Hafco HM52 CNC Conversion

[landslide]

thanks for the info. after looking at a few drawings using two ball nuts back to back to eliminate backlash I was wondering if the Y axis would suffer.

it is really tempting to buy one of these mills and try a conversion also.

the z axis is the only thing holding me back. chich2 seemed to have good success using the knee, but latter in the thread the issues start appearing.

using the quill as the Z looks just as intimidating.

good luck, looks like great fun.

[letray]

Hi Ray, I am trying to interface Yaskawa SGDH-02AE ServoPacks with Mach3 using Step/Direction using the SN75174 line driver interface. Do you have any idea what the ServoPack parameters should be? I tried the parameters you listed above in this thread for +-10v analog control. These settings had no effect on my results. Is the +-10v analog control considered Open-Collector with with an external power source? Do you have any idea what to do with pins 14 & 15 "Clear"? Any advice you can offer would be greatly appreciated.

Ray

[RayGardiner]

Hi Ray,

The analog input is a voltage input that varies from -10v to +10v, to use the step direction inputs you don't use the analog signals.

You want to configure it for digital inputs NOT analog. The digital outputs are from the parallel port (on your PC running Mach3) and need to be buffered to drive the digital inputs on the servopack.

If you look at this circuit diagram, you will see that all the signals you need to drive the servopack are driving opto-isolators inside the drive, so you need to supply external power to drive the signals.



The step signal connects to PULSE input, and the direction input connects to the SIGN input, you don't need the CLR signal. make sure you get the polarity correct.

The other signals you need are the 24v dc signals that is the switch inputs as per the diagram above.., S_ON, and don't forget the limit switches should be connected to the N_OT and P_OT, if you are just bench testing, then you can just wire these inhibit inputs to be on all the time. But the idea is that the travel limit for forward will inhibit forward motion, but not inhibit reverse, so you can back off the limit switches under program control. If you don't provide these signals the drive won't run.

Finally...
The configuration should be set to pulse train reference.
This is Pn000 digit 1 == 1

Do you have the manual?


Regards
Ray

[BMSTECH]

Letray,

I have Samsung drives, which are very similar and use the same connection terminology, running using Mach3 and a simple buffer board. I have later added a smooth stepper board to improve motion control and reliability.

King Rich KRV-2000 Knee Mill CNC Conversion

Takes a bit to get your head around but I hope you find something there that is relevant to your project.

Cheers,

John

[letray]

Ray, Thanks for the reply. I now have two drives running under MACH3 control. I was setting the Pulse Train "1" in the zero position not the one of Pn000. When I figured this out everthing started to work properly. I built a buffered two axis breakout board that seems to be working. I am now gathering the parts to make a four axis breakout board. Do you recommend turning the servo on (S/on) on when the system powers on or controlling it some other way? Some of my servo drives have 24v holding brakes. I was thinking about using one of these to drive the Z-axis. Do you know a way to release the brake just prior to a Z-axis move?

[RayGardiner]

Hi Ray,

Good to hear it's up and running, I have servo_on whenever system is powered, the servo's will hold position without needing brakes... I'm not entirely sure (it depends on your equipment setup) but I don't think you need brakes on Z, if you do then I'd interlock it with servo on, so that whenever you drop the servo_on signal the brakes are engaged. Then if you want to manually move, like a hand wheel or something, then manually disengage the brakes. I'd avoid having the servo's enabled and brakes on at the same time. You would risk breaking something..


Regards
Ray

[carbon-rod]

Hey guys,

Great thread! I read chich2's entire thread with enthusiasm... he sure went to a lot of work to convert that sucker.... I am very glad that the prices of ball nuts have come down in price so much as I don't think I would have the know how to convert a mill in the same fashion that chich did!

Alas it will be a while before I can even attempt a conversion as I haven't even got my shed built! but thanks Ray and chich (and others) for posting your great progress pics and know how to help others over come these issues..

How has your conversion been going any way? did you end up finding a effective way of converting the quill? It seems this is the most difficult axis of them all.. I am glad I am not pioneering this work!

Cheers!

Murray

[RayGardiner]

Hi Murray,

The HM52 conversion is in a "holding pattern" state at the moment, I've been distracted by a couple of other projects, and as they reach completion, I'll be back on the CNC conversion.

Thanks for the kind comments, and apologies for the slow reply.

Regards
Ray

[ELM3060]

Hi Ray and nice to see another HM52 thread, though I only have the HM50, it is still very interesting reading.

Would be great if you can include a bit about the casting as well. Sounds like you have done a bit before.

Eddie

[RayGardiner]

Hi Eddie,

I've just finished a heat treatment furnace, and the CNC conversion is getting back to being top of the list..

I did a bit of a write up on casting on another forum, it's by no means complete you might get some tips or ideas.

I'll re-post it here... hope you can get something useful from it.

Regards
Ray

[epineh]

Hi Ray, nice write up, I am just getting into some casting myself - only aluminium for me (for the moment at least) just to make some machine parts and a few other bits and pieces.

Appreciate the time it took you to put that all together.

Cheers.

Russell.

[ELM3060]

Hi Eddie,

I've just finished a heat treatment furnace, and the CNC conversion is getting back to being top of the list..

I did a bit of a write up on casting on another forum, it's by no means complete you might get some tips or ideas.

I'll re-post it here... hope you can get something useful from it.

Regards
Ray

Nicely laid out PDF Ray, thanks.
I do frequent AlloyAvenue Network at present, as I am gearing up to do some casting as well. Only looking at aluminum at present.
Didn't realise you were an Aussie and those addresses will come in handy later on, what suburb are you in? Also if you don't mind; What was the name of the other forum (PM if you wish)?

Eddie