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- Feb 2, 2013
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- 3,627
I see the predicament, if you were to use steel instead of aluminum, it may offer more resistance to slippage. Adding some rosin may add to the grip
I'm using brazed carbide bit- in the photo. Got a micro grain carbide coming in tomorrow Mcmaster describes them as specific to SS. Interested - I don't work with carbide or SS much, mostly alum and HSS.You may be taking to deep a cut and/or too high a feed and the insert gets caught on the thread and unwinds the bolt. Also the type of carbide cutter and profile. I use CCMT inserts and haven't had any issue with the bolt/rod turning. Ideally you would want something like a 5C collet. Make sure it is free of any oil or lubricant as this can significantly decrease the holding power. I routinely either turn down SS bolts and/or thread cut down bolts w/o any issues. The other approach would be to use a through the spindle stop system.
I have 5c collets but not sure what that gains me- I mostly use them on the mill.You may be taking to deep a cut and/or too high a feed and the insert gets caught on the thread and unwinds the bolt. Also the type of carbide cutter and profile. I use CCMT inserts and haven't had any issue with the bolt/rod turning. Ideally you would want something like a 5C collet. Make sure it is free of any oil or lubricant as this can significantly decrease the holding power. I routinely either turn down SS bolts and/or thread cut down bolts w/o any issues. The other approach would be to use a through the spindle stop system.
True, but I like using a softer metal than the thread, brass or alum, to baby them - they are going to be used in a product. And I'm not an engineer but maybe a softer metal grabs better bc it conforms more? Not sureI see the predicament, if you were to use steel instead of aluminum, it may offer more resistance to slippage. Adding some rosin may add to the grip
it was never tightened w/o the stud loaded so nowhere to really deform to you know? couple dings maybe. I didn't reef on it.I was wondering if having to over tighten the chuck was deforming the aluminum for subsequent chuckings , maybe I’m overthinking this
That's what I did. Worked fine. Then I rounded off the back and it all went to south.Better yet, make a fixture out of hex stock- threaded and slit so it clamps the bolt tight