How do I Weld 2 parts without moving them or using Weld Constraint?

[Soulsplosion]

I have models with parts I’d like welded or otherwise attached together without using Weld Constraint.

I have a bunch of models that currently use WeldConstraints and I’m using this code to convert them from WeldConstraints to Welds

This works almost all of the time but sometimes it doesn’t. Only sometimes. I have no idea why

This is an example of the result of it not working, with the bottom one being a converted model and the top one being a model originally put together with WeldConstraints. After converting the WeldConstraints to Welds using that ^ code, 99% of the model is fine except for the shoulder spikes & green spots on the neck spikes specifically. I have no idea why the code doesn’t work properly for these, and I can’t figure out how to fix it manually because moving parts destroys the weld

A lot of threads I see just suggest using WeldConstraint, but I can’t use WeldConstraint because its incompatible with my method of adjusting a model’s size in-game, which I do using this code. Alternatively I could find a solution that makes this feature function with models that use WeldConstraints, but I haven’t found a way to do that either

So anyway: I need to figure out how to weld parts together using something that counts as a JointInstance. Alternatively I could get the size-changing function to work with WeldConstraints, but I haven’t found a way to do that either.

[DasKairo (Cairo)]

Try using a Motor6D, It will weld the Parts and can be animated.

[Soulsplosion]

Thank you, but I’d like to avoid that as much as possible because attaching parts with Motor6’s causes them to show up in Roblox’s animator, which makes animating a hastle. These are models with a lot of aesthetic-only parts

[jeynkins (Jaynes)]

If you cannot use weld constraints, you can use a hinge constraint to keep the parts in place while you weld them together. To do this, create a hinge constraint and set it to “locked”. Then, attach it to the two parts you want to weld together. This will keep them in place while you weld them together.

[Soulsplosion]

Thank you, that looks like it works but then starts breaking when I move the model. (I could not find any “Locked” property of HingeConstraint)

The models after running the code to convert from WeldConstraint to Weld (everything is in place):

What happens to the model after I start moving it around, even though all Hinges have been deleted:

It breaks like this in-game as well when being animated

This is the code I used:

[Soulsplosion]

okay after more struggling I figured out that you can move a Welded part by changing the C0/C1 of the Weld, and I figured out how to automate that like so:

Now using this I can easily create models using WeldConstraints, then convert those WeldConstraints to Welds as I need models to use Welds for a certain purpose

yeehaw!