Keyway cutter for Myford

Hi I want to make a keyway slotter for a myford s7 any body made one David hunn

Edited By JasonB on 12/12/2017 14:21:33

Hi,

See ME 17jul1970

Lathe planing adapter by LC Mason

P

Hi, Yes, made one from the casting and drawings available from College Engineering Supplies.

jim.

This one was made by the previous owner of my lathe. I believe it is the Mason design as mentioned above. It works very well.

HTH,

Rod

Hemmingway do a kit for a slotting attachment.
http://www.hemingwaykits.com/acatalog/Keyway_Slotting_Attachment.html

If you want to make up one from bar stock, have a look at
http://files.thor-hansen.webnode.no/200000005-d15e8d34f4/Emco_Slotter.pdf

Another design: http://www.cnczone.com/forums/attachments/2/8/1/5/0/127440.attach

Dave
The Emerald Isle

Stan Brays' simple design was published in Model Engineers Workshop issue no 1. As drawn its to go in a tool post but the carrier is easily modified to suit your preferred mounting.

Clive.

As much as I like the designs here, some of which I have considered making, for an occasional use, is there an issue with just using the saddle handwheel for movement with a keyway cutter held on the topslide? I appreciate a few turns of the handle each stroke is less convenient than a single swing of a lever, but the same overall effect?

No problem, I have cut keyways a couple of times using the hand wheel.

Tony

I have done quite a few with the handwheel upto 3/16" wide in steel.

That was before the availability of reasonably priced broaches from the far east which may work out less expensive than buying castings and materials. That is the way I went and can simply knock up another bush if required if I don't have one of a particular dia..

Do you need an arbor press as well, I would imagine a Myford 7 tailstock screw or vertical mill table screw would be up to the job, but not actually used broaches?

Tony

Keyway cutting / slotting on a lathe goes a lot easier if you can arrange to get most of the metal out with a suitable drill. Obviously has to be done before boring the hole or by inserting a plug.

Apart from relatively low speed of operation a major drawback to using the tailstock screw or carriage hand wheel feed is lack of feel. Its quite easy to apply unkindly large forces without realising what's going on.

Clive.

I have just recently cut several keyways 2.5 and 3mm wide for my Minnie Traction Engine using a tool in the toolpost of my Loughborough Training lathe and using the handwheel to feed it. This machine is a more substantial than a Myford but I was definitely in fear of something breaking. Today I have started making a slotting tool that does not depend on the lathe mechanism at all. I have designed it to replace the topslide and be lever operated similar to Rod's photo.

Edited By norman valentine on 12/12/2017 18:50:30

Norman,

Not to be recommended for a Raglan Litte John - and I suspect the Loughborough uses the same parts in the apron, for the longitudinal carriage travel. The L/J pinion, shaft and apron bearing were a weak point - the 5" was beefed up considerably, but I would still not use it for cutting keyways in that fashion. The hemmingway and other examples where the cutter is moved with the long travel locked down is, by far, the better option IMO.

You will shortly have a PM, regarding another matter.

Tony, upto 1/8" with a broach can be done in a drill press, just put a bar end in the chuck and pull down the quill lever, not tried using the tailstock screw.

These 3/16" ones on the left are 1" long and done in steel using the WM280 carrage handwheel and would be as big as I would be happy to do, probably 1/8" may be as big as you would want to go an a myford.

I made a home brewed one similar to Rod's which seems to work well enough for keyways and splines shafts.

Bill

How many internal keyways are you going to make? I've made one in anger, for a bushing to adapt a pulley to fit the shaft of a 3 phase motor. I used an inserted bit boring tool with a square tool on its side in the tool post, fed with the saddle hand wheel, taking IIRC round about 0.2mm cuts. It took a while but not as long as making a special slotter! Next time I may just write some gcode to do it as my lathe is CNC.

John, my answer to your question is more (keyways) than I am prepared to risk damaging my lathe for. That is the reason that I am making a slotting tool. If I only use it occasionally it will have been worth it. I have a few more to do in my current project so the time will be well spent. I have plenty of time as I am retired.

Good to hear I haven’t been abusing my S7 then, since so many others have done rather more than I! I don’t mind admitting I have done so now I know people who know what they are doing do it too...

A long time ago, I made a Slotting Tool to the design of the late Peter Robinson. It is intended for the Myford 7 Series, but I use it with a raising block on my BL12-24 (Warco BH600 / Chester Craftsman lookalike)

The casting came from College Engineering. Presumably, the new owners can still supply?

The rest of the material was awaiting to "come in handy"

Much better, and quicker, than a lot of winding of the Tailstock or Apron handwheels.

Howard

I've done at least one job like that on my Drummond M-type, a 5/32 keyway in an old Myford-style cast iron change gear. It works but very tedious. If I had more than one gear to do, I would rig up something like Rod Jenkins posted above, a long handle attached to the top slide.

On the Myford ML7 I would be wary that the apron casting is fairly flimsy Mazak attached to the saddle by three 1/4" Allen bolts so too much racking back and forth might be a bit much for it. (The Mighty Drummond's apron is a piece of 9/16" thick steel plate held on by 3/8" bolts so more durable.)

I plan to make a rig like the one Rod posted, but with the addition of three-position stop so it can be used for graduating hand dials etc. I have found that on homemade graduating tools it's hard to get rid of that last thou or two of slop between moving ram and body, which makes it difficult when cutting lines only four thou deep. So the topslide should provide a readymade precision slideway with zero slop.