Cutting a keyway without a broach

[John BaronParticipant @johnbaron31275]

Posted by Michael Cox 1 on 08/11/2018 21:59:27:

Here is an easily made adjustable broach:

http://mikesworkshop.weebly.com/small-hole-slotting-tool.html

I would suggest that you remove most of the material by drilling or milling first and then use the adjustable broach to clean up the slot.

|Mike

That tool is based on the one that I published on another forum some years ago

One of the things that makes it unique, is the method I used of retaining the cutter.

[Michael Cox 1Participant @michaelcox1]

Posted by John Baron on 10/11/2018 16:55:57:

Posted by Michael Cox 1 on 08/11/2018 21:59:27:

Here is an easily made adjustable broach:

http://mikesworkshop.weebly.com/small-hole-slotting-tool.html

I would suggest that you remove most of the material by drilling or milling first and then use the adjustable broach to clean up the slot.

|Mike

That tool is based on the one that I published on another forum some years ago

One of the things that makes it unique, is the method I used of retaining the cutter.

My broach was not based on yours but it does use the same principle. My broach has been on my website for about 10 years and an article on it was published in MEW 184 in December 2011.

Mike

[John BaronParticipant @johnbaron31275]

Hello Mike,

Yes I published mine in 2010, so that would have been just before you're article. The similarity prompted my reply to the post. Since I didn't even know that you're web site existed.

I recall that the method of retaining the toolbit caused some interest at the time !

It seems that great minds think alike. I'll have to go and have a wander around and see what else you have done

Regards:

BaronJ.

[BWParticipant @bw]

Does that little bit of wire really hold the toolsteel securely ? Am I missing something here ?

?

 

Edited By BW on 11/11/2018 06:48:45

[John BaronParticipant @johnbaron31275]

Hi BW,

Why don't you try it !

I'll guarantee that you can't pull it out by hand !

That retaining method has been around for a great number of years ! One of its uses is to retain two round shafts that are not in perfect alignment and provide drive from one to the other. You can find examples of this in some of the old radios of the 20's and 30's. I do believe that its used in some rotary tools today.

[jacques maurelParticipant @jacquesmaurel42310]

This process was also described in "post bag" in the january 2004 issue of ME.

JM

[Howard LewisParticipant @howardlewis46836]

Screwed in keys are known as Dutch keys.

If no hand slotting tool sis available (I use one designed by the late peter "Bushy" Robinson, intended for a Myford 7 Series lathe, using a casting from College engineering Supplies) On a raising block, it still finds use on my larger lathe.

But lacking such a tool, with a toolbit ground to 5mm, in a suitable holder, in either the toolpost , by racking the saddle to and fro and putting on the cut with the Cross Sl;ide, a keyway can be cut. As already said, make life easier by drilling out first of all, so that only the corners need to be cut.

Once needing a central 1/8" square socket, for a speedo drive, I used the tailstock in similar manner.

Howard

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