I really like this little engine and how it's coming along. I printed something similar for a friends mini bike project. I'd increase 10% infill every time it broke. The only time it didn't break was at 100%. Now, anything like that gets printed with 100% infill. Takes longer to print and uses more material, unless you consider how much time and material is wasted when you have to reprint because it breaks.
It was mostly that I didn’t know if it would fit why I didn’t 100% infill straight away. Some of the other guys a commenting to use flexible filament I have some TPE maybe I will try that
@@DktheWelder I can only imagine. Custom jobs like this require a lot of hours invested into them. I have the same printer as you so I know the pain of medium size pieces especially with dense infill. Keep at it! We're rooting you on!
Its like Christmas every time one of these videos come out! I have a couple of printers and i love this way of using 3d printing to build what you want
I would try TPU (Shore ~95A for example) for the coupling, so it can handle the vibration better than PLA/PETG. And make it with like 10 perimeters plus 60-80% infill maybe? Awesome work!
That's actually a really great idea you at 95A i think would be the perfect filament for this kind of application. Stretchy but not to stretchy would be like a hard rubber coupling. With alot more resistance to shear of at the layers. Good idea!
@@DktheWelder tpu prints pretty similar to tpe i think, so very slow. Main factor is the hardness. With a bowden machine i would stick to shore 95A and upwards (i use the prusa mini in stock form). We had a play with 85A tpu on a prusa mk3 (dual gears and direct drive) at work. What hardness is your tpe spool?
Instead of using higher infill, use more walls. That way the geometry of the part goes all the way through itself and it should be stronger. If you're interested look up CNC Kitchen, he has loads of tests with all sorts of different printing techniques. Really looking forward to see this one in the water!
When I say less infill, that's rather than more.. Above 20% you don't see that much increase in strength, only increased print time. More walls will give stronger parts. Just remember that the weakness is the layer lines, even when printed at an angle - that's why I advise machined parts with something like that motor. Save you some pain in the end..
when you print the engine coupling doing it at an angle like you did the drive coupling is a good idea for shear resistance (even at 100% the layer lines are still viable to delaminate especially in such a high shock high torque application) and if you just have it floating in the air in the slicer it will generate supports under it so it doesnt have to actually be printed oblong like the drive coupler was if you didnt already know. also thinner layers and thicker lines will lead to a stronger part, with a .4 nozzle .16 layers and .6 lines printed at 230* (or whatever the max is on the spool) gives good results for me. using petg might also be a good idea since it is almost as strong but more compliant than pla so its less likely to outright snap and has a slightly higher softening temp than pla which i suspect will come into play when in use sandwiched between a pair of hot engines running full bore.
The build is awesome, I always enjoy watching your videos. I always laugh at your little camera tricks. I have thought about coupling 2 engines together. I hadn't thought about using 2 strokes, which is probably the easiest way to go. I love it!!!
I come across your channel a week or two ago ans so far i like wot i see so have subbed and will be watching from now on..i like your style and the the progects you create,keep up the awsom work.
this is excellent engineering! i was so pumped to sit down and watch this. good solution with the cooling of using copper tubing, smart and relatively simple!. and nice job of the cyl water jackets. I know nothing of 3d printing, but maybe using a less-brittle plastic such as TPU to add some level of vibration dampening within the engine coupling ? that engine sounds like a beast, its gonna thrust like crazy 😁😁😁👍👍 oh and some kind of rubber mounts of the engine assebly to the hull/board may be a big longevity saviour
@@DktheWelder maybe just some bolts with big fat rubber washers (or a cluster of them) on either side 🤔 or some old jetski ones from a used ski parts guy *bulky though*. or steal ideas from a chainsaw.. hmm. bit of improvisation
@@DktheWelder maybe if the engine is free to twist/wobble on its vertical drive axis (in line and counter clockwise with the drive shaft) on rubber covered bolts or a knee joint pivot knuckel of solid rubber. hmm.
Those carbs definitely need to be vacuum synced. That should take care of the binding in the coupling. In theory, your mock up coupler shouldn’t have exactly ripped apart that fast. Especially with the engine(s) not under any kind of load. That thing sounds badass though!!!
I could be wrong, but i think half your bore is going to overheat, also, the engine will overheat having hot water to cool the engine. If the engine is cold when you start pushing water thru it, it will work flawlessly.
Great video mate ! Luv your engineering. You should’ve been a mechanical engineer! Again pulling it from an idea to fruition is something most folks cannot achieve. Lee up the great work!
Nice work! I recommend to use bigger diameter and shorter pipe for water cooling. I am afraid you don’t get enough coolant flow with the diameter and length you use now. Also I would make some kind of o-ring to seal the waterjacket to the cylinder head. Good luck!
You might not even need to 3D print the coupler solid. Try adding more vertical shells (walls) to increase the print strength. That project looks awesome!
I wouldn't wrap the copper pipe around the exhaust , it's just heating up the water before it gets to the most important part (the head). Just go straight to the head of the motor and straight out, or go straight to the head then around the narrow part of the exhaust before the expansion chamber then out. You wouldn't "cold shock that little motor at all". You should also just make a hole at the top of the bottle to release the vacuum so that the water can actually run through the hose.
Great work Daniel. Love the cam work especially on the broom clean up. Maybe a little pond pump on the water cooling.... You've probably sorted that by now though.
I was literally typing a question about why you wrapped it around the exhaust, you just covered that which i had i suspicions nice! Cool shiit man wish i was this skilled
You should really consider some stiffer TPU like the sainsmart stuff. It has enough flex and is also stiff and does not crack at all. very durable stuff
Great work. Print in ABS, 100% infill. Or, maybe Tpu is a better material? Elastic polyurethane, but it prints very slow. And a tip to make a better fit for the coupling. Take a picture of the fan profile and import it to the cad. Then you can copy the profile and scale it. There are tutorials on how to do that here at Yt.
Print the couple same again. And use ot to make a mould and cast a polyurethane coupler. 2 part castable is readily accessible. Ive rebuilt old rubber enfine ounts by casting my own. Even reinforce it with a steel or aluminium insert.
I was going to do that just put the tube between the fins which would have been way easier , I wanted to try making the water jacket and I think it will cool more maybe
@@DktheWelder the cooling jacket you made sure looks better and made a better video. I just have never done it that way and I’m curious to see how it goes with most of the heat being generated on the cylinder head but the piston heat being cooled through the barrel. You are a very clever man.
I would move the outlet nipple of the second cylinder to the opposite corner like it is on the first cylinder so water is forced around instead of going straight past one corner of it
I dont quite get why you made the water flow from the exhaust to the engine, would you not end up cooling a lot of exhaust gas that could be used to cool the engine? Would it not make more sense to use the coolest water to cool the hottest part?
You really should 3D print a kit to make them engines 2 cylinder I'm going to do it soon you could make money from your design your designed it works I'm thinking about how I'm going to do it
Liking the series so far definitely late on responding. Should have checked the squish witch is the distance between the cylinder head and top of piston at tdc to tell you hoe much playing room you have on cutting the base back flush as well as the top of the cylinder. Anyways well done on the whole setup buddy!
Running the cylinders at 180 deg will cause some horrible stresses on your coupling. Might be better printing a mold, & casting a fairly stiff polyurethane coupling. Interesting project, look forward to next video. Keep up the good work 😊
Get some Nylon or ASA filament. Run gyroid infill and 20% with 3 or 4 walls. Only way it will handle the load and/or heat. Otherwise do a lost cast with some 2 pack hard resin. Don't use TPU as other people have said it will shred from the heat and the force. You will need engineering level filament to handle it due to the heat/ vibrations
I was thinking TPU to negate the vibrations. but you are right! it won't hold up well. a resin cast mould would be good if the 3d prints arnt strong enough
could he 3d print the 'inverse' of that coupling design and use it to cast a mould for an epoxy resin, then break off the print material and be left with a solid resin part? 🤔
@@DktheWelder yes, I have done loads of structural components. Have never done a direct engine coupling though but worked on enough engines to understand the environment the print will be in. Increasing wall thickness is key to structural integrity. Once you go past 25% you get deminishing returns on the strength vs weight/ material used due to the inherent weakness of layer adhesion. Make sure youre printing the coupling at 90' to the load factor so that layer shear is minimised even if you use loads of support material.
@@phildawe7172 100% you can do molds using cura and cast a mold. Depends on what 2 pack plastics he can get whether it will be cost effective in comparison to a 3d printed version.
Man those little engines sound great, beautiful expansion chambers! Can't you use a rigid coupling? Maybe the solid one will hold up. Any idea how.much power those engines make? The power pulses are what shreds the plastic, solid wil be much better.
The water will be too cold coming straight from the jet unit so the exhaust heats it through the copper pipe first . Marine engines do a similar thing but with a water jacket
Love the “ Cam”:work! You should def give your kidneys a break and take a leak more often!! , Mums a nurse and used to nag ( ahem gently suggest) we look after our selves with such suggestions….
Great job. But I don’t suggest running the cooling through the pipes first. Always run them through the motor and then to the pipes. You’ll risk blowing the motors
@@DktheWelder that makes absolutely no sense the motor will get hotter than the exhaust. And who cares about the pipe. What’s gonna happen. Just maybe it will get red. But that’s unlikely. So u send hot water to the motor. That doesn’t make sense at all
@@checkforfleas9452 it only needs to heat it to operating temperature. If cold water hits a hot cylinder it could crack . A car is a closed loop so it heats up evenly, a lot of boats use a heat exchanger but those that don’t need the water to heat up a little bit before it hits the cylinder
@@DktheWelder we’re talking freezing cold waters. I wouldn’t have a boat running in 40 degree wheather lol. If it’s too cold for me. It’s too cold for my boat. Your talking about 70 80 degree weather on a 210 degree motor. I ride my dirt bike in colder weather than that and hit puddles. Been doing it for a long time and two smokers aren’t water cooled.
@@checkforfleas9452 I hear what you saying, I had this discussion with some of the old boat guys at work and that was their advice. All mx 2 stroke bikes after the early 80s are water cooled? Also here’s a link to a diagram of a JetSki cooling system 👍images.app.goo.gl/72b1UF5u4ubzKadKA
Sweet piss cam😂😂😂😂😂 use how about rubber or polyurethane or something like that for the joiner instead of plastic 🤔 since you have the power stroke of each motor at opposite ends 🤔just a thought coming along nicely though jet look good to keep it up bro👍
It actually runs pretty smoothly with them opposing also the pull start is fighting two engines compression at the same time . I might try it though it would be less load on the coupling 👍