[laamar]

Is it aceptable or safe to turn 1 5/8 alu bar using a 1 3/4 liner on a Haas ST20 with a servo 300 bar feed my boss says yes, i'm not sure, and Haas don't supply a liner at that size.

[jimmyo]

i cut bars to shorter lengths to reduce the "whip" when the tube is a bit big.

you can make you own liner with spacers or at a push, stick some tape around the bar to make it a better fit in the tube

[laamar]

thank you for the prompt reply, i will try that

[gizmo_454]

Yes yes! On bars that large, I tend to cut them 2 to 3 feet long instead of the full 4 feet our SL-10 can run. It definitely helps with the whipping/vibration.

Mike

[laamar]

Thanks mike you're lucky we've been told not to cut any bars no longer than 1 meter or 40". 2ft sounds ok but could end up wasting alot of bar with ends of about 2-3 ins ejected every time.

[fseeley13]

We have two Haas SL20's (one with live tooling) with Servo300 Bar feeders. We have delrin pieces with dimensions 1-3/4 OD, with a slightly bigger ID than 1-5/8 measuring between 9in and 1ft in length to insert into the 1-3/4 ID spindle liner. Works really well considering we order all of our material in 12, 16, and 20 foot lengths. We cut 4 foot bars at the longest. Max bar length set at 52 inches in current commands. Never had a problem with the end of the bar shaking as long as you don't crank the RPM's above 4000. Really cheap considering the price of delrin and its a easy do-it-yourself spindle liner.

[fseeley13]

Being able to run 4 footers, opposed to 2 and 3 footers, really cuts down on the amount of scrap you are left with at the end of your bar. Depending on your situation at a business or machining for yourself.

[laamar]

thats a good idea, delrin inserts in the 1 3/4 liner. We got something similar on our Mazak lathes thanks fseeley 13. Why didn't I think of that ? Yes I think management would complain if I was throwing away approx 18" of bar stock.