There seem to be basically two categories of DRO's out there - inexpensive ones based on the same sort of technology used in digital calipers, and expensive ones based on what I guess is mainly optical sensors.
Anyone got any opinion on the reliability and robustness of the inexpensive ones, for light (mainly hobby) use on a mill/drill? Do they get gunked up and start skipping, do they add a lot of resistance to the movement of the table, do they break, .... ?
Don't exactly know what you classify as expensive or in-expensive, but I have the 3 axis Shooting Star DRO on my mill.... love it.... no problems and it works great (at least for me)... cost was around $645 or so if I recall (it was on sale). HTH Ken.
The Mitutoyo Digimatic DRO works on the caliper technology. I have had one on a BP for about 6 years and it has worked perfectly with zero problems. Apparently, Mitu is discontinuing the line as it has disappeared from their current catalog. However, Penn Tool has it on sale as a surplus item for $625.
Sounds like a good deal to me. No affiliation, just a satisfied user.
I have a 3-axis DRO based on Chinese scales and a homebuilt display (see shumatech.com). It works great for me. I've had no problems with it. I use it for +/- 1 mil type work (that's all my Chinese mill is really good for). If you want tenths, look elsewhere. FWIW, it it track my lead screw to about a 1 mil, so I'm doing about as good as I would by using the dials. However, it has sped up my work, reduced the number of errors and just made it more enjoyable.
I haven't had any problem with the reliability. I don't use coolant so I don't know how they would react. Chips have not been a problem. The do not add appreciable resistance. I think they are a good solution for a hobby mill/drill.
I agree with Ken, it is a good unit. I bought one of the first ones for the school where I teach. It has been used by hundreds of knob spinning, hormone driven teenagers and they haven't killed it yet, and it has been many years. I give it the highest of praises. Rick
I bought an Analam for my miller (Arboga) and for half the price, a Jenix for about $600 for my South Bend lathe. Best money I ever spent! Rejects disappeared, output climbed, read to
0.2 tenths.. If you use the Jenix on a miller, it will calculate Bolt Circles for you as a GoTo Next function....No rotary table needed. I was cutting lots of dusty stuff on the lathe and did get some in the scale...cleaned it out and did a better job of shrouding it and it never happened again..My Fault. Both easily find the exact center of a workpiece. In a tiny manufacturing operation, they paid for themselves in 60 days, and that's no BS. It is the best money I have spent, other than the Tool Gloat prices for the two machines! As a reminder, I am the guy who started the thread last year about the ball thrust bearing for the SB Model A. I do a LOT of facing, and my surfaces have no machining ridges on them. (Cosmetic item requirement..) So to sum up, Price/performance, get the Jenix. I admit to having a bitch of a time adapting one to my oddball miller, but it has been 100% reliable and repeatable. Unlike the Analam, the Jenix has a memory for position. If you shut down, and do not touch the machine cranks, and shut down the Jenix, when it boots it reads out the same position the same position as the encoders were left in. Great feature for a night business.-When you collapse for the night, you can walk right up to it the next night, turn it on, and start cutting again.
If I am not getting too feeble minded, I believe I got mine from High Quality Tools.... they have a website, I believe, but I don't know if the Shooting Star is on sale now, or maybe will be shortly. Ken.