Author Topic: Strange steel  (Read 5916 times)

Offline PStechPaul

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Re: Strange steel
« Reply #15 on: July 31, 2014, 05:27:44 AM »
There has been a lot of discussion recently regarding screw thread cutting, and it might be worthwhile to read through some of the more pertinent and informative posts and links:

http://bbs.homeshopmachinist.net/threads/63953-Proper-thread-form-and-terminology
http://bbs.homeshopmachinist.net/threads/63943-Single-point-threading-Not-understanding-the-59-5-degrees

Offline Roger B

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Re: Strange steel
« Reply #16 on: August 02, 2014, 07:01:21 PM »
I finally cut the thread, it was done with a HSS tool at my lowest speed (65 rpm?) using tapping lubricant. The swarf came off in continuous curls, but the surface was rough and torn. I cleaned it up a bit with, as suggested, a piece of hardwood and then followed with the folded edge of some emery cloth. The nut fits nicely  :whoohoo:  I bored through the centre up to 16.3 mm with out too many problems. The 40mm overhang meant I got a bit of chatter, but it's not an important bore.

I have now set up the taper using my MT2-ER25 chuck and will try and bore that tomorrow.
Best regards

Roger

Offline Roger B

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Re: Strange steel
« Reply #17 on: August 03, 2014, 04:32:44 PM »
I bored the taper at 1000 rpm without any real problems. The finish is not as good as the outside but OK.

With a 6mm collet and a length of 6 mm silver steel the runout was less than 0.02mm TIR and it seemed to position repeatably   :whoohoo:

Back to some engine building and some more normal materials now  :)
Best regards

Roger

Offline Jo

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Re: Strange steel
« Reply #18 on: August 03, 2014, 06:00:04 PM »
 :ThumbsUp: Nice one, and of course it will also fit on the nose of the mill  :naughty:

Jo
Enjoyment is more important than achievement.

Offline arnoldb

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Re: Strange steel
« Reply #19 on: August 03, 2014, 06:46:00 PM »
Nicely done Roger  :ThumbsUp:

You'll find the collet chuck very useful :)

Kind regards, Arnold
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline Roger B

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Re: Strange steel
« Reply #20 on: August 03, 2014, 06:46:28 PM »
That's part of the plan, although I also have the MT2-ER25 for the mill when headroom is not critical. Sometimes the 16mm rather than the 12mm (1/2") of the Hobbymat chuck may be useful.
Best regards

Roger

 

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