Piston engine challenge

[Pds314]

Using Breaking Ground, design a piston engine and use it to power something. The only motorized robotics part you may use is the piston and variants. All others must he unmotorized.

 

You are encouraged to give your engine the best performance and efficiency you can and make it realistic looking, and to use it for building cool piston-engine vehicles.

[doggonemess]

I may give this a try - it's a very cool idea. Getting the parts to act as a driveshaft might be troublesome, but it would be awesome if it works.

[doggonemess]

I am proud (?) to present my piston-powered car-thing!

Yeah, that's right. It's got a V-8!

The crankshaft spins at 12 rpm pushing the craft to a heart-stopping 1.5 m/s! I think that might be Jeb's "meh" face.

It's difficult (impossible?) to steer, so good luck getting anywhere.

 

For anyone who wants to play with it: https://kerbalx.com/LevAerospace/KRPS-3

[Pds314]

3 hours ago, doggonemess said:

I am proud (?) to present my piston-powered car-thing!

Yeah, that's right. It's got a V-8!

The crankshaft spins at 12 rpm pushing the craft to a heart-stopping 1.5 m/s! I think that might be Jeb's "meh" face.

It's difficult (impossible?) to steer, so good luck getting anywhere.

 

For anyone who wants to play with it: https://kerbalx.com/LevAerospace/KRPS-3

That's beautiful.

[dnbattley]

Ooh this is interesting: I have some ideas for this I'd like to try out...

[Azimech]

Interesting but using those hydraulics you're never gonna get any useful speed out of them.

[dnbattley]

My first entry: the infini-tractor Mk1.

Spoiler

While speed is nothing to write home about, this rear-wheel driven agricultural creation does have the advantage that it runs off the apparently magic power of airlocks, and thus requires no fuel/electricity to function.

Craft file here: https://kerbalx.com/dnbattley/infini-tractor

Edited July 20, 2019 by dnbattley

[Pds314]

21 minutes ago, dnbattley said:

My first entry: the infini-tractor Mk1.

  Hide contents

While speed is nothing to write home about, this rear-wheel driven agricultural creation does have the advantage that it runs off the apparently magic power of airlocks, and thus requires no fuel/electricity to function.

Craft file here: https://kerbalx.com/dnbattley/infini-tractor

Wait airlocks are magic pistons? I didn't know that.

 

I like how I posted this challenge like 3 weeks ago and it got the first 2 actual entries on the same day lol.

Edited July 20, 2019 by Pds314

[dnbattley]

25 minutes ago, Pds314 said:

I like how I posted this challenge like 3 weeks ago and it got the first 2 actual entries on the same day lol.

I'll be honest: I only actually saw this today after @doggonemess posted his submission, but it tied very nicely into some work I have been doing recently on gearing, hence why I was able to submit something so quickly, but I'm glad you posted this challenge!

[doggonemess]

2 hours ago, dnbattley said:

I'll be honest: I only actually saw this today after @doggonemess posted his submission, but it tied very nicely into some work I have been doing recently on gearing, hence why I was able to submit something so quickly, but I'm glad you posted this challenge!

I took me a while to get the hang of syncing the pistons.

[dnbattley]

8 hours ago, Pds314 said:

Wait airlocks are magic pistons? I didn't know that.

I'm exploring all the moving parts that don't need electricity at the moment... the new 1.7.3 addition of self-interaction has opened up a wide range of possibilities for harnessing them directly for motion.

[Flying dutchman]

I got something you might like. I'll try to upload it in a minute.

[Flying dutchman]

[doggonemess]

Is that an internal combustion piston engine?! I guess it's semi-internal combustion, technically, but that's awesome! Can you upload the craft file so we can play with it?

[Flying dutchman]

3 hours ago, doggonemess said:

Is that an internal combustion piston engine?! I guess it's semi-internal combustion, technically, but that's awesome! Can you upload the craft file so we can play with it?

I will do that. However i'm still working out some reliability issues.

[klond]

On 8/11/2019 at 3:40 AM, Flying dutchman said:

  Alright, look at this!  I want to know more.  I'm surprised the stayputnik's can handle the heat.  I like your gear material choice, but I'm not sure they're perfectly round yet.  Hopefully we can get some action shots soon.  Keep at it!

---

  Here's my WIP, and my workaround for the piston's slow speed - manipulate the force, not the position.

 

 I have not tweaked this yet, and I bet there's more room for even higher RPMs, through both parts choices and programming.  Let's get this in a plane.

 If anyone else get's high-speed results tag me.

 

 @Azimech stay positive my friend.  Also, I hope you are well.

[dnbattley]

48 minutes ago, klond said:

I'm not sure they're perfectly round yet

@Flying dutchman in case you weren't already aware, there is a way of generating exact symmetry for arbitrary rotational symmetry >8:

It is particularly useful for creating gearing, but does have a tendency to invoke the kraken if you go too far (e.g. I have a series of 8, 16, 32, and 64 gear subassemblies, but 96 or 128-symmetry immediately and spectacularly kraken on launch, though this may just be that my radius/n - which I made constant to allow the gears to all mesh - ratio needs to be larger).

54 minutes ago, klond said:

Here's my WIP

Impressive. With a flywheel it might be able to maintain that speed, but the key will be to understand its ability to maintain RPM under load: I've struggled to maintain airspeed with my designs (admittedly based off a narrow-band scanner, rather than pistons) and stall shortly after take off.

[Pds314]

5 hours ago, klond said:

  Alright, look at this!  I want to know more.  I'm surprised the stayputnik's can handle the heat.  I like your gear material choice, but I'm not sure they're perfectly round yet.  Hopefully we can get some action shots soon.  Keep at it!

---

  Here's my WIP, and my workaround for the piston's slow speed - manipulate the force, not the position.

 

 I have not tweaked this yet, and I bet there's more room for even higher RPMs, through both parts choices and programming.  Let's get this in a plane.

 If anyone else get's high-speed results tag me.

 

 @Azimech stay positive my friend.  Also, I hope you are well.

Whoa. This thing is literally revolutionary. And it looks like it should have decent torque. Possibility of it being on KerbalX? I think I could definitely get this in an aircraft.

Edited August 13, 2019 by Pds314

[Flying dutchman]

Hey, for clarification: the stayputniks can in fact not handle the heat. So this engine does require the temp cheat.

 

@klond

I've made the gearing a little different and it's more efficient now. I have propelled a wheel driven vehicle with it and even equipped it with a working clutch.

[klond]

17 hours ago, Pds314 said:

I think I could definitely get this in an aircraft.

 Great, I could use the help.  Collaborations can be fun.  Send pics if you have any luck.

Here's the original from above.  link  Needs tweaking.

Here's a lighter weight version with a more curvy programming.  Lower RPMs though.  link

Spoiler

 I mapped throttle to controller play speed.  No staging.  Press 1 to start the show.  Slowly ramp up speed.  I think there are certain sweet spots in the RPM range, like hitting a harmonic.

@dnbattley You were right about big flywheel, totally helps smoothing everything out.

If anyone makes improvments, please share.  I will also keep dabbling.

[Azimech]

Not interested in the challenge but I decided to upgrade my almost 2 year old stock V4. With just aerodynamic changes I was able to increase its top speed from 12m/s to 16.6m/s, which is close to the top speed of my V8 (18m/s).

 

Specs:
Dual overhead camshaft.
Cylinder bank angle: 90°.
Piston drivers: 4x Panther in dry mode.
Stroke: 90cm.
Bore: We don’t have compression so it doesn’t matter.
Conrods: fork/blade type, this way the cylinder banks are evenly placed.
Main crankshaft bearings: 3x6 RCS balls.
Crank bearings: 4x20 RCS balls.
Max engine speed: 12.5 rad/s (120 rpm).
Economy cruise: throttle at 50%.
Top speed: 16,6 m/s.
Propeller: 7 blades, fully adjustable.
Power output (estimated half of the V8): ~388KW @95 rpm.
The Goliath is just the air intake. It doesn't produce power.

Edited August 14, 2019 by Azimech

[Flying dutchman]

@Azimech what aproach did you take on the deflector plates? (The thing that blocks the thrust when the piston is coming up)

 

I'm currently refining my design and i have made it at lot less complicated and way more efficient. Currently a two cilinder which runs on a total of 4 of the smallest jet engines.

 

Edit: i'm also running into a certain rpm barrier. It seems more than 160 rpm is not achieveable. What could cause this?

 

 

Edited August 14, 2019 by Flying dutchman

[Azimech]

7 minutes ago, Flying dutchman said:

@Azimech what aproach did you take on the deflector plates? (The thing that blocks the thrust when the piston is coming up)

 

I'm currently refining my design and i have made it at lot less complicated and way more efficient. Currently a two cilinder which runs on a total of 4 of the smallest jet engines.

 

Edit: i'm also running into a certain rpm barrier. It seems more than 160 rpm is not achieveable. What could cause this?

 

 

This might help:
 

Also I'm not aware of a 160 rpm limit. That's 40 higher than I can achieve with this old engine.

[Flying dutchman]

@Azimech

 

Yes! I've achieved flight!

but only just.

 

(apparently infinite propellant was on i'm sorry..)

Edited August 14, 2019 by Flying dutchman

[Azimech]

7 minutes ago, Flying dutchman said:

@Azimech

 

Yes! I've achieved flight!

With a píston engine?!