Working on an old DTI

[ogberi]

Hi All,

I have an old Federal .0001 DTI that I'm working on. It has been in my Kennedy for quite a long time, and was so gunked up it was useless. You could barely see the dial through the plastic, and it didn't hardly move at all.

I disassembled it, and have been cleaning it up with rubbing alcohol and soapy water, Q-tips and toothpicks. Surprisingly simple device, but very precision.

The dial reads 0-4-0, with 0 at 12 o'clock, and 4 at 6 o'clock. I started cleaning the dial face at the 4, as it's the least important of the numbers. I quick found that alcohol did remove the grime, but also started to remove the paint. I switched back to soapy water, which takes longer and more effort, but isn't nearly as harsh. The tic marks are still visible, but there's a ring of grime around the entire face. Looks like it got doused regularly with cutting oil, or dropped into a bucket of the stuff.

Somewhere I have a tiny bottle of watch oil, which I'll use to lubricate everything. It's a 7 jewel movement, and at present everything at least moves freely.

I'll get it back together tonight, and check that it does function.

Then I have a favor. Would a list member please let me mail this to them, so they can compare it to a known working DTI? I'll handle postage both ways. I don't have any other measuring devices capable of measuring that fine.

If it works, and it's accurate, it saves me from buying another one. If it doesn't work, I haven't really lost anything, as it didn't work before. Yeah, a new one is only about $50 for an import, but my hobby budget is stretched paper thin right now. Hopefully getting my SB9A soon, and have to build a bench for it.

Thanks!

 

[extropic]

Hi All,

I have an old Federal .0001 DTI that I'm working on. It has been in my Kennedy for quite a long time, and was so gunked up it was useless. You could barely see the dial through the plastic, and it didn't hardly move at all.

I disassembled it, and have been cleaning it up with rubbing alcohol and soapy water, Q-tips and toothpicks. Surprisingly simple device, but very precision.

The dial reads 0-4-0, with 0 at 12 o'clock, and 4 at 6 o'clock. I started cleaning the dial face at the 4, as it's the least important of the numbers. I quick found that alcohol did remove the grime, but also started to remove the paint. I switched back to soapy water, which takes longer and more effort, but isn't nearly as harsh. The tic marks are still visible, but there's a ring of grime around the entire face. Looks like it got doused regularly with cutting oil, or dropped into a bucket of the stuff.

Somewhere I have a tiny bottle of watch oil, which I'll use to lubricate everything. It's a 7 jewel movement, and at present everything at least moves freely.

I'll get it back together tonight, and check that it does function.

Then I have a favor. Would a list member please let me mail this to them, so they can compare it to a known working DTI? I'll handle postage both ways. I don't have any other measuring devices capable of measuring that fine.

If it works, and it's accurate, it saves me from buying another one. If it doesn't work, I haven't really lost anything, as it didn't work before. Yeah, a new one is only about $50 for an import, but my hobby budget is stretched paper thin right now. Hopefully getting my SB9A soon, and have to build a bench for it.

Thanks!

Hello ogberi,

I'm not sure what you mean by "working". If you want a very rough calibration maybe the following will let you do the check yourself. Your DTI has at least a .008 range. A set of Number drills (#1-#60) has many sizes that are only a few thousandths difference in diameter. For instance, #37, 38, 39, 40 and 41 are the drills that are .1040 to .0960 . Five points of reference within .0080". Mount your DTI securely over a flat surface and position it so that you get a +.0040 reading when the #37 drill shank is rolled under the contact point. Do the same for each of the other four drill sizes and record the indicator readings. Measure all the drill shank diameters with a .0001" reading micrometer and record the sizes. The difference in measured diameters should be the same as the difference in the DTI readings. Your readings may vary from the nominal due to your set-up and experience level, but it should serve to give you a rough idea whether the DTI is "working" or not.

If I have misunderstood your intensions, please elucidate.

As you're probably aware, Federal is a quality brand of precision instruments and your DTI is probably well worth saving. Start a piggy bank to save for a proper tune up for it by a qualified instrument shop and it can serve you well for a very long time. For instance; http://longislandindicator.com/index.html

 

[astjp2]

M.R. TOOL REPAIR SERVICE
269 LANCASTER DR
CRYSTAL LAKE IL 60014

Tell him Tim from Utah sent you. Tim

 

[awander]

I'd be happy to compare it to a couple of other indicators, if you decide that's what you want to do....