Thread: Slotting - A Rough Attempt

Any more detailed pics of your slotter? I've been contemplating making one myself to hang off the back of my ram, but not sure which way to go about the mechanism at this stage....

J&H ,

That many they'll be coming out your ears. I will be selective.

BT

I would be interested in having a look as well, the more pictures the better Bob.

Here is a picture of Robs lathe mounted slotter Bob is talking about (their is a thread on it somewhere but I can't find it)
Repairing a Cub Lathe



Links to some of his other projects
Cone Centres
Knocking one off the list ,,, Tapping attachment
The story of My foundry
making progress
A bit of casting

Dave

J&H,

It started with an old casting I acquired from Hercus. The casting formed part of their superseded vertical milling head for the No. O mill.

There are a couple of sectional drawings of their slotting head in their mill handbook which formed the basis of my version. The main difference is that the newer vertical milling head and slotting head are driven by a pair of gears. The driving gear is mounted on the spindle nose, the driven gear is mounted, in the case of the slotter, to the end of the crankshaft.

My version has the crankshaft driven by dogs engaging the slotted end of the spindle nose. The dogged boss is soft 1214, the crank, 1045. The crank rides on a pair of Timken tapered roller bearings. Preload is acheived by means of the threaded, knurled 4140 nut. The connecting rod is fitted with self lubricating bronze bushes. The crank pin is an integral part of the crank and was an absolute prick of a thing to machine.

The ram body, ram and gib are 4E cast iron.

Bob.

Thanks for that photo Dave.

The slotter looks more substantial than the little Myford it's sitting on.

I'll have a look through my slotting head photos for some that might show some interesting or awkward setups. I had 3 goes at the crank and cocked up two of the ram bodies before I eventually got it right. Some setups proved just too awkward.

Bob.

Dave,

I just had a quick look at his tapping attachment. The bloke doesn't around!

Bob.

That came out great Bob, did you have to drill any holes in the machine or where you able to pick up holes already their?
Gives me an idea for my horizontal arbour, it's much easier doing some things vertical and when my mill is cnced, splines/gears would be so much easier.

Dave

Originally Posted by Anorak Bob

Dave,

I just had a quick look at his tapping attachment. The bloke doesn't around!

Bob.

Did you see John's suggestion on the last page about using the standard table support, after all that work.

Dave

Dave,

The mill has a pair of locating dowels slightly above the spindle nose. They are critical in providing alignment for the meshing gears in the vertical head.

My mill is a very early version, serial no. 08 and has the tapped mounting holes required for the old superseded vertical casting.

I had to mill a pair of recesses into the flange of the old casting to enable it to sit over the dowels. I made up a 3 Morse arbor that fits the bore of the spindle nose and has a locating spigot on it's outer end that fits into the end of the crankshaft to ensure centreline alignment.

Bob.

Here's a lathe mounted slotter I made years ago. From the very strong similarities between them it looks like this one and Rob's might have a common ancestry. An early issue of MEW ran an article on building a slotter using a casting for the main body. I used the dimensions and general design from the one in the article to fabricate the one in the photo. Rob's has a more elegant handle! The lathe is a 9 x 18 Brackenbury and Austin.

It is wonderful for cutting 1/8" or 3mm keyways in aluminium, brass and steel, not too bad for 3/16 keyways in softer metals, but hard work in steel, and heavy going for 1/4" or 6 mm keyways in aluminium and brass. I haven't ever tried to cut a 1/4" keyway with it in steel, but it would be slow and heavy going I suspect. The curved slot in the 25 mm plate base to allow keyways to be cut in tapers was made by chain drilling and filing to size before I got a mill. A slot drill and rotary table would have been quicker and easier!

Frank

Nup,

I'll check it out in the morning. I'm bushed.

Good night.

Originally Posted by franco

Here's a lathe mounted slotter I made years ago. Looks like this one and Rob's might have a common ancestry. An early issue of MEW ran an article on building a slotter from a set of castings. I used the dimensions from the one in the article to fabricate the one in the photo. His has a more elegant handle! The lathe is a 9 x 18 Brackenbury and Austin.

It is wonderful for cutting 1/8" or 3mm keyways in aluminium, brass and steel, not too bad for 3/16 keyways in softer metals, but hard work in steel, and heavy going for 1/4" or 6 mm keyways in aluminium and brass. I haven't ever tried to cut a 1/4" keyway with it in steel, but it would be slow and heavy going I suspect.

Frank

Yep looks the same to me, great work Frank.

Dave

Thanks for that Bob, always good to see how someone else has approached something! Looks like a neat job.

Just had a look Dave.

There are pros and cons for both setups. His fabricated arm, if concentric with the drill spindle allows the item to be tapped to remain in the same position it was drilled in. That's as long as that item was held in a vise and the vise was clamped to the table AND there is some way of accurately locating the tapping arm on the centreline of the hole to be tapped. Obviously, all of this is important only if the tapping of the hole on its centreline is critical.

The use of the table support arm is great if you have a bench mounted drill press and can easily mount the work piece on the base.

Both are a great way of ensuring verticality of the tap.

Bob.