feed rate

[winklershop]

Had a quick question. When you refer to what feed rate you are using, i.e. "running 30 thousandths feed rate" , which chart do you use on your lathes?

I have a 1957 lodge and Shipley and have three charts, leads per revolution, threads per inch, and feeds in thousandths. I am assuming I would use the feeds in thousandths, but what is the lathe doing if it's set at 30 thousandths feed rate (is that every revolution of the spindle it feeds 30 thousandths?).

I attached a picture of my charts.

Thanks Steve

 

[johnoder]

is that every revolution of the spindle it feeds 30 thousandths?

Exactly thus

That is why it is universally referred to as "IPR" - inches per revolution

The Power Turn won't have any problem DOING that, but you may decide its a tad COARSE

 

[Mike C.]

"The Power Turn won't have any problem DOING that, but you may decide its a tad COARSE "

True, your cutters and workpiece may also have issues with that kind of feed unless you know what you are doing and have everything set up rigidly enough to deal with the loads. Try it around .012/rev for roughing, first off.

 

[DMF_TomB]

a wiper is a cutter at a angle almost parallel to round turning part OD. you take small DOC and a higher feed to get a better finish.
.
been around over 100 years. also some softer materials you rough out at higher feed rates if it helps chips break up shorter lengths

 

[winklershop]

i see, good information, so i am very green when it comes to this stuff, i guess my question was even more simple

i hear a lot of people referring to their feed rate in thousandths, if you look at my charts, if i use the feeds in thousandths chart, and i set it to .010", that means for every revolution (regardless of speed) it is going to feed in .010", so that would be also known as ten thousandths feed rate?

I understand the threads per inch chart, for threading, but the leads per revolution? (would i ever use that for anything? not even sure what that means)

 

[redlee]

i see, good information, so i am very green when it comes to this stuff, i guess my question was even more simple

i hear a lot of people referring to their feed rate in thousandths, if you look at my charts, if i use the feeds in thousandths chart, and i set it to .010", that means for every revolution (regardless of speed) it is going to feed in .010", so that would be also known as ten thousandths feed rate?

Yes, one revolution or 360 deg on the spindle equals .01 saddle advancement.
Crossfeed will be half,on most machines.
Put a dial indicator on your ways ,turn your spindle by hand 360 deg and watch.
That machine wont stop for body parts,be careful !!!

 

[DMF_TomB]

usually tool manufacturer especially carbide insert manufacturer got fairly exact recommendations on feeds and speeds so chips break up rather than long ones wrap around part
.
usually when all else fails read the tool catalog

 

[dsergison]

..

...but the leads per revolution? (would i ever use that for anything? not even sure what that means)

I believe that terminology is for making worm gears of a particular pitch.