More on the Myford ML7 4jaw chuck mounting

Well, a year has passed since I purchased the Myford (now Oct 2001), and I now have the boring and internal threading tools I need to make the 4jaw mounting plate, so Monday 24 Sept being a public holiday, I started on it (not without trepidation - how would the flame cut plate turn? The scale was hard, but otherwise ok - in future I'll grind the scale off).

The images here show the progress.


I had 2 blanks cut from 32mm plate. I don't know whether it was hot or cold rolled plate, I didn't know what to specify so just accepted what I got. This foto shows the 2 blanks, one under the 4 jaw chuck. It also shows the piece of 120mm angle I bought to use as an angleplate for milling operations on the lathe. So far it has never been used as I have no slide with T slots to mount on it (see link for developments). The spare backplate blank has become a flycutter.

Last edited February 20 2013 08:15:14.

A closeup of the 4 jaw chuck. It is nicely made except for some stiffness in one of the jaw screws which I will fix shortly. It has 4 mounting bolts in the back, M8 if I recall correctly. It is 100mm diameter, and I'm wishing I got a bigger one at the time.

Last edited February 20 2013 08:15:15.

Shot showing the the back of the mounting plate as it is mounted in the 3jaw (from the back of the lathe). You can see the threading/boring bar, and the threads. I used the threading tool upsidedown against the back of the 'job' and it worked very well.
You can see what you're doing in the hole!

Last edited February 20 2013 08:15:17.

Showing the plate from the front of the lathe. You can see the squarish hole I filed in the boring bar to take the tool bit. The tool bit is a piece of ball bearing casing. Held in with a M4 screw.

You can also see the nice finish on the threads. About halfway through I was getting a lot of chatter, figured it was getting blunt, and swiped my fine hard Arkansas once across each face of the cutter. Presto! Nice smooth cut again.

Last edited February 20 2013 08:15:19.

Closeup from the rear. I used the flash here and it's a bit bright but you can see the detail of the thread and the tool. The tool is a bit rough and I'll be remaking it shortly.

Last edited February 20 2013 08:15:21.

Any good job needs a drawing! This is a drawing I made nearly a year ago for this job, but not having the boring bars etc I delayed actually doing the job till now. I use TurboCAD V5 Pro for all my drawings, and this was printed on a very time expired HP Paintjet which I hope to replace soon.

Last edited February 20 2013 08:15:24.

Showing the blank now mounted on the spindle with it's own threads, chuck removed, and now faced and partially reduced in diameter. The blank was 125mm diameter, and the chuck is 100mm, so there's still a bit to be removed so they match.

The tool is an old brazed carbide tile cutter, slightly reground, with the shaft cut short.

Last edited February 20 2013 08:15:26.

Showing the rear side of the blank mounted and partially faced. The tatty piece of foil is held on with magnets and is there to revent oil from beign flung at me from the spindle end. The whitemetal bearings are drip lubricated and the stuff flows right through them even with the valve just open.
I have moved the carriage away here for clarity. I had it up close and locked it down, then used the topslide for cross feed when doing the edge which was rough from flame cutting.
This image was taken with the camera set to 'daylight' colour balance.

Last edited February 20 2013 08:15:28.

Finally, showing the chuck mounted. I used the cross-slide to mark the diameter at which the bolt holes were to go (off the drawign in the chuck manual), then used the spindle gears to divide the plate in 4. Center punched and drilled 4 then 8mm, countersunk to clear some fillets on the bottom of the capscrew heads, and presto! it fits and runs true. The capscrews are actually just a little too stiff in the holes to finger turn, but go in ok with the allen wrench, which means they're holding it firmly in several directions, apart from the recess on the chuck locating on the matching part on the mounting plate.

I didn't have the camera handy before I assembled it, hence no interim fotos at this time.

Last edited February 20 2013 08:15:30.
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Last modified: February 20 2013 09:47:30.