Handy with a Lathe ?

Is there anyone handy with a Lathe, and is bored ?
or can give me some good advice and tips.

as mentioned here I er <cough> snapped <cough> a piece that is very much needed for my forks to work.

I recon it can be made from a 20mm Aluminium Rod.
Since I may be able to get access to one, I assume from my rudimentary knowledge of using one many years ago I'll need two drill bits, one 8.5mm and one 10.0mm (hole all the way though the middle is 8.5mm and then along same hole is 10mm leaving 1.8mm of the 8.5mm at the end)
I would then need to whittle away a large chunk from the 20mm diameter down to 12.9mm leaving just 1.6mm of it at the end ...

picture might be easier

No I don't know what type of drill bits I would need or where to get some decent Alu rod from (rod probably ebay).. drill bits to get a flat end ?


The 'ring' in the middle of the wide bit is not suppose to be there really... the crack that goes all the way around it and make it two pieces, is not suppose to be there and thethine wide part part is suppose to be flat



more pics here http://picasaweb.google.co.uk/bensimmo/ ... directlink

Of course I need to double check all measurements

Depends how desperate you are, in the process of getting a lathe set-up, not sure when it'll be up n running. Not had my hands on one for many years but i reckon it can all be done on a lathe and the the end cut to make it a hollow, if you get what i mean :?

lost me on the 'end cut to make it a hollow' . The hole in the middle ?<ponders for some time> you mean not drill twice but say drill an 8.5mm hole (using the lathe btw) then machine out from the middle the 10.0mm section ?

Once I have this part I can ride my Kona again.

I mean have the piece longer than you need, say 20mm (or however much needs to go into the chuck), machine the outside diameters, including a cut for the chamfer edge, then hollow out 10mm, then the 8.5mm to the depths required using a variable diameter cutting tool, then cut the hole piece to length at the chamfer edge cut done previously.
I think that makes sense now

Start with a piece of something like 2024 T3 round bar, anything over 20mm (say 25mm diameter).

Chuck in 3 jaw, centre drill and drill first 8mm and then finish to 8.5mm (drill, bore or ream depending on tolerances, finish requirements).

Turn OD to size (20mm) and then turn the 12.9mm diameter section. If you can have something like a 1mm radius rather than a square shoulder the component won't be as likely to fail in the way that the original has done.

Chamfer to 45 degrees the 12.9mm section and just break the corner on the 20mm diameter.
Part off at .25mm over finished length and (if you have any) bore a set of soft jaws to suit the 12.9mm diameter. If you don't have any soft jaws then you'll just have to hold ( carefully) in "normal" jaws, but run a DTI on the 20mm section to check for concentricity.

Then face off to the required length and counterbore the 10mm diameter.
Break the corner on the 20mm dia. and the 10mm bored hole.

That's about it - while you have everything set up for the job you might as well make 1 or 2 extra in case you (or anyone else) ever need any more.

Ah, there are so many ways you could skin that cat

^Andy R has it dialed though

collingwood engineering in barton could replicate that. i take it the part in the picture is yours - you could physically give it to him and say " make that but without the crack"

tell him nigel lewis from meldan's reccommended him. that's my dad

01652632388

Not that I would wish to volunteer anyone else's services but the DIY CNC thread had a few keen folks, possibly one of them would help? Elite does machining work to order too.

No soft jaws??
Use two thin bits of wood

dyna-ti":1ueneioh said:

No soft jaws??
Use two thin bits of wood

Click to expand...

The idea of using soft jaws in a lathe chuck is that you are able to bore the jaws to a) suit the shape/diameter of the workpiece that you wish to hold and b) because they are bored in-situ, you are assured of perfect centering.

I don't think that a "couple of bits of wood" are an adequate substitute somehow. We're not talking here about holding something in a vice......