# Dro help



## themayor (Mar 5, 2013)

Looking to get a nice Dro for my grizzly g4003g lathe what is a good dro name that i should look for?


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## 350xfire (Mar 5, 2013)

You can get the chepaer China ones from Ebay thast are good. I forget the brand but I think usually come from Australia or China and have like $100 shipping. There are US suppliers that sell them but they run about $150 more. Oh, just came to me... Sino or Simpo


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## darkzero (Mar 6, 2013)

Can't go wrong with the good fellas at dropros.com. They're here in the US & offer great support.


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## themayor (Mar 6, 2013)

thanks guys


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## unterhausen (Mar 10, 2013)

would I hate myself if I were to install a mill DRO on a lathe? I have an Accurite 2 axis mill DRO sitting in my parts room. It's not one of the ones that switches to lathe mode


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## BVH (Mar 10, 2013)

I think once you work with a DRO, you'd never go back. I have one on my lathe and appreciate having it every time I use it.


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## precisionworks (Mar 10, 2013)

unterhausen said:


> would I hate myself if I were to install a mill DRO on a lathe? I have an Accurite 2 axis mill DRO sitting in my parts room. It's not one of the ones that switches to lathe mode


As long as the scales are long enough the reader head won't know the diff. Most mill scales are shorter than the X&Y travels on a lathe.

Don't forget a Z reader for the tailstock ram.






Not necessary if you can count 48.41 turns as shown above ... without missing a turn count. Pretty essential if you bore to depth, ream to depth or drill to depth using the TS ram.


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## darkzero (Mar 10, 2013)

unterhausen said:


> would I hate myself if I were to install a mill DRO on a lathe? I have an Accurite 2 axis mill DRO sitting in my parts room. It's not one of the ones that switches to lathe mode



You should be fine. Some mill specific DROs will have all the mill specific functions/buttons on the face of the unit for convenience, all it will do is add unnecessary clutter. But for the lathe there's only a few functions that are actually useful & you'll quickly learn which ones you'll use the most. Not sure which Accu-Rite display you have but the current ones look nice.

As Barry mentioned the scales will not be sized correctly for your lathe. Proper replacement scales from Heidenhain are probably not cheap. The current Accu-Rite displays seem to use the TTL input & D-sub 9 connectors so that means you should be able to use import glass scales. Most import glass scales have the same output & also use D-sub 9 connectors. If your display does use the 5v TTL 90°PD encoder inputs but have a different connector, you can buy cable adapters or make your own.

Replacement scales for your lathe from DROPROs will run about $370 for the X & Z axis. If you call them & tell them what DRO you have, they will help you with what you need to get going.


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## gt40 (Mar 10, 2013)

I had to replace a scale on my lathe and was extremely happy with zs instruments. I found them on ebay but called them and they were very helpful and the price was 20 dollars cheaper than on ebay. Most importantly, the scale was clearly better than the 2 import dro scale sets I had previously ordered. good hardware and a nice curved shield included too. 

http://www.zsinstruments.com/

The other thing was they shipped it right away and I got it in 2 days instead of 2 weeks like most of import outfits. They were also very knowledgeable about all the different brands and made an effort to make sure I got the right connector and something compatible. They also made a point that thes scales are assembled, tested and calibrated in West Lafayette, Indiana.


Here is their ebay link but I would give them a call for likely a better price:

http://www.ebay.com/itm/260858985144?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

No affiliation but i can't remember the last time I was so impressed with a company...


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## unterhausen (Mar 10, 2013)

Do people usually just buy a scale that is as long as the carriage rack? I remember that my dro is discontinued, but it's fairly recent.

Just went and measured the travel. Gear runs off the rack at 28" and it really can't get closer to the head than about 4" I am pretty sure I have a 30" scale floating around. Looks like I can change the resolution of the scale manuall This is the display manual (PDF)


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## darkzero (Mar 10, 2013)

unterhausen said:


> Do people usually just buy a scale that is as long as the carriage rack? I remember that my dro is discontinued, but it's fairly recent.
> 
> Just went and measured the travel. Gear runs off the rack at 28" and it really can't get closer to the head than about 4" I am pretty sure I have a 30" scale floating around. Looks like I can change the resolution of the scale manuall This is the display manual (PDF)



No, you should measure the actual travel that you have for the carriage & cross slide, then add an 1" if you have the room. But it doesn't hurt to go longer if you have the room to mount it, it'll just cost more as you go longer.

For example, move your carriage all the way to one side as far as it will go. Then mark a line somewhere on the carriage & onto the bed. Then move the carriage all the way to the other side & measure the distance you get. Do the same for the cross slide.

I forget exactly but on my PM1236 I think I had somewhere around 33-35" of full travel so I think I choose a 900mm (35.4") or 920mm scale. On my cross slide I had 7-8" of full travel before the leadscrew disengaged so I choose a 220mm (8.6") scale. Again I forgot exactly, I know my cross slide scale is a 220mm but I foget if my bed scale was 900mm or 920mm, I think it's 920mm though. The full size of the actual scale will be around 6" longer than it's travel, will vary on manufacturer. So if you have a 900mm/35.4" scale, the actual length of the scale will be around 41.4" long, chip guard will be even longer than that.

The resolution setting should be set to the resolution of the scale. The common is 5 micron (0.0002) & the 1 micron is (0.0001). Unless the resolution setting for the Accu-Rite is for something else.


EDIT: Lots of great info on the DROPROs site to help you choose scale length.

Scale Specs
Scale Sizing

BTW, I don't have any affiliation with DROPROs. I only mention them cause they have great info online & they're in the US, so if you have problems with something, you won't have to mess with sending it back to China.

Never knew about the guys Mark posted, looks like they're in the US as well.


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## gadget_lover (Mar 11, 2013)

unterhausen said:


> would I hate myself if I were to install a mill DRO on a lathe? I have an Accurite 2 axis mill DRO sitting in my parts room. It's not one of the ones that switches to lathe mode



One of the things you get with the lathe version is the option to display the diameter instead of radius. That's not usually a big deal since we are used to thinking about taking off .025 to remove .050 from the diameter. 


Daniel


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## precisionworks (Mar 11, 2013)

gadget_lover said:


> One of the things you get with the lathe version is the option to display the diameter instead of radius. That's not usually a big deal since we are used to thinking about taking off .025 to remove .050 from the diameter.
> 
> 
> Daniel


Mine always stays on radial feed as it's easier (for me) to deal with. It stays on "fine" display which is .0002" increments - not terribly fine but close enough.


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## unterhausen (Mar 11, 2013)

z scale on the tailstock is pretty neat. I'll have to see what I can rig up for that.


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## precisionworks (Mar 12, 2013)

unterhausen said:


> z scale on the tailstock is pretty neat.


Thank you 

When boring most lights (the exception being those that use a flat PCB contact) a small shoulder is left at the front of the tube. The normal shoulder is .050" thick but some owners want .025" - not sure why but it's no prob because of the TS DRO. Counting turns isn't hard on a 1-cell but becomes challenging on a 2-3-4 cell light. Missing one turn, and everybody always misses by 1.00000000000 turn rather exactly, is disaster. 

Haven't done that ... yet.


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## wquiles (Mar 13, 2013)

precisionworks said:


> Mine always stays on radial feed as it's easier (for me) to deal with.


+1
Dividing the difference by 2 is now totally automatic and normal.




precisionworks said:


> It stays on "fine" display which is .0002" increments - not terribly fine but close enough.


I keep both the X & Y on 0.0002" as well. Good enough for the work I do.


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## precisionworks (Mar 14, 2013)

Two gears were brought in early yesterday & each had a callout out 3.5025" minimum/3.5034" maximum (bores for pressure lubed bearings). Nice to have a big LZ to hit. Bored each to the minimum.

Smaller bores have progressively smaller LZ's (bandwidth). Not at all unusual to see 1.1001" minimum/1.1004" maximum ... those are more challenging for a couple of reasons. A 2/10th radial move on the DRO means a 4/10th diameter increase - meaning it's possible to be too small & blow right through the callout on the next pass. Measurement also becomes critical & that requires that both the OD mic & the ID mic be in calibration. The standards that come with individual mics & mic sets are sometimes OK & just as often junk - no exception to this as the standards are never traceable to NIST. If you need your mics to be dead nuts the standards have to go to a cal lab (least costly) or buy a master standard ... if you have to ask how much they cost it's a bit less than a heart transplant. 

OD mics are relatively easy to use, meaning ten readings on a part produce ten identical results (within a tenth). ID mics are where some jobs go south as ID mics require a delicate touch. I use a Starrett 124BZ set, accurate to 1/10th, but Mitu & some other companies make similar sets. Well worth the money if you don't already have one. IMO the 124BZ is a metric ton easier to use than a telescoping set like the S229GZ. Either set requires investing some time to develop the feel for centralizing the mic tips & the telescoping mics can be a challenge - practice until ten readings are identical & you'll be good.

http://www.starrett.com/metrology/p...nd-Tools/Micrometers/Inside-Micrometers/124BZ 

http://www.starrett.com/metrology/p...and-Tools/Hole-Gages/Telescoping-Gages/S229GZ


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## darkzero (Mar 19, 2013)

> precisionworks said:
> 
> 
> > Mine always stays on radial feed as it's easier (for me) to deal with.
> ...



I have a lathe specific DRO display on my lathe, axes labeled Y & Z with no mill specific functions. I have a button that changes display from radial & diameter for the X axis only so it's easy to switch back & forth rather then setting the parameter in settings. Some "universal" displays do not have this button like the Easson ES-8A that Matt now offers with his lathes but my ES-12 on my mill does have it.

I do switch back & forth often. What's convenient about diameter mode, once I indicate the cutter to the work piece by taking a pass, I measure the diameter & enter in the value in the DRO. Then I just feed to my mark by reading the diameter on the display rather than how much I need to remove. So those without the R/D button, setting to diameter mode in the settings is another option if they don't have much of a need for radial feed.


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## unterhausen (Mar 20, 2013)

never thought about scaling the x axis. I think I can multiply by 2 though


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## themayor (Mar 21, 2013)

The dro came in got it from the dropros hope to start the install this weekend thanks for the help


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## gt40 (Mar 21, 2013)

pics for sure!


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## precisionworks (Mar 25, 2013)

I spoke with DRO Pro's about a Bpt mill install. Very knowledgeable & helpful tech support.


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