Got a nice finish on 303 stainless

Just out of curiosity, did you set the cutting edge to the center of the bar before you made those passes? Place a 6" steel scale between the cutter and the bar and feed the cutter in enough to hold the scale in place. If the scale is standing straight up and down the cutter is on center. If it's leaning back toward you it's below center, if leaning away it's to high.
 
Holescreek said:
Just out of curiosity, did you set the cutting edge to the center of the bar before you made those passes? Place a 6" steel scale between the cutter and the bar and feed the cutter in enough to hold the scale in place. If the scale is standing straight up and down the cutter is on center. If it's leaning back toward you it's below center, if leaning away it's to high.
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The big aluminum block that holds the tool holder I made just for that holder, and it was measured to put the tip of the cutter exactly at spindle centerline, so it should be centered. I dont have that piece chucked up anymore otherwise I'd try the test and see, next time for sure
 
You can test it on any piece of round stock, center is the same regardless of diameter.
 
Holescreek said:
Just out of curiosity, did you set the cutting edge to the center of the bar before you made those passes? Place a 6" steel scale between the cutter and the bar and feed the cutter in enough to hold the scale in place. If the scale is standing straight up and down the cutter is on center. If it's leaning back toward you it's below center, if leaning away it's to high.
Click to expand...

This is a perfectly good way to bugger a nice scale and ruin some inserts.
Measure from the ways to the tool edge with a scale, write this dimension on the front of the machine, say 8 11/16" for example, then set all tool heights there, it will be more then close enough. All of the lathes in our shop have this dimension written on them with a permanent marker. As a hobbyist you will be chasing tenths anyway and taking multiple passes to reach your finished dimension so adjust accordingly.

That is how I do it and I do this for a living.
 
Wreck™Wreck said:
This is a perfectly good way to bugger a nice scale and ruin some inserts.
Measure from the ways to the tool edge with a scale, write this dimension on the front of the machine, say 8 11/16" for example, then set all tool heights there, it will be more then close enough. All of the lathes in our shop have this dimension written on them with a permanent marker. As a hobbyist you will be chasing tenths anyway and taking multiple passes to reach your finished dimension so adjust accordingly.

That is how I do it and I do this for a living.
Click to expand...

I've been doing the scale thing 35 years now...

You've got a better way. Not often an old dog learns a new trick.

Karl
 
Wreck™Wreck said:
This is a perfectly good way to bugger a nice scale and ruin some inserts.
Measure from the ways to the tool edge with a scale, write this dimension on the front of the machine, say 8 11/16" for example, then set all tool heights there, it will be more then close enough. All of the lathes in our shop have this dimension written on them with a permanent marker. As a hobbyist you will be chasing tenths anyway and taking multiple passes to reach your finished dimension so adjust accordingly.

That is how I do it and I do this for a living.
Click to expand...

my main problem is that I have no way to adjust that toolpost I made. well..I can shim the holder up or down a few thou, but thats it. If I open the slot up more I can shim it alot more than that..that might work out.

But I think I need to make it a "rev 2", where I can install 3/8" tools because I have a ton of those, along with the 5/8" insert holder I have on the way...and then be able to adjust the whole thing up or down say 1/2"...

That little ridge on the cross slide where its reliefed for the toolpost would appear to be machined/ground..maybe I can use it as a reference and make it so my tool post can be rotated and hold 2 or more tools with precision repeatability?

Or should I just dump all of it and get a QCTP? The nice thing about the one I made is how rigid and cheap it was.
 
Holescreek said:
You can test it on any piece of round stock, center is the same regardless of diameter.
Click to expand...

Or test it against the point of a dead center. As Karl says, you need only do it once. Then you can make a gage (which I've not gotten around to doing).
 
Yeah, I've been doing it wrong for 33 years now. Even wronger since I've never ruined a scale or an insert! :roflmao:
 
Holescreek said:
Yeah, I've been doing it wrong for 33 years now. Even wronger since I've never ruined a scale or an insert! :roflmao:
Click to expand...

No offense intended, I am wary of jogging a machine to a scale on the part, how do you do it?
I don't trust these CNC machines all that much. (-:
I did the rule thing years ago on manual lathes, it works a charm.
 
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