Stamp-O-Tron issue

[Turbo Ben]

I tried to set up a Mun mining base on flat ground but it slowly drifted accross the surface. As a solution I tried using a Stamp-O-Tron ground anchor with a docking port attached, and land my base on the docking port. Worked perfectly with no drift, until I noticed a problem.

On scene load or exiting time warp, all craft jump about 100mm in the air. Problem is the anchor stays there and doesn't fall back down. This repeats with the anchor getting higher until it is meters off the ground. When the anchor is first placed, it does fall back down. After a scene change or save/load, it doesn't.

In my save file, the anchor has a setting called "skipGroundPositioning" which is set to false. When set to true it stopped the 100mm jump, but reverts to false after a scene change.

So, I have several routes to a solution:

1> Fix the drifting issue (best solution but I think this is a quirk of KSP)

2> Stop the skipGroundPosition setting reverting to false.

3> Get the anchor to fall back to the ground like everything else does.

4> Stop all craft jumping 100mm.

I think the jump is stock behaviour as I removed most of the mods that might cause it.

Any suggestions would be welcome, I've been trying to set this base up for days now!

[miklkit]

This sounds familiar.   I have had similar problems with things moving and in my case I believe it is the landing legs causing the problems.  Long story short, when the landing legs are folded up and it sits on the ground all the problems go away.

[Lisias]

22 hours ago, Turbo Ben said:

1> Fix the drifting issue (best solution but I think this is a quirk of KSP)

Yeah, I had detected the drifting some time ago. Worked around it with success until KSP 1.10.x (IIRC), when the anchors were created in an attempt of fixing the issue - what wasn't the best of the ideas IMHO. 

I had worked around the problem with success using KSP-Recall (using the Driftless PartModule) but the Anchor stunt revealed to be incompatible with it, and so since the KSP version where the Anchor was created KSP-Recall doesn't apply the respective patch.

Gory details here:

Spoiler

 

I don't know if the Anchor works with deployed legs, but since drifting have at least two caus

es, what follows may help:

With the craft at rest, open its PAW and set Spring/Dumper from Auto to Override. Remember to adjust the Dumper and Spring stiffness in order to keep the craft stable. This should prevent KSP from thinking that the craft is in movement (what it really is, but on imperceptible ways), and hopefully the anchor will not be disengaged.

 

23 hours ago, Turbo Ben said:

4> Stop all craft jumping 100mm.

I think the jump is stock behaviour as I removed most of the mods that might cause it.

Try to reproduce this problem on a clean KSP. Failing on it, try to create the most simple craft possible where this happens.

Then publish the craft file. I will be able to keep digging from there.

— — 

In time, what do you have installed on your rig? The problems you are describing also happens on a clean KSP instalment? You may had found a collateral effect from something else inside KSP, letting it get the blame.

[Turbo Ben]

@Lisias Thanks for taking a look at this for me.

19 hours ago, Lisias said:

With the craft at rest, open its PAW and set Spring/Dumper from Auto to Override.

My craft does not have legs or wheels. The mining base originally sat on the surface on a 2.5m kspie ISRU module. I later added a large docking port to the bottom so I could dock to a ground anchor. It's designed to be landed at a very specific location. Once in position, the lander disengages and returns to kerbin. The mining base is left with no propulsion so cannot be moved once the lander detaches. This is why even a tiny amount of surface drift is an issue for me.

19 hours ago, Lisias said:

Try to reproduce this problem on a clean KSP. Failing on it, try to create the most simple craft possible where this happens.

I had several craft at the landing site, including the mining rig, a rover, the deployed ground anchor, a spare docking port and a dropped EVA pack. So there were 3 one part "craft" in the area. Everthing jumps 100mm in the air when coming off rails. The ground anchor when first deployed falls back to the ground the same as everything else, but after a save/load cycle or scene change, this no longer happens. The ground anchor continues to jump up every time it comes off rails and, because it no longer falls back, gets higher and higher of the ground.

 

The following is on a clean install (wow, I forgot how much mods add to the game!)

Landed a similar craft in about the same place as in my modded game. I noticed drift, but realised it was because I had SAS on which was fighting the very tiny incline I was on (I'm now wondering whether this is what was causing the drift in the first place, I need to check that when I get my modded game running again).

As for the craft jumping when coming off rails - it still does it but not as much as in the modded game. Maybe a 50mm jump rather than 100mm. Suggests this is maybe being caused by a mod. I'm going to start adding mods to the game to see which one causes it.

The ground anchor I tested is also behaving much better. When first deployed, it will jump slightly and then fall back to the surface. After saving and reloading, it jumps off the surface very slightly and no longer falls back to the ground. However, it also doesn't jump every time it comes off rails, so stays in place. So it looks like a mod is also affecting the behaviour of the ground anchor. I docked the mining rig to it and everything seems to work fine.

Next step is to start adding mods until the misbehavior starts. I'll post back after.

[Turbo Ben]

Progress. Installed the following mods:

Kopernicus + dependancies

Community Fixes ---- This actually seemed to improve the jumping when coming off rails even further.

Joint Reinforcement

Recall

Restock

Tweakscale

Tech tree + Hide empty nodes

Restock+

Tweakscale companion for Restock+

KSPIE

Scatterer

Parallax ------- Bingo!

On installing parallax, the 100mm jumps and repeated lifting of the ground anchor started. Reinstalled fresh KSP keeping just settings and save game file. Installed only parallax and dependencies and again, ground anchor lifts every time I come off rails.

That's an issue. Parallax is an amazing mod that i don't think I could play without. The only other option so far is to regularly tweak the save game to reset the altitude of the ground anchor.

Edited February 17 by Turbo Ben

[Lisias]

6 hours ago, Turbo Ben said:

I had several craft at the landing site, including the mining rig, a rover, the deployed ground anchor, a spare docking port and a dropped EVA pack. So there were 3 one part "craft" in the area. Everthing jumps 100mm in the air when coming off rails. The ground anchor when first deployed falls back to the ground the same as everything else, but after a save/load cycle or scene change, this no longer happens. The ground anchor continues to jump up every time it comes off rails and, because it no longer falls back, gets higher and higher of the ground.

Humm… This may be related to the amount of parts being simulated at one time - parts enough are in the loop, the code that do the simulation starts to drag a bit and the PIDs starts to overreact (it's the reason I gone the brute force on KSP-Recal's Driftless).

I suggest you make a backup of this save game, then load the backup and start to remove things gradually to see if the drifting stops at some point!

 

4 hours ago, Turbo Ben said:

Parallax ------- Bingo!

On installing parallax, the 100mm jumps and repeated lifting of the ground anchor started. Reinstalled fresh KSP keeping just settings and save game file. Installed only parallax and dependencies and again, ground anchor lifts every time I come off rails.

That's an issue. Parallax is an amazing mod that i don't think I could play without. The only other option so far is to regularly tweak the save game to reset the altitude of the ground anchor.

Ouch! Yeah, I had heard of some ground collider issues when using Parallax - as a matter of fact, we used to have this problem too when the part is pretty old and don't have the proper colliders that start to be demanded by KSP since 1.3 or 1.4 - I had these problems on Impossible Innovations - but instead of jumping 1M, the whole craft jumped a few KMs high.

Anyway, it's a somewhat heavy handed way of KSP to prevent the craft from exploding when it spawns inside something else's collider.

This is happening all the time, or just when some specific parts are used?

Did you tried using only Parallax (without KSPCF or anything else installed)? You know, sometimes one add'on interferes into another into unexpected ways.

[Turbo Ben]

37 minutes ago, Lisias said:

This is happening all the time, or just when some specific parts are used?

Yes. When coming off rails everything teleports 0.1m in the air before falling back to the ground. I checked with a different mining base I have on Minmus and that does it too, along with a rover there. The only thing that doesn't seem to do it are Kerbals themselves. The 0.1m hop when coming off rails isn't a problem for anything other than the ground anchor.

37 minutes ago, Lisias said:

Did you tried using only Parallax (without KSPCF or anything else installed)? You know, sometimes one add'on interferes into another into unexpected ways.

Yes, I deleted everything and re-downloaded KSP and just installed parallax and it's dependancies. The only things I kept from the first clean install were the settings file and the quicksave on the Mun.

I suspect the 0.1m hop is a feature of parallax to stop collider issues when coming off rails. It's must be there for a reason, it just borks the ground anchor.

I've left a post on the parallax thread with a link here, hopefully gameslinx can give some advice.

37 minutes ago, Lisias said:

Humm… This may be related to the amount of parts being simulated at one time - parts enough are in the loop, the code that do the simulation starts to drag a bit and the PIDs starts to overreact (it's the reason I gone the brute force on KSP-Recal's Driftless).

I suggest you make a backup of this save game, then load the backup and start to remove things gradually to see if the drifting stops at some point!

I don't think it's this. I designed the mining rig to have as few parts as possible (about 12, including that scaled TriAlpha reactor I was having problems with). I've also since moved the rover well out of range. PC is very high spec too, I never see a yellow or red clock unless using 3x or 4x physics warp in atmosphere. Still, I can check easily by also moving the lander craft out of range which will just leave the mining rig and ground anchor. Edit, confirmed. There is still drift with just the mining rig and ground anchor in scene. 14 parts in total. It's very subtle, about 1 cm/s, but enough to move the base out of position over time. (this was tested on my fully modded game)

As an aside, the 0.1m hop is also stopping my KSPIE mining drills as they shut down when the vessel is not landed.

Edited February 17 by Turbo Ben

[Kronixz]

Parallax Continued is now in early access and is a rewrite of Parallax 2.0 - will see if this affects anything - I've only been experiencing 1-2m  raises using Parallax 2.0

[Kronixz]

Parallax Continued does indeed no longer have this issue