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Sat Feb 03, 2018 9:48 am

Could some post a tutorial/link on how to properly set up and use one?
I was given a mitutoyo 511-106 and repeating measurements seem elisive
Thankyou

Sat Feb 03, 2018 11:14 am

Youtube. How to measure a bore using bore gauges. measuring a cylinder of an engine. Lots of options for how to re:using the bore gauge.

Sat Feb 03, 2018 5:33 pm

A bore gauge will not give you an absolute measurement, only a measurement relative to what you zero it at. Say you are measuring a bore that has a 4" std, you use an inside mic set to 4" ( after zeroing it with the calibration rods with the mic set). Set up your bore gauge to read 0 when set to the inside mic. Then when you measure the bore with it, it will tell you if you are over or under what you zeroed it at. The bore gauge tips have to be perpendicular to the bore walls, you know it is right when the needle is at it's lowest reading and any movement on either side of that results in a higher reading. Probably easiest just to watch a youtube.

PS - A Mitu bore gauge is a very nice gift :D

Sun Feb 04, 2018 6:54 pm

You use an OUTside mic to set the desired diameter.
A dial gauge is a comparator measuring device.
It will only show over under your zero’d diameter.

Set your outside mic to the desired dimension.
Secure the bore gauge in some suitable device.
Sweep the measuring points of the dial gauge with the mic.
Adjust the dial in the dial bore gauge so that the dial sweeps to zero when the mic is passed over the measuring points on the bore gauge.

It’s vital to ensure you are keeping the bore gauge perpendicular and square to the measuring diameter.
Sweep at several locations.
This will show you both taper and out of round.

Constrain your movement to the perpendicular plane when both measuring and setting.

Be gentle.
Be patient.
Repeatability will come with experience.

Owen

Sun Feb 04, 2018 7:06 pm

I have used several of them, they are OK. Use it for measuring piston pin bushings without removing them from the machine.

i have two beefs. One is they are so light that you cannot just set it down on a table and set it, need to hold it with your third hand or something. Especially after the plastic surround around the indicator breaks, which it will if it hasn't already or wasn't even included.

The other is the force with which it measures is a bit high. Can't use it on soft bearings or it will scratch them up.
One day if I had nothing to do I would put a lever on the beam so you can retract it, and affix a big weight to the dial end so I can set it easier. Probably you are supposed to gently clamp your micrometer in a vise, to act as the third hand, but I prefer the opposite due to habit

Sun Feb 04, 2018 7:22 pm

And _Always_ screw your mouth up into the exact right measuring position when using a dial bore gauge.

Imperative that you hold your mouth right..

Sun Feb 04, 2018 8:31 pm

modok wrote:

The other is the force with which it measures is a bit high. Can't use it on soft bearings or it will scratch them up.
One day if I had nothing to do I would put a lever on the beam so you can retract it, and affix a big weight to the dial end so I can set it easier. Probably you are supposed to gently clamp your micrometer in a vise, to act as the third hand, but I prefer the opposite due to habit

I have found lightly clamping the micrometer in the vise with aluminum soft jaws gives me the third hand and easiest method to control/postion the dial bore guage squarely between the micrometer anvils.
Marty

Sun Feb 04, 2018 9:55 pm

Guys....buy a damn micrometer clamp!

http://www.wttool.com/index/page/product/product_i...dQQAvD_BwE

You can get a functional multi angle one for less than $25. A good one for about $50.

I made a nylon sleeve that snaps onto each end....the spindle and anvil....to center the probe and fixed pin of the dial bore gauge when setting the basic width of the gauge and zeroing the dial.

It is still as others have mentioned.....a "sweep" check of a bore size. You move the gauge slightly looming at the minimum and maximum at at least six points in a bore. Ray

Sun Feb 04, 2018 10:01 pm

The plastic case would also benefit from adding 1bl weight.

I think they made the stuff extra light to save on shipping costs. :P

Sun Feb 04, 2018 11:33 pm

raygreenwood wrote: Guys....buy a damn micrometer clamp!

http://www.wttool.com/index/page/product/product_i...dQQAvD_BwE

You can get a functional multi angle one for less than $25. A good one for about $50.

I made a nylon sleeve that snaps onto each end....the spindle and anvil....to center the probe and fixed pin of the dial bore gauge when setting the basic width of the gauge and zeroing the dial.

It is still as others have mentioned.....a "sweep" check of a bore size. You move the gauge slightly looming at the minimum and maximum at at least six points in a bore. Ray

Or better yet, buy the proper micrometer setting base.
A good bore gauge will not damage Babbitt bearings if used correctly.

Pin bores are better measured with either an intra-mic or pin gauges and an outside mic.

My .02

Mon Feb 05, 2018 8:10 am

Yes, OUTside mic. Using an INside mic to set up a bore gauge would be a trick for sure, LOL at myself. :roll:

Next up are snap gauges..

Mon Feb 05, 2018 9:14 am

rodeking wrote: Yes, OUTside mic. Using an INside mic to set up a bore gauge would be a trick for sure, LOL at myself. :roll:

Actually....you can do this with an INSIDE micrometer.....dependng on how you plan to use the dial bore gauge.

The most important aspect or usage of a dial bore gauge....at least to me.....is checking for roundness of crank journal bores and cylinders.

Lets say in this scenario....your dog ate your outside micrometer....but you have an inside micrometer.....which would actually be ideal for measuring bores....but it does not have the sperical anvil and spindles needed for meazuding bores (I have actually been there).

With crankcase bores.....you clean the case well. I pre-mark it in axes I plan to check with a Sharpie marker. Clamp it together. Some say with the 6 big bolts.....I say with all the bolts and nuts just like you are assembling.
Take your inside micrometer.....and get a quick measure. Now you know the diameter RANGE. This allows you to select the correct extension mandrel for the dial bore gauge.

If the bore is PERFECTLY round (never happens).....when you insert the dial bore gauge and tilt it back and forth.....the high point reading with be dead on the same for each measuring axis.
In reality.....you will find some of the points higher and some points lower. In a good bore.....no more than. 001" or .0015" in a very narrow range.....and usually +/- variation ranging from .0001" to .00015.

What you are doing with the dial bore gauge right now.....is not measuring the EXACT diameter....but actually by measuring six axes between 12 points.....and writing down the variances....you are building a MAP of how round or how eggshaped the bore is.....to decide if it needs an align bore or not.

You can tell the reasonably accurate size of the bore....with a simple telescopic gauge (buy the best quality telescopic gauges you can). The more important function of the dial bore gauge is checking for out of round.

I have also found that many of the dial bore gauges scratch the out coating of rod bearings. Technically......that is just the outer surface coating which is pretty much sacrifical and is gone fairly quick anyway.....but I still do not like to do that. I would rather verify the diameter and roundness of the torqued together rod with no bearing.....with an inside mic or telecopic mic.....measure the crank journal with and outside mic.....then select the correct bearing....install with plastigauge.....and check actual oil clearance.

I have been toying with changing springs in my cheaper dial bore gauge to lower the contact point tension.

For cylinders.....the dial bore gauge is great for checking for taper and out of round.....and actual bore size since it will not scratch them. Ray

Mon Feb 05, 2018 7:58 pm

raygreenwood wrote: Guys....buy a damn micrometer clamp!

http://www.wttool.com/index/page/product/product_i...dQQAvD_BwE

You can get a functional multi angle one for less than $25. A good one for about $50.

I made a nylon sleeve that snaps onto each end....the spindle and anvil....to center the probe and fixed pin of the dial bore gauge when setting the basic width of the gauge and zeroing the dial.

It is still as others have mentioned.....a "sweep" check of a bore size. You move the gauge slightly looming at the minimum and maximum at at least six points in a bore. Ray the same as the mitsupaid toomuchiou for about $19-$25 on flebay. and a few more and some less.. if it si too tight as morlock says and scratches the bearoings you can take it appart, deburr clean, and possiably re sporing it for less spring force.it's good to clean this stuff when it needs it :shock: not true!!!. clean it before it needs it :wink: . if the gauge is dead it's dead get a new one there so effing cheep I just got 6 digital ones for about $12 each. the same one mit & many others use and sell for$$$$$$$$$. if digital isant your thing a std one will cost less. no not this kind of std :shock: a standard type with a needle.and little needle for the real fine reading units. dont get the single needle gauge there useless...unless your mesureing tire size or pressure..

I was going to make a dial bore gauge setting fixture one day..I turned it into another setting gauge...ow well. it would be nice to have a set of mics with 1/2" faces on them...... hear is a quick bit of info.. your mic does not have to be calibrated at all. or even be a "real mic" you just want to transfer the size of whatever your micking to the dial bore gauge. the dial bore gauge will read the clearance . thus mic the crank set the lock, then set the dial bore gauge and check the hole, read the clearance. no math required.

Mon Feb 05, 2018 8:45 pm

No tool is perfect for doing everything, that's why there are so many kinds of tools.
No complaints about wear or accuracy, on the real deal or the cheap copy, and I've used them...probably more than most ever would.
I changed the spring to a weaker one, and that improved it, but it's still no Sunnen. I like this one better

Mon Feb 05, 2018 9:14 pm

I've just picked up this little starrett #452 and it's not like a traditional dial bore indicator. It is intended for measuring the inside of cylinders, so it has two spring loaded "skis" on the back, they hold the gauge and anvil perpendicular to the bore. Pretty easy to use, as the anvil is easily set to any length in the collet, and just rotate the face to zero it. There's two longer anvils in the handle. Only problem is the minimum size that can be measured, is probably about 2.25"
Not the right tool for case main bearing bores, but really nice for cylinders. No third hand needed!
SD

Tue Feb 06, 2018 8:29 am

thats a old sterrett....dam old. as for the sunnen modocktor shows...I hated that dam thing.....only used it a few times as we had that one and the next shorter version witch was more user frendly for me. yes the sunnen was the best Ive ever used as well as the setting fixture that i miss so much. now I have a old NSK that i bought new back in...the 80's and a new folwler with 2 diferent size heads I got last year( mainly for the small range head it has that I have already modifyed some.) I like tools, I like them a lot, especialy messuring tools, I just put a new dro on my big mill,got another dro for my big lathe.fixing to add afancyer dro (it's got one now but going bluetooth as will the lathe)added to my small mill that will probably be a dedacated seat &guide machine , it's a part timer now...

Tue Feb 06, 2018 12:48 pm

Yes....some of what makes a good dial bore gauge is shape, feel and balance. Spring tension and accuracy aside for one moment....all of that is what can make one gauge nicer to use than another gauge that is just as accurate or even more accurate.

The Sunnen gauges have that feel. The Mitutoyo's are similar but it depends on the length.

I have used a couple of very nice Sunnen dial bore gauges (borrowed of course).

When I borrowed those gauges....I had a Mitutoyo 511-743 gauge with a .0005" dial indicator I bought used. I borrowed the Sunnen because I need one that was a little longer and I also wanted one that was .0001" increments.

The one thing I do remember about the feel of the Sunnen tools I used were that they were very well damped...and the dial movement/spring pressure was like butter.

Aside from that...I have found that the Sunnen gauges were no more accurate than my Mitutoyo.

I really needed a better gauge on my Mitutoyo...but the cost of a good gauge was more than I wanted to spend at the moment. I had a couple of VERY good Starrett .0001" dial bore gauges...but they would not fit my Mitutoyo gauge properly.....so I ought a cheap $69 Chinese dial bore gauge...brand new off Fleabay.

The Starrett gauge dropped right in.....and guess what....with that dial gauge...the Chinese dial bore gauge showed to be JUST AS ACCURATE as either the Sunnen or Mitutoyo.
The feel and damping are not quite as nice....but its nice and light and skinny...and works quite well.

I traded my used Mitutoyo for a very nice satin chrome, brand new Mitutoyo 2"-3" 0.0001" micrometer with standards and ratchet thimble in the case.

Recently I acquired an English made Bowers dial bore gauge in trade for some work I am doing. It nice because its longer than my Chinese gauge.
Basically brand new. It has "feel" equal to the Sunnen. It has all rubberized surfaces, is very well balanced.....and a very good gauge calibrated to 0.002mm increments...so each .002mm increment = .000157".

My only issue with it is that it has a VERY strong spring tension.

The Bower dial bore gauge (13" reach with the gauge head protruding so ist about 17" long)

As I was getting at in the last post and others have mentioned....the spring tension can be changed. I have had all of the dial bore gauges I have "owned" apart for cleaning and oiling...but not the Sunnen's...because I did not own them. I have thought about changing the springs...but never have.

So thinking about this I went home yesterday and took mine apart and tried them with and without the transfer rod springs.

The Bower gauge head, spring and rod

The Chinese gauge head, spring and rod assembly

I cannot yet vouch for the metal quality but its a decent design and pretty well manufactured.

My take away is that the Chinese gauge with the .0005" gauge it came with...loses 75% of the spring tension it has...and is buttery soft. I did not try my Starret gauge in it yet.

The Bowers gauge ...looses right at 50% tension without the spring....and it makes it very nice.

I surmise...without taking one apart....that the Sunnen gauge is not using a transfer rod spring. It is just using the spring damping of the dial bore gauge itself.

I would also gather that springs are really only installed on the transfer rods of dial bore gauges to be used with the somewhat rare now...dial gauge that has no internal return spring....or for positive return to keep from damaging the gauge from bumps. Ray

Tue Feb 06, 2018 4:32 pm

Ray, thank you for those observations. I have the same chinese dial bore gauge, and use it with my Brown&Sharpe indicator. Like you, my only complaint is the spring tension; I scratched the first bearing to the point of being unusable. Previously, I had used a borrowed Mitutoyo, which has a butter smooth movement and never scratched the bearings. So, next time I have a need for the gauge, I'll pull out the spring first to see if it makes the same improvement.
SD

Tue Feb 06, 2018 7:42 pm

another good way to set a bore gage is to get a cheap set of gage blocks and a precision tool makers vise, stack up the desired size in gage blocks and clamp in vise lightly, this gives you a better area to zero the bore gage vs the small anvils of a mic, and is much closer to the way you should use and set a bore gage, import sets of gage blocks prolly cost less then 1 good 4-5 mic, vise also, much easier the fumbling with a mic, plus you have gages to calibrate your mic now,

Tue Feb 06, 2018 7:56 pm

Setting a dial bore gauge without any special tools is no harder than tying your shoes.
Took you awhile to learn but your glad you did, right?