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'Living with an old Synchro' and other tales from my shed.

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Pete.:
Yes there is a thrust bearing . The top lever pulls another arm which presses in the top sliding pulley to adjust the pulley width. There's a shiny dome cover on it and inside that is the thrust bearing.

DavidA:
Pete,

Thanks, I have a look at that and see what is in there.

Dave.

DavidA:
Is this another 'sign of the times' ?

In preparation for the upcoming MOT on my Citroen I went to our local Citroen agent (Citroen , Crosshills) to get a replacement part. It is a kind of bush holder that secures one end of the front anti-roll bar to the bottom steering arm.

Only to find that they have changed their parts policy.

They now only fit parts. they don't supply them to the public.

So, I could have got them to order in the part and paid them to fit it, at about £50 per hour, maybe more, but they wouldn't order the part for me to fit myself.

However, I was told, their Harrogate branch will supply the part.

But I have to get it from Harrogate. Which is about 25 mile from where I live.

As both branches will probably get the part from the same Citroen holding store, why can't they sent it to Crosshills which is only five mile from me ?

Fortunately the part is only a simple aluminium block with a few holes in it. So I will make my own.

Dave.

DavidA:
Just a bit of an update.

As I mentioned on Bob's home brew milling machine thread, I have the same EMCO head and also the same X,Y table. But I wanted to use the EMCO on my Denford in the way that it was intended. Just to see how it compares with a proper milling machine.

SO, it is up and running with my three inch machine vice bolted down to the cross slide.

I have mentioned the problem with the backlash. And following Seadog's lead (no pun intended) I tried using it tonight with the gib tightened right up.

It seems to work. At least on Aluminium. I use a Dural type ally for experimental stuff as I have a fair stock of bits and it doesn't knock hell out of my milling cutters.

But I find a second problem.

Imagine that you have a small block of material. maybe two inches square by 1/2 an inch thick.  The two faces are parallel to each other, but non of the edges are square to each other.

So, clamp it in the vice with your best edge more or less horizontal and take a skimming cut. Just enough to clean it up.

Now comes the problem.

Next thing I would do is turn the block through 90 degrees and using the newly milled edge, set this at 90 degrees to the bed.

But on the lathe/miller you can't do that. There is nowhere to sit your square. At least nothing true like a milling table will provide.  Agreed, you could make up some kind of false bed to sit the square on, but getting it true would be awkward.

I suppose all this hassle comes from trying to use a machine for a purpose it wasn't really intended .

You can do it. But it is really difficult.

Time to go back to my Micro Mill.

Does anyone here use the EMCO attachment for milling ?

Dave.

Dave.

DavidA:
A quick update. and a short tale of woe that may help some one else avoid the same problem.

I decided to make a dummy spindle nose to be used when making things like backplates for my old red lathe.

So I took the measurements, chucked up a piece of leaded steel in the Denford lathe and proceeded to make something as near exact as I cold get it.

Got the register spot on. ground up a tool to cut the 8 tpi thread that the chuck, faceplate etc screw onto, 55 degrees.  cut a short parallel diameter at the end to indicate the depth of cut. And away I went.

I have no thread counter on this machine, so it was a case of forward/ reverse. no disengaging the lead screw.

Got down to the indicating diameter. tried the red lathe's faceplate. Wont fit.   Cut a bit deeper. Still won't fit.

measure everything in sight. Everything looks ok. Why won't it screw on ?

After a couple of hours, when the stove had gone out and it was starting to get cold in the shed, I decided to call it a do for the day/ But I first took the cutting tool from the Denford and tried it in the red lathe nose thread. And the problem was revealed (well, at least I think it will be). My tool has a sharp point. the bottom of the lathe's thread has a rounded form. And the calculations didn't allow for this.

So, when the point of the tool is down to depth, it really needs to go a bit more or the thread will be (is) too tight.

All I need do is stone a nice radius on the tool tip and then fiddle about re-engaging the tool with the thread, and the job should be a good one.

Moral; don't forget the tip radius when machining things like spindle threads.

Dave.

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