PM dro reference datum and origin

[Batmanacw]

I absolutely love my PM835S.

I am trying to understand how to use the reference and find origin fuctions.

I tried doing the find reference fuction, then finding the abs zero i want to find again after the power was turned off. The find origin doesn't seem to work.

Is there an order of operation I'm not doing right?

My goal is to save subdatums that simply save my z zero as it relates to the bed of the vise. I can record them in my notebook for future reference. I can reset a particular subdatum if I change the endmill or drill.

 

[Batmanacw]

I might have been over thinking it. I'll try using just the reference datum recover zero function in the morning. I though you had to use the ref datum and recover zero function somehow combined. Nothing was making sense.

 

[Batmanacw]

Okay. I think i figured it out.

It's called the reference datum function.

You want to pick your zeroes, x,y, and z.

Then push the ref button. Pick ref with the up down button and hit enter. Then pick each axis in turn and crank it until you find the reference datum point in the middle of the slide somewhere. I marked mine with a sharpie.

Once this is done the reference datum to zero distance is stored in memory that does not go away after the dro is shut off.

You can turn the dro off and move any or all axis'. You can also change the abs zero and recover your original reference datum.

Turn the dro back on and hit the ref button. Then scroll to org and hit enter. Then pick your axis and crank until you hit the reference datum and the display will correct. Then do the rest of the axis' and your zeroes should return.

It took a lot of fiddling to get it figured out. Some folks might really benefit from this explanation.


Now I know I can save the corner of my solid vise jaw and the bed of the vise as my reference datum permanently. The next step is saving my pre-set tools as sdm datums which are also in memory that stays after shut down.

 

[RJSakowski]

I never bothered with the ref datum function since I seldom turned the DRO off. I also didn't keep a vise as a (semi) permanent fixture on the mill table so zeroing my work coordinates was my first machining operation. At some point in the distant past, I did run the ref datum routine so I presumably have that information stored which is probably why I don't lose my coordinates when I power the DRO off.

As to storing tool offsets as subdatum points, I don't have enough tool holders to allow me to switch the entire tool and holder so reestablishing tool offsets was a requirement prior to use at each tool change. Even in the case of an end mill holder, the z position depends upon how far the R8 holder is drawn into the spindle socket which in turn depends upon how much torque is applied to the drawbar. For maximum accuracy, resetting the tool offset upon loading is desired.

This changed when I started using the Tormach TTS system as the ER tool holder seats with repeatable accuracy on the face of the spindle, regardless of the amount of drawbar torque. I also have some 20+ tool holders so I can leave tools in the holders. I have an external height gage with means of easily re-referencing it so in the event that I need to replace a tool, it can easily be done external to the mill. As a result, I have only a single initial zeroing of my work reference prior to machining.

 

[Batmanacw]

I never bothered with the ref datum function since I seldom turned the DRO off. I also didn't keep a vise as a (semi) permanent fixture on the mill table so zeroing my work coordinates was my first machining operation. At some point in the distant past, I did run the ref datum routine so I presumably have that information stored which is probably why I don't lose my coordinates when I power the DRO off.

As to storing tool offsets as subdatum points, I don't have enough tool holders to allow me to switch the entire tool and holder so reestablishing tool offsets was a requirement prior to use at each tool change. Even in the case of an end mill holder, the z position depends upon how far the R8 holder is drawn into the spindle socket which in turn depends upon how much torque is applied to the drawbar. For maximum accuracy, resetting the tool offset upon loading is desired.

This changed when I started using the Tormach TTS system as the ER tool holder seats with repeatable accuracy on the face of the spindle, regardless of the amount of drawbar torque. I also have some 20+ tool holders so I can leave tools in the holders. I have an external height gage with means of easily re-referencing it so in the event that I need to replace a tool, it can easily be done external to the mill. As a result, I have only a single initial zeroing of my work reference prior to machining.

I started torque wrenching my drawbar so I have consistency. I'm going to try preseting my z height with a tool I'll make for the reference datum and set each tool up in the machine to set the sdm. Once the tool is set as an sdm and stored in my chart I can see how accurate they repeat.

The nice part is if they repeat even relatively close I can rough out my part and then measure to adjust my final dimensions. It would be nice to be pretty close on the x and y to start and adjust as needed.

 

[Batmanacw]

I finally stored 10 different tools in SDM memory. I made a couple t-nuts and the stored dimensions were pretty spot on. I adjusted 0.002" at most on the finishing pass to hit my dimensions. It was extremely nice to be able to do 90% of a part in the vise without measuring or edge finding.

If I call up a tool I can crank my height to the measured height of my parallels. Then I can go to my incremental mode and zero the Z. I had already matched my x and y to ABS mode so now I have position and flexibility to pick a different zero like the center of my part.

My buddy is giving me a tool height setter so I should be able to get the tool height spot on. It's extremely easy to store tools since I am simply not changing my x and y zero. Just the z.

I logged the tools on my phone as I store them.

I didn't think about how handy it would be to store my face mills.