[calzages]

Hello, I'm from Spain and I'm new in this forum, sorry for my english, I'm going to explain my case.

I'm building my own cnc machine, I have a THK Linear actuator KR30H-300-D, you can see it in page 11 : http://www.thk.com/documents/us_pdf/...t/en_B_263.pdf

I want to use it in the Z axis, it has a ballscrew and a guide block integrated in the actuator body, but I don't know if the guides integrated are enough to do the work in my machine, I can put aditional guides and use the THK actuator it like a simple ballscrew, but it will be better if I can use it without aditional guides and trust in the rigidity an accuracy of the THK actuator to do the work.

I want to use my CNC machine to mill wood, plastics and in some cases aluminium.

Thanks in advance.

[awerby]

on a machine we built; I was favorably impressed by the rigidity of the actuator's construction. Still, I question whether it will be rigid enough to cut aluminum at full extension. This also depends on the rest of your machine - it's only going to be as rigid as the weakest component you use. Your dual nut-block configuration should help with rigidity; whether it's enough won't be clear until you try it. But I think it's worth trying it, it's probably not going to work any better if you add slides to the back of it.

I found that with my Z-axis, it helped to add some constant-force springs to keep it from unwinding and dropping when the power's turned off. But maybe your screws are finer-pitched than mine were (1"/rev).]

Andrew Werby
www.computersculpture.com

Hello, I'm from Spain and I'm new in this forum, sorry for my english, I'm going to explain my case.

I'm building my own cnc machine, I have a THK Linear actuator KR30H-300-D, you can see it in page 11 : http://www.thk.com/documents/us_pdf/...t/en_B_263.pdf

I want to use it in the Z axis, it has a ballscrew and a guide block integrated in the actuator body, but I don't know if the guides integrated are enough to do the work in my machine, I can put aditional guides and use the THK actuator it like a simple ballscrew, but it will be better if I can use it without aditional guides and trust in the rigidity an accuracy of the THK actuator to do the work.

I want to use my CNC machine to mill wood, plastics and in some cases aluminium.

Thanks in advance.

[ihavenofish]

kr series rails are designed to be self supporting according to the thk engineer i was talking to. im using kr46 rails for a ganty.

with the kr33's, if they are the precision grade with 2 carriages they should be strong enough to handle 4" of Z extension without reinforcing. if you expect a heavy load or want more travel, you should pair it with a 15 or 20mm linear rail with one or 2 carriages and a thick plate or an extrusion for extra rigidity. this will prevent it from twisting and deflecting.

if youre using it like a traditional column mill, you will need a supporting rail because the leverage on the spindle will likely be too much.

likewise, if you are using the non precision grade slided, these are designed to have play, so they would be useless alone and need a supporting rail to preload them.