Author Topic: Shaft clearance - horse  (Read 3680 times)

Offline Ian S C

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Re: Shaft clearance - horse
« Reply #15 on: June 11, 2015, 01:41:30 PM »
IF your shaft is a tight fit after you ream to .625", put a sliver of wood in one of the flutes of the reamer, and put it through again.  Thats one way, or you can make your own reamer with a bit of silver steel.    Ian S C

Offline sshire

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Re: Shaft clearance - horse
« Reply #16 on: June 11, 2015, 02:37:18 PM »
Ian
Now that's fascinating. Never heard that one. How does that modify the geometry?
Another to add to the bag of tricks.
Best,
Stan

Offline tvoght

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Re: Shaft clearance - horse
« Reply #17 on: June 11, 2015, 04:22:38 PM »
I've also heard it said that just a slip of paper in one of the flutes will do the job. The same source (a fantastic craftsman giving a seminar at NAMES) said that some old-timers simply lay a cloth shop towel over the hole and plunge the reamer through.

--Tim

Offline Steamer5

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Re: Shaft clearance - horse
« Reply #18 on: June 12, 2015, 05:06:45 AM »
Hi Stan,
 Further to Ian's comment on the piece of wood in the reamer, you can use the same idea in a tap, I was fitting a sprocket to an angle grinder head....I was using the angle part as part of the drive for my Toby Tram... Had the right tpi tap but the size was just a bit tight. So tapped the sprocket then put a match in one of the flutes it was enough to open out the thread to make it a nice tight fit

Cheers Kerrin
Get excited and make something!

Offline sshire

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Re: Shaft clearance - horse
« Reply #19 on: June 12, 2015, 12:20:03 PM »
Guy Lautard (Bedside Reader) does mention using a hardwood sliver in a tap's flute to make it cut very slightly oversize. It's putting just a bit of pressure on one side to "offset" the tap. This is done as a second pass (the first has no wood)

Also, an old (1913) machining text (Google books) describes inserting a wire into the flutes of a reamer. The wire diameter is slightly higher than the reamer's flute. Same concept as the tap.

These were found after much "Googling."

The old guys had many tricks (probably learned during their apprenticeships or after years on the job) that have been lost over time. Some, like filling the reamer or tap flutes, are still know. Others, unfortunately, are not. In a time before the Internet, this information wasn't readily shared or indexed. The forums contain an astounding amount of knowledge. They've been my "apprenticeship."

Best,
Stan

Offline Ian S C

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Re: Shaft clearance - horse
« Reply #20 on: June 12, 2015, 01:01:48 PM »
There was an artical in "Model Engineer" somewhere in the last twenty years on reamers and using a wood strip to expand the hole.
With the tool makers reamer, if you sharpen it with a stone it will get a little burr on the cutting edge, this can be left on to enlarge the hole,  If the tool is hardened properly, this burr will be only tenths of a thou.  For one off holes in brass and aluminium, you don't even need to harden it, a bit of the shaft you'r going to use ground off at about 20*, put it through once, try for size,  If it's still too tight' (unhardened)file the face, this will throw up a burr.
Ian S C