I need RPM settings please

muscleflex

muscleflex

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Hi, I need rpm settings please for the below material and usage if anyone can help?

FACING:
aluminum rod: 6mm diameter
mild steel rod: 5mm diameter
stainless steel rod: 3mm diameter

PARTING:
aluminum rod: 6mm diameter
mild steel rod: 5mm diameter
stainless steel rod: 3mm diameter

I have a 7x14 mini lathe. It has a digital readout.
For facing.. I started using between 400-600rpm for the aluminum rods
I have not parted yet. I just got the parting tool last week: http://www.ebay.co.uk/itm/141031590854?_trksid=p2059210.m2749.l2649&ssPageName=STRK:MEBIDX:IT

Any help pls would be greatly appreciated. Thanks
 
When I part I run it as slow as it goes which is about 100rpm. Thats to fast some times on my 9x20. Go very very slow on the feed.
 
Thanks - I have looked at this in the past and it just really confused me! :(
so... for example for my 6mm aluminum rod (just a tad smaller than 1/4"), is it 250rpm or is it 400-700? there's two columns which I don't understand on that link. One is Ballpark CS and the other is Cutting Speed.


chuckorlando said:
well you need to find the cutting speed for the material. Then calculate the rpm and such. (CSx4)/Diameter. Then your feed is number of teeth x rpm x feed per tooth

http://www.southbaymachine.com/setups/cuttingspeeds.htm#Feed Rates
Click to expand...
 
Is this right?
Ballpark CS for aluminum is 250. and if my rod is 1/4" then using the formula (CSx4)/diameter will give me
250x4 = 1000
1000 / .25 = 4000??? that can't be right? 4000rpm?
 
Seems to me on steel be about 1500rpm. Now cut that in half and work up towards it till you find the right finish.

http://www.custompartnet.com/calculator/turning-speed-and-feed

The real trick to these things is knowing the cutting speed for the material. Not the rpm or your feed rate. Use the CS to calculate the rpm

http://www.custompartnet.com/calculator/turning-speed-and-feed

This site has all the info you need to figure out all this stuff. I just open a window for the info's needed and a window for the calculator
 
I believe I gave you milling calc first..

Cutting speed (100) x 12/.25 = 1528rpm
 
Wow I never thought it would be so complicated!!! :(
Thank you for the help tho. I have something to go by now.
 
It's not complicated so much as alot to learn at one time. This is the page I was really looking for here in the link. It has everything you need to know. Use the chart to find the cutting speed(sfm). For your machine I would start at the lower number in each given range.

http://its.fvtc.edu/machshop2/Speeds/RPMcalc.htm

I have to go over all this every time I do it so dont feel bad
 
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