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Author Topic: Thread Milling.....Single pass  (Read 3955 times)

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Thread Milling.....Single pass
« on: March 04, 2009, 07:14:52 PM »
Hi All,
  Wondering if thread milling brass and aluminum with a pitch of 48 an 54 TPI could be done with good results using only 1 pass, using a single point cutter.
PD tolerances would be about +/-.0015.
 Can flood as well.
Any informed opinions welcome.......you too Hood >:D.
Thanks,
RC :)
« Last Edit: March 04, 2009, 07:16:38 PM by Overloaded »

Offline Hood

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Re: Thread Milling.....Single pass
« Reply #1 on: March 04, 2009, 07:58:00 PM »
Thread milling is done in one pass as far as I am aware.
Hood
Re: Thread Milling.....Single pass
« Reply #2 on: March 04, 2009, 09:37:05 PM »
There's 2 basic types of thread milling that I have read about.
One uses a full length cutter with multiple "teeth"and cuts all of the threads at once, one or more times around to rough and once to finish.
The other is with a single point tool, like a little woodruff cutter with 60 deg teeth. I read where this usually runs multiple passes to generate the full thread form.
I would be using the single point type.
Never tried it before.......Actually, I'm considering mounting a motorized spindle on the lathe carriage and generating the threads with a single pass of the rotating cutter synchronized to the lathe spindle in an attempt to cut down the cycle time from cutting the threads with a conventional lathe tool in 5 passes.

Thanks,
RC

Offline Hood

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Re: Thread Milling.....Single pass
« Reply #3 on: March 05, 2009, 02:24:32 AM »
I have not seen a lot of threadmilling and have only doneone myself as a test but all have been done in one pass, have never seen multipass but as I said I have only seen a few.
 I think fdos has done quite a bit of threadmilling with single point and Mach, might be worth giving him a PM.

 Oh and you didnt need to tell me how you were going to do it, I knew right away you would be building something unconventional to do it ;D
Hood

Offline Graham Waterworth

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Re: Thread Milling.....Single pass
« Reply #4 on: March 05, 2009, 03:39:24 AM »
I do a fare bit of thread milling, it is always done in one pass, the quality of the thread is more down to rigidity of the tool and machine, keep the tool as short as possible and solid carbide is better than mild steel tipped tools.

1" UNF with carbide single form runs at 2500rpm and 200mm feed, it works well for us, the machine weighs in at 14 tonne so its quite rigid  ;D

Graham
 
Never give up, time will pass, the cloud will clear, the sun will shine once more.
Re: Thread Milling.....Single pass
« Reply #5 on: March 05, 2009, 07:23:16 AM »
Quote
I knew right away you would be building something unconventional to do it
Hey...I defy convention whenever necessary. I'm politically incorrect as well. >:D.
But...I can see from Graham's response that this is a bit TOO unconventional in that the cycle time would be increased quite a bit. ::)

Just looking for the fastest cycle time possible.
Stuck right now at 100 parts/hr.

Graham.....what is the diameter of the cutter mentioned in your reply ?

Thank you both......very much,
RC

Offline AJA

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Re: Thread Milling.....Single pass
« Reply #6 on: March 05, 2009, 08:50:19 AM »
I have had good luck single pointing cold rolled using a modified carbide boring bar with multiple passes.  I would think in brass and aluminum and the fine pitch you would have good success.  Two passes would provide a better finish.
AJ

Offline Graham Waterworth

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Re: Thread Milling.....Single pass
« Reply #7 on: March 05, 2009, 01:43:41 PM »
the tool is 1/2" dia solid carbide.

Graham
Never give up, time will pass, the cloud will clear, the sun will shine once more.