PM-932M DRO Question

[RebelJD]

I have an PM-932M with the installed DRO on the X,Y,Z. It is the PM labeled DRO but I'm sure it is a generic import. I love the DRO, but I really never use the Z axis readout. There is a separate quill DRO which is very useful, as most of you know. However, the Quill DRO readout is small, and it requires batteries. I often forget to turn it off and later have to replace the battery before I can use it. Ahhhh. And it's a little hard to read at times.

I'd like to display the quill position on the Z axis readout and was wondering if anyone has every figured how to do this. I'm fairly certain I'll have to replace the scale on the quill, but I don't know where to source just the scale. Any help would be appreciated.

 

[verbotenwhisky]

I have an PM-932M with the installed DRO on the X,Y,Z. It is the PM labeled DRO but I'm sure it is a generic import. I love the DRO, but I really never use the Z axis readout. There is a separate quill DRO which is very useful, as most of you know. However, the Quill DRO readout is small, and it requires batteries. I often forget to turn it off and later have to replace the battery before I can use it. Ahhhh. And it's a little hard to read at times.

I'd like to display the quill position on the Z axis readout and was wondering if anyone has every figured how to do this. I'm fairly certain I'll have to replace the scale on the quill, but I don't know where to source just the scale. Any help would be appreciated.

Yeah, the Quill DRO isn't awesome but it serves its function for me. I like the Z connected to the Head because I like to track it because I tend to move it during setups, I lower the head down close to the work when milling then use the Quill for the fine adjustment; so, during milling operations the quill is rarely out more than an inch.

 

[B2]

Quill DRO readout is small, and it requires batteries. I often forget to turn it off and later have to replace the battery before I can use it. Ahhhh.

Yes, me too..forget to turn it off. Because I also used them else where, I finally just ordered a set of 500 of them off of Aliexpress. I think the total cost was under $10. Likewise, I stock CR30xx for my digital gauges and other equipment. By the way, keep your batteries in the refrigerator and the shelf life will be much longer! The Arrhenius Equation says that the chemical reaction rate goes up by ~2x for every 10C increase in temperature. Anyway, keep them out of the heat. Ever notice how your emergency flash light that you keep in your car glove box always seems to have dead batteries! What does that say for your EV cars? Drive North!

Dave L.

 

[gb1551]

RebelJD,
I think your ticket is an M-DRO Linear Encoder Summing Interface. You do need to add a magnetic scale on the quill along with a scale on the gear head and link them to a summing interface box. Both scales are combined to give you one Z-axis reading on your DRO.
Please see the pictures of my mill. I purchased the summing interface from:

M-DRO Linear Encoder Summing Interface

The summing interface combines the output of quadrature encoders into a single quadrature output. Applications include combine mill quill with knee travel or lathe compound travel with main carriage travel.

www.machine-dro.co.uk

​

 

[RebelJD]

Thanks GB1551, just what I was looking for. However, my DRO is different from yours, my machine is less than 2 years old. Where did you purchase the linear scale? Do know you if there is a standard electrical interface for these scales? I need to make sure things are compatible with the DRO I have.

I assume the knob at the top is a quill lock, I like it.

Thanks
Jim

 

[gb1551]

I contacted Machine-dro.co.uk for guidance before I purchased anything. They answered all my questions.
Yes, the knob is a spindle lock.
Good day

Machine DRO Contact Us - Machine DRO UK

Hand measuring tools, including Digital Readout DRO Systems, calipers, height,depth gauges & angle protractor, micrometer, scales, indicators, bases

www.machine-dro.co.uk

 

[RebelJD]

I tried to contact Machine-dro.co.uk but never heard back from them. So, I did some research and determined that my DRO and glass scales use 5V TTL interface signals. I found a compatible glass scale from VEVOR for $39 including shipping. I mounted it on the quill and connected it to the DRO in place of the Z Axis scale. It worked fine and I was able to read the quill position on the DRO instead of the small original readout.

I replaced the front cover with a temporary sheet metal version until I get time to build a proper one.

However as mentioned above it is advantageous to sum the Z Axis and quill together, so I designed and built my own summing module using an ESP-32 micro controller. I had a circuit board made and mounted it in a small aluminum box I had. I'm very happy with how it works, and I learned a few things along the way. I've got a few extra circuit boards if anyone is interested send me a PM.

 

[Wilson Perf]

@gb1551 ...First time poster here with questions on which way I might want to go. I'm not so concerned with combining the column and the quill Z travel, mostly with setting up a proper scale on the quill. I have an earlier 932M with an Easson X,Y,Z (Column) DRO and the cheap inaccurate spindle DRO. I ordered a glass scale to add to the front of the gearbox and attach to the spindle base. However, I just learned of the iGaging 6" DRO Scale (look up on LittleMachineShop's site. A stand alone magnetic pickup scale with it's own readout and mount. Much better quality stuff than the little digital caliper style I currently have. I'm now torn as to do I set up the glass scale and see how it goes or is the iGaging a better route overall. My question for you would be, is your gauge glass or magnetic? It looks super compact and that's NOT what I'll have with the glass scale I ordered.
Thank you in advance and I look forward to your response.

Regards,
Bill W.
Lee's Summit, MO

 

[RebelJD]

I've been using the machine a lot lately and I really like having the quill travel showing on the DRO with the X &Y. Its one place to look and more comfortable than looking at the front of the headstock, which is not always in the same place. Summing the quill and Z axis really doesn't do much for me, but I liked the challenge of building the summing module.

Assuming the glass scale you purchased is compatible with the DRO you have, then you could simply remove the Z Axis connection and connect your new scale. Try it and see how you like it and then decide if you want to go with the iGaging.

Most glass scales and DRO's are 5v TTL devices based the research I did but you should make sure yours a compatible before you try it.

Good luck.

Jim

 

[Wilson Perf]

I've been using the machine a lot lately and I really like having the quill travel showing on the DRO with the X &Y. Its one place to look and more comfortable than looking at the front of the headstock, which is not always in the same place. Summing the quill and Z axis really doesn't do much for me, but I liked the challenge of building the summing module.

Assuming the glass scale you purchased is compatible with the DRO you have, then you could simply remove the Z Axis connection and connect your new scale. Try it and see how you like it and then decide if you want to go with the iGaging.

Most glass scales and DRO's are 5v TTL devices based the research I did but you should make sure yours a compatible before you try it.

Good luck.

Jim

Jim,

Thank you for the reply. I called Dro Pros to confirm that it was compatible before ordering, so no worries there. Just thinking of the bulk of the glass scale vs. the magnetic. But like you say I should try it and see.

I'll keep you posted.

Regards,
Bill W.
Lee's Summit, MO