machining titanium

[paul8899]

hello,

managed to get about 2ft of 3in dia ti from work and was thinking of making a set of conrods and a crank for a ypvs.

The questions I have are these.

will the ti pick up on the bearing faces ?

does ti stretch more than steel ?

will it wear more than steel ?

Its just an idea at the moment

Thanks

[blow_away]

I don't know much about materials, but I doubt that Ti would be a significantly better choice than standard for those applications. We once made some very heavy duty rods for a CBX 6 drag racing bike from 6082 alu. By the time you allow for clamping and holding the jobs I'm not sure that you have enough material either? Ti is not particularly friendly to machine?

Have a read of these links and see what you think

http://www.keytometals.com/Article122.htm

http://www.titanium.com/titanium/tech_manual/tech2.cfm

[speedy sie]

titanium rods will have a life expestance shorter than standerd rods as they will strech,and can over heat easyley as well,if the tolerences are to fine,not worth the hassel realy,get a set of after market race rods,will be easyer and reliable.

titaniul in the lathey is ok,but you have to be realy carfull as to much heat will worp the stuff.

[spacemonkey]

hello,

managed to get about 2ft of 3in dia ti from work and was thinking of making a set of conrods and a crank for a ypvs.

The questions I have are these.

will the ti pick up on the bearing faces ?

does ti stretch more than steel ?

will it wear more than steel ?

Its just an idea at the moment

Thanks

I think most ti rods are forged before machining aren't they?

I don't think racers are allowed to use titanium cranks so you'd probably be on your own there.

I'm also pretty sure that it'll be more flexible than a steel shaft, so you'll need to be more clever with the design, you won't be able to just copy a steel crank. And you may lose some power due to the flexing...

Any wearing parts will need to be coated to avoid galling.

[paul8899]

I had a sneaky suspicion that it would pick up easier than steel, Ill have to have an ask at work to find out about stretch etc.

I was thinking of putting hardened inserts on the rods to hopefully stop any picking up

Was only an idea as I have the ti and I get a bit bored at work

Thanks anyway

Paul

[speedy sie]

would like some titanium wheel spacer if you can do them?

[morepower]

Cranks are usually made from materials like EN40B which is nitrided in one peice cranks or the flywheel parts are made from steel which can be case hardend and the pins made from a high quality steel Not sure what is used usually but I have made the pins from EN40B which was plasma nitrided. But this was to a customers spec.

I am not sure if anyone has used Titanium for a full crank though as it is a lot more flexible but there was a rumour Porsche had used Ti for some GT sports car cranks... But again only a rumour as we used to make a lot of Billet EN40B or EN40C steel GT cranks for various Porsche teams.

[Adam]

You're right, you will need to sleeve the eyes of the rods.

Titanium has a high coefficient of friction on just about any other metal.

As for machining, if you're using HSS tooling, sharpness is everything. Titanium, much like stainless work hardens under the tool if rubbing rather than cutting occurs.

If I were you, go for it. (Rods I mean)

Depending on what grade you have of course, I assume it's Grade 5.

Alpha Bearings do steel inserts.

I had a sneaky suspicion that it would pick up easier than steel, Ill have to have an ask at work to find out about stretch etc.

I was thinking of putting hardened inserts on the rods to hopefully stop any picking up

Was only an idea as I have the ti and I get a bit bored at work

Thanks anyway

Paul

[paul8899]

You're right, you will need to sleeve the eyes of the rods.

Titanium has a high coefficient of friction on just about any other metal.

As for machining, if you're using HSS tooling, sharpness is everything. Titanium, much like stainless work hardens under the tool if rubbing rather than cutting occurs.

If I were you, go for it. (Rods I mean)

Depending on what grade you have of course, I assume it's Grade 5.

Alpha Bearings do steel inserts.

I can make the necessary bushes for the rod eyes, Im not sure which grade ti it is but I know where it came from and if its good enough for its intended use Im pretty sure it will be ok in a a ypvs engine

Im interested in trying to make a complete crank out of ti, I was thinking that the pins would need to be hardened steel but not sure if it would flex, I wouldn't of thought so as the crank bearings would take most if not all the strain.

I was going to use carbide cutters and inserts, do you know which is best to use when turning as the carbide tips aren't as sharp as hss ?

Thanks

[Superdunc]

I can make the necessary bushes for the rod eyes, Im not sure which grade ti it is but I know where it came from and if its good enough for its intended use Im pretty sure it will be ok in a a ypvs engine

Im interested in trying to make a complete crank out of ti, I was thinking that the pins would need to be hardened steel but not sure if it would flex, I wouldn't of thought so as the crank bearings would take most if not all the strain.

I was going to use carbide cutters and inserts, do you know which is best to use when turning as the carbide tips aren't as sharp as hss ?

Thanks

Titanium, as has been stated, suffers from "picking up" or gauling, when it slides against another metallic surface. To this end rod bolts for titanium rods are often silver plated to prevent the threads in the rod picking up during assembly. It strkes me as a bad idea to have both the rods and crank made from titanium and moving against each other at 12500 rpm, even if it is only in thrust as it would be on the webs. I'm sure you can get some trick surface treatment to over come this, but it won't be cheap.

I've seen some of your other work on here, so if you are succesful with the rods put me down for a pair.

[paul8899]

Titanium, as has been stated, suffers from "picking up" or gauling, when it slides against another metallic surface. To this end rod bolts for titanium rods are often silver plated to prevent the threads in the rod picking up during assembly. It strkes me as a bad idea to have both the rods and crank made from titanium and moving against each other at 12500 rpm, even if it is only in thrust as it would be on the webs. I'm sure you can get some trick surface treatment to over come this, but it won't be cheap.

I've seen some of your other work on here, so if you are succesful with the rods put me down for a pair.

Im pretty confident on the rods as I can put an insert where the big/little ends go,so there would be a hard edge which would stop any wear or picking up (basically a headed insert) I can then spark the oil slots into them and hopefully that would be ok

wouldn't the thrust washers stop the picking up ? what about putting a hardened insert on the inside of the crank webs ? what is the tensile strength of ti compared to other mild steel?

I wouldn't trust any surface treatment to last as I would of thought it would wear off pretty quickly ,still only in the thinking about it phase,got to build my mito up first and Ive only got a frame at the moment but I have a plan !!

cheers for that, if they are reasonably easy to make Ill let you know

Anyone got an r1/gsxr/zx6 front end clogging their shed up they want to sell