So I have a linearVelocity that should propel the root part of a model forward, but it sends the thing FLYING.
And I have no idea why. All im doing is setting the velocity to be based on the attachment0 have maxforce as math.huge and the velocity being (0,0,-5).
Can the amount of parts welded to the main part effect how far it goes? Or am I doing something wrong?
From the look of it it seems to move incredibly fast.
Why is the velocity making it go so fast when it shouldnt be this fast? I have other parts with the same velocity and they are moving much slower even though their VectorVelocity is significantly higher.
Hello again 
Are you updating LinearVelocity.Velocity at all? Or is the velocity applied by Attachment0 orientation?
Idk what you mean by that but I dont change the value of the linearVelocity ever,
How does that work?
If LinearVelocity.RelativeTo is set to Attachment0, the velocity is applied to the part using Attachment0’s Up, Right, and Front direction, which rotate with the part. If LinearVelocity.RelativeTo is set to World, the velocity is applied in the direction of the worlds Up, Right, and Front directions.
See the bottom of this page to get a better understanding LinearVelocity | Documentation - Roblox Creator Hub
Ok does that mean the force is applied to the parent of the attachment?
If not this still doesnt solve my problem.
Yes, it’s always applied to the parent of LinearVelocity. I forgot to add that I don’t know what could cause LinearVelocity to behave like this. Have you checked its position and AssemblyLinearVelocity properties?
Well that made it go even faster :0
I can look but what should they be? What about them am I looking for?
Usually whenever something flies out of control it’s because I’m forgetting some force, if it’s especially bad the position gets set to NaN, signifying something went badly.
Id look but it appears to be so bad all the parts got deleted lol
Maybe it’s the velocity property you are using? This is one of the slightly annoying things about LinearVelocity, I find myself forgetting to change the VelocityConstraintMode, which disregards other velocities set that don’t match the specific mode.
I forgot to add the link 
Specifically look at the LineVelocity, PlaneVelocity and VectorVelocity properties. By default, VectorVelocity is used.
Ok ill try just using AssemblyLinearVelocity and ill tell you how it goes