Maximat V10/ Emco FB2 4-speed milling head

What a technically interesting reply, taking things on from an initial Materials perspective.

I see you have had a reply from the OP, which totally ignores the Materials aspects you expanded on, seemingly concentrating on the geometric aspects ("...perhaps you worry too much on the issue of the engagement of gears..."). This may be due to his unfamiliarity of the crucial differences between plastics and metals for engineering purposes.

The OP mentioned having some nylon in his junk box, but not only is the grade and type unknown, but also whether it was extruded or moulded, for example - which can have a significant effect of the properties of the sample.

Nonetheless, it cannot be stressed too heavily that engineering solutions in plastics are not the same as the solutions found with metals, and the OP has shown no signs of comprehending this fundamental difference. Doubtless the majority are happy with the contribution you made.

Progress report...

When the split Tufnol gear was pulled off, it snapped tightly shut at the split, suggesting that gluing might be an option; however the Evostick wood glue (the white stuff that sets hard and impenetrenable) does not seem to have the same power as on wood, and, although I bored out the hole in the gear, it again split open at the same point.

So....a call to HPC gears, and a metal gear came by return.

So - turn down the splined shaft. Bore out the HPC gear to be a force fit. Part off the HPC boss. Damn - got a dig-in and it has marked some of the teeth.

Drill and ream for a taper pin, apply Loctite (Britland jointing compound) and wait overnight.

Will report later.

Tufnol/wood...two entirely different materials. In general, when an adhesive specifies a material in its name it's a fair bet that it's not likely to be much cop on other materials.

Loctite is a Henkel brand, Henkel is a German company. Loctite was originally an American company.

Oh no...not again....is there no limit to this person's ignorance?

http://68.72.74.108/history.htm "Loctite Corporation began in the Trinity College basement laboratory of Dr. Vernon Krieble of Hartford, Connecticut, in 1953. This entrepreneurial chemistry professor developed a cure inhibition system for a unique liquid bonding resin that hardened in the absence of air

-- an anaerobic sealant -- based on a conversation with his son, Robert, also a Ph.D. chemist."

Progress report.....

Re-assembled the gear head (It came apart very smoothly and went back again equally so)

Try spinning the gears - uh-oh - runs for 3/4 turn then stops.

Upon inspection there's no clearance available to have even the smallest whisper protruding for the taper pin. Take it all apart, out with Dremel (or Chinese equivalent) and grind away.

Re-assemble, all nicely greased, and it seems smooth.

Final task is to adjust the gear selectors - small die-cast-ali arms. When I acquired the milling head, one of the selectors was already broken, so I filed up a replacement out of mild steel. Now, whether a result of the extreme cold making the diecasting fragile, but the other one snapped, diametrically across the hole for the shaft. So, before being able to report a successful repair of an obsolete Emco 4-speed head, another bit of filing up will be needed.

Perhaps I should have bought the Myford ML7 that was offered to me at the same time, because there's no shortage of spares for a 1948 Myford! However, a 1970 Emco, long since abandoned by its makers has resulted in running repairs to the 4-speed milling head so far.....

Right Hand Gear Selector Dogs holding Milling head to vertical shaft. Replacement 24-tooth gear, as detailed above and below. Left Hand Gear Selector (underway, as above)

And, by a previous owner, the gear selector casting for the Norton gear box had sheared and had been repaired (although it jumps out of gear, needing further attention)

Perhaps I should investigate becoming an expert in gear-cutting before something "gives" in the lathe itself? It certainly seems to be a truism that we spend more time making bits and pieces for our lathes than actually producing anything useful with them!

Cue Mrs.Nugatory.....

Plod's C> Progress report...

On the 50Hz model, (but not the 60 Hz model, only 2 windings shown in the manual), the motor appears to be a fully-fledged star-connected 3-phase motor, normally run via a capacitor.

I have now obtained a second-hand single-phase to 3-phase converter to drive the milling head, and so the success of any repair affecting 2 of the 4 speeds has suddenly become immaterial, as I now have a wide range of speeds available.

Subjectively, it seems to be runn> Progress report.....