I need a DRO for my lathe

[PBMW]

I just got done with a job on my CNC and thought I'd take a little of that money and buy my 12 by 36 manual lathe a DRO...
Any advice?
Jim
Phinney Bay MAchine Works

 

[Milacron]

Yes, buy one and put it on it

 

[PBMW]

Thankya, Thanka very mush...

 

[Michael Moore]

Jim, if you search on Newell you'll find some previous threads on this subject.

cheers,
Michael

 

[MikeG]

PBMW

I put a Mittutoyo on my Jet 1340 and I like it very much. Check out Penn Tool, that's where I got mine, good people to work with.

Usual disclaimers apply

MikeG

 

[adammil1]

I personally would want to get the Newall system. I've done some research into DRO's and would find theirs to be the best I've seen. Unlike any other DRO Newalls use their own patented magnetic ball in a stainless tube to do the linear locating as opposed to glass scales. While the glass scales salesmen may tell you that glass is more precise, and used on all the high end german machinery, I would think that the Newalls. Are far more rugged. Virtually any shop I've been into that has had glass scales in service for a lenght of time will often have a read out or two with bad scales where dirt has gotten into. This summer I ran a Bridgeport with semi dying scales. It would read fine to a point then it would occasionally skip on you. It ruined one part before I realized what happened. a bolt cirlce on a 13"dia $400 part was no good with 1 hole located .100" from where it should have been. That was all due to a skip in the dro's when it failed to pick up a dimension on a reader. More so, if you have flood coolant on that lathe I'd only imagine this could be worse of a problem. The glass scales salesmen all boast of great seals but they are rubber and potentially prone to drying out as far as I'm concerned. Anyone who has ever worked on machine tools for any short period of time can tell you chips always go everwhere you don't want them. They always find a way, I'd think the from what I've seen and heard the Newalls would be bullet proof.

I can say my one complaint with the Newall Topaz readout that I have used was the .000" readout display. Since a lathe readout reads diametrally, it works nice for +/-.002, but any more then that it gets real hard. For a mill this should usually be fine but on a lathe I'd perfer something a little better for the simple reason my lathe dial was in .001" infeed incriments. When hitting a dimension +.001/-.000, this can be a real pain in the butt to hit. As if you are borderlined on hitting it say +.0015" over there is little way to take off that last .0005". You can look down at your dial, and try to move it in .00025" but that gets mighty tricky. So always get one for a lathe with slightly more precision then you need.

Adam

 

[matt_isserstedt]

I just installed a Newall C80 DRO on a mill...not exactly the same animal, but similar scale technology.

The procedure is relatively easy, once I got over the nerve wracking hesitation of drilling the mill with a Dewalt cordless...and then hand-tapping. That part alone took 6 months

However, you mount the reader head, indicate the two machined flats to .002" or better in 2 planes, then install the scale tube into the reader head. You run the scale to the extreme end of the travel, and then transfer punch the scale mounting bracketry. Same thing at the opposite end...the scale brackets are very forgiving clamping devices and have 3 degrees of freedom and a decent range of adjustment so you aren't putting anything into a bind.

I did machine a simple steel bushing of .625 OD and .250" ID so that I could square the .625 cylinder against the machine and transfer punch with a 1/4" transfer punch. Simply using a .625 transfer punch doesn't assure squareness as the mounting bracket has a rotational degree of freedom that will allow that misalignment to occur...and it will compensate for it...but I didn't feel good about it.

Then it's just to organize the cables and mount the CPU/face.

Also...for general purposes, the cross-slide scale must have finer resolution on a lathe...it essentially reads linear "radius" (although can be programmed to digitally read in "diameter") however a .001" movement in radius leads to a .002" change in diameter. Conversely, if you want to be able to hit .001" on a diameter, the scale must detect a .0005" linear (radius) movement, and usually if it can detect half that movement it will be precise enough, so .00025" (or .0002") which is what the Spherosyn readers are capable of. There is another version of the same technology called Microsyn which is just a physically smaller device.

-Matt

 

[3t3d]

I found a Heidenhain scale on eBay along with an EXE box to digitize the output for it. One micron of resolution on the X axis gives me .0001" resolution on the Diameter. Sweet. And it connected up (with a homemade cable) to an ordinary Sargon (Enco) readout. Again from eBay. Most readouts are setable to the resolution of the scale connected to it.
All of this was really cheap, and well worth the trouble! The Sargon readout was cheap, since it came with a dead scale, and was originally setup for a knee mill. The Heidenhain parts were cheap too.
Just Do it! And get the highest resolution scale you can find for the X axis. The Z Axis can be much lower resolution. It is as big an improvement as electricty, or lighting in terms of operating the lathe.
Pete