Feed and Speed for Facing off Spindle Nose?

[philbur]

The TTS manual says low speed on the spindle when facing. 0.001" per rev would be considered a reasonable feed rate for a finishing facing cut. With a lathe on a finishing cut the lower the fed rate the better if you are looking for good surface finish. If you use a carbide insert lathe tool you should use a good sharp insert of the correct type otherwise you risk it rubbing rather than cutting.

Phil

very odd to me that .001" on the nose is acceptable. That means I have roughly half of the allowed error.

This inspired an additional test that I overlooked which is to try 3/4" drill rod in the TTS collet as the collet itself may be causing the error.

I already smacked my forehead, so tonight I'll chuck a 3/4 em and check the collet, then give a go with a lathe bit since its free and see where I am. If I'm not happy I'll buy a diamond dresser

Still would like any input on speed and feed for the lathe tool.

[AiR_GuNNeR]

I just performed this operation last week.
It was a great excuse to buy a new tool because a dremal isn't up to the task. I ended up getting a proxxon tool. It has MUCH better bearing and runs smooth as silk.
http://www.proxxontools.com/store/pc...&idproduct=206
I made a simply collar to mount it on my vise. I borrowed a friends 3/8" diamond point dressing tool for his surface grinder and dressed the wheel by simply putting it in the collet. Run the tool so that the axis is perpendicular to the mill spindle axis.
I ran the tool spindle at 10,000 rpm and the mill at around 150rpm. I took two .001 cuts and then let it spark out. My indicator doesn't wiggle at all now.

[WOTDesigns]

The TTS manual says low speed on the spindle when facing. 0.001" per rev would be considered a reasonable feed rate for a finishing facing cut. With a lathe on a finishing cut the lower the fed rate the better if you are looking for good surface finish. If you use a carbide insert lathe tool you should use a good sharp insert of the correct type otherwise you risk it rubbing rather than cutting.

Phil

Boy am I glad I asked! At 300 rpm thats only .3 ipm... I was debating going as low at 2ipm. Guess I'll warm the dovetails up good before I run it to reduce the friction for such a slow cut. Lots of cutting oil and a book to read

I think I'll lightly chamfer the two pin holes to reduce cuter wear too

[AiR_GuNNeR]

Boy am I glad I asked! At 300 rpm thats only .3 ipm... I was debating going as low at 2ipm. Guess I'll warm the dovetails up good before I run it to reduce the friction for such a slow cut. Lots of cutting oil and a book to read

I think I'll lightly chamfer the two pin holes to reduce cuter wear too

Personally, I would stick with grinding. That spindle is pretty hard and grinding minimizes the cutting forces involved. Plus you get a visual indication when you have the face cleaned up.

[WOTDesigns]

THANK YOU EVERYONE! I shot some videos of before and after of indicating off of a 3/4" EM in the tormach collet, 3/8" tool in Tormach SS holder, 1/4" tool in ER20, 3/8" tool in Smithy SS Holder, and the face itself. Long story short: ER20 holder went from .003" run out close to the collet to "vibration" at .75" from the collet! face went from >.0005" to just "vibration".

admittedly I use a cheap import dti so I do not expect the actual distance to be spot on, but it will repeat the same reading 10 times in a row so for comparative purposes its good enough.

Tormach SS holder still shows about .0004 ish TIR and SO DOES SMITHY SS Holder. I'm going to post a new thread on the smithy holders in the benchtop section and post a link here.

Last night I Checked the 3/4" tool in the Tormach collet and it was about a half thou... same as my taper which tells me it isn't likely causing the issue. threw a RH Lathe bit in the vise facing right, put the spindle in reverse, .0004" DOC, .3ipm, Tapping fluid brushed on the nose. I was a little nervous so I set it high so the first two passes didn't even touch (i wanted to skim the forgave because of the holes). It was REALLY hard to see since my "enclosure" comes up level with the table.

3rd pass made a chink chink chink sound only on the holes, 4th took some off the outer edge, 5th took a light pass across, 6 the made contact the whole way.

Indicated the face and the needle barely vibrated. the indicated the er20 and had to move it several times, then indicated the TTS collar just to make sure the DTI still worked because I couldn't believe it went to virtually nothing from .003"+. both set screw holders went from almost 2 thou to less than half. Not sure more can be expected from them.

all in all it far exceeded my expectations and cost $0.00 since I already had the Lathe tool.

Thanks again. Especially TXFred- the S&F worked perfectly!