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SteveC
09-23-2004, 08:53 PM
I’m looking to install a digital readout on my H.F. mill drill, and I’m planning on using the fairly inexpensive Digimatic (the digital caliper type). The 3 axis will only cost about $200 total, which is a lot cheaper than a “real” digital readout system.
As anyone done this? The “Z” axis travel on my machine is 5”, and the shortest scale they have is 6” with a total length of 11”. I’m not sure how I’ll deal with this extra length.

Thanks,
Steve

roberlt
09-23-2004, 10:02 PM
I dont know about the digimatic however, R. W. Friestad has had articles in HSM (Sept-Oct and Nov-Dec 2001)about using digital calipers for X and Y readout. I just got a RF45 and noticed a serious error on the quill feed so I am going to use something like what he describes on the quill.
I will let you know how it works,however it will be at least a week till I can work on it (hand surgery yesterday)

Rob

John Stevenson
09-24-2004, 01:50 AM
You can cut the beams down on the digimatic scales with no problem.
Just wrap tape round one end to protect the covering strip and hacksaw thru with a fine new blade.
I ordered a 6" one for the Z on a bridgy and they sent an 8" one instead as they were out of stock of the 6".
It actually worked out better as I got to make it the length the machine needed as opposed to having to make it fit.

John S.

JCHannum
09-24-2004, 06:41 AM
There will be a dimple at one end of the covering strip. Cut the other end. They also caution to cut in one direction only, ie: raise the blade when retracting for next cut, when cutting through the strip.

I cut down a Mitutoyo beam, and a hacksaw would not touch it. Had to use a Dremel cutoff wheel.

The import beams are so cheap now, it is much simpler to use them than cobbling up something from a digital caliper. You can get them with the readout in the proper orientation and add a larger readout later if desired. Kits and complete readouts are now available.

Paul Alciatore
09-24-2004, 10:57 AM
I bought a 12" Digital Depth Gauge for use on my lathe. They are available on E-Bay from time to time at reasonable prices. Chinese import.

The advantage of using a depth gauge instead of a caliper is that they have a better outline for this kind of thing so they don't have to be butchered as much. With careful planning of the mount, it can even be quickly removed and used in it's original role.

I haven't done the installation yet but will post the results when I do. As for accuracy, I guess it may be a thousanth or two off but it has to be worlds better than nothing.

Paul A.

Paul Alciatore
09-24-2004, 11:14 AM
I believe that many Asian imported mills have an error on the quill feed. The units were apparently designed metric. The quill feeds are based on one revolution equaling 25.0 mm for metric operation instead of 25.4 mm or 1" for English. So the feed is off by 0.4 mm or 0.016" per inch. They put English leadscrews in them for the table but do not go to the trouble of changing this gearing for the downfeed.

I built an Excel spreadsheet that lists the downfeeds required to achieve a given actual distance. It does it both by table lookup and via a handy box that shows the calculation for any value input. If anyone would like it I uploaded a copy to the Yahoo mill-drill group files area.

Paul A.



<font face="Verdana, Arial" size="2">Originally posted by roberlt:
I dont know about the digimatic however, R. W. Friestad has had articles in HSM (Sept-Oct and Nov-Dec 2001)about using digital calipers for X and Y readout. I just got a RF45 and noticed a serious error on the quill feed so I am going to use something like what he describes on the quill.
I will let you know how it works,however it will be at least a week till I can work on it (hand surgery yesterday)

Rob</font>

John Stevenson
09-24-2004, 01:06 PM
Anyone wanting a cheap near professional DRo would be advised to look at the Shumatech one
http://www.shumatech.com/

This uses either the cheap chinese scales or an encoder .
How you connect up is purely personal choice.

John S.

JCHannum
09-24-2004, 06:32 PM
A fully assembled 3 axis display for use with the Chinese scales is available from CDCO Machinery for $175.00. www.cdcotools.com (http://www.cdcotools.com)

I have no affiliation with them, and don't have the unit, but it is another option that does not require the fiddling around of the Shumatech unit.

I would be interested to hear from users.

sidneyt
09-24-2004, 09:50 PM
I have constructed Roland's project and posted a few photos in the Yahoo group, Mill_Drill under the name "Poormans DRO" in the photo section. I did make a couple of changes to the design such as substituting magnets for wire in the attachment of the measuring portion of the caliper which you can see in the photos. I am using Scott Shumate's DRO-350 which I am quite pleased with.

fixxit
09-25-2004, 12:20 AM
I visited the CDCO tools display at the Iron Fever expo in Pennsylvania. They had a stand alone 6 inch vertical LCD digital readout designed for mounting on a milling machine for about $50. It looked and felt pretty solid. The unit came with all the mounting brackets, pushbutton english/metric display and zero reset at any position.

I am seriously thinking of purchasing it for my drill mill. I have the same problem with the with the spindle depth. For $50 I think that I will take a chance.