JMC iHSV57-30-18-36-21-38 servo for Z axis ??

[thegreatwaldo]

Has anyone any experience of using a JMC iHSV57-30-18-36-21-38 180watt servo motor on a Zaxis cnc with a standard 2.2kw spindle motor, without using a brake on the servo. I was wondering if the weight of the spindle motor would be enough to spin the ballscrew and drop the Z axis causing damage to any tools in the collet when the cnc machine was powered down.

Cheers
Andrew

[cncdrive]

I think it is likely that it will spin the ballscrew down, ofcourse the chance is higher if the ballscrew has higher pitch, but even with a 5mm pitch ballscrew and nicely sliding and properly aligned linear rails the 2.2kW spindle motor has enough weight to spin the Z axis down.

[thegreatwaldo]

Hi Balasz
I think I will try to fit a gas strut to support the z axis or should I just use a closed loop stepper (I've got a spare one)
Cheers
Andrew

[eabrust]

Hi Balasz
I think I will try to fit a gas strut to support the z axis or should I just use a closed loop stepper (I've got a spare one)
Cheers
Andrew

Hey Andrew

Go with the gas strut, try to estimate the weight the ballscrew is holding up (axis parts, spindle, etc), and balance it best you can with the strut load rating.

I have a stepper driven axis with high pitch acme screw, and my z axis will sag on power down without the strut. The strut was the first 'fix' I added to my router, as I hated it drooping bits and touch probes to the table...


regards
Eric

[thegreatwaldo]

Hi Eric
Thanks for the reply, the gas strut seems to be an economic (cheap) way to solve the z drop problem and also ease any extra strain on the z axis components. Just out of interest are you going to do a 2.5d version of your probe it plugin?
Cheers
Andrew

[eabrust]

Hi Andrew,

What is your definition of 2.5D?

I'd define 2.5D is tracing perimeters and geometry in x/y plane, while also saving along the z height data to the file (dxf, csv, etc). That's the first thing the plugin did

Additions since have been working on point clouds and rotary axis stuff.

regards
Eric

[thegreatwaldo]

Ah Sorry Eric
I have'nt tried the plugin yet, more fool me. Yoiur definition is what I would need. I would like to copy some guitar neck profiles which would be easier for me to make by hand and then scan with a probe rather than go with a software package that would probably take me forever to learn. Cheers Andrew.
Ps I'll buy the plugin now to see how it works.

[flugzeug]

iHSV57 servos are actually available with a brake for a little more money. I am not sure why they don't stock them in stores.