Author Topic: What thread - pneumatic drill gear/body?  (Read 2960 times)

Offline PekkaNF

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What thread - pneumatic drill gear/body?
« on: April 14, 2013, 02:12:25 PM »
Bought I cheap pneumatic drill like this:
http://images.toolstop.co.uk/product/7c42b405d9d3bf9f761d7a0a4a55be63.jpg

I want to know what thread is likely between the gear shell and pistol grip.

Thread is pretty rough and my measurements are not very consistent. Closest approximation I came up is M38*1,25. OD is somewhat less than 38 mm, but thread is rough. Judging from 6 thread lead is about 1,28 mm, but it is rough approximation.

I'm not very convinced about the thread being metric - lot of the dimensions on that drill could be approximately metric or imperial - or something between.

Any ideas?

Pekka

Offline Bluechip

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Re: What thread - pneumatic drill gear/body?
« Reply #1 on: April 14, 2013, 02:41:02 PM »
Pekka
 
 
Possibly 1 1/2" x 20 TPI ???
 
20 TPI Constant Pitch was fairly common on ( AFAIK ) Printing Machines.
 
I was given a set of 20 TPI WF Taps and Dies in a fitted case from 3/8" to 1" dia. by 16ths
 
Huge kit, in a posh wooden box. Included drill bits with long pilots and all sorts of weird stuff.
 
The ( deceased ) man who owned it was a printing press engineer.
 
It was going to be dumped so I rescued it. Then could never find anyone who wanted it so I dumped it.
 
Cries of Philistine ( and worse ) from Whitley Bay no doubt...  :)
 
Dave BC
 
EDIT Sorry WF is 'Whitworth Form' 55o
 
 
 
 
 
I have a few modest talents. Knowing what I'm doing isn't one of them.

Offline chipenter

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Re: What thread - pneumatic drill gear/body?
« Reply #2 on: April 14, 2013, 03:38:50 PM »
That's close to 32 tpi which is ME thread ,  do you know where it was made .
Jeff

Offline PekkaNF

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Re: What thread - pneumatic drill gear/body?
« Reply #3 on: April 15, 2013, 02:36:57 AM »
Thank you.

1 1/2" x 20 TPI is pretty close to my measurement D38,1mm and 25,4mm/20tpi = 1,27 mm/r. I'll try to figure changegear to make that 20 tpi and try it. Maybe I should try firs ali to nominal diameter and pich and see if I have to come down from there.

This drill is first one I found and it is made in china. It's this very generic form factor and probably there are quite a few manufacturers making these for very many brands. That picture on my first post is very close to drill I have.

It's probably copy of a copy and made cheaply. There is no way to assertain which units are used....probably it is a copy of imperial drill at one point, but dimensions are probably fudged to produce aproximate on materials available.... Bearings are metric (somewhat undersize), length measurements are very close to metric, but diameters and outside dimenssions looks imperial. Therefore I tought that if there were any universal or prefered dimenssions on these machines, that could be a good starting point. Like chuck threads are imperila and pneumatic fittings are imperial.

Pretty much only imperial tap I have is for G1/8" for smal selfmade pneumatic stuff.

I'm building here just a "proof of context" from odds and ends....I got this great idea, but there are guite a few uncertainties and I don't want to thrash the better drill just yet.

Pekka


Offline Meldonmech

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Re: What thread - pneumatic drill gear/body?
« Reply #4 on: April 15, 2013, 02:50:18 PM »
Hi Pekka
                Do you have a set of metric and imperial thread gauges? if not they are available on ebay and are not too expensive.                                                                                                                                                                                                                  David