Author Topic: Red lathe woes..or 'The joy of owning a piece of history'  (Read 8888 times)

Offline DavidA

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Re: Red lathe woes..or 'The joy of owning a piece of history'
« Reply #25 on: December 01, 2017, 08:59:16 AM »
It's been  a while.

But something did happen a few nights ago that I will add in as a precautionary tale.

I started doing some more work on the Fowler 4F loco.  Making the crank webs. I need something to present at the club next spring.

A simple task. four bits of inch wide 1/4" mild steel each 1 1/2" long with two half inch reamed holes.

What could be hard about that ?

The webs were cut to length and trued up on the Mini Mill.

Just the holes to make. But which way to do it ? After all, they must be pretty exactly placed.

A bit of thought assisted by a coffee and it was decided to mount the parts in a four jaw and drill. bore/ream them.

But the four jaw is on the Denford in the dreadfully cold shed. I have the red lathe in the nice warm machine shop (read 'outhouse with heater) but it doesn't have a four jaw chuck.

But wait ! I do have a brand new four jaw chuck bought for this machine. A Zenith, still in the box: Unused. And the mounting spigot is the same as the three jaw. The bolt holes are on the same PCD.  What Joy !. There are four holes needed as against the three on the three jaw. But I can locate one bolt and then drill three more holes. easy.

Now, this is where it all starts to go wrong.

When the chuck came I noticed that the picture on the box was of a three jaw. First thoughts were they have sent the wrong chuck.  So I opened the top of the box and it was indeed a four jaw. Note, I didn't remove the chuck from the box at this stage.

A couple of years go by and we are back up to date.

I take the chuck (didn't notice) drilled the holes. I don't like a close fit on the mounting shoulder as I like to be able to move the chuck around a bit to true it up. And being a four jaw it isn't as important as it is with a three.

(still haven't noticed).

Right, so I have been handling this thing for a couple of hours, and it is now on the lathe.

(still haven't noticed).

Time to clamp one of the webs and centre it up.

NOW I NOTICE.

It's a self centering chuck.  My parts are rectangular.

I mean, what use is a self centerig four jaw chuck ?

Why did I buy this perversion ?

Huge disappointment descends upon the land.

Looks as if I am going to have to heat up the shed and use the Synchro.

Bugger!

Dave.

(Anyone want to buy a Indian self centreing Zenith 4 jaw ? Brand new, unused.)