GoldForest Posted June 5, 2019 Share Posted June 5, 2019 So, has anyone else attempt to do a piston engine replica? I'm attempting it now, but it's kind of difficult, and I'm not that great at building complex designs. I got the core design down, I just can't get the cylinder to act right inside the cylinder housing. It's constantly wanting to bend out of the casing. Quote Link to comment Share on other sites More sharing options...
Kerbolitto Posted June 5, 2019 Share Posted June 5, 2019 I'd say you should use rotor on the crankshaft, telescopic cylinder as connecting rod and another motorless-rotor below the piston. With a fine sequence on the KAL 1000 it may be possible to drive the shaft but I don't know how it would work with multiple cylinders, would probably creat bad harmonics because of the floppy parts.. If you can create a good connecting rod you're almost done with everything else imho ! Quote Link to comment Share on other sites More sharing options...
KerikBalm Posted June 6, 2019 Share Posted June 6, 2019 Check out what @Triop recently posted in the what did you do today thread Quote Link to comment Share on other sites More sharing options...
Triop Posted June 6, 2019 Share Posted June 6, 2019 (edited) 5 minutes ago, KerikBalm said: Check out what @Triop recently posted in the what did you do today thread Thanks for leading me here, haven't seen this topic. Yes, I'm building a working piston driven steam engine: Edited June 6, 2019 by Triop Quote Link to comment Share on other sites More sharing options...
Klapaucius Posted June 6, 2019 Share Posted June 6, 2019 16 minutes ago, Triop said: Thanks for leading me here, haven't seen this topic. Yes, I'm building a working piston driven steam engine: I used to have a model one of these, almost identical to this. I love you even added the blue-coloured burning fuel and smoke coming out of the stack. Quote Link to comment Share on other sites More sharing options...
Triop Posted June 6, 2019 Share Posted June 6, 2019 24 minutes ago, Klapaucius said: I used to have a model one of these, almost identical to this. It's a replica of the Wilesco D-6, I still own mine, the kids love it, playing with fire and stuff. Quote Link to comment Share on other sites More sharing options...
Klapaucius Posted June 6, 2019 Share Posted June 6, 2019 (edited) 1 minute ago, Triop said: It's a replica of the Wilesco D-6, I still own mine, the kids love it, playing with fire and stuff. Yup, that's' the one I had as well--actually, my older brother had it and I inherited. I don't know where it is now. Mine had a grey base and did not have the glass end on the boiler, but otherwise, identical. Edited June 6, 2019 by Klapaucius Quote Link to comment Share on other sites More sharing options...
Triop Posted June 6, 2019 Share Posted June 6, 2019 1 minute ago, Klapaucius said: Mine had a grey base and did not have the glass end on the boiler, but otherwise, identical. You have an older model, that thing is worth a lot of money, hope you still have it. But I wouldn't sell it though. Quote Link to comment Share on other sites More sharing options...
ezaroo Posted June 7, 2019 Share Posted June 7, 2019 I had the same idea today! I managed to make a single piston engine with crankshaft to drive a small mass - using servos as clutches and bearings and a hinge as a pivot. The trick to making it somewhat stable with decoupling a support for the drive shaft, without that support it wobbles all over the place and that completely damps the drive you can get out the piston. More than 1 piston is certainly possible, but I tried two and the instability problems double, the bouncing causes the engine to flip directions - sometimes just one piston, and that causes issues. Here is the craft file and a video https://kerbalx.com/ezaroo/Crankshaft https://m.youtube.com/watch?feature=youtu.be&v=vc67R3NXEYo Quote Link to comment Share on other sites More sharing options...
GoldForest Posted June 7, 2019 Author Share Posted June 7, 2019 7 hours ago, Triop said: Thanks for leading me here, haven't seen this topic. Yes, I'm building a working piston driven steam engine: Hmm, not what I was looking for, but still really kool. Btw, how did you get the piston to stick to both parts at once? Quote Link to comment Share on other sites More sharing options...
FleshJeb Posted June 7, 2019 Share Posted June 7, 2019 (edited) 1 hour ago, GoldForest said: Btw, how did you get the piston to stick to both parts at once? He didn't. Some weird strut interaction is doing it. Triop, ya shoulda used a docking port somewhere! On his request, I switched it from rotor-driven to piston-driven. I only knew the value of the extension at the 6 o'clock position (1.97m). I couldn't disassemble it, because the root part of the craft is the flywheel rotor. First, I measured components using the piston extension value and my eyeball. The largest piston, when closed, is 2.21m. The radius of the attachment point was 0.83m (not shown). Then I drafted it in AutoCAD and found the extension lengths at eight points around the circle. It's not just a simple sine wave because of the geometry. Then I plugged the values into the KAL while holding the rotation speed as a constant, so the 8 points are evenly separated in time. It runs fairly well after the first few seconds. The RPMs vary between 55 and 65 (goal 60). You might choose to run your reciprocating engine with connecting rods that are BG pistons affixed to hinges on the cylinder head. They can drive the crankshaft. If you do, you'll need to use my method above to get the timing right. Edited June 7, 2019 by FleshJeb Quote Link to comment Share on other sites More sharing options...
GoldForest Posted June 7, 2019 Author Share Posted June 7, 2019 3 hours ago, FleshJeb said: He didn't. Some weird strut interaction is doing it. Triop, ya shoulda used a docking port somewhere! On his request, I switched it from rotor-driven to piston-driven. I only knew the value of the extension at the 6 o'clock position (1.97m). I couldn't disassemble it, because the root part of the craft is the flywheel rotor. First, I measured components using the piston extension value and my eyeball. The largest piston, when closed, is 2.21m. The radius of the attachment point was 0.83m (not shown). Then I drafted it in AutoCAD and found the extension lengths at eight points around the circle. It's not just a simple sine wave because of the geometry. Then I plugged the values into the KAL while holding the rotation speed as a constant, so the 8 points are evenly separated in time. It runs fairly well after the first few seconds. The RPMs vary between 55 and 65 (goal 60). You might choose to run your reciprocating engine with connecting rods that are BG pistons affixed to hinges on the cylinder head. They can drive the crankshaft. If you do, you'll need to use my method above to get the timing right. Hmmm. I think everyone's confused by what I meant. I wanted to know if a gasoline piston style engine had been made, not a steam piston engine. Quote Link to comment Share on other sites More sharing options...
AngrybobH Posted June 8, 2019 Share Posted June 8, 2019 Like @FleshJeb was getting at, attaching the BG pistons to a cylinder head and the down to the crankshaft similar to the piston driven steam engine shown. So, the up/down of the pistons is what drives the crank. It's about as close as you'll get to a reciprocating piston internal combustion engine considering we don't have gasoline, ethanol, diesel, etc and we don't have controlled explosions. Well gasoline doesn't explode in an engine, it burns but, I bet if Kerbals had gasoline it would explode. Quote Link to comment Share on other sites More sharing options...
Klapaucius Posted June 8, 2019 Share Posted June 8, 2019 Have you seen this? https://kerbalx.com/jmark1213/Flat-4-Piston-Engine Also check out @Azimech' s stuff on KerbalX https://kerbalx.com/Azimech/77I--Piston-Engine-Prototype-2L6-2 https://kerbalx.com/Azimech/77I--V4-Diesel-Type-A-v10 Quote Link to comment Share on other sites More sharing options...
GoldForest Posted June 8, 2019 Author Share Posted June 8, 2019 (edited) 9 hours ago, Klapaucius said: Have you seen this? https://kerbalx.com/jmark1213/Flat-4-Piston-Engine Also check out @Azimech' s stuff on KerbalX https://kerbalx.com/Azimech/77I--Piston-Engine-Prototype-2L6-2 https://kerbalx.com/Azimech/77I--V4-Diesel-Type-A-v10 That is what I am looking for! But with robotic parts instead of stock hinges. Edited June 8, 2019 by GoldForest Quote Link to comment Share on other sites More sharing options...
Kerbolitto Posted June 8, 2019 Share Posted June 8, 2019 That is absolutely amazing xD Quote Link to comment Share on other sites More sharing options...
Klapaucius Posted June 8, 2019 Share Posted June 8, 2019 Just to clarify, if it was not clear, that engine in the video I posted above is not mine. I don't know if the builder is on the forum, but if so, s/he is under a different moniker (jmark1213 on KerbalX) so I was unable to credit them properly. Quote Link to comment Share on other sites More sharing options...
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