07-06-2012, 01:23 AM
Henry,
I am no great fountain of knowledge about DRO's, but I do have a fair number of years in using them (about 30 at last count), and you follow my recommendations only if you want to.
Having DRO's on your lathe (or mill) isn't the be all and end all to getting accurate machining done, as some people seem to think, you have to fine tune your lathe (or mill) to be able to use them correctly, and in your situation, it could mean a lot of strip downs of your setup. I am lucky in that I have tapered gibs, so I can tweak them without resorting to strip downs.
When you first come to use them in anger, you will most probably find that when you put on a decent cut, your tooling will get 'kicked back' by the cutting pressure, and your DRO will show that, and you will start chasing your own tail trying to get a cut to stay on accurately.
You have to balance the gib pressure enough to stop that throw off without making the handles too hard to turn, or maybe do the mod that I showed on locking up the cross slide and use that to balance the pressures out.
Forget about backlash in your leadscrews etc, your DRO's are giving you absolute measurement of where the the tool tip is, and you have to train yourself to respect and trust your DRO set up, otherwise it was useless fitting it in the first place.
You cannot beat experience in finding what is best for your type of machining requirements, so stick with it and you will soon get used to it.
Get that sorted now, and you should end up with a well balanced system that will give you years of accurate and trouble free service. In fact, my mill hasn't had anything touched now for well over 3 years, and the lathe, a couple of years (I had to take the cross slide off to do a little job). My DRO's stay rock solid (within a couple of tenths anyway) all the time, no matter how much cut I put on.
John
I am no great fountain of knowledge about DRO's, but I do have a fair number of years in using them (about 30 at last count), and you follow my recommendations only if you want to.
Having DRO's on your lathe (or mill) isn't the be all and end all to getting accurate machining done, as some people seem to think, you have to fine tune your lathe (or mill) to be able to use them correctly, and in your situation, it could mean a lot of strip downs of your setup. I am lucky in that I have tapered gibs, so I can tweak them without resorting to strip downs.
When you first come to use them in anger, you will most probably find that when you put on a decent cut, your tooling will get 'kicked back' by the cutting pressure, and your DRO will show that, and you will start chasing your own tail trying to get a cut to stay on accurately.
You have to balance the gib pressure enough to stop that throw off without making the handles too hard to turn, or maybe do the mod that I showed on locking up the cross slide and use that to balance the pressures out.
Forget about backlash in your leadscrews etc, your DRO's are giving you absolute measurement of where the the tool tip is, and you have to train yourself to respect and trust your DRO set up, otherwise it was useless fitting it in the first place.
You cannot beat experience in finding what is best for your type of machining requirements, so stick with it and you will soon get used to it.
Get that sorted now, and you should end up with a well balanced system that will give you years of accurate and trouble free service. In fact, my mill hasn't had anything touched now for well over 3 years, and the lathe, a couple of years (I had to take the cross slide off to do a little job). My DRO's stay rock solid (within a couple of tenths anyway) all the time, no matter how much cut I put on.
John