I'm rebuilding my shopbot, and I picked up a linear actuator for my Z axis (Ebay). I like most everything about it- its the right stroke, lead, and size. Its got THK bearings and a precision linear ball screw, even has the NEMA motor mount I need.

But the sucker is HEAVY! I mean, its gotta be 100 lbs. When I stand the actuator up, the carriage block spins to the bottom quickly, and takes considerable force to hold in place. I'm now concerned that this sort of weight will create problems.

1) Will this sort of weight cause inertia problems on the XY plane, and if so, how can I deal with this?
2) How do I counterbalance the weight of the block and my Porter Cable router?

Because its so heavy, I'm considering stripping the components I need off of it- the ball screw, and maybe the THK bearings/rails. I could then mount these on aluminum plate, and replace the heavy duty cast iron carriage with an aluminum plate.
3) Will the bearings explode into hundreds of teensy parts when I remove them from the rails?

Are there other things I should know about dismantleing and reusing these parts?

I really like the design of this unit- its very accurate and stout. I'd appreciate any help. I can try to get a pic posted in the next day or so.

Wayne from White Salmon

Sell it, or strip it, I like the first better.

Inertia sucks....

I'm gonna strip it. The screw and bearings are great, very precise and in good shape. It also has the motor mount that lines up perfectly, and the lovejoy coupler, etc.

I checked prices on new actuators- outta my price range for sure. I'll have to do a bit of improvising to get this stuff to work, but at its worst it will be far less than the cost of a new actuator of similar quality.

Thanks for the advice.

Wayne

Wayne,

You don't have to buy new. I never have, and still end up with industrial quality and precision, that blows away all this roller bearing, Drylin and MDF crap around here.

Just unload yours on ebay and buy another one on ebay.

I have never bought a used stage on ebay that was below my expectations when I received it.

All types and sizes, and weights. You can probably get a really nice "Z" for around $100-150.

If you need help locating on ebay, just say the word.

Regards,
Justin in AZ