Member postings for Hopper

Probably related to the Pitman arm used on old cars - pre rack and pinion - to convert the rotary motion of the steering box into linear motion to turn the wheel linkages?

That is the first time I have seen a lathe on wheels. Yes could be a bit tricky to set up to turn true over the full length if your shed floor is not a surface plate!

When you get to the stage of setting the lathe up, with or without wheels in place, here is a link to a good run down on how to set it level, with or without an expensive engineer's precision level, by Harold Hall.

http://www.homews.co.uk/page309.html

Here is his take on the precision level debate for the home shop amateur:

"Unfortunately, a precision level will be very expensive, especially when taking into consideration that it will be used very infrequently. Fortunately, all is not lost if a precision level is not to hand, as has been said, it is not necessary that the bed is exactly level.

Having mounted and adjusted the lathe (both across and along the bed) using a basic spirit level a test piece can be turned and measured, from this, the direction of adjustment required can be determined. After adjustment, the test piece is again turned over its length and again measured. Further adjustments can then be made and the process repeated until a virtually error free parallel result is attained."

His test piece procedure is quite complex and thourough so well worth a look.

Ha! Nobody else in the world has ever gotten the IT department to do something for them, why should editors be any different? Rank means nowt to the pointy heads.

Saw a similar one to this somewhere recently and it turned out to be the headstock thrust bearing was set too loose.

It's worth a try.

+1. Or does he have to make it half scale to qualify? Maybe it was a 250cc half-scale model of a 500cc "real" bike?

And what about all the home-designed Stirling engines, flame-eaters, IC engines etc. They are not models of bigger engines. They are engines in their own right, not models. Should we say they don't qualify?

I have both old bikes and models in my workshop, being worked on with all the same tools and machines. That qualifies as Model Engineer's Workshop content to me. Some tool or dodge I work out for fixing an old bike will be used next time same thing is needed for a Stirling engine.

Happy to discuss bike stuff with anyone anytime, anywhere.

Be happy.

Edited By Hopper on 08/03/2013 02:57:17

+1 here. Knocking off 10 minutes before the factory siren blew and cleaning down the machine, workbench etc was drilled into me for life when I was a spotty apprentice. Still do it at home. Flipside is, you walk into a nice clean, tidy workshop next day ready to start work without wading through cr.ud

Another reason surface plates were hand scraped to a final finish was so they transfer bearing blue better. A precision ground surface may be too flat to allow room for the the marking medium. So the old timers always said.

Scraping of course needs a master plate to mate the job to. The old boys where I served my time used to aim for about 30 bearing spots per square inch across the whole surface, using straight alcohol as a the marking medium, which allows you to see the metal-to-metal contact points. Don't think there are many of those guys left today.

I think you are out of luck on that one.

Metal spraying might be the way to build up the shaft, then it would have to be turned/ground back to size.

Here's an interesting way to check for twist when you bolt down a new lathe.

Sit lathe on its bench with mounting bolts in place but not tightened.

Put a steel bar in the chuck, say a foot to 18" long and 3/4" diameter for a Myford/Drummond etc, and tighten chuck.

Put magnetic base on the bed way with dial indicator registering on the far end of the steel bar in about the position the tool would normaly take.

Tighten down the mounting bolts good and tight.

If the dial indicator does not move, you are good to go.

If the dial indicator shows movement, you need shims under one or more feet of the lathe.

Surprising how much movement you get if you don't shim before tightening.

Edited By Hopper on 24/02/2013 11:05:26

Edited By Hopper on 24/02/2013 11:06:21

Too much fuss is made over levelling of small lathes. Unless there is large weight involved it is not critical.

As pointed out above, lathes on ships at sea turn out perfect work. I have a couple of model engines entirely made in a ship's engine room at sea and they have run perfectly for 50 years or more.

More important is the bolting down to the bench or floor of the small lathe.

Put it on the bench and stick feeler guages under each mounting foot. Then put shims of correct thickness under each foot as needed. That way, when you tighten down the mounting bolts they won't pull the bed out of line.

Ditto when bolting the bench to the floor, which should be done first.

Should be no perceptible shake at the spindle/chuck.

Could be the headstock spindle bearings need adjusting - something that requires a handbook/manual to be done properly.

If perceptible shake on the toolpost or cross slide, you might be able to adjust the gib strips - small strips of metal that fit against the ways and can be adjusted with three little grub screws on many lathes.

Best to get hold of a handbook/manaul first though and have a good read until you understand how it all works. See the page on www.lathes.co.uk on your lathe. It has a link at the bottom to a manual you can purchase.

http://www.lathes.co.uk/colchester/page17.html

But first thing is to get a good tool in place, quality carbide, new, or correctly ground High Speed Steel finished off on an oilstone and set at centre height with minimum overhang. (see those two books I recommended.)

Some pics of your set up would help.

And what model/year of Master is it?

Edited By Hopper on 19/02/2013 02:16:43

Edited By Hopper on 19/02/2013 02:23:40

Edited By Hopper on 18/02/2013 12:03:14

Oh, and I had forgotten about the Japanese submarine that sank off the Australian coast near Fraser Island in WW2. It contains tons and tons of very valuable mercury, used for balasting etc. But still had enough air trapped inside to have just less than neutral buoyancy. So, according to local scuba divers, they keep finding what they reckon is the hulk of the submarine in a tidal trench. But when they go back with salvage gear, it is never in the same place twice, sliding up and down various tidal trenches for miles underwater as the current flows between the island and the mainland. Apparently theyre is a network of criss-crossing underwater trenches out there so it is like looking for a needle in a haystack. But if a person could actually find, blimey that mercury would be worth a fortune...

I just finished tidying up my father's 1939 Drummond M-type and it does a superb job. Cuts exacty to size and does a beautiful job - once the headstock bearings were correctly adjusted. And modern flat belt materials grip heaps better than the old leather jobs.

It spent most of its life as a hobby lathe with only occasional use to make motorbike parts etc when needed, after starting life in a UK aircraft factory during the war. So has given good service yet the ways etc are little worn. The brass halfnut is the only thing I shall have to replace eventually.

By comparison, my brother bought a $1200 Chinese lathe and curses it every time he uses it. Reckons it cuts right on size one cut, way undersize the next cut way oversize the next etc.

Of the two, I would take the Drummond any day.

Well, I know of at least two sites in Australia where there are loads of 1942 military Harley-Davidsons buried, all wrapped in Cosmoline, still in their crates. The Yanks used them to fill in the swamps so they could build aircraft runways over the top. Then at the end of the war when the Yank ships headed home, they simply heaved all the leftover crated Harleys over the side into the harbour.

Thanks Ian.

I had not realised you could just use mild steel for the dsplacer. Might make life a bit easier, but I like the battery case idea so might try that too.

Lovely little engine, Ian.

What did you use for a displacer inside the AA battery casing?

Will a AAA battery casing work, or is it too small?

Hopper