Blind Hole Keyway

[platypus2020]

I have a National Machine keyway miller, bought by my FIL in about 1967, that I have used to cut keyways in a blind hole. They don't allow you to run the keyway all the way to the bottom of the hole, it it comes close.

[Tel]

How I would get rid of most of the metal first is to turn a plug to fit the hole with a head on it, then mark out the keyway position on the head, place the plug in the hole and drill a hole through it, which basically gives you nearly a whole keyway that you only have to clean up.
I use this method quite often for a blind keyway I have to do, I also drill a hole in through the side of the shaft for the keyway to end in.
Will

And that gets my vote as well - it's how I usually start internal keyways and saves a lot of work. It often pays to make the plug pretty firm, and drill and tap the centre of it for a pulling screw as well.

[madman]

Thanx

Tis Job was in Stainless it sucked and i spent some time filing it in. Tool all night to make one work out then started the other one but didnt even finish it. I checked the tram of the head last night it was also way out .perhaps from my 240 pounds ramming a cutter up and down the Hole like a big Monkey, Thought of quitting but .. Jobs are scarce. Also last night hand tapping 2 inch dia taps into holes ,,that sucked also. ha ha Life of the Old machinist .

[Black Forest]

A plug weld is just a weld in a hole. The weld attaches the inner part to the outer part. The hole is completely filled in with the weld. After that you can finish off the surface how you want. Where you see the blue through the red is where you would weld making a plug weld.

[dian]

what does "plug welded" mean?

[John Stevenson]

Get quite a few converter bushes to make for small motors, these are harderto do than larger ones which can be slotted on the slotting machine [ OK I know he doesn't have one - bear with me ]

The smaller ones are usually 14mm diameter, 5 mm key blind into a 30mm long hole.

I usually make a thru hole bush 30mm long and keyway this using broaches then press this into a piece of material that the final part is made from.

Prior to pressing in I drill 3 equally spaced holes in the larger piece then once pressed in these are plug welded and the OD turned down to suit.

Once done is nearly impossible to tell they are two piece items.

The project can be scaled to any size.

[Black Forest]

What I run into alot over here is say a pulley mounted on a shaft and then a hole drilled and tapped at the junction of the shaft and pulley. Sometimes on opposite sides, meaning there will be two of them.

THen there is a allen screw threaded into the threaded hole to act as a keyway.

[Mcgyver]

Mikey, you still have that shaper right? ergo that horizontal slotting machine? drill a relief hole at end and away you go

guess you're doing this at work.....and they threw out their shaper 30 years ago, right?

homework?

[Rustybolt]

how about one of those "key way mills" that come up every now
and again?

all i can say is "ouch" it hurt just reading.

edit.. maybe that was vague.. i'm referring to the mill tool that has a cutter
on the end (the width of the desired keyseat) and spins in a plane along your
Z axis, effectively "milling" the slot out). would leave a radius at the bottom
I suppose.

LOL.
We used to use one of those to mill the 1/2 inch keyway on Davenport screw machine cams. Each tooth on the cutter is offset a little from the one before.
Ours was mounted on an old Rockford camelback drill press, we called shakey marvin. Once it got to cutting it was pretty good, but the initial approach could shake the change out of your pockets.

[wbleeker]

How I would get rid of most of the metal first is to turn a plug to fit the hole with a head on it, then mark out the keyway position on the head, place the plug in the hole and drill a hole through it, which basically gives you nearly a whole keyway that you only have to clean up.
I use this method quite often for a blind keyway I have to do, I also drill a hole in through the side of the shaft for the keyway to end in.
Will

[Richard Wilson]

Sounds like a job for a slotting head, but you would need an undercut at the end of the blind bore to let the tool run out into. Could do it in the shaper as well, with the clapper box locked, and cutting on the reverse stroke.


Richard

[Tony]

how about one of those "key way mills" that come up every now
and again?

all i can say is "ouch" it hurt just reading.

edit.. maybe that was vague.. i'm referring to the mill tool that has a cutter
on the end (the width of the desired keyseat) and spins in a plane along your
Z axis, effectively "milling" the slot out). would leave a radius at the bottom
I suppose.

[armedandsafe]

Here is another approach I found.

http://www.youtube.com/watch?v=XcU0L...eature=related

Pops

[Forrest Addy]

I assume you were slotting the keyway with the quill using it as a vertical shaper ram. 1/4" wide cut takes a lot of thrust and the pinion and shaft in a turret mil quill is dinky and ftail. I suggest you start with narrow tools and increment so each cut =takes the same amount off each side.

It goes pretty quick once you get tooled up. You can cut the depth of a 1/4" keyway in about 20 strokes per tool and it saves wear and tear on your quill pinion.

[armedandsafe]

This is not a BLIND hole, but it does show how a key broach works. TubalCain, to whom I was introduced recently through this site, has more information than I can absorb easily, but he has solved a couple of problems for me already.

http://www.youtube.com/watch?v=8tAz5YDFtAs

Pops