Anyone ever tried machining their own titanium parts?

[ljamesb]

I doubt it. Id go as far as to suggest you dont waste any more on trying to make your own in the manner suggested. Ti is very hard, you would need a die for Ti, if such things exist, and it wont br cheap. Cutting a thread that runs true aint easy either. Most of the Ti bokts on ebay are cut but lathe.

Glueing on a nut? Doubt that'll be stong enough.

I would suggest contacting probolt, seem to recall they can make custom bolts, if they do i predict you are looking at £ 30. (That is my guess)

Btw whats the best price youve found?

I don't have a Ti specific die unfortunately, but my die set is Ti coated so would hopefully do a bit better than a standard die if I try. Provided that isn't just a marketing gimmick.

Thanks for the links everyone. I'll probably give those suppliers an email and see how much they'd charge if they can machine one for me.

The epoxy is just to fix the threaded allen key nut (pictured) to the threaded end of the ti rod. This would only ever come loose when you are loosening the stem bolt. The join mostly just needs to hold up to more torque than is necessary to loosen the stem bolt from the wedge. I've used epoxy to join aluminium to steel in a similar way and it's worked fine. A bunch of threadlock would probably work too.

As for price, I haven't been able to find any 150mm m6 Ti bolts anywhere. I've found m8 (the standard size) for £18.50 on ebay.

The funny thing is that an m8 Ti stem bolt is 29g. An m6 stainless bolt is 36g and I happen to have an m6 quill stem wedge which is 7g lighter than my m8 quill wedge. So basically using a titanium m8 bolt is only for cool points and doesn't save weight.

 

[ljamesb]

General turning and milling is easy enough as long as it's kept cool and your using rigid equipment. Drilling can be slow and painful, threading can be a pain too. Grade 2 is pretty easy to use. I have some here that is very difficult to thread.

Some bolts here, ask them if they can make a longer one. Or just use the. 130mm one and cut the quill down a bit.

http://www.torontocycles.com/Selling/Ti ... Bolts.html

Hmmm, very interesting. They have m6 130mm and m5 170mm. SO CLOSE! I'll give them an email and see what they say .

Yes.

Awesome! Nice work. I need a lathe. he he

 

[FMJ]

Ti? With a hacksaw? Rookies.

 

[ljamesb]

I'll see your expertly machined parts and raise you a machined gold nanocrystal.

Do tell though, what are we looking at in your photo? Looks like some pretty serious stuff.

 

[syncrosfan]

I just used the lathe to machine down the part to the right diameter. That was the easy part. I cut the thread by hand, that was the difficult part. The Ti-coating on the dies doesn't really help. As far as I know the dies for cutting titanium have a different tooth geometry that's specialized for the job (preventing chipping of the cuttin teeth, which will happen if you use a regular die). Honestly I would say give it a try (worst case you wrecked a piece of titanium rod and a die) not exactly the end of the world... Best case you made yourself a neat,cheap, bolt. Lots of naysayers on the site... Look at sites like Alibaba, sometimes you can get Ti bolts a discount prices.

 

[FMJ]

Do tell though, what are we looking at in your photo? Looks like some pretty serious stuff.

Cast Ti manifold for microwave guides for a satellite transmitter.

 

[FluffyChicken]

Re:

Ask the chap who sells to M8 bolts as I think they are custom anyway.

Also ask our local probolt here.

Why not just use a long Alu bolt, its what Syncros used in their stems for many years. (Zircal brand Alu iirc)

 

[LittleSkink]

fwiw my expertise is as a metallurgist not machinist but my understanding is the "Ti coating" on dies is TiCN (Titanium Carbo Nitride) and reduces friction when working steel -as others have said, wont do a whole lot of good when working with Ti

the other thing about working Ti is it adheres to the tool and galls, so you will need to do everything you can to reduce that - ie go slow, cut gently, clean tool reguarly

Titanium stuff is so expensive because it is so hard to work with

 

[02gf74]

The epoxy is just to fix the threaded allen key nut (pictured) to the threaded end of the ti rod. This would only ever come loose when you are loosening the stem bolt. The join mostly just needs to hold up to more torque than is necessary to loosen the stem bolt from the wedge. I've used epoxy to join aluminium to steel in a similar way and it's worked fine. A bunch of threadlock would probably work too.
.

Its been a while since ive messed with quill stems but my memory of them is the bolt is susceptible to seizing as well as the quill itself, it being freed by a tap with a hammer. Its likely the nut will undo, not a problem when taking apart but what would happen if it did when riding? Wont the bars come lose and you effectively lose the steering = crash and possible injury?

Also the top has recess for the hex bolt head, youll need a larger one so that there is room for the socket.

 

[FluffyChicken]

They only seize if you man handle them in and don't lube them up etc.
That or leave them for 20 years and the weather gets to them.
The quill needs a tap as you've just wedge it in there, you can't expect it to just drop out of place.

Recess, depends on the stem style, I would assume ljamesb has considered that.

Once set though there is little reason to remove it.







Why not just buy threaded bar stock and save the hassle of threading if you must stay as Titanium?