# LATHE TOOL HEIGHT GAUGES



## epanzella (Nov 9, 2019)

Another lathe tool height gauge design.  One on a bridge to go across the ways for long tools like boring bars. One that sits right on the cross slide for shorter tools, These things are great time savers.


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## ddillman (Nov 10, 2019)

nice


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## Toolmaker51 (Nov 16, 2019)

Before embarking on a centerline gauge, it's good to know the physical and correct centerline to attain.
The dependable method of determining _accurate _centerline height follows.
If your cross slide is flat or rough casting sets the procedure. If cast, measure from the bed ways.
Chuck a short piece of stock with a decent diameter. 
Take a light pass to insure its surface concentric with centerline. 
Measure and note that diameter, and result dividing by 2. 
Use a height gauge, even caliper and 1-2-3 blocks to ascertain position of upper surface. 
Subtract noted 1/2 diameter from height reading. That is spindle centerline from what ever surface height gauge was positioned on. Likely the same area will be used for the gauge itself.
How you construct gauge is a matter of preference and resources; from nuts, hotrolled strip and all-thread, to heat treated finely ground works of art.
A good feature is to provide reference surfaces that can read from above AND directly on plane with tool tip.


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## mickri (Nov 16, 2019)

Here's mine.  I put a dead center in the spindle and scratched a line across my square.


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## Toolmaker51 (Nov 17, 2019)

Your square method is a reasonable center representation; dependent on interpreting point of center. Sure minimizes sine error of some bent or floppy scale.
But....
That carries one limitation, maybe two. A scribed line is visual. A true CL gauge is tactile; an improvement of just a few thousandths. On a 6" lathe on thing, can be proportionally greater with larger lathes. When speed, finish, accuracy, & repeatability matter, that equals unrecoverable costs.


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## mickri (Nov 17, 2019)

I hear you.  I am a hobby guy.  If I was doing this for a living I would have the best tools that I could afford to buy or make that would give me the speed, finish, accuracy and repeatability needed for the job at hand.  In using my square I am learning just where the point of the tool bit needs to be.  I fiddle with until I get it as close as I can.  Then it repeats to that point with my QCTP.


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## Toolmaker51 (Nov 17, 2019)

Not to lecture, just a viewpoint, whenever I hear this called a hobby. There is a distinction. A hobby is done for pleasure; maybe completing something parts aren't made for, or building an object from scratch. 
But profit is the only real difference; we [you] duplicate operations the largest manufacturers perform on a daily basis. 
So,
Where cottage industries are prevalent, many shops are not equipped much differently than a home shop.
So
Should there be a major breakdown of society, who do you think will be supporting the efforts to restore order to the infrastructure?
The 'best' tools bought or made are advantageous, not critical. The important factors are willingness to improve, learn, and make best possible use of resources.


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## epanzella (Nov 19, 2019)

I put a .500 gauge pin in a collet. Then a I put .250 gauge blocks on top my center fixture and adjusted until a DTI read the same across both.  Done.


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## pontiac428 (Nov 20, 2019)

What I use:


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## Tim9 (Nov 21, 2019)

I like that Pontiac. I actually have a couple planer height gauges. Might just take your suggestion and break one out for that use.


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## doc55 (Dec 18, 2019)

Here is how I set tool height.


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## mike44 (Jan 20, 2020)

doc55 said:


> Here is how I set tool height.


I find the center the same easy way. I was using a shop made height gauge one morning when a friend stopped over. Jesse told me that there was a simple way, no height gauges ,just a 6" scale. Been using the scale ever since, 20+ years or so.

mike


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## middle.road (Jan 21, 2020)

pontiac428 said:


> What I use:


Mine is missing that round, shaftie, knurled thingy...


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## pontiac428 (Jan 21, 2020)

middle.road said:


> Mine is missing that round, shaftie, knurled thingy...



Make one!  Square face required, knurls optional, dimensions arbitrary!


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## ThinWoodsman (Jan 21, 2020)

Knurls are never optional.


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