PM DRO Manual???

mksj said:
You could replace just the DRO head ............
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Mark, unless I'm mistaken, in order to gain full functionality of the tool offset function you need to have scales that have a built in reference point. The scales that were sold with my 1440GT (used to me and originally sold in 2017) do NOT have this function.

Stefan Gottenwinter (sp?) has a youtube video detailing his lathe DRO and shows how the DRO can determine it's position each time it's powered up relative to this known point within the scale.

My point being, unless I'm mistaken, that if your scales don't have this built in capability replacing the head unit will not gain full functionality.
 
Jake you are correct that the DRO will not remember absolute positions once powered off and there are few scales that have specific reference points built in. Some of the newer magnetic scales are absolute reading, but quite a bit more expensive. But my understanding of the datum file is that is based off the absolute position, so you should be able to zero an absolute reference point and then all the tooling datum points would be relative to that 0 point. So I could use my dial indicator in a fixed holder to say get a known zero point or diameter reverence and all the other cutters should give the same relative point once that tool is loaded. Not too dissimilar than setting the height gauge on a mill and then loading the specific tool/cutter. I could see if doing a lot of repeat parts that it would be quite helpful.
 
I find the tool offsets quite handy even on a manual lathe. To Mark's point above, they hold true to whatever zero point you set. You don't even have to use the center origin like a CNC machine. You can select your own start point and work from there. Using the offsets tends to give you more normal numbers when creating what I call a "formula" for making a part. I have a couple of videos on using tool offsets with a DRO on a manual lathe for repeatability on multiple parts. Recent one posted in this thread.

5C Collet Stop Review and DRO Tool Offsets
 
mksj said:
Jake you are correct that the DRO will not remember absolute positions once powered off and there are few scales that have specific reference points built in. Some of the newer magnetic scales are absolute reading, but quite a bit more expensive. But my understanding of the datum file is that is based off the absolute position, so you should be able to zero an absolute reference point and then all the tooling datum points would be relative to that 0 point. So I could use my dial indicator in a fixed holder to say get a known zero point or diameter reverence and all the other cutters should give the same relative point once that tool is loaded. Not too dissimilar than setting the height gauge on a mill and then loading the specific tool/cutter. I could see if doing a lot of repeat parts that it would be quite helpful.
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Mark, you did a better job of detailing the use of this function than I did in post #19.

The relevant takeaway here is that with the proper scales (and DRO) you can go right to cutting with properly registered tools and go straight to a finished product with pretty tight tolerances and no measurements, whereas without the proper scales (even with the proper DRO) you are going to have to make some kind of reference measurement or cut each time you start the system back up.

Is that a big deal? Of course that will depend on individual needs. For me as a hobbyist it’s no big deal to make the reference cut. Certainly not a big enough deal that I am going to replace an otherwise functioning system.
 
Thanks for the replies fellas. Yeah all I need is the datum file (tool offsets) to function off the ABS zero position for both X and Z. My current DRO remembers the ABS and INC zero positions but you cannot move the dials if the DRO is off. So either don't touch those dials or simply leave the DRO on. Works fine. But being able to remember more the two tools would save me a lot of time during those repetitive steps for my short production runs. I watched your vid BladesIIB, and yeah that's what I'm looking to do. I have one part in particular that uses about 7 different tools to produce in first and second operation machining. So I was hoping to finally get my tool offset setup, only to find my DRO is less than.

MKSJ, thanks for the recommendation. I see you're in Fallbrook, I'm in Temecula so maybe we could meetup so I can see your setup and/or vice versa. Would be cool if you're up for it.

PM did say they have other, newer LCD models that are full function with tool offsets, and they are supposed to get back to me sometime this week. I'll keep ya'll posted for informational purposes. I know they are a good company with a good reputation, just hoping they come through on this one.
 
mksj said:
Jake you are correct that the DRO will not remember absolute positions once powered off and there are few scales that have specific reference points built in. Some of the newer magnetic scales are absolute reading, but quite a bit more expensive. But my understanding of the datum file is that is based off the absolute position, so you should be able to zero an absolute reference point and then all the tooling datum points would be relative to that 0 point. So I could use my dial indicator in a fixed holder to say get a known zero point or diameter reverence and all the other cutters should give the same relative point once that tool is loaded. Not too dissimilar than setting the height gauge on a mill and then loading the specific tool/cutter. I could see if doing a lot of repeat parts that it would be quite helpful.
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This is how my Ditron works. No reference point built into the scale is required. All that is needed is new or old zero and all the tools in the library reference off that.
 
Quick update...PM is going to contact the DRO OEM to see if there is any sort of Z-axis tool offset function with this display module. I'm not holding my breath here. I also asked about getting a different DRO display that has what I need that will work with my current scales. I'm looking for a plug-n-play solution so I don't have to buy and install new scales because I change DRO display modules. PM told me they don't have any other unit that will work with my glass scales as they are all different. I didn't know that, I figured they were somewhat universal.

So in the spirit of manual machining, I've begun to precisely measure my Z-offets manually and work out new "step-over-numbers" if you know what I mean. It works and helps me save time, but its not ideal nor what I thought I was buying.
 
The scales tend to use the output, but the pins may be different. On my ES-12B I use a combination of glass scales and magnetic, the original X and Z glass scales came with the DRO, I later added a magnetic scale to the tailstock. Prices have come down on the magnetic scales that the cost increase over glass is small. You can get complete 3 axis packages for $550-650. Coolusername PM me with your contact info if you want to swing buy.
Mark
 
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