# Adding a dro



## werowance (Mar 2, 2015)

Hi, i bought an igauging dro for the mill head, and cross slide for my Bolton at750 combo lathe.  (almost identical to a smithy 1220ltd  i understand they are manufactured by the same Chinese foundry).

the mill head i was able to do no problem,  but there are no holes drill in my cross slide and im not sure i really want to drill them either.

so i have looked around and saw several options for this but wanted a little more information.

1. have seen epoxy used,  but didn't see what type,  how well it worked and how well it held?

2. i have seen magnets used,  i just cant see a magnet holding it good enough,  but would like to hear if you have used it, how did this work out for you?

and last,  don't laugh,  can i get the definition for x,y, and z?

example:
x = way
y = cross slide
z = mill head ?


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## Philipintexas (Mar 2, 2015)

X = Left to Right
Y = from your belly-button out
Z = Up & down on the mill quill

I made an aluminum "saddle-clamp" for my cross-slide to mount DRO, just a bar with a cut-out that fits snugly across the rear end with a screw to snug it up, worked well until a changed lathes.


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## bazmak (Mar 2, 2015)

There are no problems drilling and tapping small holes in your machine
If you dont then any future mods will be very restricted.Keep them to a min and unobtrusive. Regards barry


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## werowance (Mar 2, 2015)

Philipintexas said:


> X = Left to Right
> Y = from your belly-button out
> Z = Up & down on the mill quill
> 
> I made an aluminum "saddle-clamp" for my cross-slide to mount DRO, just a bar with a cut-out that fits snugly across the rear end with a screw to snug it up, worked well until a changed lathes.


 
use a clamp,  now there is a thought,  I like that idea.

also on the mill,  when going downward is it customary for it to read negative when going down or not?  I realize it doesn't matter, but just wanted it to be "normal" all I have to do is turn the dro around and it will ready positive when going down.  (2 screws)


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## Swifty (Mar 2, 2015)

werowance said:


> use a clamp,  now there is a thought,  I like that idea.
> 
> also on the mill,  when going downward is it customary for it to read negative when going down or not?  I realize it doesn't matter, but just wanted it to be "normal" all I have to do is turn the dro around and it will ready positive when going down.  (2 screws)



Any Z movement down will be negative, on the X axis when the cutter moves to the left of the job it will be negative, on the Y axis when the cutter moves to the front of the machine it will be negative.

Paul.


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## digiex-chris (Mar 3, 2015)

I used very strong magnets out of computer hard drives to mount the sensor on mine. It's totally fine and allows adjustment if I find that it's hitting part of my job. Also a plus when you've forgotten something and you collide with the sensor, and instead of breaking it, it just pushes it out of the way.

I drilled and tapped for the scale supports though. I hate re-aligning those when I bump them.


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## Twizseven (Mar 3, 2015)

I've just fitted magnetic read heads to my Cowells Mil.  I know the feeling about drilling, but in the end had to bite the bullet.  Ended up having to drill 9 x 3.3mm holes and then tap out to M4.  As most of these were about 8mm deep.  It was quite delicate job.  The taper tap hits bottom well before its done lots of threading.  In the end ground a bottom tap to be properly bottom, i.e. no lead at all.

Couple of photos attached showing the end results.











The end result was worth the stress.

Colin


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## werowance (Mar 8, 2015)

Well ended up drilling and tapping 2- 4.0 x .70 holes and that fortunately came out just fine.   Held my breath the whole time.   But that cast iron drilled and tapped easier than any steel I have ever done

Next on the list is some aluminum u Or c Chanel as a chip guard if I can find it

Else I might try to talk a buddy of mine into breaking some aluminum sheet for the dust guard

What are others using for a dust guard?   Most I have seen have broke their own sheet metal.  But has anyone found common material as an alternative?

Example found some j Chanel for by vinyl siding that almost was close enough.  Unfortunatly it was just a tad to small


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