# Ditron DRO



## mf294-4 (Feb 14, 2019)

Just got a D80-3v DRO. Manual says it will do rpm but a chart shows that is an option? Anyone done RPM?


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## Jackle1312 (May 13, 2019)

You have to order the readout with the rpm option.


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## MikeInOr (May 14, 2019)

I have been considering that exact DRO... well the 4 axis version for my mill so I can read off the quill and knee.

I came across a video (on aliexpress or alibabi I think) where they were demostrating the RPM functionality using an inductance sensor (If I remember properly) to get the RPM off the spindle.  It looked like the RPM would just pop up under the coordinates when it was configured to do so.  Since the screen is LCD based I do not believe the hardware changes at all... just the sensor added.

Please post your results with the D80-3v!!!  I would really like your feedback.  My concern is how easy the LCD display is to read vs a standard 7 segment LED display.


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## MikeInOr (May 14, 2019)

Make that a "HALL sensor".


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## Jackle1312 (May 21, 2019)

Easy way to find out would be if there is a option for RPM in the menu. If not then there is most likely a software difference. 
As far as the reading of the screen, I have no issues as the brightness can be adjusted and there are 4 options for background/text color
White with black text
Black with white text
White with blue text
Green with white text

I have both of mine set on black


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## pontiac428 (Oct 8, 2019)

I just ordered a D80 configured for 4-axis with slim magnetic scales.  Cost just under $700 shipped.  I went direct through alibaba, which is actually a pleasure to use.  The few experiences I have with ordering stuff from alibaba (not express) in the $500-$1000 range has been good, so I was comfortable with that part.  I just gotta wait for the shipping...


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## MikeInOr (Oct 8, 2019)

pontiac428 said:


> I just ordered a D80 configured for 4-axis with slim magnetic scales.  Cost just under $700 shipped.  I went direct through alibaba, which is actually a pleasure to use.  The few experiences I have with ordering stuff from alibaba (not express) in the $500-$1000 range has been good, so I was comfortable with that part.  I just gotta wait for the shipping...



The 4 axis D80 with RPM is on my list when I can afford one.  May I inquire:
1) Why Alibaba and not Aliexpress?  I actually thought they were pretty much the same thing?  Alibaba for large whole sale lots and AliExpress for one-sies, two-sies.
2) Which scales did you go with?  Glass or Magnetic?  Precision? 
3) Did you buy everything all together from the same vendor?  The last I looked I think I found the 4 axis with different options for scales but couldn't find 4 axis + RPM with different options for scales.  Being new to DRO I couldn't figure out which scale was compatible with which D80 version.
4) What size mill will it be going on?
5) Would you mind posting a link to the supplier you went with?


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## Winegrower (Oct 8, 2019)

My D80 has a menu option for RPM but does not have a sensor connector.   So no.


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## Jackle1312 (Oct 8, 2019)

I purchased mine from Ditron on Ali Express. I contacted them with what display and scales I needed. They provided a price along with a link to buy. They will make the scales to any length that you need so they fit your machine. Took about 2 weeks to receive them after ordering.


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## pontiac428 (Oct 9, 2019)

MikeInOr said:


> The 4 axis D80 with RPM is on my list when I can afford one.  May I inquire:
> 1) Why Alibaba and not Aliexpress?  I actually thought they were pretty much the same thing?  Alibaba for large whole sale lots and AliExpress for one-sies, two-sies.
> 2) Which scales did you go with?  Glass or Magnetic?  Precision?
> 3) Did you buy everything all together from the same vendor?  The last I looked I think I found the 4 axis with different options for scales but couldn't find 4 axis + RPM with different options for scales.  Being new to DRO I couldn't figure out which scale was compatible with which D80 version.
> ...



1.  Alibaba has a really nice communication module for chat with the manufacturer.  I wanted to be sure I was getting the scales and specs I need, and have a record of the transaction.  I also got a better price by about 30%.  This is my third purchase from Alibaba.  The other two went smooth as can be, and I was happy with what I got and what I paid.
2.  Magnetic, mainly for size but also for resistance to chips.
3.  Everything came from the same vendor.  If you ask, they will bend over backwards to accommodate. 
4.  This is going on a big Lagun FTV-3.  16x36 travel, 11x58 table.
5.  I bought from Chengdu Ditron, the manufacturer of the Ditron D80.  All of the research I could manage from this side of the bamboo curtain indicated that they are indeed the makers of this DRO head.


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## TorontoBuilder (Oct 17, 2022)

Question to fellow Ditron D80 owners with the RPM option.

Is there any additional functionality, such as entering a diameter to have the surface feet per minute output instead of rpm? If not then this is criminally stupid of the manufacturer.

Asking because I'm just about to install mine on the mill and design a ring mount for the magnet array, as well as sensor brackets. It's a lot easier to design for two sensors right off the bat if I need to try to run a separate mach tac unit


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## pontiac428 (Oct 17, 2022)

TorontoBuilder said:


> Question to fellow Ditron D80 owners with the RPM option.
> 
> Is there any additional functionality, such as entering a diameter to have the surface feet per minute output instead of rpm? If not then this is criminally stupid of the manufacturer.
> 
> Asking because I'm just about to install mine on the mill and design a ring mount for the magnet array, as well as sensor brackets. It's a lot easier to design for two sensors right off the bat if I need to try to run a separate mach tac unit


I don't have the RPM conversion, but a look through the manual and unit software shows that it *only* reports RPM, and does not allow user set variable input or capture from a scale input to allow computation of SFM values.

In fact, there are a few areas where this unit COULD provide fantastic output, but it is not implemented.  The mill mode is well done, and the lathe mode has vectoring, but certain possibilities aren't available due to software limitations.  Such as (on lathe) subtracting [longitudinal travel] from [quill travel] to yield the distance from tool to origin, or distance from quill to tool point.  Could be done, but isn't there.  So, ultimately, these are readout displays first, and computational displays in very few cases.  If you could crack the firmware, it would probably be easy to implement SFM conversion, but I'm just guessing.  It's not like the DRO head is powered by ARM with an Android OS.

Just a closing thought, but a simple SFM standalone head unit might not be very hard to build with analog electronics.  Take a pulse, multiply it by an input variable that includes pi and the multiplier (even it it takes DIP switches), and the display will read SFM.  Or just get good at the rough math, diameter times RPM  divided by 4 should get you close enough to pick the right sheave.  At least I think so this late in the day.


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## TorontoBuilder (Oct 17, 2022)

pontiac428 said:


> I don't have the RPM conversion, but a look through the manual and unit software shows that it *only* reports RPM, and does not allow user set variable input or capture from a scale input to allow computation of SFM values.
> 
> In fact, there are a few areas where this unit COULD provide fantastic output, but it is not implemented.  The mill mode is well done, and the lathe mode has vectoring, but certain possibilities aren't available due to software limitations.  Such as (on lathe) subtracting [longitudinal travel] from [quill travel] to yield the distance from tool to origin, or distance from quill to tool point.  Could be done, but isn't there.  So, ultimately, these are readout displays first, and computational displays in very few cases.  If you could crack the firmware, it would probably be easy to implement SFM conversion, but I'm just guessing.  It's not like the DRO head is powered by ARM with an Android OS.
> 
> Just a closing thought, but a simple SFM standalone head unit might not be very hard to build with analog electronics.  Take a pulse, multiply it by an input variable that includes pi and the multiplier (even it it takes DIP switches), and the display will read SFM.  Or just get good at the rough math, diameter times RPM  divided by 4 should get you close enough to pick the right sheave.  At least I think so this late in the day.


Thanks for the reply. That's what I expected.

I had been wavering for the past few years between machtach and an arduino unit, never got around to either so just bought an rpm meter and a calculator. But I think it's time to pull the trigger on a machtach if henry has a couple boards and ICs left


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## Winegrower (Oct 18, 2022)

Pontiac428 is correct above.   The Ditron only displays RPM, and to get that your DRO must have an optional DB9 connector marked “RPM”.  The Hall effect sensor and some magnets come with the option, the rest is left for you.

I have installed the sensors on two lathes so far, and have a thread somewhere here on how I did that.   It’s a very clean installation, does not interfere with change gears, collet closet, etc.


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## TorontoBuilder (Oct 18, 2022)

Winegrower said:


> Pontiac428 is correct above.   The Ditron only displays RPM, and to get that your DRO must have an optional DB9 connector marked “RPM”.  The Hall effect sensor and some magnets come with the option, the rest is left for you.
> 
> I have installed the sensors on two lathes so far, and have a thread somewhere here on how I did that.   It’s a very clean installation, does not interfere with change gears, collet closet, etc.



I did order the DRO with the rpm option and the first thing I did was inspect the DROs to assure that they had the input and sensor. I think I paid $25 more to get that option. 

I guess I'll cheap out and just use the DRO calculator to calculate the sfpm from the given rpm.... or work backwards to determine the rpm to select to match my machining requirements.


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