Tenths Indicator Choices

Take what Long Island Indicator has to say with a grain of salt. They seem to despise Federal products and bad mouth them at every chance they get. I have over a dozen Federal indicators, and none have the problems they describe. None have solder blobs, all are accurate, repeatable, and well jeweled.

Also check prices elsewhere before making a purchase or getting something repaired. I've tried to purchase new units from them, and the prices were outrageous. I've also tried to get things repaired and the cost was generally 2/3 the price of new and often more than the cost of the original unit.
 
I thought I’d add my two cents. A number of years ago I performed a test which although unscientific was kind of interesting to me. I checked the accuracy of several 1” dial indicators I had. I compared the accuracy in terms of travel of a Starrett and Mitutoyo against a couple of Chinese made indicators that I had. I have a Moore 1 1/2 jig bore which is in pretty good shape. These are known for their accuracy especially the lead screws. Moore has a tolerance of .000025 inch in any 1 inch of travel and .000070 in 14 inches of travel. I used this machine as my standard.

What I found was the Starrett and Mitutoyo were as accurate as I would have expected and just as important, they were consistent. What I learned about the Chinese indicators was that while they could be accurate in certain distances, they could also be inconsistent over their full travel. Long story short, you get what you pay for.

With regards to tenth indicators an example of their use in my shop would be checking spindle bearing spacers. I use one on a surface plate in conjunction with gauge blocks to check for height differences and parallelism. Spindle bearings in my 10EE are expensive and they need to be right, so it came down to what I trust, and for this I use my Intrepid tenth indicator. I trust its repeatability. For around-the-shop use on my machines, I use a Mitutoyo .0005 indicator. I guess I would be in the camp of sometimes less is more when it comes to test indicators. Tenth indicators can be fussy but necessary for some operations.
 
Late to the table but I have a few Federals, Fowlers and at least one Interapid. I tend to go to the 0.0005" ones and have Mitutoyo, Interapid, Starrett and Fowlers in those.

I've used the 0.0001" resolution ones very sparingly. I first used one to check the runout in the spindle of my new to me at the time Grizzly G0709 lathe.

I also checked the runout of a 5C collet chuck that was on my Clausing. The chuck was from CDCO and had around 0.002" of runout. I ended up truing it up by turning down the register of the backing plate a few thousands, and placed shim between the register and the chuck.

Bruce
 
I appreciate everyone's input on the subject. It seems like a tenths indicator is less mandatory than I thought. I do have a lot of confidence in the resolving power of my half-thou indicator, so I guess I'll press on with that until I have a have a measurement that I truly can't perform with it.

Thanks again!
-Kyle
 
@KyleG

I wanted to see if my lathe cross feed magnetic DRO was accurate. It is suppose to have 1 micron resolution, but what about the accuracy? So I purchased one of the cheaper digital display dial indicator. 0.001mm (1 micron) resolution with a 25mm stroke. I paid about $45 for it and connected the digital gauge to the lathe and compared its reading to the DRO.. But this left me with even more questions. It seems to be pretty good at measuring small differences if you are sliding it along a surface or even if you pull the plunger back and set it down on a surface repeatedly, but it turns out to be really hard to determine accuracy over the full stroke.

What do you used for a reference if you do not have anything that has been certified? I have a number of micrometers, but nothing that was certified in the last 10 years if ever. I even built a fixture to hold the digital dial indicator opposite a 1 micron resolution mechanical micrometer head and let the head push the dial indicator .... taking a reading from both and plotting the error. I found that even the cheap $45 unit appears to be accurate over the 25mm stroke to withing ~15 microns (~0.0005"). I think it may have even been better at the beginning, but I may have clamped it too hard or abused it before I started the measurement... causing some friction for the plunger.

More recently I purchased a slightly more expensive version of one of these from Clockwise. Amazon: "Clockwise Tools DITR-0105 Electronic Digital Dial Indicator Gage Gauge Inch/Metric Conversion 0-1 Inch/25.4 mm 0.00005 Inch/0.001mm Resolution with Back Lug Auto Off" There is also one with a probe tip set for just a bit more. https://www.amazon.com/Clockwise-Tools-DITR-0105-Indicator-Resolution/dp/B08H4943GZ
or their store https://www.amazon.com/stores/page/...b663-04d6-40a7-a4e3-9272a8cb582a&ref_=ast_bln

I paid about $63 (no probe tip set) because they promised to send an error curve, which they did. It is much better than the first as It is more robust, the parts inside are all metal, machined, thicker, etc.... and the plunger moves extremely smooth with no obvious friction. I also purchased the RS232 cable: "Clockwise Tools DTCR-01 RS232 Digital Indicator Data Transfer Cable" It has a small box with push button switch inline with the connection to the dial indicator and the USB port on my computer. Push the button and the data appears in Excel or Word and drops the cursor down one line to capture the next data point. Very slick and handy. It also has an external trigger so that you could automate getting the data with a computer or you could implement a foot switch. The cable costs about $40.

This DITR-0105 digital indicator has a 1 micron resolution and appears to function that way pretty well. Performing an entire 25mm stroke the accuracy seems to be ~ 7 micron worst case. I think this is pretty darn good for only $63. The Amazon seller even sent me a message asking if I was dissatisfied or had any problems. If so I was to simply say so and they would replace it. All of the metal parts in it are thicker and stronger and appear to be machine worked, rather than just cast or made from plastic. The inside guide is brass not plastic. The probe shoulder used for mounting is thicker and larger in diameter so is also better to clamp to. It uses a 3V coin Li-Ion battery (CR2032 I think) where as the cheaper unit uses a 1.5v button cell so it probably last longer and should be more stable. I have run them both for hours and the batteries seem fine.

By the way, while all of these digital micrometers I have looked up have an Off/On button this only turns off the display. So even if the display is off, and you move the probe the micrometer is still functioning to take data! The only way to truly turn off the power is to remove the battery. If you are going to store these things and not use them I would recommend removing the battery. When I got the devices from the sellers they both had batteries in them. But the batteries needed to be replaced. The $63 unit came with a spare battery 3V cell.

Anyway, I am going to purchase a couple more of these Clockwise units. There are a lot of these things being sold, but this Clockwise version appears to be the best of them unless you may want to spend a few hundred dollars. While a lot of the others say that their devices are cable ready they do not sell the cables..... Clockwise also seems to be one of the few sellers that sells an RS232 cable.

PS. There is also a Clockwise unit that is slightly cheaper model number which seems to end in "N", i.e. DITR-0105N which do not have the cable interface. There are also versions that only have 1/2" stroke or which only have 0.01mm resolution. The prices are cheaper.

If I ever finish with, and am happy with, my calibration procedure of these devices vs my micrometer heads or the lathe DRO I will post the results. However, I must admit that when one gets down to trying to measure distances to only a few microns a lot can go wrong in the process.

Dave L.
 
Joe blocks and Cadillac gauges
Yes, but have yet to purchase as the need is not great. The other problem is, I like plots with lots of data points and .... I was spoiled by using an HP laser interferometer ......
 
To calibrate Z axis on a lathe, you use the carriage stop and joe blocks over the longest stack you can assemble - in my case 9". The setup for X is more complicated, and depends on your lathe.
 
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