At high speeds (approximately 200 km/h), the hinge constraints on the airplane’s wheels begin to behave strangely.
They disconnect from their intended position, returning to their place afterward (this behavior repeats if the vehicle returns to high speed).
The airplane’s wheels are connected to the landing gear by hinge constraints, which are connected to the base of the landing gear, which is connected to a MainPart to which all parts of the airplane are attached.
The airplane’s force is provided by VectorForce on 2 BaseParts, which are connected to the MainPart.
The physics of the aircraft are calculated on the client-side.
Thank you for your report. Can you share a simplified reproduction that we can use to investigate? From the video, it looks like the solver is becoming unstable but we will need the mechanism to confirm that. If that is indeed the case, there are likely some minor tweaks we can make to get things working. Thanks.
Thanks so much for providing the repro, super cool model!
What you’re seeing is referred to as the high mass-ratio problem, where physics solvers can become unstable when simulating very light parts connected to very heavy parts. In your case, the mass ratio of the fuselage to front wheel is about 1000:1, so the solver goes unstable when the wheel spins rapidly.
I found that by increasing the density of the wheels by a factor of 10 gave great results, let me know how that works for you.
It worked perfectly, I could reach +700km/h without any problems! Thanks!
There’s another strange bug happening, just to let you know; the plane requires a slight touch on the wheels before entering it, otherwise the plane will go crazy
The physics is being calculated in this slight touch on the wheel, however, the plane is anchored, I don’t know how that’s possible.
Interesting, I’m not able to repro on my machine. One thing to try would be to set the network ownership of the plane to the player just before entering it, there might be something weird going on with the seat weld.
Well, unfortunately it didn’t solve the problem, but I’m happy with the result of the wheels. It’s not worth wasting time on this. I can live with having to give the wheel a slight tap.
Thanks again!
