Small Ship Pistons...

[CelticChaos]

Have small ship pistons always been so weak? I had an idea to create a small ship ore dumper. A small craft that would shuttle back and forth with ore in a bucket, dump the bucket (similar to an mining ore cart) and then return for more.

The project was going very well. I used a small piston to create the dumping mechanics.. so far so good. When I got to the point of creating the bucket to be used for the ore, I could build the bucket to a certain point, mechanics working fine, add a few more blocks and the ship would flip upside down, or sink into the planet instead of dumping the bucket.

It's almost like there is a mass limit to the piston. Once exceeded the physics just go bananas. If I take the last few blocks back off the bucket operates just fine. Anyone else see this type of issue with small pistons?

[Karmaterrorᵁᴷ]

What setup do you have? Piston opperated rotor joint so it tipps the stuff out?

As far as i know it should work fine, they can take a hell of a lot of weight in that config. Remember that white T rex black armour built. Thats all supported by thise joints and has to weigh more that your cart.

You could see if its just a current bug by trying that walker :)

[CelticChaos]

Thanks, Karma I will give that a look. Yeah I was using the piston to push against a free wheeling rotor to push the bucket up. The piston was at a 45 deg angle so that might of had something to do with it. The builds that I have seen working all had the piston pushing straight up.

I am still experimenting.

[cptsavarus]

No TL:DR I'm afraid. Got too much info for you. Hope some of it is useful.

Angles....
As long as there's a rotor at either end of the piston & it's free to move, the angle you have the piston at shouldn't matter too much (within reason).
45° is a good angle - neither acute or obtuse, which means it should work perfectly... and you've already proven that it does, so all's good there.

For future reference, the main thing about angles is to give the piston as much leverage as it can get. Acute & obtuse angles require more force, as the moment on the rotors gives the piston less leverage than it would have at a more equal angle. Too little leverage and the piston can effectively become trapped, whereby any force it applies longitudinally has to be expressed in lateral movement instead... basically meaning the thing will deform, bounce around, realise it can't go anywhere, then explode.
This is one real life bit of mechanical physics that SE actually manages to emulate really well. Ironically though, when a gamer looks at it, all he sees is a bug because his piston exploded!

Removing & adding blocks...
As to what you're seeing with adding & removing just the right amount of blocks...
Yes, this is a thing. A very weird thing for which there's no good explanation or guaranteed workaround. Sometimes it'll just work, other times it'll do what you're seeing. Sometimes a simple exit & reload will fix it. You could also try blueprinting it & pasting in a fresh copy.
There's no rhyme or reason to this behaviour, you just have to keep playing around til you find a configuration that you like & that works.

Common causes of...
The cause of it seems to be to do with how mass of sub-grids is calculated & re-calculated. Basically each time you add or remove a block, the game re-calculates the mass of the whole sub-grid... and it's prone to making some pretty terrible errors. When it re-calculates & realises there's an error, it attempts to correct for the error and you may see the whole thing "snap" to an invisible point in space. Sometimes this can cause a vehicle to ping off across the map or to bounce around or even explode.

I've also noticed that certain block types cause the effect you're seeing more than others. Blast Door blocks are a major culprit. Heavy Armour blocks can also be a pain when they want to be. Pretty much any block with high mass can choose to make itself a problem.
In my experience I've found it's best to make the moving part as light as possible. If you can avoid using Blast Door blocks or Heavy Armour then do so.

Note on piston force...
Something that doesn't help with builds like yours is that the force settings for pistons are deceptive in their descriptions.
The Lateral Force setting actually affects longitudinal force as well, which it's not supposed to do.
Best practice is to keep both settings identical at all times.
Also, don't be afraid of whacking both settings up to max. The numbers will go red as a warning of potential instability but frankly, what you're building is inherrently prone to instability anyway according to the powers that be, so a little more instability really wont make any difference - except in that it can either work or it can do the other thing.

Would love to see this build of yours when it's ready. There's a disappointing lack of mechanical stuff on the workshop, so I hope you'll publish it at some point.
Good luck with it anyhow. Enough trial & error and you're bound to get it working right.

[CelticChaos]

Great information Cptsavarus - I am getting closer. I actually tried some of what you suggested and after a couple of reloads I have a pretty stable mechanism. I am now trying to apply the mining cart to a workable cyclical pattern.

Waypoints using the remote autopilot has it's fits and starts - the jury is still out on that as a solution. I am also considering a track, the implementation of this type of operation can be cumbersome.

I will certainly publish when I have it done. I can give you a heads up if you like when it's finished.

[cptsavarus]

Excellent! Glad to hear you're getting somewhere.

Since you mention possibly using the cart with a rail, maybe these can help give you some ideas...

This one is a really clever design & although it uses pistons to move the sled (read "door") up & down the track (hence has limited range), it's really smooth & very hard to damage. Could be good for use in tandem with a lift or something - lift brings the ore up & deposits it into the truck / sled, which carries it out of the mine on a set of pistons.
Might also be possible to make it mobile or ship-portable so it can be moved from one mine to another when the vein is depleted.
https://steamcommunity.com/sharedfiles/filedetails/?id=1526680529

That one was based on one of my own designs (though in many ways its a big improvement on what I did)...
https://steamcommunity.com/sharedfiles/filedetails/?id=1400499297

In the second link you'll also find links to the designs that inspired mine. May be a bit of extra inspiration for you there.

You're right though of course - rails are unwieldy to build & results are not that reliable. There's also the problem of fitting the truck to the rails one they're built, which presents its own engineering challenges.

The other thing you could do is simply turn your truck into a script-automated ground or air vehicle... something like this but obviously without the drills...
https://steamcommunity.com/sharedfiles/filedetails/?id=619449097

Just some ideas for you to play with anyhow.
Yes, please do drop me a message on my profile when you're published. I love stuff like that & will definitely want to check it out!