Digital scales (DRO like)

Shamless plug:

What specific question do you have regarding the scales?

Nick

Will be cheap scales useful at all on my vertical mill? What are the pros and cons?

There doesn't seem to be that much difference in quality for the cheap ones. If you get a Mitutoyo (they do have similar ones since maybe two years), they will be more accurate, but much more expensive.

Well pro: You can work quicker and don't have to count revs of your handle, get lost and no compensating for backlash. Cons: You have to protect them from swarf, coolant and oil. If you mount them without an external display (many have done that), they might be a bit hard to read. Batteries have to be replaced every 1/2 to 1 year (use only SR-types).

Nick

I've had one my Bridgeport for many years. My only problem is mine doesn't turn off automatically and the battery is a PITA to change. Bet the newer ones don't have either problem. I find the unit extremely useful.

Karl

Guys,

does anyone have a picture how these scales are attached?

Thanks, Alex

Here:

But I used a shielding that would stop you from reading. :-)

Here (in German): (end of page) (end of page) (end of page)

HTH, Nick

Wow, this site looks like a lot of work just to save a few pennies. My Bridgeport scale was maybe $50 and came with a mounting kit to just bolt right on the machine beside the quill. I haven't looked for them is quite a while, but I'm sure MSC, J&L, Enco etc. still carry them.

If I misunderstood your original post, and you're looking to do readouts for the X and Y axis instead of just the quill, there are linear digital encoders that can be read with a little hardware and an old PC - very inexpensive setup if you scrounge.

Karl

Karl

...

... You may be interested in the sites this search turned up.

Alex,

DROs dont have to be expensive. Check out:

Its a DIY DRO, that can use HarborFreight & alike, scales. I built my own and have had a 3 axis DRO on my mill, all for something like $160. Works like a charm, can do bolt patterns etc. Very functional.

Alex wrote:

I just purchased a DRO setup from CDCO Machinery for my Grizzly (3103) mill. The order included 4 scales, for the x (24"), y (6"), and both z (is this the correct way of saying it?) axis's (5" and 12") and cost about $450, including the display. So far I only have the y and z (knee) axis's mounted and it seems to be working great. I had to send the 24 inch scale back as it was defective. But I had mounted it on the back of the table verses the front due to interferences. I haven't mounted the quill scale yet, but I hope to eventually build a switch so that I can switch from the knee to quill scale on the display (not sure if the plug for the display is proprietary yet). The y scale is mounted on top of the stops on the right hand side of the mill using the t-slots already there by making t-nuts to fit. The knee z axis scale is mounted on the side of the base. I haven't installed any shields yet, but plan to use a thin rubber sheet over them for protection.

Again, I've barely used them as I'm still in the installation mode, but so far they are working fine. I'll probably have to use a bit of silicone/rtv to glue the plug from the remote display where it goes into the scale in place.

Dave Young

Alex wrote:

It shouldn't be hard to make a "permanent" power supply. Imagine a faux "battery" made of delrin with two contacts that goes into the caliper with a clip to hold it in place, and two wires to a 1.5 VDC supply using an LM317L regulator and a wallwart. If you wanted battery backup, the supply could be a pair of NiMH cells on trickle charge with an LM317L to regulate down to 1.5 volts.

=============== As a long time cheap screw home shop machinist I suggest you consider a magnetic back dial drop test indicator, or possibly two. Easy to set up, and can be used for other things. Enco has these on sale. I found that one "mightymag" type holder and one magnetic back worked the best for me. I have a 2 inch travel indicator, but 1 inch takes care of almost all my needs. Use an inexpensive 123 block as a spacer.

see:

1/3 way down page.

That's a pretty good idea but I need to be able to measure table travel more than 2"

I use the 2" travel indicator + MightMag :) on me lathes, all the time. I attaches real nice & EZ onto the ways and disappears as quickly onto the chip-wall. I while back I made a longitudal DRO for the lathe, but didn't use it much

F. George McDuffee wrote: