I bit the bullet and bought a smith and Wesson made under liscense by Woodstock. Anybody use these? It's got to be the same dial indicator as the one labeled Grizzly, but a whole dollar cheaper. I can't spend name brand money right now and I felt better with new than used right now.I wanted a dial that would read that far for tramming my mill and indicating work in a vise to find the source of a problem. The dials I had were dad's old ones and I didn't want to try to lube them /fix them for fear of ruining tools I hope to inherit. They are sticky. I'll find someplace to fix them up in the future. I think I can test this new indicator for repeatability against a gauge pin sent with a micrometer set. We'll see what happens.
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import dial indicator reliable and accurate?
- Thread starter LEEQ
- Start date
- Joined
- Nov 24, 2013
- Messages
- 1,791
Ebay is loaded down with cheap tools. I went and got a new dti that was china made. I never used it. It simply was not smooth. I searched ebay for a few weeks till I found a sweet deal and picked up my starrett dti for 60 bucks and my starrett last word for 15 bucks. Both work great and the dti is as close to brand new as one could get. I paid 40 bucks for a machinist lot that included a 0-1 and a 1-2 starrett mic and I picked up mu mitutoyo 2-3 mic's for 12 bucks. Toom them apart and cleaned and oiled them, then throw them on a test block and calibrate them
It's a gamble for sure. So I do my level best to make it cheap enough to resale if there is an issue. Hell the 40 bucks I paid for the lot with the mics had more then 40 bucks in end mills and clamps and odds n ends
It's a gamble for sure. So I do my level best to make it cheap enough to resale if there is an issue. Hell the 40 bucks I paid for the lot with the mics had more then 40 bucks in end mills and clamps and odds n ends
Buy a used ebay and check it against some jo blocks. If you buy decent names and take agood look at the pics you can do well. by preference
Interapid. best in class. sturdy, accurate
Brown and sharp bestest/tesatest, I have a few large dials that I like
compac, girodtast and mercer. these are nice but arent as sturdy as an interapid.
one thing i did was get a metric interapid for 40 on ebay. since I use it for dialing in vises, chucks etc parallel I don't really care what it reads. when the dial isnt moving I'm gtg.
Most other brands even some starretts are made in china. the one Chinese dti I bought was junk within 3 weeks. paid 50 or so for it (thanks edco tooling in columbus for gouging me on that one), lesson learned there.
Get something swiss, you will be well ahead.
Interapid. best in class. sturdy, accurate
Brown and sharp bestest/tesatest, I have a few large dials that I like
compac, girodtast and mercer. these are nice but arent as sturdy as an interapid.
one thing i did was get a metric interapid for 40 on ebay. since I use it for dialing in vises, chucks etc parallel I don't really care what it reads. when the dial isnt moving I'm gtg.
Most other brands even some starretts are made in china. the one Chinese dti I bought was junk within 3 weeks. paid 50 or so for it (thanks edco tooling in columbus for gouging me on that one), lesson learned there.
Get something swiss, you will be well ahead.
- Joined
- Nov 24, 2013
- Messages
- 1,791
Dude a metric intrepid for tramming is genius. Intrepids dont come cheap even when there cheap. But in the US mm dont hold their value. I think I will try to find one. I agree, intrepid is top of the line. They just cost a good bit new so they aint as easy to find cheap deals on.
I calibrate equipment for my day job, & I have seen some 30 year old name brand dial indicators that still work great. The ones I've had the most good readings from are Mitutoyo, Starrett, Brown & Sharpe. Most times when they don't move freely it's because they are dirty or the shaft is bent. If it's just dirt you can clean them.
The import ones from china, & India don't seem to last very long. I don't think the materials they are made from are the same, they wear out faster & the movement gets sloppy. The the harbor freight one I had was fine when it was new, but 6 months later with infrequent use, it was off by a whole division when changing directions (Backlash). The e-bay brown & sharpe one I purchased was fine even though the lens wasn't very clear anymore.
I say if you can't afford a brand new indicator look at buying a used name brand indicator over a cheap made in China no name one. If you get a dud try again.
For the best accuracy, & repeatability you have to look at the needle dead on straight at the center of the dial each time. Looking at the indicator from above or the side will give you a different indication, this is called parallax error. The same reason your wife thinks your speeding when she looks over at the speedometer from the passenger seat, & says your going 80 when it only says 70 to you.
You can check your own dial indicator with a good solid stand & mount a surface plate & some gage blocks. Make sure everything is clean & mount the dial indicator to your stand. Make sure that the indicator movement is perpendicular to the surface plate. Move the indicator down until the plunger touches the surface plate & the needle moves at least a few divisions to preload it. Set your zero, then pull up the plunger & set it back down on the surface plate a few times. It should return to zero each time. This tests your repeatability. If it didn't return to zero each time check the rigidity of your setup & try again. Make sure that the plunger doesn't 'hang up' or stick if you clamp on to the outer shaft. It's best to mount it from the back if that is an option. Once you have a repeatable zero indication you can continue. Select a gage block or stack that will put the indication at 3 o clock on the dial. Slide the gage block under the tip (every thing is clean& you should use a round tipto prevent damage. Lift the plunger only enough to clear the gage block(s). It should indicate correctly. Check it again at 6, 9, 12 o clock positions. This checks the dial linearity, some times the indicator will read a little off at some points in it's rotation. Then if the dial goes around more than once check it at at least 25%, 50%, 75%, & near full scale. This checks the linearity of the full travel as the needle goes around & round. Then remove the stack & go back down & check it again at least one other point that you already checked. This time pull the plunger the whole way up & (slowly) lower it. The indicator should give you the same reading you had before when you only lifted the plunger just enough to clear the gage block. This checks the backlash.
Alternatively you could check the indicator against a micrometer if you have one large enough to fit & a way to mount everything in perfectly inline. This method would also work for last word type test indicators set the micrometer to zero & plunger on it & zero the indicator. Rotate the micrometer up & compare the indication to your dial indicator as above at a few points. Move it up & back down & check it again at the same micrometer indication, the needle should return to the same position. If not your dial indicator probably has some backlash. It could be your setup isn't correct (loose, out of square with each other, dirty, etc... but micrometers are usually pretty linear (even the cheaper ones).
Either way you will see the error in your dial indicator, provided your setup was correct. Clean, perpendicular to the measurement surface, & parallel to the micrometer spindle, & mounted securely. If you see that your indicator has excessive backlash then you can still use it in the same direction of travel to minimize the backlash from affecting your readings or if it's not linear you can still use it for minimal deflection checks. If you take care of that tool it could still be useful even if it isn't "accurate".
When I calibrate dial indicators at work I use an Optimar 100 made by Mahr. It is amazing, & shows a zig zag indication on a computer screen so you can see the variation at each test point. I've learned though experience that even the best most accurate dial indicators will still vary a bit at each test point (usually less than half the resolution), but it's more often the fault of the operator reading the indication than it is the equipment.
Maybe one day if there is interest & I have time & motivation, I will post a series of how to calibrate your own micrometer, caliper, dial indicator, level, etc. etc. etc.
How ever like someone else pointed put the resolution is not the accuracy. A lot of times the accuracy if it's even publicly available is worse than the resolution. On top of that the accuracy goes down after the first two & a half revolutions of the dial. Not 2½ from the beginning of the travel, but 2½ from where you set your reference. I believe that this is an international or DIN standard. Also best practice is don't try to take a good measurement in the first 1/4 revolution or last 1/4 revolution of the needle. Sometimes at the ends of travel the indicator results are a little wonky. It's way less, only a couple of divisions with the last test type dial test indicators that only have 1 revolution to begin with.
Lastly as someone else pointed out a metric indicator used for minimal deflection of the needle is a good idea. I have NEVER in 10 years calibrated a metric indicator that did not meet factory specs. They just don't get used much compared to the the inch standard ones, at least here in the states.
The import ones from china, & India don't seem to last very long. I don't think the materials they are made from are the same, they wear out faster & the movement gets sloppy. The the harbor freight one I had was fine when it was new, but 6 months later with infrequent use, it was off by a whole division when changing directions (Backlash). The e-bay brown & sharpe one I purchased was fine even though the lens wasn't very clear anymore.
I say if you can't afford a brand new indicator look at buying a used name brand indicator over a cheap made in China no name one. If you get a dud try again.
For the best accuracy, & repeatability you have to look at the needle dead on straight at the center of the dial each time. Looking at the indicator from above or the side will give you a different indication, this is called parallax error. The same reason your wife thinks your speeding when she looks over at the speedometer from the passenger seat, & says your going 80 when it only says 70 to you.
You can check your own dial indicator with a good solid stand & mount a surface plate & some gage blocks. Make sure everything is clean & mount the dial indicator to your stand. Make sure that the indicator movement is perpendicular to the surface plate. Move the indicator down until the plunger touches the surface plate & the needle moves at least a few divisions to preload it. Set your zero, then pull up the plunger & set it back down on the surface plate a few times. It should return to zero each time. This tests your repeatability. If it didn't return to zero each time check the rigidity of your setup & try again. Make sure that the plunger doesn't 'hang up' or stick if you clamp on to the outer shaft. It's best to mount it from the back if that is an option. Once you have a repeatable zero indication you can continue. Select a gage block or stack that will put the indication at 3 o clock on the dial. Slide the gage block under the tip (every thing is clean& you should use a round tipto prevent damage. Lift the plunger only enough to clear the gage block(s). It should indicate correctly. Check it again at 6, 9, 12 o clock positions. This checks the dial linearity, some times the indicator will read a little off at some points in it's rotation. Then if the dial goes around more than once check it at at least 25%, 50%, 75%, & near full scale. This checks the linearity of the full travel as the needle goes around & round. Then remove the stack & go back down & check it again at least one other point that you already checked. This time pull the plunger the whole way up & (slowly) lower it. The indicator should give you the same reading you had before when you only lifted the plunger just enough to clear the gage block. This checks the backlash.
Alternatively you could check the indicator against a micrometer if you have one large enough to fit & a way to mount everything in perfectly inline. This method would also work for last word type test indicators set the micrometer to zero & plunger on it & zero the indicator. Rotate the micrometer up & compare the indication to your dial indicator as above at a few points. Move it up & back down & check it again at the same micrometer indication, the needle should return to the same position. If not your dial indicator probably has some backlash. It could be your setup isn't correct (loose, out of square with each other, dirty, etc... but micrometers are usually pretty linear (even the cheaper ones).
Either way you will see the error in your dial indicator, provided your setup was correct. Clean, perpendicular to the measurement surface, & parallel to the micrometer spindle, & mounted securely. If you see that your indicator has excessive backlash then you can still use it in the same direction of travel to minimize the backlash from affecting your readings or if it's not linear you can still use it for minimal deflection checks. If you take care of that tool it could still be useful even if it isn't "accurate".
When I calibrate dial indicators at work I use an Optimar 100 made by Mahr. It is amazing, & shows a zig zag indication on a computer screen so you can see the variation at each test point. I've learned though experience that even the best most accurate dial indicators will still vary a bit at each test point (usually less than half the resolution), but it's more often the fault of the operator reading the indication than it is the equipment.
Maybe one day if there is interest & I have time & motivation, I will post a series of how to calibrate your own micrometer, caliper, dial indicator, level, etc. etc. etc.
How ever like someone else pointed put the resolution is not the accuracy. A lot of times the accuracy if it's even publicly available is worse than the resolution. On top of that the accuracy goes down after the first two & a half revolutions of the dial. Not 2½ from the beginning of the travel, but 2½ from where you set your reference. I believe that this is an international or DIN standard. Also best practice is don't try to take a good measurement in the first 1/4 revolution or last 1/4 revolution of the needle. Sometimes at the ends of travel the indicator results are a little wonky. It's way less, only a couple of divisions with the last test type dial test indicators that only have 1 revolution to begin with.
Lastly as someone else pointed out a metric indicator used for minimal deflection of the needle is a good idea. I have NEVER in 10 years calibrated a metric indicator that did not meet factory specs. They just don't get used much compared to the the inch standard ones, at least here in the states.
- Joined
- Apr 12, 2012
- Messages
- 579
I have a slightly different outlook on dial indicators. I have several good ones in different styles B&S, Starrett, a couple interapids, etc. and also several different styles of imports. Most of my work with a DI is comparative and not empirical, also most of my work just doesn't require readings in tenths. I use the imports a lot as I'd rather drop one of them or have them played with by a visitor.
What I'm saying is if I'm doing a repair job and it needs to be dead on I'll pull the best one for the job out of the cabinet and fix it to the most suitable mount and do the job. Then take it apart and store it back in the cabinet.
My imports are pretty much stuck to a cabinet and ready to be used for new work or just general dialing in. I know my 3 jaw runs out about .003. So if I'm curious about a shaft runout and the 3 jaw is in place I'll toss a magback import onto the tool post and have a look. If it comes out about .003" even as it is rotated 180° in the jaws then the problem is likely elsewhere and if need be I can regroup to collet or centers and a good indicator.
I drop things! I knock things off shelves, I don't wear my Sunday best in the shop. I'm just saying if a 15$ import meets your needs and budget, go for it. No matter what you buy 1st it probably won't be the last you buy.
Steve
What I'm saying is if I'm doing a repair job and it needs to be dead on I'll pull the best one for the job out of the cabinet and fix it to the most suitable mount and do the job. Then take it apart and store it back in the cabinet.
My imports are pretty much stuck to a cabinet and ready to be used for new work or just general dialing in. I know my 3 jaw runs out about .003. So if I'm curious about a shaft runout and the 3 jaw is in place I'll toss a magback import onto the tool post and have a look. If it comes out about .003" even as it is rotated 180° in the jaws then the problem is likely elsewhere and if need be I can regroup to collet or centers and a good indicator.
I drop things! I knock things off shelves, I don't wear my Sunday best in the shop. I'm just saying if a 15$ import meets your needs and budget, go for it. No matter what you buy 1st it probably won't be the last you buy.
Steve
Ok where can I get ahold of a S&W DTI ? Got to have one NOW
I got mine through Grizzly. It was on the same page as and within $1 of the same tool marked Grizzly instead.
- Joined
- Nov 21, 2012
- Messages
- 793
Strange that there is not a single recommendation for Mitutoyo.
I have a friend who works in the metrology department of Kongsberg Automotive, where they have measuring equipment worth millions and a granite surface plate you could park a car on and he said of all the indicators you can buy, Mitutoyo was the most consistent. His department has it's own certified repairer for the various calipers, micrometers and indicators (both electronic and mechanical) and this guy seconded my friends comments.
For the price of a new Mitutoyo dial test indicator, I would not purchase a no-name or Far East import. I have 2 and have never had a problem.
Paul.
I have a friend who works in the metrology department of Kongsberg Automotive, where they have measuring equipment worth millions and a granite surface plate you could park a car on and he said of all the indicators you can buy, Mitutoyo was the most consistent. His department has it's own certified repairer for the various calipers, micrometers and indicators (both electronic and mechanical) and this guy seconded my friends comments.
For the price of a new Mitutoyo dial test indicator, I would not purchase a no-name or Far East import. I have 2 and have never had a problem.
Paul.