Allchine Bibcox

SBWHART · Feb 6, 2012

A friend ask me if i could make hime some Bibcoxs for his 1 1/2" Allchine traction engine, Bibcox is the old fasion name for a tap.

This is the drawings

Tiny little buggers arn't they.

First make the D bit

Slew the compound over 3 deg and turn a taper on a length of silver steel, give it a bit of a polish. Now so that the cox matches the taper in the body perfectly don't change the setting of the compound until the job is finshed.

Section the D bit you want to make them just over centre

Heat them to cherry red and quench in water, I didn't bother with tempering them.

Give the flat face a rub on a smooth stone to get a nice sharp edge. I glued a collar round it to act as a stop.

Then in a bit of 5mm brass bar on the centre, put through a 2mm drill then follow it up with the D bit to cut the taper for the body.

Thats the hard bit done

Mill a 2mm square on the cox.

Chuck it up in the lathe and thread 10 BA and turn the tapere length, and the handle bit part off, and aneal it before bending the handle.

Put the body in the lath assemble the cox and drill through 1.5mm: remove the cox and finish turn the rest of the body and thread 5/32* 40 ME again aneal before you bend the spout.

To make the square hole washer make a 2mm square punch from silver steel just harden the square bit, turn up some brass washers with a 2mm hole in them and use the punch to knock the square bit out.

Thats it Job done

Stew

tel · Feb 6, 2012

Nice work Stew! Oh, and it's BIBCOCK btw!

vcutajar · Feb 6, 2012

Very, very nice. :bow:

SBWHART · Feb 6, 2012

Thanks Guys

tel said:
Nice work Stew! Oh, and it's BIBCOCK btw!

You know I looked at this three times before i twigged on about the ck not x bit:- I just can't see these things

:big: :big: :big:

Some more set up pics

Turning the taper and 10ba thread problem was getting the compound back to the same pint ended up putting a stop on it, you just had to turn engough taper so that the square pockes through the hole.

Also rigged up a magnifier, I also found that blacking the bit with felt tip help in seeing what was happening

After turning the taper seat pulled them out of the chuck a bit and turned the taper for the handle.

Parted them off anealed them and bent the handle this is only a part bend, I may leav them like this or aneal them again for another bit of bending.

Assembled them in the bit that will make the body and drilled through 1.5mm so the hole will line up

I'm making a few more so I'll post some more pics when I do the bodies.

Stew

tel · Feb 6, 2012

Very interesting stuff. Just one point, I usually leave the tapered spigot un-drilled, and drill through the lot once it is assembled in the body.

SBWHART · Feb 9, 2012

Very interesting stuff. Just one point, I usually leave the tapered spigot un-drilled, and drill through the lot once it is assembled in the body.

Tel:- that how i would have done it but these things are so small I thought I'd have a bit more to grip on, I did keep them in pairs by wiring them up after i'd drilled them.

I thought I'd got lucky bending the first one, I was right putting those bends in was a bit of a headace. I was using scap yard material I think it was leaded free machining brass so it wasn't the most ductile of the brasses hence i had to aneal it and bend it in stages, I also found it best no to drill the hole all the way through and to leave it blind that way the wall got a little support to stop it colapsing and I turned the spout twice as long as required and cut the surplus off after bending.

Also found it best not to go with to sharp a bend I held the part in the vice and bent it with a bit of tube moving the tube towards the end a bit at a time so that it gave a gradual bend.

I formed the midle bit of the body with a form tool

Ended up with these good ones

And this is some of the scrap

Back to the Simpson and Shipton now

Stew