Lathe owners with DRO’s

COMachinist

COMachinist

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I have decided to put a DRO on my lathe. I have done a lot research on DROs it seems that the biggest majority are .5um resolution for both the x and z axis. I under stand the cross slide dilemma on .5 or .1um resolution. Having never used a lathe with a DRO, I was wondering what end users think of the .5 compared to .1 that have used both.
I will be using the magnetic encoders, most likely DRO Pros kits. The major problem I have now is my eyes can no longer read the dials as well as the used to, yeah I know bifocal safety glasses, I hate them. Seems they just don’t do as good a job. Any input is greatly appreciate.
Thanks for looking.
CH
 
You may have a decimal point transcription error. Most that I have seen are 1 micrometer and 5 micrometer, not 0.5 micrometer. If you are working with the 5 micrometer scales, that translates to roughly 0.0002 inch resolution (0.00019685") per "step". For most hobby machinists, that is close enough. Keep in mind the display has to translate the metric scales to English Inch values, and you get some minor "rounding errors" in the math too.

With the 1 micrometer scales, you get 1/1,000,000 of 39.37 inches of resolution per step, or 0.00003937 inch per "step". Assuming the scale is accurate, that pushes it down to 4/100ths of 1/1000th of an inch. This is likely more resolution than most home users actually need. The slightest vibration of your cutting tool will make a much bigger difference than your trailing digit on your display.

I am currently using a different sort of DRO on my lathe, which simply encodes the rotation of the dials. As such, it does not know what slap/slop exists in the mechanism. However, as most of my cuts are towards the workpiece, once they are zeroed to a reference point, then all cuts relative to that point are accurate. My eyes are old as well, and having a DRO has made things much easier (and less error prone). Hitting and holding sub 1/1000 cuts seems to be a bit easier.
 
Seems like an interesting start to a subject that I have been pondering myself.
In my experience, bifocals are great as long as you are in the zone. Most of the time I’m not.
 
My DroPros setup is 5um on the Z (carriage) and 1um on the X (Cross Slide). This gives me 0.0002" on the carriage and 0.00005" on the cross slide. In practical terms you can use these to 0.0005" on the Z and 0.0001" on the X. More than my skills and equipment can be expected to hit.
I have been VERY happy with my DrosPros magnetic scales.
 
There are other factors that degrade accuracy beyond the stated resolution of the scale/reader. The error will at best be plus or minus a half count for perfect scales, and my experience with mag scales is that they are indeed not perfect. Most if not all all the imported DROs are natively metric, so there is a conversion to inches internally that in my opinion is not done with great mathematical care. So there is some error introduced there. Then even linear compensation is an approximation. And when in diameter mode, which i believe is most useful, the total error is doubled automatically.
i was unhappy with 5 micron resolution, went to 1 micron. It’s better, but it also unmasks the other error sources. So overall, for just trying to hit a diameter to less than 0.001, 1 micron is ok, not wonderful.
 
Boswell said:
My DroPros setup is 5um on the Z (carriage) and 1um on the X (Cross Slide). This gives me 0.0002" on the carriage and 0.00005" on the cross slide. In practical terms you can use these to 0.0005" on the Z and 0.0001" on the X. More than my skills and equipment can be expected to hit.
I have been VERY happy with my DrosPros magnetic scales.
Click to expand...
I will second the Dropros magnetic scales, they work great. I had to replace one that was damaged before I bought the mill. The customer service was good. Prices are competitive
 
Oh my mistake on . Just looking for input.
Thanks
CH
 
I installed the EL400 DROPros on my lathe last year. Works perfect and wasn't too big of a deal to install. There's plenty of videos on their website to watch.
 
Highly recommend dro pro also. Put an EL-400 on my lathe 5-6 yrs ago and its been a wonderful addition. No problems other than once in awhile the buttons fail to register when pressed. They are the mechanical type vs a membrane pad type which I prefer. At first I wasn’t sure it was worth the cost and effort to instal but now I would not want be without it.
Installing it was a project in itself but enjoyable for a hobby shop.
The key for me going with the dropro mag scales was the small size of the scales and read heads vs others I looked at.
 
jbobb1 said:
I installed the EL400 DROPros on my lathe last year. Works perfect and wasn't too big of a deal to install. There's plenty of videos on their website to watch.
Click to expand...
Did you go with the 1 or 5um cross slide encoder? The El400 is the lathe specific read out right?
CH
 
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