Setting cutter heights on a lathe?

[lazylathe]

Hi All,

I know this question has been asked a thousand times already...
Searched the forum but was unable to come up with what i needed.

How does one go about making a gauge to set the cutter to the correct height?
I know one i have the QCTP fitted it will be easier, but i was wondering how i would go about measuring and making my own one.

Would it sit on the slotted carriage or the bed?
I had a neat one for my Sherline lathe that was dead easy to use and would like to replicate it for my Myford.

Any help or links or pics appreciated!

Andrew

 

[Cedge]

Andrew
I use a trick that is a very old school, but it's fast and accurate. Place a 6 inch steel rule between the cutter and the work piece. Run the cutter lightly against the rule and observe the angle of the rule. Adjust the cutter height until the rule is perfectly vertical and you'll be dead spot on the centerline height.

Steve

 

[Metal Butcher]

Hi Andrew. I made a simple height gauge. Its a 1/2" round steel rod pressed into a 1" base a 1/2" high. To use it I set the gauge on the top slide and adjust the cutter height to match. I can feel any minor difference in height with my finger nail. I can also set a Jo-block on top of the gauge and over the tool bit to check the height with a small LED flashlight. The same way you check a work piece with a square.

The gauge needs to be the 'exact' height of the distance between the top of the table and the spindle center line. Its a very simple tool to make that will last a life time and it will save you a good deal of time over some of the other methods.

Set up an edge finder in your chuck and start stacking 1-2-3 blocks, tool bits or what ever you have that has a ground finish to meet up with the edge finder. Measure and add it all up plus half the diameter of the center finder. Make your gauge to that height.

Cedge's suggested quick method is said to work well enough too. I never tried it out of fearing damage to one of my good rules.

-MB

 

[Cedge]

MB....
Any straight edge will do. I've also used a spare cutoff tool and it worked just fine. With as many rules as I have around the shop, one is usually at hand when I need to use one.

Steve

 

[Metal Butcher]

MB....
Any straight edge will do. I've also used a spare cutoff tool and it worked just fine. With as many rules as I have around the shop, one is usually at hand when I need to use one.

Steve

Yea I was thinking that a thin strip of steel would work. The problem is....I'll misplace it and spend way too much time looking for it... since I don't know when to quit! :wall:

-MB

 

[mygrizzly1022]

Hi…Andrew

Another simple tool height trick is to set the tool height with a center held in tail stock.
If when you have a tool that you are satisfied is in fact on center, you can then use it to scribe a (short light) reference line in the side of the tailstock barrel. Simple and works like a charm, plus you are not likely to spend a half hour looking for the gauge that was just right there…. a minute ago…..


Regards… ..Bert

 

[Shopguy]

Hi Andrew,
I usually use the straight edge (aka 6 inch ruler) method of finding the centre height. Some years ago I made a little gauge with a level in it to enable me to find tool height. I took a couple of pictures just now to show what it looks like. The vial was out of a old combination square. Took a bit of time to get it set up just right and set in plaster. Note the lathe has to be level back to front for this to work properly.
Regards
Ernie

 

[lazylathe]

Thanks for all the replies!

I have known about the ruler option for a while now but would really like to make one that you can just set on the cross slide and set the tool height to an indentation or something.

I think M.B's idea is the one i am looking for although without an edge finder i will have to improvise!
If i had to place a dead centre in the headstock and measure the distance from the cross slide to the extreme tip of the dead centre would this also work out the same?

Thanks to Bert for the centre idea!!! ;D
Seems simple enough when you know the many possibilities of a single tool!

Andrew

 

[mklotz]

I think M.B's idea is the one i am looking for although without an edge finder i will have to improvise!

If you have a height gage, you can do the following:

Shim a flat-topped tool until it faces stock without leaving a center pip.

Swing the toolpost so the tool is over the compound.

Use the height gage to measure the height of the tool above the top of the compound.

That's how I did mine and it's been working faithfully for many years. Human fingers/nails are remarkably sensitive comparators.

 

[Metal Butcher]

If you have a height gage, you can do the following:

Shim a flat-topped tool until it faces stock without leaving a center pip.

Swing the toolpost so the tool is over the compound.

Use the height gage to measure the height of the tool above the top of the compound.

That's how I did mine and it's been working faithfully for many years. Human fingers/nails are remarkably sensitive comparators.

Once you shim up your lathe tool till a faced piece of stock is "pip" free using Marv's suggestion. You could use a rule instead of a height gauge. Make the height of the set up tool slightly taller. Trim the base using .001" cuts and checking till the 'set up tool' matches the height of the lathe tool. It will take longer this way but it should give you an accurate set up tool when your finished.

I blackened mine with 'Tool Black', but you could put a thin coat of spray paint on the non working surfaces e.g. silver, gold, red or whatever you like to make it easy to spot in a drawer or on a shelf.

-MB

 

[mklotz]

Allow me to add one thing...

Relieve the base of the gage so it does not "rock" when set on the compound.

Many lathes are set up to intentionally face slightly concave but I never trust that feature.

 

[Bill Gruby]

Ebay search "Lathe Tool Centering" Industrial Section. There is a whole page to choose from.

"Bill Gruby"

 

[shred]

I made a really simple chunk of rod one day-- I faced (and relieved) a short length of 1" rod. Then I put a little layout dye on it, put a sharp point on a bit of rod in the spindle, set the bar vertically on the carriage and scratched it across with the point. Then I faced the bar down to the mark. Fingers/nails from then on.

 

[Omnimill]

Have a look here, pic about half way down:

http://www.homemodelenginemachinist.com/index.php?topic=11242.30

 

[lazylathe]

Thanks Vic,

That is exactly what i was looking for to make! ;D
Did you sandblast the inside of it?
Or is that an acid etch?

andrew

 

[Bill Gruby]

Have a look here, pic about half way down:

http://www.homemodelenginemachinist.com/index.php?topic=11242.30

Yup, gonna turn one of those today. Thank you Vic. And thanks for this thread Andrew, without it that little jewel might not have been seen.

"Bill Gruby"

 

[Omnimill]

Thanks Vic,

That is exactly what i was looking for to make! ;D
Did you sandblast the inside of it?
Or is that an acid etch?

andrew

You're welcome guys. It's Sandblasted Andrew. I just thought It'd make it look nice. ;D

Vic.