Learn me about dial indicators.

[Numerator2142]

I need to pick up a dial indicator, but there's enough options that I don't have a good feel for what's practical. I'm a DIY'er, so I probably don't need 0.0001" accuracy and have no idea on range.

Initial use case is brake disk run out. Next up is table saw setup, the rest of it's life is probably checking stuff on motorcycles.

Is 0.5" a practical range? inch or metric? What other specs should I care about?

Thanks.

 

[signcrafter]

This is what I have for rotor runout

Amazon.com

 

[CB350F]

I am sure you are going to get a lot of good information here...they are not that complicated...take care...CB

 

[278horn]

Mag base and indicator

 

[gahrajmahal]

I just have a cheapie from Harbor freight. It came with a mag base which works great. When you get yours home check it using a set of feeler gauges. Clamp it to your drill press table or table saw table or anything that is machined flat. Zero it out, then slide a few feeler gauges under the pin and see that it reads accurately.

 

[alfadan]

The HF is probably good enough for what you'll be using it for. They are used primarily for comparative readings, rather than truly accurate measurements.

 

[alfadan]

I should note, I've had a couple. One I dropped and it started sticking so I tossed it, 25 bucks down the drain lol.
Second one is surprisingly accurate, though they have need higher pressure to move (probe pressure?) but that really doesn't matter for most things.

 

[RoninB4]

-I've used dial indicators on the job for several decades (toolmaker) every single day and often multiple times during the day. I also use them at home for the same purposes the OP mentioned. Alfadan is correct stating that indicators are used more for a comparative reading than an absolute numerical value. They can be used for a true linear measurement but that's another discussion, Indicators can fall into two general groups:
1) Plunger type- used mostly for setting machinery and general automotive work. Can be less expensive for use in garage
2) Lever contact- favored by machinists for machine shop and inspection. Often several hundred dollars for a good one

You'll want the plunger type as it's less expensive and easier to set up. No need for a .0001 resolution, you would find it difficult to use and way more expensive than your needs call for. A relatively inexpensive .001 resolution, having .100 travel in a plunger type will serve you well for your purposes. Avoid purchasing used as they can often be damaged and/or unreliable. Also avoid the Starrett "Last Word" model as the mechanism often becomes sticky and unreliable.

What the indicator is mounted to is important in that it must be rigid so there's no play/movement. I have the flexible arm type that's great for adapting to different things but it is also less rigid and susceptible to vibration. I use one of several different types besides the flexible arm most of the time. Also, the distance from the base to the indicator should be kept as short as possible. A longer arm is more influenced by how rigid it is, vibration through a longer arm will show the indicator needle in small, but constant motion/"buzzing" with the vibration. Even a truck passing your house can do this.

-Set the indicator so the plunger is perpendicular in two directions (left/right and up/down) to what you're checking or you'll experience cosine error in your readings. Cosine error will be a percentage of the indicated reading, the more you move the greater the error. You will not obtain an accurate reading if movement is greater than .030 but it should still be accurate enough if you've set the indicator fairly perpendicular, Keep the indicator in whatever box it comes in don't store it in an unheated garage or rust will likely ruin it in a year or two.

-Ask more questions if you wish, I tried to keep this reply short.

 

[Rusted Nut]

I have a Fowler Precision dial,indicator, along with some other stuff from Fowler. I find them to be a very value.

 

[Numerator2142]

...
You'll want the plunger type as it's less expensive and easier to set up. No need for a .0001 resolution, you would find it difficult to use and way more expensive than your needs call for. A relatively inexpensive .001 resolution, having .100 travel in a plunger type will serve you well for your purposes. Avoid purchasing used as they can often be damaged and/or unreliable. Also avoid the Starrett "Last Word" model as the mechanism often becomes sticky and unreliable.

What the indicator is mounted to is important in that it must be rigid so there's no play/movement. I have the flexible arm type that's great for adapting to different things but it is also less rigid and susceptible to vibration. I use one of several different types besides the flexible arm most of the time. Also, the distance from the base to the indicator should be kept as short as possible. A longer arm is more influenced by how rigid it is, vibration through a longer arm will show the indicator needle in small, but constant motion/"buzzing" with the vibration. Even a truck passing your house can do this

0.1" is a good travel range for stuff like runout and parallel? I think that makes sense. I imagine a rule would be sufficient to show things are messed up for more than that.

If you had to get 1 mount would you lean towards the flex ones like 278horn and signcrafter linked or the rigid bars with locking hinges type?

Thanks All. This is helpful.

 

[AEAdam]

0.1" is a good travel range for stuff like runout and parallel? I think that makes sense. I imagine a rule would be sufficient to show things are messed up for more than that.

If you had to get 1 mount would you lean towards the flex ones like 278horn and signcrafter linked or the rigid bars with locking hinges type?

Thanks All. This is helpful.

Re: .1" travel I don't think so.

I think the terms you need to know are "Dial Test Indicator" vs "Dial indicator" (or whatever @RoninB4 calls them). Machinists use crazy terminology that only they can understand (hope that makes Ronin laugh). "Test indicators" have levers and, while they can take absolute measurements, we almost never use them for that. Dial indicators have gobs more travel and can take very accurate measurements if the plunger is perpendicular to the measured surface. Well here are some pics:

This is a Dial Test Indicator. Notice the little lever. This guy reads 0-.030" but is marked +/- .015 because readings can be taken in either direction. This is an important first lesson. In use, you "preload" the indicator. You don't start in its natural zero. So you need more travel in the indicator, than the range you want to measure.

This specific example came from LittleMachineShop.com. It's a good quality tool. The problem with these Chinese indicators is that they use non-standard dovetails and provide all the studs you don't need. The black one, is the 8mm 5/16" stud all my holders want, filed to fit this stupid indicator (which I subsequently sold).

In general, machinists use these to align things, align our vises to our mills, check runout on lathes etc.

The other kind, I think the kind you are interested in, is the standard plunger type dial indicators. They generally look like this:


This guy (doesn't belong to me) looks like a 1" travel indicator that reads in .001" increments. These longer travel instruments can be easier to setup on something like a table saw that's pretty far out when you start. The re-zeroing can be fiddly (more about that later).

My sense is, the tool itself is less important than the holder for the tool. And the plural on "holder" is intentional. On a table saw, you might want to start with a surface gauge as a holder like this one:


Adapting the indicator to this holder, which is not technically designed to hold indicators, will require specialty hardware, starting with something called a "snug".

You can see a variety of holding fixtures in this picture. Top left is a "lug back" that attach to standard sized indicators. Different size studs attach to the lug (must be sized accordingly) then provide an attachment stud for the "snugs" below them which basically clamp the indicator to a shaft (mast) of a surface gage or whatever.

You would use this set up to indicate one surface relative to another and be able to slide the gage along the reference surface as you see me doing below:

 

[RoninB4]

0.1" is a good travel range for stuff like runout and parallel?

-That .100 travel isn't a so;id requirement to go shopping for either. It was just a number I picked to explain that this is more than adequate, there are many that have far more travel than .100 and cost more. You won't be needing/using that capability so no point paying extra for what you won't even be using.

I think that makes sense. I imagine a rule would be sufficient to show things are messed up for more than that.

-Runout for brake rotors is probably .012 or so, the OEM specs should be consulted for trusted numbers. For other things like wheel rims, shaft end float, return-to-position, etc. then attempting to measure travel distances in excess of .100 would call for different measuring instruments anyway. Should you find a good deal on an indicator don't let the .100 travel stop you.

If you had to get 1 mount would you lean towards the flex ones like 278horn and signcrafter linked or the rigid bars with locking hinges type?

-One of the first indicator holders I got in 1979 was the flexible type. It worked well for me because it was a new design and made well. It did show itself to be susceptible to vibration and the arm length got in my way a few times. The type with rigid bars that's a bog standard (and inexpensive) in most shops would be my suggestion just because it would be more solid/rigid. Make sure it has a good magnet to stick the base.

Thanks All. This is helpful.

-Sure, glad to be of some help

 

[AEAdam]

Many indicators also have integral dovetail mounts. Think of them as the "Picatinny rail" of the machine shop. These dovetails provide super rigid attachment of accessories, the venerable "Noga Arms", chief among them.


Noga arms come is various sizes and configurations. You can't really see the dovetail mount on the 2 on the right (see below), but you can on the spindle arm on the left (sorry about the glare). (This test indicator is a low priced Swiss model (Fowler/Giordtast) I bought second hand.


EDIT: This is the NOGA mount I use that's pretty common. You can see the dovetail at the end. The 3 holes are 6mm, 8mm, and 3/8". IIRC, 1/4" studs don't fit the 6mm. I may have had that backwards earlier. I think Chinese indicators can ship with 4mm, 1/4" and 10mm, which are all the wrong sizes (that part I remember). Just know this CAN be an issue to save yourself the frustration I had.

I mentioned several things in the post above you need to pay particular attention to:
Studs that come with indicators - Chinese test indicators often ship with 4mm and 10mm studs. 10mm is too big for 3/8" 4mm is too small for everything. 6mm can sometimes be Chinese code for 1/4". Technically, I find 6mm doesn't fit stuff that wants 1/4". The universal attachment in machine shops is generally 5/16" which is 8mm.

The dovetails on Chinese stuff are typically 11mm. This is frustrating for so many reasons. The Swiss dovetails are all smaller. Chinese manufacturers make dovetail mounts that are compatible with the Swiss indicators, but not their own indicators (cause China be like that).

The backs of Dial indicators are sized and have hole patterns that are governed by ANSI or ISO standards. Most I encounter are "Series 2", but not all the Chinese indicators are. A series 2 back may fit, but may not seal, which is important.

LAST: I said the indicators themselves aren't as important as the base we use to hold them. That is 100% true. But the key is, you need an indicator that fits on the bases you have, can buy, can find on eBay, garage sales etc. Buying a cheap indicator from SHARS or Harbor Freight may be an attractive option, but I can pretty much guarantee you will encounter snags later. Said differently, before purchasing, verify that tool will fit a Noga Arm for example. Otherwise pass.

There is a reason why I have so many digital indicators:

1. They are all multi $100 indicators, I found on eBay for around $50. All are functioning fine. The digital test indicators were a little more but well under $100. You just have to be patient on eBay and know what to look for.
2. They are super convenient to zero, which makes them very easy and fun to use. The test indicators have a delay function, where you hit zero then let go and the tool zeros after a couple seconds. Very cool feature.
3. All mechanical indicators ranges and resolutions are linked. If you want an indicator that reads in the .000X", you probably won't get a high range. The digitals don't have that. These are all super fine resolution with decent ranges. The test indicators are .060" IIRC.

Depending on your needs, I would seriously look at a digital indicator. HF sells them. The question I would ask is, how much cheaper than $50 are they and is that worth it to you?
This is another tool I bought and sold and can offer my lessons learned. Questions I would ask about this today are:

1. +/-.001" accuracy? I can do as well with a digital caliper.
2. It comes with a lug back- that's good. Hope the hole is really 1/4" and not 6mm
3. Stem diameter says 3/8". I can live with that. But if its really 10mm, that may not work.
4. IIRC, this was not that inexpensive. It may have been $44.95. Compare with eBay for Mitutoyo, which are older $200-300 indicators for $50-60. (in the old days of eBay, I use to search for "Mitutoya" and other misspellings and find even better deals!

 

[RoninB4]

-With all due respect to AEAdam I disagree with his suggestion of a digital indicator for garage use. I've never had much faith in budget priced electronics from China. Are the Chinese capable of producing good electronic equipment? Certainly, but not in lower priced items. To be fair I don't and probably will not own any digital measuring instruments (except the DRO on my jig borer) in the future. I find digital instruments to be more bulky, less applicable, and have batteries that tend to go dead while in the toolbox. For the clean environment of inspection digitals often have an SPC port for outfeed of data. For the often filthy world of the garage I question whether this is a good idea. A rinse off with lighter fluid is good for mechanical movements, not so with electronics. I often advocate purchasing well made tools, sporadic/occasional use isn't one of those times. There's many indicator/base packages available for under $50 or so. There are also many fake Mitutoyo instruments out there for much more money. JMO

 

[L.Cheapo]

As a DIYr myself, I use Starrett (USA) for analog and Mitutoyo (Japan) for digital. Overkill, but I like nice tools.

For run of the mill automotive stuff, anything decent should work just fine. I'd get a 1" travel .001" resolution dial indicator, as that's what I use for measuring rotors/ball joints/track bars/gear setup, etc.

 

[Steve_P]

No idea what HF is selling now, but the dial indicator I bought from them decades ago was junk and not repeatable.

I have a Mitutoyo and Peacock. 4? dials and one digital.

 

[RTM]

-I've used dial indicators on the job for several decades (toolmaker) every single day and often multiple times during the day. I also use them at home for the same purposes the OP mentioned. Alfadan is correct stating that indicators are used more for a comparative reading than an absolute numerical value. They can be used for a true linear measurement but that's another discussion, Indicators can fall into two general groups:
1) Plunger type- used mostly for setting machinery and general automotive work. Can be less expensive for use in garage
....

You'll want the plunger type as it's less expensive and easier to set up. No need for a .0001 resolution, you would find it difficult to use and way more expensive than your needs call for. A relatively inexpensive .001 resolution, having .100 travel in a plunger type will serve you well for your purposes.

One thing my tiny brain wants to add to this is the use of a mushroom end tip on the plunger. Makes checking the saw blade much easier, wont fall into the gullets as easily.

I disagree with his suggestion of a digital indicator for garage use.

I do also, especially for the saw blade use. I want to watch the needle "not move much" for most of its trip around the sawblade, then jump when it gets to the bad tooth or teeth. This goes back to the relative (comparative) reading from above. Your don't really care what the dial says, you just want to watch it change.

 

[alfadan]

No idea what HF is selling now, but the dial indicator I bought from them decades ago was junk and not repeatable.

I have a Mitutoyo and Peacock. 4? dials and one digital.

I have one bought probably 4 years ago. I use it for "rough, dirty" work. Works fine and is surprisingly accurate.

Just for the sake of conversation, when checking accuracy with a -dial indicator-, one needs to have it perpendicular to the surface in all directions, or you get cosine errors and it wont read what you expect.

None of this really means **** to the op though!

 

[RoninB4]

One thing my tiny brain wants to add to this is the use of a mushroom end tip on the plunger. Makes checking the saw blade much easier, wont fall into the gullets as easily.

-Never used one but if it has a rather large radius on the end, instead of it being flat, then I can see an advantage to using it setting up a saw blade.

I want to watch the needle "not move much" for most of its trip around the sawblade, then jump when it gets to the bad tooth or teeth. This goes back to the relative (comparative) reading from above. Your don't really care what the dial says, you just want to watch it change.

-That, to me, is a principle difference between analog and digital. I prefer analog for a gauge, car speedometer, VOM, dial caliper, or indicator. I gather data by observing the "sweep" for the rate of change, profile, and location/clocking in analog that's not the same in digital.

 

[no704]

-I've used dial indicators on the job for several decades (toolmaker) every single day and often multiple times during the day. I also use them at home for the same purposes the OP mentioned. Alfadan is correct stating that indicators are used more for a comparative reading than an absolute numerical value. They can be used for a true linear measurement but that's another discussion, Indicators can fall into two general groups:
1) Plunger type- used mostly for setting machinery and general automotive work. Can be less expensive for use in garage
2) Lever contact- favored by machinists for machine shop and inspection. Often several hundred dollars for a good one

You'll want the plunger type as it's less expensive and easier to set up. No need for a .0001 resolution, you would find it difficult to use and way more expensive than your needs call for. A relatively inexpensive .001 resolution, having .100 travel in a plunger type will serve you well for your purposes. Avoid purchasing used as they can often be damaged and/or unreliable. Also avoid the Starrett "Last Word" model as the mechanism often becomes sticky and unreliable.

What the indicator is mounted to is important in that it must be rigid so there's no play/movement. I have the flexible arm type that's great for adapting to different things but it is also less rigid and susceptible to vibration. I use one of several different types besides the flexible arm most of the time. Also, the distance from the base to the indicator should be kept as short as possible. A longer arm is more influenced by how rigid it is, vibration through a longer arm will show the indicator needle in small, but constant motion/"buzzing" with the vibration. Even a truck passing your house can do this.

-Set the indicator so the plunger is perpendicular in two directions (left/right and up/down) to what you're checking or you'll experience cosine error in your readings. Cosine error will be a percentage of the indicated reading, the more you move the greater the error. You will not obtain an accurate reading if movement is greater than .030 but it should still be accurate enough if you've set the indicator fairly perpendicular, Keep the indicator in whatever box it comes in don't store it in an unheated garage or rust will likely ruin it in a year or two.

-Ask more questions if you wish, I tried to keep this reply short.

I’ve got a Last Word that I got used probably 15 years ago that I use regularly.

 

[RoninB4]

I’ve got a Last Word that I got used probably 15 years ago that I use regularly.

-I'm very happy for you. That still doesn't refute what repair techs and many people in the precision metal working trades have stated of theirs, Had yours cleaned and evaluated in the last 15 years?

 

[AEAdam]

Lots of machinists refer to Long Island Indicator's advice on indicators and indicator accessories. Their (pretty clear) slant is toward Swiss made stuff, as it's long lasting and repairable. But if you look at the fine print on their reviews, the China made stuff performs okay. I never recommended Chinese digitals. 100% of my digital stuff is either Japanese (Mitutoyo) or Swiss, (Starrett, Tesa etc).

My only point was, just keep the holders in mind when you buy.

One more thing: I guess I have a lot of machinists tools, having a hobby machine shop. I've collected precision tools over years and years. Some of it is really special, was made VERY carefully. I really love machinists tools and they are probably the only tools I actually collect and polish (say what you will). But the thing about them is, they typically don't hold their value.

I have Starrett #20 squares in pristine condition that would cost $600+ new, that I bought on eBay for $40. You can find AMAZING deals on old machinists tools on eBay. I guess pros want brand new with calibration records or NIST traceability. I don't need that and can buy really nice stuff for pennies. The Mitutoyo digitals are just as cheap now as they were when I bought mine (I checked). Mitutoyo make really nice tools and especially nice digital stuff.

Some things don't seem to be readily available second hand like Noga arms. Good luck scoring one of those for cheap. The snugs and studs and backs I buy from Starrett on eBay for a couple bucks.

 

[RTM]

Never used one but if it has a rather large radius on the end, instead of it being flat, then I can see an advantage to using it setting up a saw blade.

Argh, I just realized I crossed up two saw /dial indicator thread. I was thinking this was the one about a crappy cheap saw blade, where I wanted to measure the side to side error on the teeth tips.

I compared two budget table saw blades

Typically I keep a 40T blade on the table saw for general purpose cutting. For some time now it's been a Freud Fusion blade. It's served me well, but on the latest project I found it was burning its way through the cuts; might be time to replace it. I cut a lot of jatoba, which is hard on...

www.garagejournal.com

 

[paulsomlo]

-With all due respect to AEAdam I disagree with his suggestion of a digital indicator for garage use. I've never had much faith in budget priced electronics from China. Are the Chinese capable of producing good electronic equipment? Certainly, but not in lower priced items. To be fair I don't and probably will not own any digital measuring instruments (except the DRO on my jig borer) in the future. I find digital instruments to be more bulky, less applicable, and have batteries that tend to go dead while in the toolbox. For the clean environment of inspection digitals often have an SPC port for outfeed of data. For the often filthy world of the garage I question whether this is a good idea. A rinse off with lighter fluid is good for mechanical movements, not so with electronics. I often advocate purchasing well made tools, sporadic/occasional use isn't one of those times. There's many indicator/base packages available for under $50 or so. There are also many fake Mitutoyo instruments out there for much more money. JMO

Agreed - I have one digital plunge indicator that came with my lathe, and I find it to be a pain in the ***. Being able to watch an analog dial move is much more useful to me, than watching numbers flash by. And the batteries are always dead when I need it.

Regarding a mag base - without one, the indicator is useless and the "wrong" one can be really frustrating. I have a Noga copy that I really like, even more so than the flexible one with segmented arm: https://www.shars.com/aventor-magnetic-base-with-articulating-arm

 

[GeoBruin]

The Noga mag base is truly one of the most amazing things ever. I smile every time I use it. Somehow it goes from the most flexible, articulating thing ever to rock solid with the twist of a knob. Like magic.

 

[hobie18]

Deleted
Wrong thread
Oops

 

[RoninB4]

Lots of machinists refer to Long Island Indicator's advice on indicators and indicator accessories. Their (pretty clear) slant is toward Swiss made stuff, as it's long lasting and repairable. But if you look at the fine print on their reviews, the China made stuff performs okay. I never recommended Chinese digitals. 100% of my digital stuff is either Japanese (Mitutoyo) or Swiss, (Starrett, Tesa etc).

-I didn't think you were recommending Chinese any more than I was. Apologies if I've misinterpreted or implied that you were. Long Island was one of the repair facilities I was referencing and based all my purchases on the aspect of repair and the long haul of my career. The Chinese stuff probably is capable of adequate performance, I just question how long it will render their stated capability because it was made as cheap as possible. For someone that uses the instruments every day to earn a living this should be a big concern. For someone that uses it now and then in the garage then COO shouldn't be a concern.

-While I'm at it I should mention that COO isn't the last word on performance either. I've probably got 12-18 indicators from various makers, a few from China I suspect. I've also got a few from Federal, which used to be considered a "standard" for tooling and fixtures. I wouldn't buy a Federal based upon a review from Long Island stating the potential unreliability of soldered components and wear items needing replacement IIRC. I have a somewhat rare Lufkin vertical model with the extra long contact point (jig borer model) that I retired decades ago due to lack of replacement parts. There's also other brands that I would have loved to own (Compac, Alina) but they haven't been made in decades and replacement parts are likely long gone. To me, this essentially makes some very good indicators a disposable item if it can't be repaired. If it's disposable then you might as well get one that you expect to be a disposable when it goes bad. Sounds like I am advocating a cheap Chinese indicator doesn't it?

My only point was, just keep the holders in mind when you buy.

-I think this is a very valid and important point. Early in my career I wrestled with the same problem. The Federal dovetail wasn't the same as the Brown & Sharpe. Gem used a collar grip that nobody else did. Wow I got a new indicator.....well **** nothing I have will hold it. About then I limited my indicator purchases to Interapid for the pivoting stem mount because I could always make something to attach a round stem easier than cutting a tiny dovetail clamp. You're right, the indicator has to have a solid mount or it's just a delicate watch movement that won't even tell time.

One more thing: I guess I have a lot of machinists tools, having a hobby machine shop. I've collected precision tools over years and years. Some of it is really special, was made VERY carefully. I really love machinists tools and they are probably the only tools I actually collect and polish (say what you will).

-Ok I will say something: You've taken care of your instruments/tooling over the years, perhaps more so than I have, and are to be complimented for doing so. You have an appreciation for what they are, how they're used, and I applaud your efforts.

But the thing about them is, they typically don't hold their value.

-No they don't hold value, neither do the machines. A nice Moore jig borer can go for little more than scrap value. I bought a nice Mitsui jig borer (I'm the second owner) that cost over 300k for $1500 with a full compliment of tooling.

I have Starrett #20 squares in pristine condition that would cost $600+ new, that I bought on eBay for $40. You can find AMAZING deals on old machinists tools on eBay.

-Quite correct, I've purchased several expensive things on Evil-Bay for a fraction of what it was new. You have to know what you're looking at and what could be wrong with it. There's also a lot of fake brand name items (Mitutoyo is one of them) being passed off as the genuine article. There are some fantastic deals out there but "let the buyer beware".

I guess pros want brand new with calibration records or NIST traceability.

-That's part of it, wear on a used item that's expected to last an entire career is another concern. Same as a used car with a potentially tampered odometer.

I don't need that and can buy really nice stuff for pennies. The Mitutoyo digitals are just as cheap now as they were when I bought mine (I checked). Mitutoyo make really nice tools and especially nice digital stuff.

-They most certainly do make nice stuff. I'm not brand loyal but prefer some of their micrometers, analog dial calipers, and their graduated Height Master. Plenty of other professionals prefer the Mitutoyo digital calipers for durability in a digital instrument.

Some things don't seem to be readily available second hand like Noga arms. Good luck scoring one of those for cheap.

-Much like a good car, the owners don't want to sell.

The snugs and studs and backs I buy from Starrett on eBay for a couple bucks.

-Good advice.

 

[bwringer]

The OP was quite clear that he is doing mechanical stuff with this, not aerospace level precision machining in a temperature controlled .001 micron clean room.

It's going to get dirty, dropped, knocked, dunked, spewed on, stepped on, and scraaaaaaped and scratched across filthy rutted brake rotors, rusty wheel hubs, greasy sprockets, oily camshafts, wheels covered in bug guts, saw blades covered in resin and sawdust, etc.

Get a cheapo analog indicator with a magnetic base and get on with life. When (not if) it gets dropped and stepped on, toss it and buy another without shedding tears over your jewel encrusted $200 Mitutoyo.

 

[SwissMetric]

I'd get a shockproof mechanical Mitutoyo or Tesa.

Pay attention to the range (depends on the lever length) and display increment. A 0.01 mm dial tick increment is common, there's also 0.002 mm but the range will be reduced. I wouldn't recommend coarser than 0.01 mm if the corresponding range is large enough as coarse increments will make the instrument less universal (e.g. to check basic spindles while precision spindles may be measured below 0.001 mm).

The used base must allow a fine adjustment (with a screw) and must be rigid enough or the readings will be meaningless. There are also dovetail adapters, and check the diameter of the adapter mount.

Those instruments are surprisingly robust but must still be handled with care.

 

[The Bean]

I guess Kurtis at CEE Australia is doing a bit more exacting work, but I'm fascinated every time he gets one out on the lathe. Good hunting.

 

[RoninB4]

A 0.01 mm dial tick increment is common, there's also 0.002 mm but the range will be reduced. I wouldn't recommend coarser than 0.01 mm if the corresponding range is large enough as coarse increments will make the instrument less universal (e.g. to check basic spindles while precision spindles may be measured below 0.001 mm).

-With all due respect for what you're stating I don't think you have a grasp on what the OP is going to use this for. I'm well aware of what .01 mm is, that's the incremental resolution I used most often on the job. This is an absolutely absurd amount for what the OP intends to do. Were he testing machine spindles or measuring critical tolerance dimensions with a Height Master and gauge blocks then I would agree with you. A less expensive indicator with an incremental resolution of .001 (.02mm) is more than enough accuracy, especially since it will be for a comparative number NOT a quantitative number. Excessive precision that yields no benefit is wasted time/effort/money. An indicator with a .005 (.127mm) would probably even be ok for general garage work but they aren't widely available. JMO

 

[BORING HOP YARD]

In the aircraft industry that I worked in there is a rule of thumb and a requirement to use a measuring tool that is twice the accuracy of the tolerance being measured. One example could be using a pair of calipers to measure a feature machined on a lathe, is some cases the caliper is accurate enough to measure based on the rule of thumb. If you were checking features that have been ground, you most likely need to go to a Mic to measure with something twice as accurate as a feature that has been ground.
One issue that was common was to have a supplier measuring hole depth with calipers then we would measure with depth mic's and reject them for being out of tolerance.

 

[bwringer]

I guess Kurtis at CEE Australia is doing a bit more exacting work, but I'm fascinated every time he gets one out on the lathe. Good hunting.

That's the thing; he's extremely good at ONLY using the level of precision that's needed, and only where it's needed.

Same for thing like surface finish. Time is money, and if you watch what he's doing carefully you'll begin to see the thousand and one ways he saves time by planning exactly the minimum needed for each step.

Sometimes he just whacks a rusty hunk of metal with peeling paint into the three jaw, pokes a center drill into the other end, and starts hogging and even sculpting freehand as hard as the lathe and inserts will stand.

Sometimes it's worth setting up the four jaw, tapping it in to .01mm with a dial indicator, and using a fine depth of cut with a new insert to get a mirror finish. But that's actuall fairly rare.

Skilled hobby machinists (Blondihacks, for example - great channel) can take all the time in the world to nail every dimension and make pretty parts. Kurtis is there to make money and carefully picks his battles. It's really a fascinating process once you start to see how it works.

 

[The Bean]

U

That's the thing; he's extremely good at ONLY using the level of precision that's needed, and only where it's needed.

Same for thing like surface finish. Time is money, and if you watch what he's doing carefully you'll begin to see the thousand and one ways he saves time by planning exactly the minimum needed for each step.

Sometimes he just whacks a rusty hunk of metal with peeling paint into the three jaw, pokes a center drill into the other end, and starts hogging and even sculpting freehand as hard as the lathe and inserts will stand.

Sometimes it's worth setting up the four jaw, tapping it in to .01mm with a dial indicator, and using a fine depth of cut with a new insert to get a mirror finish. But that's actuall fairly rare.

Skilled hobby machinists (Blondihacks, for example - great channel) can take all the time in the world to nail every dimension and make pretty parts. Kurtis is there to make money and carefully picks his battles. It's really a fascinating process once you start to see how it works.

When Kurtis is making custom shop tool or repairing his machine, he cuts no corners. Those battles are meticulously planned and all are won.

 

[no704]

-I'm very happy for you. That still doesn't refute what repair techs and many people in the precision metal working trades have stated of theirs, Had yours cleaned and evaluated in the last 15 years?

Nope, but I just use it for tramming and center finding.

 

[AEAdam]

-With all due respect for what you're stating I don't think you have a grasp on what the OP is going to use this for. I'm well aware of what .01 mm is, that's the incremental resolution I used most often on the job. This is an absolutely absurd amount for what the OP intends to do. Were he testing machine spindles or measuring critical tolerance dimensions with a Height Master and gauge blocks then I would agree with you. A less expensive indicator with an incremental resolution of .001 (.02mm) is more than enough accuracy, especially since it will be for a comparative number NOT a quantitative number. Excessive precision that yields no benefit is wasted time/effort/money. An indicator with a .005 (.127mm) would probably even be ok for general garage work but they aren't widely available. JMO

@RoninB4 doesn't need my help explaining, but I'm reading between a couple lines above and not sure everybody is hearing what I'm hearing. Here are some details, since the OP is asking:

1. A lot of machinists/inspectors prefer dial indicators over digitals because the movement of the needle is significant to them. More below:
2. Run-out: In engineering/manufacturing, a run-out inspection would involve mounting an indictor to a spot on the brake rotor (for example), then rotating the rotor and measuring the amount the rotor varies. That variation is typically called T.I.R. or total indicated reading
3. TIR, in use, indicators can travel in 2 directions. We typically position them, zero them, then the answer we seek is the total needle travel, negative plus positive or the "total indicated reading". The only other way to use these is to probe until you find the low spot (or high spot), zero there, then all the variation will be positive (needle only moves in one direction). This can be fiddly to physically do, especially with mechanical indicators and way worse on indicators held in place by chewing gum and rubber band holders. This is why we rant about the importance of the holder. This can be a maddening and inaccurate process.
4. Total Run-out is where the brake rotor is rotated, and the indicator is traversed (example, from the edge to the hub) to better understand if the rotor is conical for example. Run-out alone wouldn't tell you if the root was cone shaped or if the section you checked run-out on, is the only planar surface. To do this, you would need some sort of surface perpendicular to the axle (like a hub). I would probably have an arm like the mast on a surface gauge and swing the arm while turning the rotor.

Why not just buy the most precise tool you can buy? What could it hurt? Answer: The super precise indicators' needles will shake as you rotate the rotor. They are sensitive enough to find scratches, pits, corrosion pockets and rust patches. This makes finding the status of the rotor difficult since you can't really tell what is out of shape vs a surface defect. So I THINK what @RoninB4 is saying, you really don't want more indicator than you need.

Not to beat a dead horse:
Some digitals have bar graphs that sorta serve the function of a needle. Some have a way of limiting how many decimal places you see to help them function as a coarser tool.

The OP was quite clear that he is doing mechanical stuff with this, not aerospace level precision machining in a temperature controlled .001 micron clean room.

It's going to get dirty, dropped, knocked, dunked, spewed on, stepped on, and scraaaaaaped and scratched across filthy rutted brake rotors, rusty wheel hubs, greasy sprockets, oily camshafts, wheels covered in bug guts, saw blades covered in resin and sawdust, etc.

Get a cheapo analog indicator with a magnetic base and get on with life. When (not if) it gets dropped and stepped on, toss it and buy another without shedding tears over your jewel encrusted $200 Mitutoyo.

All indicators are sensitive. The mechanical ones are probably more sensitive than digitals, not less so. They are more easily bunged up by oil as they have gears inside. The digitals just have a little rack and pinion type thing usually. There isn't much mechanical inside them.

The mitutoyos I own, the one's I saw on eBay, were like a trip to McDonald's more expensive than the cheapos. I am not suggesting buying new Mits to work on a brake rotor.

Tho I've never tried it, some of the Mits have SPC ports that, in theory, would allow you to output their results to .xls for analysis or to hand a customer, which could be cool for certain situations.

Last: I just picked up the cheapest Noga rip off from Amazon. I think it was Amazon warehouse "like new" (looked new) for like $25. Has a 176lb mag base and seems to lock up reasonably well. The micro adjust head has a dovetail that looks like the right size but is otherwise uninspiring. I'll report back if anyone is interested in the coming days. This could be good enough for automotive or woodworking work.

 

[RoninB4]

So I THINK what @RoninB4 is saying, you really don't want more indicator than you need.

-Pretty much sums up my opinion yes. Runout can be described as a deviation from a plane or an axis.

All indicators are sensitive.

-Yep, so get a cheap(er) one that you won't shed a tear over when it gets bunged up

Last: I just picked up the cheapest Noga rip off from Amazon. I think it was Amazon warehouse "like new" (looked new) for like $25. Has a 176lb mag base and seems to lock up reasonably well. The micro adjust head has a dovetail that looks like the right size but is otherwise uninspiring. I'll report back if anyone is interested in the coming days. This could be good enough for automotive or woodworking work.

-I'd be interested in hearing your opinion of them. The Noga design was just appearing in catalogs when I was transitioning from the shop to engineering so I've never owned one. The genuine Noga is considered, by many, to be an outstanding product.

 

[L.Cheapo]

-Pretty much sums up my opinion yes. Runout can be described as a deviation from a plane or an axis.

-Yep, so get a cheap(er) one that you won't shed a tear over when it gets bunged up

-I'd be interested in hearing your opinion of them. The Noga design was just appearing in catalogs when I was transitioning from the shop to engineering so I've never owned one. The genuine Noga is considered, by many, to be an outstanding product.

Not a machinist, but I've had genuine Nogas for close to a decade. Won't use anything else.

 

[RoninB4]

Not a machinist,

-Maybe not but you've had genuine Nogas to work with while I haven't. Envious? A little....

 

[RTM]

On the topic of holders, do you prefer lug back or shaft mount attachment points on the dial indicator? Gotta review what I have at home, was shuffling stuff last night, and didn't add notes to my tool list.