revtothelimit - motorbike forum

Another little job for the lathe. This has come off a tractor that's been sat outside unused for a long time, maybe 20-30 years.

One of these needs some work:



Between centres on the lathe. I had to do very light cuts, 0.1mm, as there wasn't friction driving it.



Turned to diameter:



I need to modify a die holder and cut a split die into two parts so as to be able to recut the thread from the good end. The other option is screwcutting in the lathe but that involves much faffing with gears and feed speeds. The cheap die holder hasn't arrived so that will have to wait.

Next is the steering column. On the lathe to clean the bit a new collar will fit over. The cardboard is to stop abrasive grit falling onto the lathe bed.



The collar, made of brass, will fit in here and will help take the play out of the steering system.

cheb wrote: Fri Oct 08, 2021 12:18 pm
Between centres on the lathe. I had to do very light cuts, 0.1mm, as there wasn't friction driving it.

How fast/slow is the lathe turning to reduce the vibes from the offset weight?

About 200rpm, and no noticeable vibration*. The mass of the lathe keeps it down I think, and there's not much weight and not much offset.

The postie delivered the die holder too so I should have this finished today.

*All controls fall easily to hand but I'm not sure it'll get up Porlock hill in top and fully advanced.

Correction: 306 rpm according to gearbox chart.

Anyway, hole. The plastic is there to stop the workpiece creeping back and to ensure I don't stick the tool into the chuck jaws.



Fitted, with one mistake. I forgot to allow for the chamfer so that's as far in as it goes. The protruding part won't foul anything.



That's the die slit :



And assembled onto the thread. Cutting fluid was added after the photo was taken.



First pass:



It came out really well. I ran the die up and down a few times, tightening it slightly each time.

The brass collar did get in the way, the steering shaft goes up and down when the steering wheel is turned. Odd as it sounds, it's very simple, there's a coarse threaded rotating insert at the top of the steering column that the steering shaft threads into. Turning the wheel rotates the thread and the shaft rises or falls. There's an arm either side at the bottom of the shaft pushed up or down with the shaft, that's bit I repaired the thread on. The lump at the other end to the thread is the bit pushed on. The splines on the arm locate on steering arms that lead to the front wheels and connect to the track rod ends.


There's a reason I don't write technical manuals.

Excellent thread

Thank you.

Nicely done.

Le_Fromage_Grande wrote: Sat Oct 30, 2021 12:33 pm Excellent thread

Badoom tish.

Indeed it is a very interesting thread. Grey fergie?

I'm not sure about the make of tractor, it's owned by a mate of a mate and was his father's. It's been stood outside up here for an age and he's restoring it.

It's grey fergie era for sure.

I love threads like this. I rarely understand anything written about making stuff on a lathe, but bloody love trying to understand and seeing the pictures

Not seen that trick with splitting the die before. Neat.

Count Steer wrote: Sun Oct 31, 2021 10:00 am Not seen that trick with splitting the die before. Neat.

I recall from years ago that dies used to be split and the three screws on the die wrench were there to open up or tighten the die depending on the diameter of the bar / cleaning up existing threads

Silly Car wrote: Sun Oct 31, 2021 12:09 pm

Count Steer wrote: Sun Oct 31, 2021 10:00 am Not seen that trick with splitting the die before. Neat.

I recall from years ago that dies used to be split and the three screws on the die wrench were there to open up or tighten the die depending on the diameter of the bar / cleaning up existing threads

AF699127-336A-45C8-8108-A7E1D6392603.png

Now you mention it, I think I remember that. But, I haven't had or used a set of taps and dies for ooh...40+ years! (Those pics look rather like the ones I had. I do remember that the wooden cases that they all came in were a piece of craftmanship in themselves!).