Gauge blocks/method to set bore gauge?

[PekkaNF]

Got small bore gauge to play with and to try out what can be done with it. Tried to set it with a micrometer. Fiddly at it's best and even tought I don't need exact reading (mike bearing, lock the mike and use it to set the gauge) I don't feel overly confident with it.

Is there a method or design to use a bearing as gauge block to set a bore gauge more reliably in good Madmodder spirit? Some kind of self made fixture?

My bore gauge is
http://www.arceurotrade.co.uk/Catalogue/Measurement/Dial-Bore-Gauges/Dial-Bore-Gauge-Metric-18-35mmx001mm-100-035-10200
and it's a little on delicate side.

Actually thinking of this kind of combo, but pain to clear it from customs:
http://www.westportcorp.com/gages/BoreGagesProductPage.asp?ItemNum=53-646-000-0

If I just could "clamp" a bearing and use it's OD to set the dial bore gauge, without too much complications.

PekkaNF

[75Plus]

A height gauge setting on a surface plate would provide a wide ranging set-up tool for a bore gauge. That is assuming you have one at hand.

Joe

[BarryG41]

Generally you use the bore gauge in the bore first.  Adjust it touch the bore sides - remove the bore gauge then measure the diameter with a mike of vernier/ digital calipers.  It takes some experience to get the feel required to accurately  measure the bore.  Experience can only be gained by  using the tools.

Barry G

[PekkaNF]

I have a decent piece of granite for a surface plate, but I have been putting on handing out cash for height gauge.

I have tried vernier, inside mike and just few times telescopic gauges. I'm getting there, but as stated, things get together only with practice.

I never used bore gauge during machining just been playing with it, to get the feel.

My newest application is to make body for to or three bearings. Two different diameters, both must be concentric. My idea was to use vernier to get down to last 0,1 mm of required bore, then set the dial bore gauge for the bearing and account for a fit, set tolerance arms, adjust for two finishing cuts and check in between with a bore gauge.

Is there a reason to use bore gauge for a measurement of a numerical value vs. using it as comparator (gauging)? I know it's basically same, just a point of view. For me it would be more natural to adjust bore gauge (dial zero) to a desired value (forget the real value, because target has been allready set) and then adjust the cut until I'm getting readings that are close enough?

So my reasoning is that I need a method (the ones I have tried hasn't felt right and I'm not getting consistent results) or a fixture and method to set the bore gauge "right" to be able to trust it only (!!!!!!!) concentrate on trying to get the bore diameter and geometry good enough.

I'm thinking something like height gauge, but top and bottom anvils that are adjusted to bearing and then bore gauge is set to it, without bothering to measure anything (pointless really, bearing are probably pretty damn close that data sheet claims them to be), and only allowance is made to fit and tolerance.

Am I completely off the track like a mile or something?

PekkaNF

[PekkaNF]

 Small 

Woke up early this Sunday and tested telescopic gauge, vernier and dial bore gauge with 28mm ID ground/hardened/industrial needle bearing ring.

Vernier is most familiar to me and I'm getting pretty close to readings that I should be getting anyway, but finnish is good, freshly bored hole not that easy on all sizes.

Telescopic gauge was most random method to me. Firsts of all, it's cheap one and not very smooth to start with. Lot of feel is involved in measuring and often I get close, but there are few times that I'm off way too much for comfort. Should visit someone who has a good set and knows how to use it. My problem seems to be nipping just right before tilting the shaft and holding it right. When I'm measuring it with mike, I'm on more familiar ground.

Now, the new cheap bore gauge: Fiddly to find the right anvil and set, but I'm getting pretty good consistency with it, takes a little wiggling, and to get last division right takes a little time, but I found that it's easier to get pretty close.

However, I'm very aware that because I know the "number" I'm trying to read it. Everyone knows this mind trap.

I'll have to test it with something before real thing. Just to figure out how measurement goes on a bore I'm making on lathe and all those tool post and rough finish to deal with.

I turned one plain back plate register today (4 mm deep, 100mm ID) used vernier. I was aiming a little shy, but in the end I was reading 100,00 mm. But it was hot and my left ear channel was filling up with cast iron dust/swarf. Check that tomorrow. If it comes too big, it will be fine catch plate!

PekkaNF