Linear Module Seal

I was wondering how sealed the linear modules actually are. I know they are supposed to be dust-resistant, but I’m curious how sealed they actually are. Are they adequately sealed against dust? How about fumes/liquids? Kind of curious if using the cnc with coolant would be feasible, even though you would probably run into frame stiffness and spindle power issues before material cooling issues.

Not very.
They keep most dust out but definitely not all. When I had to adjust the play in my linear modules there definitely was some sawdust in there. That was only after a couple months, but I do a lot of really dusty cnc. But it wasn’t enough that I felt I needed to worry about it. When I hit my one year anniversary in a couple months I’ll probably disassemble and clean and re-lube them.
Definitely wouldn’t rely on them to keep liquids out, let alone fumes. Not sure what kind of fumes you’re worried about. Unless you’re using the laser on vinyl or pvc which you definitely shouldn’t be since it releases chlorine gas.
If you wanted to use a cooling liquid or spray you’d definitely want to have some type of shielding/shroud/containment.
I think as you pointed out you’re going to have more problems with bed stiffness and power issues. There are ways to re-inforce the bed and some people have had some success with higher power spindles.
-S

2 Likes

No, and it has nothing to do with how sealed the linear rails are. The motor is just not powerful enough to cut metal at a rate that would ever need coolant. If I’m not being clear, it will barely cut metal at all. And long before you got the point where you might need it, the relatively poor frame stiffness would mean that you don’t want to be cutting metal.

I put on a little accordion jacket spring thingy. 2 pieces. Has a plastic collar on the ends that bolt together but hugs around the brackets. I can’t remember the name but that bracket that moves along the rail. One piece for the back, one piece for the front. And I attached a little rail on each side with 3M double sided foam tape that holds a formed lip of the collar. I formed the collar so it doesn’t want to bend out of the rails as it moves back and forth. Keeps dust out really well. And actually does look like an accordion now.