Dividing head onto an ML4

[goldstar31]

Bearings aside for a moment, i would like to learn to cast Ali, and even brass, though I'm told brass is a pain because it burns off the zinc, so more needs adding. So a little melt pot is on the cards to start some simple Ali castings.

Now bearings, i dont think the bearings are too bad just user error, they do need replacing granted. However they are adjusted to zero play in vertical movement, and nipped up to less than 1thou horizontal movement.

The tool has quite a bit of rake on the top, (makes nice tight swirly swarf). The large dia wasn't dialed in very well, so had anything upto 10-12thou wobble at its furthest most end. When the large (for my myford) 40 dia cut was applied and the tool hit the extra 10thou of wobble it dug in with the top rake and the pulled the soft Ali out the jaws a little (1/2" at most) switched machine off and released the tool, rechucked the Ali and set about cutting just a 20thou dia cut instead.
Unless the ML4 should be capable of taking something like a 40-60thou cut on dia? It was also only chucked in the 3jaw so less holding force as opposed to using the 4jaw.

In your earlier incantation, you were probably one of our Diesel fitters.

The ones in Darlington Market who held up ladies under garments and said 'Diesel fitter':hDe:

There ARE other expressions but ladies might be present:wall:

N

 

[JCSteam]

Norm I don't think I can adjust them up any better! If I tighten the round lock nut anymore the spindle won't turn. As it's locked against the headstock! The only way round this is a thrust bearing between the headstock and the lock nut. But I haven't seen any other ML4 fitted with one.

 

[goldstar31]

It's LONG time since I pulled an early Myford ML to bits but I recall a more recent episode with a Zyto which seems similar- perhaps on 40 or 50 years ago! It had a thrust washer in the front.

My ML10 is still here- soon to go. The front of the spindle is held with an integral PB b earring with a collar and so is the rear bearing.

My thoughts are that you should replace the bearings because of the risk of possibly cracking the clamps.

These should have shims in- have yours???

Now don't get me on that topic because I'm going to 'improve' the gibs etc on my new T&C.

Rocking like a pea( pee) on drum. Take yer pick

N

 

[JCSteam]

Yes there was a whole thread on that saga if you remember. Possible slipped bearings, and horrible chatter, when in actual fact I was looking at the thrust washer. (I hadn't realised that was there). The spindle assembly I think goes like this from chuck end to change gear end.
Spindle
Bearings
Thrust washer
Split bearing
Bull gear
Drive pulley and back gear
Split bearing
Lock nut
Gear
Gear retainer/spacer
The results of turning Ali are quite good. As can be seen from a 2" flywheel I made below

 

[Hopper]

If you can get a finish like that, sounds like your bearings are OK. But you might have a bell mouthed chuck or similar problem if you struggle to take a 40-50 thou cut in aluminium (presuming it is a free cutting alloy and not pure ally) without it coming loose. My old Drummond M-type, similar vintage and format to the ML4, will take 100 thou deep cut in steel under power feed without dramas. Ally I would expect to be able to take triple that.

 

[JCSteam]

Hi noted Hopper, there may be a few issues with accurate HSS tool grinding.
As I said originally I blame the operator not concentrating properly, i was rushing and I think? I only light nipped the chuck up, usually I double nip by winding in the next hole on the 3jaw for the key.

You may well be correct in the jaws been bell mouthed, but I don't think it's a large amount if they are. Though as I've read only gets worse due to the hardened surface gone the soft surface easily becomes squashed.

Perhaps a test?? I have reversible jaws, would just mean a slightly less access for close working. Though would determine if the jaws were locking evenly on the work.