Member postings for Simon Williams 3

That split collar - which is the nut - doesn't have any gaps in it once it is inside the outer body. Fairly obviously it is an interference fit inside the outer sleeve.

There are two radial grooves in the outer surface of the nut, these are stress raisers so the nut is broken int two along these lines, leaving a unique rough surface at the interface between the two halves which keys the two parts together.

The drive from the chuck key to the two halves of the nut is only by the friction of the interference fit of the outer over the split nut. That's why its jolly tight!

+ 1 for the swaged theory for me. I've played this game with several of the industrial grade Jacobs chucks successfully but never managed to get one looking like this apart. That rounded edge rings alarm bells.

And even if it is something that will come to bits and be OK to re-assemble, you'll need a lot more urge than an arbor press, or just hitting it with a hammer, even a big one. My 10 tonne hydraulic press will do this job but only just. Squishing it in a vice comes nowhere near.

HTH Simon

I read that mnemonics are the more effective the more outrageous they are.

Thus SOHCAHTOA, becomes instantly rememberable as "Sock it to her" especially to those of an age and disposition to remember Rowan and Martin's Laugh In

Rgds to all

Simon

The problem I've encountered with plunging a slot is all about re-cutting the swarf. Although it makes a mess, I've had better results by setting a compressed air jet against the cutting area to blow the chips out of the way.

Jason's suggestion to drill right through at the start helps too. That way you can wash the chips down the holes and let gravity clear the cutting area. Ideally this means flooding the cutting area with plenty of suds.

edit for minor but confusing typo

Edited By Simon Williams 3 on 07/01/2022 19:37:00

Having pursued the same adventure myself, I found the gap needed to be clocked in with a DTI and a few gentle reprimands from a plastic hammer to get the relevant surfaces true to the rest of the bed.

I had believed to this point that the dowels would be sufficient to align the gap on replacement, but not quite.

And cleanliness was indeed next to (or an appropriate substitute for) godliness.

Happy New Year!

Rgds Simon

I'm 100% with this, I find it annoying beyond all reason that I put them down and turn my back for a few minutes by which time the screen is blank. If the "ON" button was a bit more enthusiastic it would help. It would also help if the delay before auto-turn off was a more sensible timeout, say 15 or 20 mins.

It can't be beyond the wit of man (i.e. Moore and Wright) to re-program their otherwise nice calipers to be a bit more user friendly.

In days of yore I had a pair of Mitutoyo ones which not only self turned off, but re-zeroed when you pressed the ON button, Now those really were annoying.

So I bought a pair of (even more) expensive Starrett ones, which turn on automatically (retaining their zero setting) when moved. Much improved, but they still don't like being dropped.

Bottom item (long tapered tube) is a blow pipe, used in conjunction with a methylated spirit lamp to heat small items (eg jewellery) for hard soldering. Could also be used with a bunsen burner to direct a very small very hot flame sideways out of the main flame. Also used for heating precious metal ore for assay on a charcoal block.

Top item is a spirit burner, fill it with methylated spirit and light the wick. The flexy rubber tube with a pretty shaped (ivory?) mouth piece is missing, would attach to the bottom of the curved blowpipe tube.

To use either convincingly you need to learn the wood-wind player's discipline of being able to blow out down the tube using air stored in you mouth whilst at the same time inhaling via the nose.

HTH Simon

PS Late to the party as ever, someone came to the door and I was pipped to the post.  Story of my life.

Edited By Simon Williams 3 on 28/12/2021 12:38:31

Jason has it - that initial picture of Andrew's has the position for the "L - H " switch for the two speed motor, but somebody has removed the switch. So no two speed pulley drive as per the pictures of the Colt from Lathes.co.uk.

I converted mine to single phase, hated it, converted it back to three phase but with a VSD, making the best of both worlds. I've got mine configured so the original L - H switch is now a digital input to the VSD to tell it to run at 100 Hz to get the higher set of speeds, though I hardly ever use them. The other trick I've found is to set the VSD to run (low speed) at 60 Hz, then the lower speeds through the gearbox are all set up by 20%. I use mostly carbide tooling - the faster speeds are a bonus.

The original L - H switch is a 6 pole 4 position rotary switch, probably still available out of the Kraus and Naimer catalogue. It switched the motor windings to change speed electrically. With a VSD all you need is a simple single pole changeover switch.

There is some stuff about converting a Student HERE and some more HERE and HERE

HTH Simon

R8 is much the nicer taper as it is not self-holding so it lets go when you undo the drawbar. It used to be true that you could find a better range of tooling on R8, that's probably no longer true. But things like collets work better if they are not self holding.

BUT

If you have no other method to turn an MT3 drill then a mill with a MT3 socket up the spindle is the better option by far. It is true that you can get a R8 to MT3 socket adaptor but it will take up too much headroom as the R8 isn't big enough for the MT3 to sit inside it, it has to be below it so the overall length of the adaptor is problematical.

Seasons greetings all

IIRC Dryad were a purchasing agency for school handicraft equipment - in days of yore when handicrafts was viewed as an honest occupation.. Not sure they actually made anything, they had a catalogue of co-ordinated and reasonable quality range of stuff from a pottery kiln to a paintbrush. I've got a steel straightedge here with their mark on it, recommended for use with a Stanley knife like wot you'll never see in a class room ever again.

Methinks this is a job for some bigger technology than a Myford. If you are in the general area of West Gloucestershire I'll volunteer to do the repair for you for a contribution to charity. My ideas are running in terms of drilling a hole lengthways for some studding to hold the bits where they belong, then light the gas and toasty warm for a bronze welding repair. Have you got two baubles, if you'll forgive such a personal question?

PM me if it's of interest.

Rgds Simon

Dunno how to test the theory, but I have read in connection with battery life in quartz watches that how long the battery lasts is affected significantly by how much the battery was handled while being replaced. The proposition is that sweat or grease or general gunk off your hands bridges the battery terminals and provides a path for a significant proportion of the stored electricness.

I bought a Starrett digital caliper a couple of years ago having previously coped well with el cheapo ones. At £138 it was a special occasion. Eventually I have managed to catch it with the tail of my coat and knocked it to the floor. The expensive ones don't bounce any better than the Lidl ones.

It's lost the function of the inch/mm swap-over button. Not sure if that's it's retaliation for the ignominy of being dropped. Time for another new one (Santa, are you listening?)

Season's Greetings All

Simon

Just put two on my Santa list. MSC Direct was the cheapest I found (one needs to make sure Santa knows where to look), though Amazon also offer a very limited range but at more spendy prices.

If anyone finds a better UK source do please share.

Rgds to all

Simon

If it is any consolation I doubt that you would ruin a single phase motor on stop/start cycling in any normal lifetime. You might blow the upstream fuse if you really went hammer and tongs at it, but the motor itself is pretty solid. The clutch is there for controllability and ease of use, particularly threading. I have a lathe of a similar vintage to yours wherein the clutch is either solid or loose, and the lever doesn't allow you to choose between them. I use it with the clutch intentionally defeated (jammed tight). It's been like that for 40 years plus, and while it is true I have fairly recently changed the motor for a three phase one it wasn't because the single phase motor was protesting. I changed it for an experiment just to see if the lathe was better with a VSD and soft start - and concluded it is much improved.

I rather think that taking the countershaft to bits isn't going to reveal anything you can't do already, as the countershaft pulley will still have the clutch horseshoe jammed tight inside it, and you won't be able to dismantle the operating linkage without resolving this somehow.

Might just conceivably be worth popping the whole countershaft in the freezer? Then heating the outer cone multi-pulley quickly? If you can get the clutch shoe to let go just enough to line up the adjusting screw I think that's your only chance.

It would be a shame to take it part way to pieces then get stuck, and not be able to reassemble the countershaft again. You're better off as you are!

Good luck,

Rgds Simon

Pictures as from the relevant bit of the user manual here

Welcome to the forum!

From the description and the date, this is the old style horseshoe shaped clutch made out of cast iron, located inside the top multi step pulley under the drive cover.

Unfortunately I rather think you've boxed yourself into a corner with this one. Best I can come up with is to observe that the clutch has slipped under the start-up load, otherwise the adjusting screw hole would still be lined up below the screwed bung hole. If I've interpreted this correctly it means that the clutch is not rock solid.

Let's see if we can reverse the symptoms and recover the original situation by slackening the belts taking the drive down to the spindle, then grab hold of the countershaft motor pulley and the multistep pulley and see if brute force will prevail. I'd try turning the multistep pulley backwards to see if the clutch will allow a little bit of movement.

Bit crude, but it's the best I can offer so far.

I've been trying to import a pdf from the service manual with an exploded view of the offending bits, but I haven't succeeded.

HTH Simon

Brian - good afternoon to you. I was hoping you'd be able to chip in with a more coherent explanation of this than I managed, thank you.

I feel I ought not to let the concept of a 33.5 T gear pass into Myford myth. I hate to spoil a good story, but it was a 16.5T gear (or the functional equivalent thereof) John and I devised.

In fairness to everyone who has contributed this is a red herring, as we've established that the gearbox is the later type and thus the 33 and 34 T gears will offer the neat and workable solution for cutting the common metric pitches for which they are rightly popular. I was concerned not to assume that Frank's lathe and gearbox combination were contemporaries, as there would be a whole world of confusion awaiting if someone had fitted an old gearbox to a late date lathe.

As to sourcing the 33 and 34T gears, hopefully the forum can provide. Unfortunately I can't help at the moment, or at least not until after Christmas as I'm part way through a project for my nephew for his Christmas present, and I beginning to wonder if I've bitten off more than I can chew!

Best regards, stay healthy!

Simon

Diagnosing the gearbox vintage is straightforward. There are pictures of the differences in the threads referenced above, but the simple way is to first check that the thread cut is that indicated on the gearbox top label. So check - for example - if the levers are set for 20 TPI then 20 TPI is what you get.

Now open the gear cover to look at the changewheels carrying the drive down to the fat 72 T gear on the input shaft of the gearbox. If the gearbox is the later type the input gear on the mandrel (first stud below the tumbler gears) will be 24 tooth. It will be mounted on a 30 T which meshes with the tumbler gears. I don't have a picture of this to hand but maybe someone else can add one. There are pictures in the threads referenced above.

If the gearbox is the older type the gear driving the chain down to the input to the gearbox will be a 12/30 compound gear as the old gearbox runs at half the speed of the newer one. Here's a picture of the gear cluster for the older gearbox:

The Myford one is the steel one on the left; the bronze one on the right is another (related) story.

If you do have the older gearbox don't buy the 33 and 34 T gears - they are no use to you. If this is the case report back on here and I will introduce you to the alternative solution (it's that bronze gear!).

Best rgds Simon

xxx

Dunno if it helps, but this thread has got some further information about the 33 and 34 tooth gears:

More details

HTH Simon

Centec owner here!

I've had two of them, an Automill Mk1 converted to manual X direction feed and now an Automill Mk2 which has presently still got its original hydraulic feed and is in the throes of being converted.

I reckon the Automill is much more interesting than (say) a series 2 or 2a, it's more heavily built and - presumably because of the hydraulic to screw feed conversion necessary - a whole lot cheaper to buy.

Centec Automill on Lathes.co.uk

Tom Senior made a nice machine or two, but the price they attract is according.

Have a look at the little Harrison horizontal mill

Harrison Horizontal Mill on Lathes.co.uk

HTH Simon

edit : I wouldn't chance my arm going grinding on any of these machines, although the top speed on my Centec is 3000 rpm it's far too vulnerable to getting grinding dust in the dovetails which would wreck it.  Andrew's comments about the feed rate are also relevant.

Edited By Simon Williams 3 on 15/11/2021 22:47:57

Reverting to Frank's question "is there more to it than that", well, yes there is.

I did a search on this forum and came up with this as being pretty typical of the collected knowledge:

33 &34 T gears

It includes a useful table courtesy of Roderick Jenkins (first page of this thread) detailing what to set the QCGB to for a wide section of metric pitches.

There are other references, also the definitive text is Brian Wood's book "Gearing of Lathes for Screwcutting". Amazon say they have stock.

Please note you need to know if you have an early gearbox or a late gearbox. This thread :

Myford S7 metric threads

explains why, and how to tell the difference.

HTH Simon