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View Full Version : Another import caliper DRO.



BadDog
11-24-2006, 11:18 PM
Well, I pretty much finished my DRO for the saddle of my Rockwell. It's based on the $15 HF calipers and some aluminum mounting blocks. The blocks are considerably more complicated (and beefy) than need be, but I just wanted to try some more elaborate stuff rather than distilling it down to the simplest possible mount. This is the result.

The blocks have recesses for the trimmed down jaws on the caliper. These recesses were constructed very carefully and the caliper fits in precisely with a firm “finger press fit” and no “slop” is detectable even without the screws. I kept one back and one front jaw and removed the depth pin. It was originally going to hold the caliper to the blocks with toe clamps seen in one of the pics, but I eventually borrowed a carbide drill and countersink so that I could use screws in the hardened jaws. The blocks are also notched so that they fit together and only surrender about 0.200 of the 6" travel.

Hmm, that's about all I can think of that anyone might care about, so here's the pics!

http://www.members.cox.net/thebaddog/rockwell/DRO4.jpg
http://www.members.cox.net/thebaddog/rockwell/DRO3.jpg
http://www.members.cox.net/thebaddog/rockwell/DRO2.jpg
http://www.members.cox.net/thebaddog/rockwell/DRO1.jpg

Your Old Dog
11-25-2006, 12:01 AM
Nice looking project. What did you use to drill out the caliper? I had to mount mine using no holes as I couldn't get a damn drill bit thru it !

torker
11-25-2006, 01:43 AM
Yod...I used carbide dental burrs to drill through mine.
That was before Darin (weird) told us how to use carbide mason bits for this.
BD...good one! Lotta machining on that (little???) project.
Russ

torker
11-25-2006, 01:44 AM
Hey...BD...you just joined the "Home Shop Innovators Club" :D
Russ

Mike W
11-25-2006, 02:07 AM
I am thinking about getting the dro from http://www.yadro.de/. Has anyone else used one?

BadDog
11-25-2006, 02:27 AM
Thanks guys. It was a lot of work, but not that bad really. As I said, it could have been done more easily, but I just wanted to play with some ideas, and over all, it came out well I think.

I drilled the hole and did the counter sink with a solid carbide drill and carbide countersink. It went really smoothly considering that nothing else I tried would even touch it.

Alas, there is still one minor problem in that I can't figure out how to drill and tap the saddle (near) perfectly perpendicularly without taking it off the lathe, which I'm too lazy to do. So, that SHCS you see stuck on the top of the saddle block (where the original toe clamp was mounted) will be switched to a button head and a plate will hold it in place over the top. Not the neatest setup, but it will allow easy removal if required...

Your Old Dog
11-25-2006, 07:10 AM
Baddog, don't underestimate the use and power of common 5 Minute Epoxy when used on alcholhol cleaned surfaces. I could see your pincher assembly being built up and then glued to the carriage.

Your Old Dog
11-25-2006, 08:34 AM
I kept one back and one front jaw and removed the depth pin.

Will these indicators work without the depth pin? Sure makes life a lot easier if they will. I just bought a 12" from Harbor Freight yesterday (blue with much larger lcd window) for the x on the mill but thought I needed the pin?

Orrin
11-25-2006, 11:07 AM
BadDog, I'm impressed. Good job.

I have some HF calipers that look like yours, but they seem to eat batteries rather fast. They are probably five years old, so I'm hoping the newer ones are better in that regard.

Have you had yours long enough to find out how they are on batteries?

A short while back an acquaintance showed me his HF DRO set-up. His calipers were new and had an automatic "ON" feature and mine don't. So, the design has changed for sure.

He equipped his mini CNC mill with three axis DRO for $75, compliments of HF calipers.

Orrin

sidegrinder
11-25-2006, 11:32 AM
YOD, you can go ahead and zip that depth bar off without any ill effects. Just be sure you throw the cutoff in your junk box--otherwise, Mr. Murphy will make sure you'll need a piece of metal just that size next week ;)

BadDog
11-25-2006, 02:18 PM
Dog:
I thought about Epoxy, but I want it easily removable as mine is only the 6" model and it will need to be removed for anything over 5" travel. I could also just lock the gib screw on the caliper and loosen the way block to let it follow along, but binding on a piece of swarf could foobar the whole thing.

As for the pin, yes it can come off easily. When you dissassemble the "head" (or whatever you call the electronic box) you'll see that the pin is just soldered(?) into the back plate. I just nicked it with the cut-off wheel that I was using to cut the points off, and bent it up to break it off flush. You can see the results in my first/top picture. It is also hardened so it makes a dandy little scraper thing now that I shapened and edge onto it. ;)

Orrin:
Yes, they do. Part of the reason is that they NEVER turn off. "Off" to the Chinese apparently means "just blank the display". That's where the "auto on" comes from, and that's how it "remembers" it's zero. Fortunately, the battery door is easily accessible so if I'm not going to use it for a while, I plan to take the batteries out. They seem to last about 6 months (from what I have read, no experience yet), so if I forget it once in a while, who cares. <shrug> If yours does not have the "auto on", then maybe they fixed that and yours will last longer?

Your Old Dog
11-25-2006, 07:03 PM
Thanks for the info baddog on the depth thing.

I must have explained what I meant. I'm thinking you make a mount that you attatch to the DRO in a way that you can remove it easily. Then, glue that mount to your cross slide. When you need to do longer work just unhook the dro and let the mount go along for the ride.

BadDog
11-25-2006, 10:27 PM
Ahh, that would work. Maybe just a 1/4" thick piece attached with epoxy or flat head counter sunk screws (not needing to be as perpindicular as the main screw). That piece could then be tapped for the main screw. Sometimes I overlook the obvious. :o