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Axkiker
07-01-2015, 02:45 PM
I have a part with a 1.75" ID that will need a key slot cut. Any ideas out there on how to accomplish this without a broach or hand filing?

Thanks

skunkworks
07-01-2015, 02:57 PM
do you have a lathe?

https://www.youtube.com/watch?v=XcU0LTavzDM

Mcgyver
07-01-2015, 03:03 PM
or a mill?

Axkiker
07-01-2015, 03:17 PM
Yes I have both a mill and lathe...


I did think about doing it like the video above describes but didnt think it could be done with steel. Do most think that it could be accomplished the same way with steel?

Gary Paine
07-01-2015, 03:22 PM
Yes I have both a mill and lathe...


I did think about doing it like the video above describes but didnt think it could be done with steel. Do most think that it could be accomplished the same way with steel?

I've done it several times over the years.

mickeyf
07-01-2015, 03:22 PM
This sounds like a job for ...Ta Da! ...Shaper Man! (https://www.youtube.com/watch?v=NKu6xhAAC5A)

But of course you can do it on a lathe, manually moving the carriage with a properly shaped tool in a boring bar.

mickeyf
07-01-2015, 03:25 PM
I have done this with a lathe on steel before I had a shaper. Just don't be to ambitious with either the depth or width of your cuts. Even with a shaper there are times when you'd want to make a first, narrow keyway then widen it to size, or in some other way do it in multiple passes.

Mcgyver
07-01-2015, 04:19 PM
Do most think that it could be accomplished the same way with steel?

you just control depth of cut each stroke. here's a 3/8 irrc key way in 2" plate done on the mill......for large keyways like this, plunge a slot cutter first to remove the bulk of the material

http://i20.photobucket.com/albums/b201/michael0100/DSC_7889-large_zpsz23kcgd9.jpg (http://s20.photobucket.com/user/michael0100/media/DSC_7889-large_zpsz23kcgd9.jpg.html)

J Tiers
07-01-2015, 09:57 PM
Do you own a file of the right size? A chisel?

the lathe shaper setup is all very well, but I agree it takes a good deal of force, and I really don't like how it feels on a smaller lathe. If you have some large old iron 14" or so, go for it.... you won't notice anything.

If you have an Atlas, I suggest you do it with the mill instead of the Atlas.... the hand feed gearbox on at least some of them may come out in pieces....

Allan Waterfall
07-02-2015, 03:07 PM
You can always bore the hole oversize and make a sleeve to fit,then cut and file or mill a gap in the sleeve and Loctite it ino the part.
That's the way I've done it in the past.

Allan

Axkiker
07-02-2015, 03:26 PM
So I think ill do it in my mill. Any thoughts on tool geometry ???

oldtiffie
07-03-2015, 01:21 AM
you just control depth of cut each stroke. here's a 3/8 irrc key way in 2" plate done on the mill......for large keyways like this, plunge a slot cutter first to remove the bulk of the material

http://i20.photobucket.com/albums/b201/michael0100/DSC_7889-large_zpsz23kcgd9.jpg (http://s20.photobucket.com/user/michael0100/media/DSC_7889-large_zpsz23kcgd9.jpg.html)

Thanks McGyver - I will "borrow" this pic temporarily as it is ideal for a "demo" of where a good "slotting head" on a milling machine is ideal:

https://www.google.com.au/search?q=slotting+head+attachment&rls=com.microsoft:en-AU:IE-SearchBox&rlz=1I7IRFC_enAU360&biw=1536&bih=710&tbm=isch&tbo=u&source=univ&sa=X&ei=TRuWVcKaOYGcgwSf4ZmYAw&ved=0CCwQsAQ

http://www.machineryhouse.com.au/M225

http://www.machineryhouse.com.au/S707?From=TopMenu

Boostinjdm
07-03-2015, 01:49 AM
Last one I paid for cost me about $20 IIRC at the local machine shop. They don't work 26 hrs a day like I do and it was an hour round trip. So now I own a broach set. They are reasonable when on sale at Enco.

oldtiffie
07-03-2015, 03:03 AM
There is always the option of buying the broaches on an "each" (per item) basis though that is dearer on a per each cost if a ful set of broaches was bought.

http://www.machineryhouse.com.au/Keyway-Broach-Sets?From=TopMenu

The limiting factor may be whether there is enough "push" in an arbor press.

luthor
07-03-2015, 07:51 AM
The limiting factor may be whether there is enough "push" in an arbor press.

Another important factor to consider is the "Throat Height" of the arbor press. I recently had to purchase a 5 ton press to get enough height to use some of the larger broaches in the keyway set Tiffie linked to.

Rosco-P
07-03-2015, 09:05 AM
Do you own a file of the right size? A chisel?

the lathe shaper setup is all very well, but I agree it takes a good deal of force, and I really don't like how it feels on a smaller lathe. If you have some large old iron 14" or so, go for it.... you won't notice anything.

If you have an Atlas, I suggest you do it with the mill instead of the Atlas.... the hand feed gearbox on at least some of them may come out in pieces....

Seriously, one keyway? If it's not 2" long, lacking the correct broach and bushing, filing it would take less time than the mill or lathe setup.

dalee100
07-03-2015, 09:11 AM
So I think ill do it in my mill. Any thoughts on tool geometry ???

Hi,

The shape is pretty simple to make with a HSS lathe bit. I use about 5 degrees positive on the front cutting edge, and about 5 to 10 degrees on each side, I keep depth of cut to .001" to .002" per pass with some "air passes" to relieve tool spring as needed.

Dalee

J Tiers
07-03-2015, 10:48 AM
Seriously, one keyway? If it's not 2" long, lacking the correct broach and bushing, filing it would take less time than the mill or lathe setup.

Well, I didn't suggest filing on a time basis..... I don't know that it would take less time, but more on the basis of some machines just not being suited to that. I don't like it on my Logan, I hate to think what it would be like on an Atlas.

Although, if you have to grind a bit, and then do the setup, it actually could take less time to file it. Filing is "OK" but if you want a good fit you do have to be careful and not file-in a "smile" profile to the length.

Getting the middle section of the groove flat with the ends (not humped-up), and the whole works not tilted, can be a pain. That's where the "hand shaper" technique can be better, it takes pretty good care of the straightness and flatness.

outback
07-03-2015, 12:59 PM
Take it to someone that has a wire EDM. Probably cost $75 to $100. Depends what your time is worth.
Jim

oldtiffie
07-03-2015, 08:10 PM
Originally Posted by oldtiffie

The limiting factor may be whether there is enough "push" in an arbor press.





Another important factor to consider is the "Throat Height" of the arbor press. I recently had to purchase a 5 ton press to get enough height to use some of the larger broaches in the keyway set Tiffie linked to.



Thanks luthor.

I have a 3 ton arbor press and what I needed to do - and the broach - would only just fit in the "Throat" of the arbor press.

My anal sphincter got a good stressing as it would not take too much of a misalignment to put the broach in peril if "bowing" side-ways and as a worst case "springing" (and shattering) side-ways.

It is essential that the broaches be as sharp as new as a blunt broach to be pushed through instead of smooth cutting may may be asking for trouble.

Same appliers if the cuts are too deep.

In a good world broaches would be "pulled" through rather than "pushed" through.

I have started my broaches on my 20 ton hydraulic press and with a lot of good care and alignment is assured it can all go quite well - but the pressure has to be released occasionally to release "spring" and then start the cut again.

My (Chinese) press has a "Porta-power" pressure system which has very good "feel" as well as a pressure gauge so that I can see how much pressure is on the ram as well as the broach and the job.

The big advantage of the press is that it has a large adjustable depth of throat as well as a good wide throat as well.

http://i200.photobucket.com/albums/aa294/oldtiffie/Hydraulics/Hydpresspressure1.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Hydraulics/Hydpresspressure2.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Hydraulics/Hydraulics1.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Hydraulics/Hydraulics2.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Hydraulics/Hydraulics3.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Hydraulics/Hydraulics4.jpg

Axkiker
07-04-2015, 10:45 AM
Well as they say I "gotter done" Its not perfect but worked pretty well using my mill and boring bar.

http://i1167.photobucket.com/albums/q633/Axkiker/Mobile%20Uploads/2015-07/7B5B7747-2171-4F14-A539-29A2D58DCFBC.jpg (http://s1167.photobucket.com/user/Axkiker/media/Mobile%20Uploads/2015-07/7B5B7747-2171-4F14-A539-29A2D58DCFBC.jpg.html)

winchman
07-04-2015, 11:04 PM
you just control depth of cut each stroke. here's a 3/8 irrc key way in 2" plate done on the mill......for large keyways like this, plunge a slot cutter first to remove the bulk of the material

http://i20.photobucket.com/albums/b201/michael0100/DSC_7889-large_zpsz23kcgd9.jpg (http://s20.photobucket.com/user/michael0100/media/DSC_7889-large_zpsz23kcgd9.jpg.html)

Why was the part designed with the keyway in the worst possible position? Shifting it ninety degrees either way would have been so much better.

oldtiffie
07-05-2015, 01:35 AM
Well as they say I "gotter done" Its not perfect but worked pretty well using my mill and boring bar.

[IMG]http://i1167.photobucket.com/albums/q633/Axkiker/Mobile%20Uploads/2015-07/7B5B7747-2171-4F14-A539-29A2D58DCFBC.jpg (http://s1167.photobucket.com/user/Axkiker/media/Mobile%20Uploads/2015-07/7B5B7747-2171-4F14-A539-29A2D58DCFBC.jpg.html)

A really nice well thought out and finished job.