# Crazy DRO Question



## DeanB (Dec 31, 2021)

So I am the proud owner of a 1978 series 1.  It came with a 2 axis acurite DRO.  It's replacing a Rong-Fu 30 that I had put a 3 axis DRO on.  My question is has anyone found a way to use a scale on both the quill and the knee such that the z axis readout sums the two scales.  So if the knee goes up the z axis value increases and if the quill goes down the z axis value decreases.  One readout for totalling both motions.


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## MrWhoopee (Dec 31, 2021)

Many new DROs have that capability, assuming enough axes/inputs. You're obviously not going to get there with the Accurite.


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## DAT510 (Dec 31, 2021)

Looks like some companies have made devices to do so in the past.  Can't find much on currently "available" units.

I did find this for the Acu-rite.   


			https://www.machinetoolproducts.com/content/Acu-Rite%20DRO%20Manuals/MSC%20-%20Multiple%20Scale%20Coupling.pdf
		


And this one, that's no longer produced.









						ESUM  TWO ENCODERS TO ONE ENCODER ADDER/SUBTRACTOR
					

US Digital designs and manufactures optical encoders, inclinometers & motion control components. Our complete product line includes either absolute or incremental optical encoder & inclinometer products, stepper motors, PC interfaces, and digital readout.




					www.usdigital.com
				




I bet it's something Yiriy @ycroosh could make/add to the TouchDRO (if it doesn't already)
​


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## mksj (Dec 31, 2021)

I do recall a summation unit for 2 inputs to one, was quite a while ago and the scales would need to be the same resolution and the connections. Newer multi-axis DRO's do provide summation on the quill + knee, I have a 4 axis DRO and combine the two axis which are indicated as "S". It works well, a bit of a challenge to install the scale on the quill and not block anything.


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## Winegrower (Dec 31, 2021)

mksj said:


> It works well, a bit of a challenge to install the scale on the quill and not block anything.


Indeed!   The mini magnetic scales might be a better match for that application.


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## woodchucker (Dec 31, 2021)

I think there's one from the UK  M-Dro if I remember correctly.

Yep, I did remember correctly:

The consoles come in a selection of single, 2 axis, 3 axis and 4 axis versions. An axis summing interface can also be installed to combine two encoder outputs, for example the quill and knee travel.





						Display Consoles
					

M-DRO has an extensive range of Digital readout consoles including LED displays or full colour LCD displays.




					www.m-dro.co.uk


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## DeanB (Dec 31, 2021)

mksj said:


> I do recall a summation unit for 2 inputs to one, was quite a while ago and the scales would need to be the same resolution and the connections. Newer multi-axis DRO's do provide summation on the quill + knee, I have a 4 axis DRO and combine the two axis which are indicated as "S". It works well, a bit of a challenge to install the scale on the quill and not block anything.
> View attachment 390361


Thanks, which DRO did you get?  I was looking at the Ditron 4 axis but can't find any info if it will do the summing.   Figuring out where best to mount the scale on the quill will be the next challenge.  It was pretty easy on my RF-30 to put the scale up into the cavity behind the quill.  No such luck on the bridgeport.


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## jmarkwolf (Jan 4, 2022)

DeanB said:


> Figuring out where best to mount the scale on the quill will be the next challenge.  It was pretty easy on my RF-30 to put the scale up into the cavity behind the quill.  No such luck on the bridgeport.


Search on Youtube for mounting quill DRO's on a Bridgeport, particularly the Mitutoyo quill scale. You'll get ideas.


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## JimDawson (Jan 4, 2022)

I have both knee and quill scales on my machine.  I could very easily sum the readings, but i have never found a good reason to do so.  I do use them independently all the time.  Great for setting tool height offsets.


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