Titanium Nuts And Titanium Spindles

[paul8899]

I "found" some grade5 ams 4928q 40mm titanium bar and thought there would just be enough to make a couple of wheel spindles for my mito. I managed to turn the diameter ok BUT when I tried to drill the middle out of the spare offcut my 1/2 inch drill decided that it had had enough and decided to melt the front off. I now have a drill that goes from 3/8" to .5" over the first 3/4" . So I won't be drilling the middles out of the spindles !

Anyway, I want to make some ti nuts and I have a couple of questions , is it ok to have ti nuts on a ti spindle and what grease do I use to stop the threads picking up ?

Thanks

[spacemonkey]

I "found" some grade5 ams 4928q 40mm titanium bar and thought there would just be enough to make a couple of wheel spindles for my mito. I managed to turn the diameter ok BUT when I tried to drill the middle out of the spare offcut my 1/2 inch drill decided that it had had enough and decided to melt the front off. I now have a drill that goes from 3/8" to .5" over the first 3/4" . So I won't be drilling the middles out of the spindles !

Anyway, I want to make some ti nuts and I have a couple of questions , is it ok to have ti nuts on a ti spindle and what grease do I use to stop the threads picking up ?

Thanks

Just get some high cobalt or carbide drills?

I believe there are specific anti seize pastes that are recommended for this purpose......

[paul8899]

I vaguely remembered reading something about anti seize greases, thought I'd ask to be sure.

Its all down to how hot the ti gets, It work hardens as your machining so you have to push past the hard surface which generates more heat so effective cooling is needed really. I think I need some of those drills with the coolant holes in the flutes.

I managed to drill down about 2 3/4s before it started binding up and melting the drill . I couldn't get the coolant to the bottom of the hole.

To be honest I'm not that bothered about taking the middle out, just have to make sure I have a poo before I go out which should more than make up the excess weight

[spacemonkey]

Me? I wouldn't.

The very fact that the FiM specifically bans Ti spindles due to past incidents makes me very wary.

If you were to design them from scratch with appropriate understanding of the structural purpose that wheel spindles fulfil when they triangulate the forks and swingarm, using a proven FEA package then maybe.....

...but binding forks and snapped swingarms - which have happened with Ti spindles in the past - would put me off.

Maybe you are right.... I suppose it depends on the diameter of the spindle. You might be able to lose weight without sacrificing stiffness if you can use a large diameter spindle but you are stuck with what your forks will allow unless you change those too.

On the other hand, the FIM bans everything. I seem to remember someone getting turned away at the TT because their standard, steel spindles were deemed too light!

[paul8899]

Me? I wouldn't.

The very fact that the FiM specifically bans Ti spindles due to past incidents makes me very wary.

If you were to design them from scratch with appropriate understanding of the structural purpose that wheel spindles fulfil when they triangulate the forks and swingarm, using a proven FEA package then maybe.....

...but binding forks and snapped swingarms - which have happened with Ti spindles in the past - would put me off.

I didn't know that, what metal is used for spindles ?

The ti I used is the high tensile ti ( grade 5 ) which as far as I know has a slightly higher strength than tensile stainless (900Mpa vs 860Mpa) if I'm reading the chart right.

Do you think they were banned because the spindles were machined away to much which caused them to fail or is there another reason ?

[Superdunc]

I'm not sure FEA is needed, If you know the tensile strenght etc, you can reverse engineer them to be as strong as the steel Items you are replacing. as for titanium threads, you need a silver based anti sieze compound, titanium is very suseptable to gauling in this application. On F1 cars titanium nuts are often silver plated on the threads and shoulders to prevent problems*, probably overkill for your application.

* Which goes some way towards explaining why the rod bolts for Ducati Titanium conrods are nearly £200 each.

[paul8899]

I just made them solid and I was thinking that it should be strong enough, I just thought I'd try and be flash by drilling the middles out ( right up until it turned out to be difficult ).

where would I be able to get the anti seize paste from ?

[Mark/Foggy]

I think you'll find that the concerns over Ti spindles were due to misapplication of material properties in service. Ti shows memory characteristics in some forms, where on extension under load and repeated application, the material stops stretching and returning within it's elastic limit and remains stretched. Nasty if you've got a spindle that needs tourqueing to a decent figure that then becomes meaninglesss at an undisclosed point in the future. I.e. the spindle undoes itself, all on it's own, after a period of time.

There are also issues with the radii used between a shaft and the head return, that can be enough of a stress raiser to cause failure.

[paul8899]

When you say that some forms of ti show memory characteristics and stretch, is this dependant on the grade of material or is it the same for all grades?

[spacemonkey]

When you say that some forms of ti show memory characteristics and stretch, is this dependant on the grade of material or is it the same for all grades?

Here's another brain teaser though..... The torque required will probably be different. Remember a certain torque value is not what you are aiming for. It is a certain level of pre tension in the spindle to reduce the effects of fatigue. This will need to be calculated I suppose.... If that level of pretension is lest than the limit of elasticity then you won't have problems of the spindle stretching.

[Mark/Foggy]

When you say that some forms of ti show memory characteristics and stretch, is this dependant on the grade of material or is it the same for all grades?

Buggered if I know, sorry. Might take a bit of research. Undoubtably the FIM acted when some pore bugger got it horribly wrong and the potential cost of constant replacement made them all scream in horror. I'd have a chat with someone from Racebolts in the states. They're helpful and informative.

Clicky

Oh and their Ti prep looks a lot like Copper Slip to me, which is what P1 always use and I've never known an issue. Although our bikes do come to pieces regularly.

[paul8899]

Here's another brain teaser though..... The torque required will probably be different. Remember a certain torque value is not what you are aiming for. It is a certain level of pre tension in the spindle to reduce the effects of fatigue. This will need to be calculated I suppose.... If that level of pretension is lest than the limit of elasticity then you won't have problems of the spindle stretching.

I'll have to ask the designers at work what torque level I would need to get the right amount of tension on the spindle. If I'm really lucky they will be able to give me a strength analysis compared to steel as well.

Buggered if I know, sorry. Might take a bit of research. Undoubtably the FIM acted when some pore bugger got it horribly wrong and the potential cost of constant replacement made them all scream in horror. I'd have a chat with someone from Racebolts in the states. They're helpful and informative.

Clicky

Oh and their Ti prep looks a lot like Copper Slip to me, which is what P1 always use and I've never known an issue. Although our bikes do come to pieces regularly.

I have just had a look at the racebolts website and they list ti spindles for a yz125/250/450, the $245 price is a bit salty though ! Ill ask them if they have any pictures and a few questions

If copperslip is good enough for you guys its good enough for me . Do you use standard spindles on your bikes ?

[Mark/Foggy]

Do you use standard spindles on your bikes ?

No. Believe it or not we have dimensional copies of ZXR750 spindles machined up, in steel. It's all about QD wheels.

Oh and the tension in the spindle question, I was more on about the deformation in the thread that generates maximum bearing between respective pitch of spindle and nut.

[marcaztls]

M1's have been running all three Ti spindles for years (aren't they FIM governed? Excuse my ignorance if they're not...), and a friend of mine runs two out of the three he has in his R1. Mind you they're all TiN coated.

Yoyodyne sell some for GSXR's and Ducati's.

I use ProBolt's Ti Prep on all my fasteners, but in all honesty, I'll be using coppaslip when I've run out of that.

[2639]

I vaguely recall something about copperslip exacerbating anodic corrosion when in contact with/between aluminium and titanium.

I'm out my depth here but something rings a bell, cos I remember the feeling wory about my ignorant assembly of a ZX6.

Is a safe/better lubricant molybdenum grease?

Anyway, good luck with the project.

[sennidott]

I vaguely recall something about copperslip exacerbating anodic corrosion when in contact with/between aluminium and titanium.

I'm out my depth here but something rings a bell, cos I remember the feeling wory about my ignorant assembly of a ZX6.

Is a safe/better lubricant molybdenum grease?

Anyway, good luck with the project.

I recall Millemille mentioning this and the correct lubricant for the job.

I've always used copaslip with out any problems, although this may be due to the fact my bike is never built up long enough for any corrosion to take place...

[margrit]

M1's have been running all three Ti spindles for years (aren't they FIM governed? Excuse my ignorance if they're not...), and a friend of mine runs two out of the three he has in his R1. Mind you they're all TiN coated.

Yoyodyne sell some for GSXR's and Ducati's.

I use ProBolt's Ti Prep on all my fasteners, but in all honesty, I'll be using coppaslip when I've run out of that.

Millemille here...

From the 2010 FiM MotoGP technical regulations.....

2.7.10 Materials

The use of titanium in the construction of the frame, the front forks, the

handle-bars, the swinging arm spindles, and the wheel spindles is

forbidden. For wheel spindles, the use of light alloys is also forbidden.

M1's haven't been running Ti spindles.

[porter_jamie]

http://argent.fia.com/web/fia-public.nsf/8...ials_a_2004.pdf

grade2 ti is has only about half the shear strength of en16t. so even if you did want to make ti spindles, (i wouldn't for most of the reasons above) you have to be sure you have the correct grade.....

what worries me is people using ti bolts to hold calipers on.

[Superdunc]

http://argent.fia.com/web/fia-public.nsf/8...ials_a_2004.pdf

grade2 ti is has only about half the shear strength of en16t. so even if you did want to make ti spindles, (i wouldn't for most of the reasons above) you have to be sure you have the correct grade.....

what worries me is people using ti bolts to hold calipers on.

Grade 2 is what you make exhausts and such like from, grade 5 titanium has 3x the tensile strength. A quick conversion in my head has it some were between a grade 8.8 and 10.9 bolt for tensile strength

[speedy sie]

my shakey bike has titnaium spindles,all the linkage bolts are titanium,the engine bolts,the yoke bolts,most of the engine bolts,in fact you can count on your hand the steel bolts.....only the swinger pivot it steel.

[marcaztls]

Millemille here...

From the 2010 FiM MotoGP technical regulations.....

2.7.10 Materials

The use of titanium in the construction of the frame, the front forks, the

handle-bars, the swinging arm spindles, and the wheel spindles is

forbidden. For wheel spindles, the use of light alloys is also forbidden.

M1's haven't been running Ti spindles.

Hmmmm... What are the gold coloured spindles that the M1 has in it's pictures then?

I asked Crutchlow's race engineer if the same looking ones on the WSB R1 were in fact from the M1 and he said yes, "Spare titanium spindles, very light, very expensive".

I can only go by what I've been told.

If they're not allowed, what material would warrant the TiN coating on them then and what would the benefit be?

[marcaztls]

And here's the link to Yoyo selling Ti spindles in case anyone wants one.

http://www.yoyodyneti.com/Category.aspx?CategoryID=2696

[porter_jamie]

Grade 2 is what you make exhausts and such like from, grade 5 titanium has 3x the tensile strength. A quick conversion in my head has it some were between a grade 8.8 and 10.9 bolt for tensile strength

accord to the list 6alv4 is 900MPa, an 8.8 is 800 and a 10.9 is 1000 for ultimate. notice the yield point is closer to the ultimate the more money you spend. you had better really know what you are doing. i don't so the mono ones are steel.

the elongation is only 8%, which would bother me. and the density is 4.42 for g5, re 7.89 for en16. you aint gonna drill a hole up the middle of a g5 spindle (in a hurry!), so just make it out of steel and it will be more or less the same weight anyway.

my point re Ti grade is make sure you have the right grade..

[Superdunc]

accord to the list 6alv4 is 900MPa, an 8.8 is 800 and a 10.9 is 1000 for ultimate. notice the yield point is closer to the ultimate the more money you spend. you had better really know what you are doing. i don't so the mono ones are steel.

the elongation is only 8%, which would bother me. and the density is 4.42 for g5, re 7.89 for en16. you aint gonna drill a hole up the middle of a g5 spindle (in a hurry!), so just make it out of steel and it will be more or less the same weight anyway.

my point re Ti grade is make sure you have the right grade..

All good.

@ Marc, TiN coating is used on all sorts of materials, from fork stansions to cheapy drill bits, It is not a particularly exspensive surface treatment, and doesn't imply the base material is Titanium. Titanium its self doesn't need surface treatment for corosion, but where sliding friction is present, such as on screw threads it does suffer badly from gauling, so it is common on high end applications to silver plate the areas that could suffer.

I suspect the spindles on the M1 are high tensile steel that have been TiN coated for corrosion resistance and because of it's low friction properties when going through bearing seals.

And while I'm being a picky twat, the caliper on Crutchlows R1 Mentioned in last months excellent artical aren't Nickel Cadmium as suggested by Matt, They will be 2014 Aluminium or similar* which has been Nickel plated. This has become common on high end aluminium brake and clutch components in the last few years rather than hard anodising, why this is so I'm not sure, possible for heat transfer characteristics, or better resistance to brake dust.

* I know Alcoa have developed alloys specifically for brake calipers in the last few years.

[Superdunc]

Haven't read the article but is it possible there has been some confusion with the beryllium alloy calipers that Brembo produced in limited numbers for Yamaha?

I thought Beryllium had been outlawed in most forms of motorsport because of the cost and health issues with machining it.

[Tennis]

Cant see what all the fuss is about with Ti when Aluminium is lighter?

[Superdunc]

Not as far as I know by the FiM....

2.7.10 Materials

Brake calipers must be made from aluminium materials with a

modulus of elasticity no greater than 80 Gpa.

I'm sure in F1 they brought in regs about the modulus of elasticity at the same time as they outlawed beryllium. Are beryllium alloys particularlly stiff, or was that just coincidence?

I'm suprised that they do still allow beryillium alloys, it is a hidieously exspensive material to produce components from.

[paul8899]

accord to the list 6alv4 is 900MPa, an 8.8 is 800 and a 10.9 is 1000 for ultimate. notice the yield point is closer to the ultimate the more money you spend. you had better really know what you are doing. i don't so the mono ones are steel.

the elongation is only 8%, which would bother me. and the density is 4.42 for g5, re 7.89 for en16. you aint gonna drill a hole up the middle of a g5 spindle (in a hurry!), so just make it out of steel and it will be more or less the same weight anyway.

my point re Ti grade is make sure you have the right grade..

the spindles I made are 6alv4 ,which has roughly the same tensile strength as stainless.

Its wierd stuff to machine, it turned ok but it really really didn't like drilling

why would the 8% elongation bother you ?

I measured the weight of the spindles and both of the ti ones weigh roughly the same as one made out of stainless

[Tennis]

Strength to weight - it's the metallic equivalent of a 5'3" Glaswegian nutcase.

Rich.

With all due respect thats a common misconseption.

Commercially pure aluminium has a tensile strength of approximately 90MPa and can be improved to around 180MPa by cold working. The heat treatable grades can develop a tensile strength of around 570MPa and even higher in some alloys (7001). This figure compares favourably with mild steel which has a tensile strength of approximately 260MPa.

7001 T5 aluminium is your friend

[Superdunc]

Millemille, just done a quick google and it appears Beryllium alloys are clased as MMCs which are speciffically banned in the FIM regs, It also seems they are very stiff, so fall foul of that regulation as well.

Tennis, on a formula one car outside of the engine, radiators, and gearbox, there are very few aluminium parts. There will be a few magnesium parts, but everything else is Carbon or Titanium. Titanium has much better strenght to weight ratios, and more importantly, stiffness to weight ratios than any alloy. They are even making gearbox casings out of titanium sheet.

Edited for even worse spooling than usual.