Tips/Techniques DRO Glass vs. Magnetic Scale Accuracy Etc.

[Tecnico]

That's odd. I thought all 4 were linear and you could configure any of them to be anglular..... Maybe I missed something.

Only 3 linear axis would stop me cold in my tracks.

You are correct, there are four linear inputs plus tach & touch probe Inputs.

In my case I am using the fourth and third combined for the Z axis of my mill but I’m pretty sure you can also config for rotary input.

D

 

[whydontu]

You are correct, there are four linear inputs plus tach & touch probe Inputs.

In my case I am using the fourth and third combined for the Z axis of my mill but I’m pretty sure you can also config for rotary input.

D

I’m clever but not smart. All it would take is a few relays and I could switch between lathe & mill as needed. Could also switch between the tach inputs. My existing DROs are both from the same manufacturer and have identical scales.

 

[Susquatch]

I’m clever but not smart. All it would take is a few relays and I could switch between lathe & mill as needed. Could also switch between the tach inputs. My existing DROs are both from the same manufacturer and have identical scales.

There used to be lots of multicontact relays that would do that for you.

 

[whydontu]

There used to be lots of multicontact relays that would do that for you.

Once again, clever but not smart. Or I could just use a multiplexer, or even a couple of 4066 CMOS switches. TTL signals. Doh.

 

[PaulL]

All it would take is a few relays and I could switch between lathe & mill as needed.

One nice feature of the TouchDRO is that the transmitter box (to which the scales are attached) tracks the scale positions/quadrature state. That means you don't lose your position as you go from machine to machine with the tablet. You get something much closer to an absolute scale rather than relative if you want to use it that way.

 

[Susquatch]

Once again, clever but not smart. Or I could just use a multiplexer, or even a couple of 4066 CMOS switches. TTL signals. Doh.

I wouldn't use a multiplexer. It might work but it's not designed for that. Prolly be problematic.

CMOS would work but then you would need drivers, worry about noise, and develop a circuit board. Plain old contact type switches are stupid simple and stupid reliable. Even if you have to use one relay per wire.

 

[PaulL]

Once again, clever but not smart. Or I could just use a multiplexer, or even a couple of 4066 CMOS switches. TTL signals. Doh.

Unless you're doing the electronics for fun, I'd just get two TouchDRO kits for ~80$ each (some soldering required, enclosures required, fully assembled is $129USD) and run that way. You'll drop that much just in prototyping your switch. Not to mention the first scale you fry from being an electronics bonehead like me.

 

[jcdammeyer]

I have a copy of TouchDRO on my phone and my tablet but never went the extra step to actually connect it to anything.
That's because I have a serious problem with accumulating project 42's. So for now the TouchDRO will remain unused with the mantra.
I will not start another project.
I will not start another project.
I will not start another project.
I will not start another project.

And the photo here shows why: Two DRO-350s, one for the lathe and one for the mill. Two DRO-550s just because...

Actually the DRO-350's work with the caliper type scale protocol. The DRO-550s can do that and quadrature and a few others. Open source software.

Also attached is a short article on a scale combiner. If I were to add a scale to the knee of my mill I could use that to sum the quill and the knee and show the absolute distance regardless of quill or knee motion.

 

[Susquatch]

Also attached is a short article on a scale combiner. If I were to add a scale to the knee of my mill I could use that to sum the quill and the knee and show the absolute distance regardless of quill or knee motion.

I assume you know that the Ditron and Touch will both do that out of the box. The Ditron on my Hartford is setup that way. I totally LOVE IT!

I should do a short video. It's pretty impressive to see.

Edit - It displays the combined result and you also get choose which of the two to display at the same time if you want.

 

[jcdammeyer]

I assume you know that the Ditron and Touch will both do that out of the box. The Ditron on my Hartford is setup that way. I totally LOVE IT!

I should do a short video. It's pretty impressive to see.

I didn't know but I'm not surprised. The Shumatech DRO files I have are all dated 2006 and I'm pretty sure the project was started around 2003. A lot has happened in 20 years.