Author Topic: recutting threads, sort of?  (Read 3450 times)

Offline reel jon

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recutting threads, sort of?
« on: April 25, 2009, 03:22:28 PM »
not being able to purchase left hand threaded bolts in the size i require i have been machining round bar down to the required size and threading it using a Die, this is labourious and not very accurate, i put a standard bolt in the chuck and ran the left hand die down it hey presto it worked (well enough for my needs)

Does anyone have any tips or thoughts to offer?. I am sure this is not an original thought i have had, is this common practise?

bogstandard

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Re: recutting threads, sort of?
« Reply #1 on: April 25, 2009, 04:14:26 PM »
Hi Jon,

Moving threads about like that would definitely make a weakened end product, but if it suits your purpose, then why not.

An easily made die holder to fit into your tailstock should overcome all your problems. An hour or two spent knocking one up will be repaid many times over with good straight threads. All they consist of is a straight bar with a sleeve than fits nicely over the bar.

If you need any help, you only have to ask.

John


Offline John Hill

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Re: recutting threads, sort of?
« Reply #2 on: April 25, 2009, 04:25:24 PM »
Not yet having experienced the undoubted delights of a die holder I have to ask is the die free to rotate with respect to the tail stock?
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bogstandard

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Re: recutting threads, sort of?
« Reply #3 on: April 25, 2009, 04:41:38 PM »
Yes

Bogs

Offline John Hill

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Re: recutting threads, sort of?
« Reply #4 on: April 25, 2009, 04:45:02 PM »
Gotcha!  :thumbup: I will make one as soon as I finish this cup of tea!
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bogstandard

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Re: recutting threads, sort of?
« Reply #5 on: April 25, 2009, 04:51:50 PM »
John,

The bar that goes into the tailstock should be fairly rigid, 10mm and above. The sleeve should be a nice sliding fit, but not sloppy.

Make the recess for the die about 0.05mm to 0.1mm (0.002" to 0.004") larger than the die, that will allow you to expand the die, not too much or the die will crack.

John

Offline reel jon

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Re: recutting threads, sort of?
« Reply #6 on: April 26, 2009, 02:43:44 AM »
Thanks for the replies gentlemen, all the recut thread does is wind in and out adjusting the magnets distance from the rotating spool on a fishing reel, so never comes under any real load.   

Offline reel jon

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Re: recutting threads, sort of?
« Reply #7 on: April 30, 2009, 11:39:33 AM »
Sometimes (not very often in my case) a little light goes on in the brain, instead of using a fully threaded set screw the idea came to me to use an over length bolt, saw off the threaded bit and cut the thread onto the plain part of the bolt. Easy really when i have spent about a month thinking about it.