Good way to set zero?

[WobblyHand]

Seem to be having a little trouble setting a zero reference when using my lathe. (I thought I bored out the hole to depth, but I'm off by 0.004". Not the end of the world for this piece, but I want to do better.) What's the best way to effectively zero?

By setting a zero, I mean somehow having the tool kiss the workpiece. Setting the DRO to zero is the easy part How much material does one scrape off before declaring it's at zero? What works for you? What do you suggest? Looking for any useful tips.

I'm using a 4J, but in this case, I'm boring a hole, so I think being off center by 0.001" won't affect the depth of the cut. (Too lazy to switch to my 0.0001" dial indicator) Using a Micro 100 BB-2301600 carbide boring bar.

I hope I worded this right. It's kind of awkward to write. Just looking for a better way of setting the zero. On the delrin piece I'm off by a little bit on the depth of the holes. Is the plastic springing back? Bad zero? Something else?

 

[RJSakowski]

What works for me is to face off and set my zero then bore to my required depth. With care, the cutting forces will be similar and my depth should be correct. Another way would be to stop short of the required depth and measure the depth. Adjust the DRO for that depth and continue boring to the required depth. Delrin does have a bit of spring back. Sharp tools will minimize that.

 

[Cadillac]

Like RJ said face your material then set zero. If having problems get some thin paper (rolling papers) and run your tool up to it then set zero. Chances are you’ll be short on measuring which then you can adjust and make your finish cut. You shouldn’t overshoot your measurements then.

 

[higgite]

Face the end of the work piece with the carriage locked and set your DRO or dial(s) or indicator(s) to zero before you move anything.

Tom

 

[mikey]

Do you have a carriage stop? This is the best way I know of to bore to a precision depth. If you set it, bore and then measure your depth and find it is off, move the stop to whatever you need and you're golden.

 

[RJSakowski]

I will make a spacer the required depth of the hole and use with the carriage stop. I face with the spacer between the carriage stop and the carriage then remove the spacer and bore my hole.. This works great when you have a number of identical parts to make as there is no measuring involved.

 

[benmychree]

I will make a spacer the required depth of the hole and use with the carriage stop. I face with the spacer between the carriage stop and the carriage then remove the spacer and bore my hole.. This works great when you have a number of identical parts to make as there is no measuring involved.

Yes, that works well, for fractional inches, I use a 123 block and step gages in 1/16" increments, for odd sizes, I use adjustable parallels, plus I have a TravaDial on the carriage, call me old fashioned, I do not own any DROs ----