Sam Thompson

Don't try to use Mole grips as tongs; it's dangerous; they only grip along a line and allow the work to move, it is difficult to reposition the metal and they can fly open with no warning (often giving your fingers a jar as they do so.

Enjoy the strained muscles and blisters.

Compared with the price of 6mm round bar (about £2.00 for 20 feet) that's expensive! John's examples use the original shape of the nails to decorative advantage, making a common rose out of the distinctive head seems counter productive, you could use anything for that.

Buying horseshoe nails is an expensive way of obtaining stock bar. Those are known as "Russian Roses" I believe; there's instructions in the blueprints.

Over here in the third world we prefer more specific terms.

Has anyone ever done any research into the proportions of heat lost through radiation into the air, into the anvil and into the stock (or tongs)?

Look sorta like part of a stud puller wrench. The eccentric wheel engages when turned.
Phil

I think you may be right, I've got a similar tool for turning studs, I'll have a look tomorrow

I agree. they do look like knurls, but knurls have one central hole, the grooves are also at the same angle on all four so there could only be halves of four pairs. If they are meant to revolve. I can't imagine why there wouldn't be a central axle. The variation of the positioning of the holes that interests me; they all look slightly different.
They were in the drawer with the dies which is why I thought they could be blanks when I first saw them but if I were making a die, I'd make the holes accurately and put a centre mark on them.

Thomas I would agree with you but I charge for all full length even if I have it in the rack.

I've always considered the off cuts as part of the profit, if you need to make a number of 3' long rails, then you can only get 6 from bar, leaving a lot of 2" lengths that can be used to make, for example, tentpegs. After a surprisingly short time you will have a selection of various sizes of bar and will only need to buy steel in for specific jobs. Spending £500 on stock to play with seems a bit ostentatious; in the UK most stockholders will deliver within a couple of days, even for smaller orders.

I bought a load of engineering stuff yesterday (mostly BSF taps and dies, drills, files and wad punches; it was in a nice box. Included in it were these four items. They are about 1.25" dia, they look like tool steel and there are no markings. My first thought was "blank dies" but the holes are not accurately central and the edges are milled. Anyone got any ideas?
The pencil was in the box, it is unused and has never been sharpened, if it is of any interest to anyone, I'll happily send it over.

Your drawings look great. If you use drill and tap the holes and use ball bolts or studs, spend the money and buy a new high quality tap and tap drill for the project. Drilling and tapping will be one of the last steps in the job, The $15-20 is nothing compared to the cost of re making a component due to a broken tap.

...and be very careful about heating and cooling any piece that will be tapped, a lot of "new" ms bar will harden unpredictably if cooled too quickly, even by the heat running away into the unheated area of such large stock.
Nice drawing though.

Have you thought about using angle section for the legs? It will give an appearance of weight to the design and be much easier to work; you could easily use 3" and rivet the braces and decorative elements to it.
I would think long and hard before trying to forge (or even heat) anything above 1.5"square.
If the client will give you the time, why not knock up a maquette of parts of your designs?

Sam - keep in mind that this was done 85 yrs ago, so today it should still be able to be accomplished, you just need to search for a shop that would be willing to do a smaller project as this. Plenty of retired machinists would be thilled to use there knowledge and skill to do this, as lots of them have shops at there homes to play in.

It was the retired engineer down the road that suggested making a tap!

Thank-you everyone for your help and suggestions.

Feeding towards the tailstock is what you would want. That would be a left hand thread: turning forward, but moving backwards. It is not necessary to run the lathe backwards.

This would be OK on an outside thread, you could turn a short length near the headstock to the minor dia and start there; for an inside thread, the tool would need to start the cut blind, there are many opportunities for frightfulness.
The thrust bearings on both Mandrel and lead screw are designed to work in the opposite direction and although with work this light, it's unlikely to make much difference, inaccuracies coud creep in.

I really don't fancy my chances of cutting an accurate 15" long thread thread on stock that size. Apart from the accuracy, with no powered reverse or thread dial, winding the tool back to the start by hand could become irksome! The "nuclear" option is to find a similar feed screw and nut from a scrap machine and modify it to fit mine.
In the mean time, I'm going to try and make a tap out of ms and case harden it.
The lathe won't care what the thread is but the micrometer will.

I don't think they make chasers small enough to go into a Hole that small, do they? I've never chased an internal thread; the possibilities for catastrophic breakage financially terrifying!
The correct tap is only £356+vat.. .

so it is left handed?

Just set the gears as a tumbler to reverse direction, you add an extra idle gear in the change gears to reverse the direction of travel.

Phil

That won't work, the tool will feed towards the tailstock. To cut LH thread the work needs to rotate backwards, the tool needs to be mounted the right way up on the opposite side and feed towards the chuck.
A lathe will not cut a perfect Whit thread form anyway as the crests and troughs should be rounded.

I should have taken some pics of it but it's now back in place; it's just an oblong block of CI with a hole through it. It's definitely 11tpi; I know that's weird. I cant cut it on this machine as I cant reverse it. It's not likely that anyone here in the UK will have a spare nut as the lathe is 85 years old and German.
Even without the X-slide feed it was still possible to use the machine by locking it up with the gib strip and using the top-slide as a feed but it's not the same somehow.

If you a make a new one and put it on the shelf the repaired part will last forever.

If you don't make a new one the repaired part will break on a Saturday afternoon with a Monday deadline.

How lucky do you feel?

That's it in a nutshell!
It also might be quite fun to try and cut the thread on my cousin's lathe.

I know this is lathe-related but it's really just a metalwork problem.Can any one help with this:

I've just broken the nut on the cross-slide feed screw of my lathe; it's a 1920s Erlich, badged IXL, identical to the pale blue machine at the bottom of this page:

http://www.lathes.co.uk/ixl/index.html

The original part was cast iron and has cracked into three. The thread is
7/16 11tpi Whit. Left-hand. The preferred spec for this dia. is 14tpi and taps for this are available, however...
I've brazed the old one together and it seems to be ok but I doubt it's going to last for ever!

Sam are you thinking of cast *iron*?
Cast *steel* AKA crucible steel was what the UK was famous for and used for the top quality levels of tools.

I am indeed thinking of Cast Iron! It makes hammers that no-one would ever want to steal and are cheap enough to lose regularly.

Rather depressing that, I've just bought some tool steel and it was made in India.

If it's got signs of having been used in the past, then it's likely to be ok. The only commonly found cast British hammers that I'm aware of were used on the railways for breaking up coal jams in tenders.

Chamber pot? Window??

You could make some small tongs from 1/2" round but you'd need to jump up the hinge area first. Smithing is all about X-section ares (and hence volume); the area of 1/2" dia is 1/4X1/4X3.14=0.196sqin, the area of 1/4X1 is 0.25.

They must be multiplying!

http://cgi.ebay.co.uk/Large-Vintage-Blacksmiths-Anvil-/330581211670?pt=LH_DefaultDomain_3&hash=item4cf82cfa16