Ways for setting Cnc lathe tool heights

[Harri89]

I have a miyano bnc-20 cnc lathe.
This is my first cnc lathe and i have not run one before.

What are the options to set tool heights accurately without test cuts?

I need to shim the tool holders in turret for right height.

 

[EmGo]

What are the options to set tool heights accurately without test cuts?

Surface plate and height gage ?

 

[Philabuster]

I have a miyano bnc-20 cnc lathe.
This is my first cnc lathe and i have not run one before.

What are the options to set tool heights accurately without test cuts?

I need to shim the tool holders in turret for right height.

Is the turret in the correct radial alignment? Shimming is usually not necessary.

 

[EmGo]

Is the turret in the correct radial alignment? Shimming is usually not necessary.

If you want to get one for facing smack-ass dead nuts on, my experience was that from the factory toolholders aren't usually exact exact, just pretty close. Good enough for most stuff but if this is a little precision guy like a hardinge, maybe needs closer. Also, there were some tools I could not get in inch, but they had them in metric. 25mm x 25mm was not exact on height, so a slash or two of weld across the bottom and a surface grinder later, some measuring was necessary.

But agree, in general, should be pretty close right outta the box..

 

[Ox]

If you take a face cut, and you have much of a tit, then your turret is most likely a bit off.

First thing is to run your dial incubator up and down your stick tool holder (no tool in it) and see if you have taper there.

If your turret top plate has the pockets milled into it, then they should all be the same (if your coupler isn't shot) but if you have VDI or similar, then you may want to sweep 2 or 3 different holders in different locations to get an average.

Youtube vids look like you don't have the milled top plate, so I would check a few different locations.


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Think Snow Eh!
Ox

 

[William Lynn]

Before loading any tools, check the clearance between the toolholder and the back panel next to the slide. Too much stick out will cause a collision when the turret rotates. Some lathes need a C length of OD tool (5") and using a D length (6") can be too long if placed in the same pocket. That's how those long gouges get in the back panel.

 

[guythatbrews]

Citizen has a routine on the control that calculates the correct y offset to put tools on the gang slide on center.

Turn (or bore) a small diameter and enter the measured size, then do the same for a bigger dia. The more difference in the two dias the better. The control figures the y offset to center the tool.

You could do the same only with shims instead of y. I've stumbled around trying to suss out the math but no luck.

 

[Harri89]

When i took out the tools which came with the machine and were installed in the turret, i noticed that they were all shimmed closer to the centerline.

 

[Ox]

Well, maybe you want to adjust your turret top plate.
(it's a bit of a job, but doo-able if you have time.)

But before you doo, line up to a drill saddle and run your Co-Ax on that, and see how that looks first...
Maybe doo all of your saddles in their normal positions and see how you average out.


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Think Snow Eh!
Ox

 

[Harri89]

I found out that there were 1mm height difference between tool blocks. Tool block with coolant lines are spot on and the ones without requires 1mm shim. Also the tooling blocks are in line within 0.01mm in x-axis direction. (turning toolholder bottom surface)

I need to check the boring toolholders when i get a job finished.

 

[pcasanova]

if its a metric machine and you put in a inch tool then your going to need the shim.
most like you have .750 stick and its setup for 20mm (.7874)