myself! There is a lot of talk below about the entrance to the pump. What it needs more specifically is a scoop grate, or just a scoop if you don't want the grate to slow it down. Look underneath a jetski! Look closely at the rear part of the entrance to the jet drive and feel with your fingers what it does inside. You have to divert some of that water flow through the pump, water does not like being made to go round sharp corners when it is flowing at speed. If you do not physically divert some of the passing water into the jet drive too much of it will simply carry on waltzing past underneath! If you unbolt the scoop grate from a jetski it will hardly move- like it will do 25mph instead of 80mph, and this is effectively what you are doing here. This is why your board is topping out at circa 10mph, that is about the speed when the jet drives are calling out for more flow and when just the suction effect of the impellers becomes no longer enough to divert enough of the water which as the speed increases is increasingly more interested in passing underneath, not turning the corner into the drives. Other than that I don't get why you have two pumps. If it's for steering at slow speeds, not as effective as a steerable nozzle on a single pump. Doubling up on propulsors is never as efficient as optimising a single one. A boat with a single 8hp outboard engine will be much faster than the same boat with two 4hp engines side by side! The parasitic drag (of the inside of the tube, the shaft, the stator vanes etc.) doubles when you double the number of propulsors, but it does not nearly double when you just make one propulsor a bit bigger and put a bigger motor to drive it. If its about motor size/ height/ diameter, you could still use two motors side by side driving one shaft- with a bit of short car cambelt and a pair of sprockets... If the height of the deck for placing your back foot is the concern, remember the diameter of the pump does not even close to have to double to double the volume/ mass being pumped. People would be amazed how only slightly larger a single pump would need to be to move the same mass of water moved by your two pumps. That's not the main problem though and would be a major rework. You could get that thing planing- I mean properly planing at foot steerable speeds- with your motors and pumps in about a week with just a pair of scoop grates (which you could make by hand in one evening with a curved bit of thin plywood and some epoxy filler) and a professionally designed impeller.
one thing I learned about jet pumps was from Finnegan's Garage, it has to do with the leading edge of the intake hole in the bottom of the boat, the softer ( smoother for less agressive flow entering the pump) you can make that transition into the jet the better performance you'll get out of the jet. I did look for the actual video but... just can't find it, it was only like a 5 min segment of a video but it made a lot of sence
Oh man, great work. The RU-vid's suggested this video to me. I have to say though, my favorite part was at the end when the wife is throwing down serious shade on the execution of this whole plan. LOL Made me chuckle.
Nice project. Scratch building is really rewarding,, after you solve all the technical details lol. TIPs: For PLA plastic use Silicone Grease only, petroleum based lubricants will degrade the plastic over time. For gluing and sealing PLA plastic I use Plastruct Plastic Solvent Cement. I coat the entire inside surfaces of the Jet drive to seal and smooth them so water flows easier thru it. I strongly recommend any printed impeller be coated completely so it withstands the forces put on it. I also recommend builders get a 3D Pen. Great for welding plastic together, mounting plastic parts and much more uses. Hope this helps builders make a better working project build.
Very nice! a few things I just wanted to give my 2 cents on: 1. I think your bearings are going to seize or are at risk of seizing. Personally, I would recommend an acetal bushing. you could easily make one on your lathe. also, lookup water-lubricated bearings, very interesting if you ask me 2. Brass suffers from something known as "Dezincification" I know it is a bit of a confusing name but it's when the zinc leaves the brass. Not sure what it's like in water but in steam it can be really dangerous 3. I would highly recommend bolting your lathe down really well. it looks a bit shacky and those little lathes (I'm assuming a 7x14) really benefit from bolting down 4. the way you are using the Dremel in one part is very unsafe. you have a brittle cutter spinning at an incredibly high speed and are putting side load on the disk. this could easily break and send shards of the ceramic cutter into you. I'm about as far from a safety Karen as you can get but those cutting wheels can be dangerous things Not being critical or anything, just some advice
@@thomasbarlow4223 I respectfully gave feedback on a project, what's wrong with that? Personally if i made a project like this i really like feedback from a different set of eyes or someone with more experience in that area. this comment was absolutely not intend to be negative, it was honest valuable feedback on a project
@@henrydando no i see it now.... i must have read that too quickly.... everyone is an armchair expert now and I thought he did a great job considering how hard it is to make a jet pump run correctly
Stainless steel bearing seizing? My only wonder about acetal bushing or nylon bushing is, what's their life expectancy vs SS ball bearings. I know Nylon is self lubricating, is acetal self lubricating too? Either plastic bearings have issues with the shaft enlarging the whole and causing the prop to hit the housing?
This is a real nice build. But man, it always gets me. Any time you grind/file/whatever on metal shafts, you always have to smooth edges out. Any time you have a sharp angle (like the flat spot for the hex drive, for the impeller), with twisting forces? That sharp angle will crack the shaft 100% of the time, the only question is when. Gotta smooth/radius it out. Stress Risers don't care if you're in a rush. That's why lots of things have undercuts on threads, and radius/fillet shoulders, and if it needs to be a hard shoulder then they undercut-fillet them. Sharp corners = cracks, always. Since this is gonna have a ton of vibration too, and I don't know what type of SS that shaft is, stress-corrosion cracking is a thing to look out for also. Such a simple thing, but one that will leave you in the cold! Great build, that impeller and pump look amazing!
Liked and subscribed because you shared your models. We need more and more of that attitude across the world. Great work great effort and great attitude. Double thumbs up 👍👍
Very nice! Here's hoping you get this working so well that you end up hungry to push it even further -- and get obsessed with adding a hydrofoil. How cool would that be!
Now that would be an awesome upgrade, I got a foil, it's the power plant that needs some figuring out! Thought about it but don't think I'm up to the challenge quite yet lol.
Andrew, your videos are very inspiring. I've been watching you for several years. Last summer I have made a sup board. I really liked the result. Thank you
Brilliant, very impressive, you got some skills. Being in Canada I figured you would make something like snow shoes that glide on snow. I have yet to see an electric sled.
The grease should be a marine grease if you haven't used one. Many greases contain soaps and the grease becomes emulsified, so the bearing then corrodes quickly. Super impressive project 👌
would love a full tutorial on the electrical. this is where i always get stuck when researching. i like the use of the dewalt batteries VS DIY battery packs and the inherent risks.
if you want more amps going through the motors you can make the angle of the jet drive blades more pronounced or the impeller longer (they should have minor overlap viewed axially, going beyond this in length or overlap doesn't help), add more blades, or make the impeller bigger radially.
You inspired me to shape my first surfboard. Watching this is a whole new level. Man you put your time in and it worked! What an amazing feat. Looking forward to what you come up with next!
@@AndrewWorkshop lol. I have that to look forward to when it warms up here. The enclosure has been one of the biggest hurdles. Thank you again and again for all the effort that goes into your videos. I watched just about all of them while planning the project. I’m trying a single, printed, 80mm jet, with an sss 360kv, and 12s Lipos.
My though on watching you power or up on the lake for the first time was to have the motors counter rotate so there's no net rotational force. Means printing one impeller mirroring the other and I'm sure much more I can't even begin to imagine. Excellent work.
@Andrew W If u tape off the spots u route out of cut on plywood u will stop all those splinters from happening its ALOT CLEANER YOU EARNED A NEW SUB SIR ... MUCH LOVE FROM NORTH OF THE WALL!
also ... EPOXY should be measured by VOLUME unless stated on the jugs otherwise.. almost always the hardener is LIGHTER that the resin . OBVIOULSY THIS ONLY APPLYS TO 50/50 mixes
It might sound dum but I always wondered how the water doesn't leak inside boats through the shaft whole, thanks to your video now I understand the concept of the oil seal :). planning to print small version of your pump and maybe make RC jet sky toy.
Awesome work! I came here after the RC Life on vid... Yeah, as you both said - dont try this at home-LOL! I build some stuff myself - not at this level - yet - but Im always amazed how much work almost any project takes.... Anyhooo - brilliant work - and you have a new subscriber!
Very nice so well built and explained. The best by far in all the RU-vid surfboard videos that i seen. So professionally made and a lot of thought went into this project..
Really nice, Andrew. To add one more suggestion: proper filleting of your models, particularly at things like flanges, will make things easier to print, MUCH stronger, and more nice-looking.
What an amazing project! Can you tell me how we can calculate the total thrust provided by the jet engine using all the variables involved i.e. Intake and Exhaust Diameter, motor RPM, impeller size, etc.?
I could use a few tips regarding a pedal boat design using a water jet engine thanks to an e-bike mid motor. I was thinking about a slight intrusion into the water to assist with a small dynamic sail
Nice ! Think about a hydrofoil set up and keep the board wide. I have two suggestions for a pump box. One make it from pink styrofoam or tha stuff you made the board with and coat it with fiberglass mesh and resin just like the board. Or it can be made with very thin aluminum flashing material but an inside and outside dual wall filled with expanding foam. No welding required. Just some hot glue maybe some pop rivets here and there for bulkheads and some spacers as well as mounting strips for pumps and motors. Listen to advice from that nice lady in case you get too excited about what you are doing and forget some safety stuff!
Fantastic! What a great , neat ,well engineered design and build. I would consider this a 1ST prototype! The next iteration could be Really GREAT! So Nice! Thank You
Thanks for sharing your experience! Maybe your surfboard will faster if shift nozzles out of water. You can experiment with their shape and try flat version too. General idea is allowing water flow to fly out of board with maximal speed, impulse. When you push water flow into lake, its speed is lower.
Really cool project, I definitely need to setup something like this to create a transport mechanism for diving! The overall design is great but maybe you would be able to make the top cover fit in line with the board to minimize chances of injury in case of a fall. Anyway amazing work!
Please, Please combine this project with the 3D printed surfboard. It would be awesome to "just print" a jetboard Another suggestion would be to build a collapsible or foldable surfboard
So awesome! I will definitely print out a few. And will definitely make my own custom board as well. Thank you for your awesome DIY videos. Incredible.
