More gear related stuff.

I've just very successfully eliminated my database of about 170 gearcutters from my hard drive, as well as defragging the disc afterwards :-((( I was just trying to make a bit of space on the disc, it must have been in the 'wrong' directory, and not being 'vital' it wasn't backed up. Silly me. There might actually be some 22dp cutters there, but it's not a 5 minute job going through them all again & recataloguing them.

Good luck, I like little challenges myself

Cheers Tim

Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

If you decide to chicken out, I do have 22dp hobs, a standard one at

20 deg., and one labelled as .098" depth (just less than standard, but much more than 29dp) for 14.5deg. If you did the groundwork of turning up blanks & a suitable arbor, and *if* I have the right changewheels, it wouldn't be much of a job for me to run them off for you.

Cheers Tim

Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

Am I allowed to call it doing the job two or three months quicker, rather than chickening out?

The tooth counts that I need, subject to me not having counted wrong, are:-

70 66x2 50 45 30 24x2 21 14x2

They can all be full form apart from one of the 14t pinions, that engages with the existing rack, That one can just get scalped to reduce the addendum.

Assuming that those counts are possible, What sort of arbour dimensions do you need to mount on the hobbing machine?

Got a bit confused today. I was making the shopping list of bearings to replace C/O Arc-Eurotrade. There are 20 assorted ball and needle roller bearings in the apron, cross-slide and top-slide. Two of the bearings seemed to be a weird size that I couldn't reconcile They seemed to be 1.260x.590.

Turns out that that's 32x15mm. This is on an English assembled America lathe that was built sometimes between 1950 and 1960. I could understand later replacement parts, but it's hard to reconcile with the obvious stupidity that has lead to the damage of the gears and bearings.

I'll have a look tomorrow, see what wheels I can sort out.

The arbor can be very simple, I'll take a pic & dimensions.

AIUI ball bearings started as being all metric, and roller bearings as Imperial. Of course there have been both types in both standards for donkeys' years, but it's quite common to find metric ball bearings on Imperial dimensioned equipment and I believe that is why.

Cheers Tim

Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

Hardly surprising as at the turn of the last century the Yanks couldn't make reliable bearings and had to turn to German imports. As they got better they used imperial ones but in a lot of cases the die was set for the continued use of metric sized bearings.

The same applied to spark plugs. Ever wondered why we and the Yanks standardised on 18mm plugs and later 14mm ? Same thing, inferior insulators forced imports to be used. By the time Henry Ford got his act together and tried to introduce gas threaded plugs it was too late.

-- Regards,

John Stevenson Nottingham, England.

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Achtually ist vas der Swedes who converted the Yanks, SKF when asked to supply, said, ve already make metric sized bearings, zu vant imperial sizes? Ze come dearer. :-) Because the US auto industry was volume oriented they made the change..

Tom

70,50,45,30,24,21 no problem 66 & 14 I'll have to dig further, some numbers I can fiddle by using the feed change gears (finer pitch) with a conversion wheel.

If I can't do that, we'd need to find a 66t and 28t from somewhere, they're 1.25 mod but Myford change wheels serve perfectly well, would only need them for a day or two & I'd cut myself a couple of change wheels.

I'll have another look in the next few days.

Cheers Tim

Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

Got a 94 T. If you use 28 teeth off that it will leave you 66, any good ?

.

-- Regards,

John Stevenson Nottingham, England.

Visit the new Model Engineering adverts page at:-

I've got a 28t Myford wheel. I could get hold of a 33t 20DP from RDG or a 66t

1.25mod from HPC. Would either of those options work?

Now I need to politely ask Macready's if they are willing to take this months pay cheque in exchange for some decent gear and pinion making steel.

Regards Mark Rand RTFM

Brilliant! two stoned birds.

Mark Rand RTFM

66t 1.25 would be the proper way. Without going out again & measuring, I think it's 12mm bore (I've made some sleeves for Myford gears),but I can sort that out. 33t *might* work, though I doubt it. I would have to try assembling the gears with the nearest size I have, to see if it's physically possible.

Do they respond to being asked nicely?

Tim

Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

I've got some 50mm EN19 which would do nicely for the smaller stuff that I could spare, how much do you need? It comes complete with a fresh patina of rust from my recent aquatic adventures.

Peter

HPC standard for that size is 10mm pilot bore with no keyway, so that'd need tidying up to work.

They usually seem to put the price up whatever I say to them. Trouble is that I've never bought more than 250kg at a time from them, and you don't get very good prices for tiny orders.

Mark Rand RTFM

Don't bother. Mild steel with modern case hardening to about 10 thou will outlive what you want to do with that machine.

.

-- Regards,

John Stevenson Nottingham, England.

Visit the new Model Engineering adverts page at:-

Machine is setup at the moment for Myford gears before I pull it down to do some 16DP's. Do you want a 66 and a 28 knocking off ? If so what width and do you want a keyway.?

-- Regards,

John Stevenson Nottingham, England.

Visit the new Model Engineering adverts page at:-

The gears are easy, the two 14t and the 21t pinion have a harder life. Luckily the pinions don't need 3 1/2" diameter stock to make them from :-). It might be childish of me, but I don't like buying less than full lengths of stock. I'll see what the nice sales lady says about the relative costs for the various grades on the bigger stuff. I could get some nice pieces from work. Trouble is, the stuff they tend to use for turbines is nigh-on bloody unmachinable :-(.

Mark Rand RTFM

My shout for the 66t if Tim can use it. Got a 28t from the Myford metric conversion set.

Mark Rand RTFM

I've got some 60mm EN1A that got left outside... by the time I noticed, it was too late. Luckily a little dampness doesn't change the size of the stock much.

I'll probably go for a length of 3 1/2" EN29 or EN32. If I'm lucky, Macreadys will have a part length I can have. At a later date, when I'm set up for it, I could do a 40DP 127/50t metric conversion set. The spare stuff will make good door stops :-)

Mark Rand RTFM

It'll certainly do the job. Width is 12mm (non-critical), the bore should be 14mm but I've got some bushes for 5/8" if that's simpler for you. Keyway yes please, though I can do that if needed.

Cheers Tim Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service