Machining titanium ball

[xu5]

I have got my self a nice titanium gear knob, however the hole for the reverse lockout is marginally too narrow and needs to be widened by 2mm.

Is this going to be straightforward job for a competent machinist, preferably without damaging the torched outer surface? Or is mounting it square in a lathe going to be a right old pain in the behind?

[donkmeister]

Machining titanium is a special skill set. It hardens as you cut it.

Can be done but you want to find a machinist who has done it before.

[Caddyshack]

I think a machinist would use soft jaws in a lathe which may then be thrown away so there would be a cost.

Look up Marc Kinsey at kinzy fabrications (he is on instagram) he would know how to do it. You can mention Toby / Caddyshack. If you can’t track him down you can message me and I will find his mobile for you.

[paddy1970]

Titanium can be challenging to machine due to its hardness and tendency to work-harden.

Mounting the knob squarely in a lathe might be challenging, especially if its shape is irregular.

[bern]

A decent jobbing machine shop will do that no problem. Getting it running true will be a bit of a faff but I know how I'd do it.

Actually cutting it is pretty straightforward nowadays.

Obviously tell them not to damage the outside finish but thay should know that.

You just need to find a friendly local machine shop.

[donkmeister]

bern said:

A decent jobbing machine shop will do that no problem.

SNIP

You just need to find a friendly local machine shop.

How many local machine shops do you reckon work with titanium?

I genuinely don't know, but the two machining companies I know don't list Ti in their materials lists. Doesn't mean they can't, but as they do lots of prototype and one-off stuff you'd think they would list it.

Ti buggers up both tools and material if you don't know what you are doing. Not sure a local shop would want that risk for a small job like that.

[Boosted LS1]

Now we have machine shops instead of engineering firms lol. Pretty sure the engineerings places near me could do it, piss of piss.

[donkmeister]

Boosted LS1 said:

Now we have machine shops instead of engineering firms lol. Pretty sure the engineerings places near me could do it, piss of piss.

The word "engineering" has been subverted over the years to include things that need neither engineers nor engineering works So "machine shop" is a fairly accurate description of a business that centres around a workshop full of machinists and machines.

If I ever return to an engineering job I'm going to insist on telling everyone I'm a plumber and household appliance repairman... See how they like it.

[Boosted LS1]

And solicitors have become lawyers. I blame the yanks.

[xu5]

Sounds like it should be doable then. I'll ask some local machinists.

@Caddyshack thank you very much, if I have no luck I will get in touch.

[gazza285]

donkmeister said:

The word "engineering" has been subverted over the years to include things that need neither engineers nor engineering works So "machine shop" is a fairly accurate description of a business that centres around a workshop full of machinists and machines.

If I ever return to an engineering job I'm going to insist on telling everyone I'm a plumber and household appliance repairman... See how they like it.

Indeed. I was on a training course yesterday, one of the questions raised was what you could do if a machine failed, I suggested calling a plant fitter, but was told that you would ring an engineer to come and fix it instead.

[Easternlight]

Looks like it's got an aluminium insert in it to me so the actual machining of it will be easy.
Holding it and not damaging the nice finish will be the biggest challenge.
I would find that easier to hold on a mill personally.

[hidetheelephants]

Titanium is an arse; unless the machinist is experienced with it the potential for fk ups is high. Is there any way the reverse lock-out collar could be reduced in diameter?

[Caddyshack]

said:

That might be a good idea

[xu5]

Unfortunately there isn't much that can be done with the standard lockout as it is a thin walled plastic cup at the top. There is an aftermarket option available from Japan so not cheap and I don't particularly like the look of it. I guess making a new one from scratch is unlikely to be any cheaper.

I have found a machine shop near me that will do it, but as suggested wil need to make a custom fixture to hold it. They did also suggest trying to do something with the lockout.

Edited by xu5 on Saturday 24th February 20:15

[V10Mike]

If that was mine, I'd mount it on a nice solid mandrel in the central hole, and try machining the recess from the chuck side.

Saves any fixturing and risk of damaging the external finish.