Prismatic Constraints stop working and fall after a certain distance which depends on the size of the part

Smaller parts tend to glitch out at shorter distances while larger parts tend to only glitch out at long distances. A 1x1x1 part usually starts glitching at around 250 studs while a 0.05x0.05x0.05 glitches out at less than 10 studs

  • As far as I can tell, this happens everywhere all the time
  • I’m unsure of when this started happening, but the first time that I’ve ran across this was today

Repro

  1. Create a blank baseplate
  2. Create 2 parts
  3. Connect them via a PrismaticConstraint
  4. Set the size of the one part to 0.05, 0.05, 0.05

This happens 100% of the time

Example: Exampleplace.rbxl (19.0 KB)

3 Likes

Thanks for the report! We’ve filed this internally and we’ll follow up here when we have an update for you.

2 Likes

Wow, a report one day ago? I was literally just having this problem today haha.

I have this same issue on an elevator system. It starts to accelerate, then after a couple seconds it shakes and rockets diagonally into space and gets destroyed. I’ve tried everything such as making the attachment part larger than its platform, smaller, equal size, everything. Hopefully this is just a fatal Roblox bug (doubt they’d fix it in a timely manner).

We ran into this issue with the forklift vehicles in our game, and it seems like making the mass of the small part higher solves the problem? Setting Density on the custom physical properties really high was what worked for us.

I agree we have a bug here, and we will look into it.
Here is a good way to go around this problem. Invert the attachments of the prismatic: place the Attachment0 on the big, anchored part, and attachment1 on the small part. Then this will not happen.

2 Likes

I am in the process of checking over bug reports and following up on some bugs that haven’t received any activity in a while.
Is this issue still occurring or can you confirm that this bug has been resolved?

Yes, it’s still bugged. I intentionally put the Attachment1 on the big part and anchored it while unanchoring the small part, and the small part fell down. Surprisingly, though, when I created a copy with the big part unanchored and the small part anchored, neither parts bugged out, even with the Attachment1 still on the big part.

Prismatic_Constraint_Bug.rbxl (24.5 KB)

alright, when there is any sort of update for this i will pass it on.

1 Like