Best material for building a worn shaft

[AndyStobbs]

Have bought a project jet ski and have a few bits to do. Driveshaft has deep grooves from the shaft seals and I want to build it up then machine back to good material. Expect the shaft to be a carbon steel capable of being hardened and tempered, has splines at both ends and was ground originally where the seals and a needle roller support bearing runs.
What is the best material for building the shaft for good wear resistance and machinability - I do intend to grind or atleast sand to final surface.
I know it will distort but its no blooming use as is so worth a go.
Have plenty of 308L still, but thought 316 might be better?

 

[AndyStobbs]

Thinking about it, it may be possible to turn it down and sleeve over the damaged area with an interferance fit. Will measure up tomorrow.

 

[711jrp]

I'm guessing they are normally stainless as they take a while to rust in salt water

 

[Robotstar5]

Get it spray welded? our local motor repair place offers it - link

 

[AndyStobbs]

I'm guessing they are normally stainless as they take a while to rust in salt water

No, its not stainless. Well I'm 90% sure it isn't. Will double check mind.

 

[steviec_lj]

What ski have you bought? Plenty of good spares available out there.

Rebuilding a Quackasaki JS550 at the moment, next up, starter motor.

Had a full stator plate rebuild, engine rebuild, then the starter threw a wobbler.

PITA getting everything straight with shims, etc...

 

[Rig Pig]

Depending on the diameter you can get speedy sleeves that just loctite on the shaft.

 

[AndyStobbs]

Its a tigershark 770 daytona

 

[normspanners]

I would have it chromed up, as is done with hydraulic rams the thickness is determined by the length of time in the bath, then ground and polished back o the exact size or as I have done in the past if imperial seals are not available i have chromed it up to the next available mm size then re machine the end bush out to suit, which is easier than making a new end bush.
I have made some irrepairable rams as goood as new for a quarter of the cost

 

[AndyStobbs]

It isn't a ram though lol. I can do welding and basic machining in house so reluctant to pay out for external services,

 

[normspanners]

I have done it with all types of shafts /cranks etc it is just advertised as ram repair or build up, as such.

 

[steviec_lj]

http://www.ebay.co.uk/itm/NEW-DRIVE...tEquipment_Accessories_SM&hash=item5d441d31ee

The above is brand new from America, so may attract import charges.

But try The Jetski Centre. I've dealt with them in the past, and can't fault their service. They offer a range of services.

No connection to either of the above, apart from using them previously on my JS550SX

 

[AndyStobbs]

http://www.ebay.co.uk/itm/NEW-DRIVE...tEquipment_Accessories_SM&hash=item5d441d31ee

The above is brand new from America, so may attract import charges.

But try The Jetski Centre. I've dealt with them in the past, and can't fault their service. They offer a range of services.

No connection to either of the above, apart from using them previously on my JS550SX

Thanks for the link, I think for £125 plus charges I can afford to spend some time on my shaft. A sleeve is looking best, need a finished dia of 22.20mm (as measured from intact area) and can slip a sleeve of minimum 19.60mm over the end of the shaft, so can get an approx 1.2mm wall thickness sleeve on there...

 

[AndyStobbs]

Thinking about it, the shaft will be 7/8" its an American/Canadian jobby.

 

[AndyStobbs]

Ok so have got the damaged section clean now and down to 20.10mm, I want to sleeve over this diameter with a stainless sleeve which I will machine, and heat up to get it on there, giving a good shrink fit. I was thinking, 21.05mm ID for the sleeve - does that sound about right?

Sleeve will then be machined down once fitted, to final size. Will keep the shaft nice and straight. It has a 20mm ID needle roller to pass through, what clearance should I give for the bearing? 19.98mm?

 

[wyn]

Ok so have got the damaged section clean now and down to 20.10mm, I want to sleeve over this diameter with a stainless sleeve which I will machine, and heat up to get it on there, giving a good shrink fit. I was thinking, 21.05mm ID for the sleeve - does that sound about right?

Won't the ID of the sleeve need to be less than 20.1mm.

 

[AndyStobbs]

Typo. Sorry, should be 20.05 and the 19.98 should be 21.98, doing too many things at once.

 

[steviec_lj]

Sounds about right, yes.

Should the 20mm ID needle bearing, be 22mm? Otherwise 21.98mm won't fit.

Other thank that, go for it! Certainly beats paying £125 plus import charges for a new one yet...

 

[AndyStobbs]

Sounds about right, yes.

Should the 20mm ID needle bearing, be 22mm? Otherwise 21.98mm won't fit.

Other thank that, go for it! Certainly beats paying £125 plus import charges for a new one yet...

Yes should be 22mm, losing my marbles, I did order 22mm.

 

[AndyStobbs]

Right then, so who wants a laugh

I set about making my sleeve from a length of 40mm F51. Drilled it out in stages to 18mm then got the boring bar in, was pretty pleased with the results, on another thread it was stated that inserts have to be worked hard to get a good finish but that hasn't been my experience with these boring bars bought from RDG. At 100mm long there is a fair old over hang on the boring bar but it still gave me a nice parallel bore with a few spring cuts taken.


Offered it up onto the shaft (which is stainless as was suggested above by 711jrp)

So far so good, got the flame on it and got it cherry red (not while it was on the shaft) picked it up with the dogs and it slid on beautifully... for 3 inches then stopped. In my annoyance I tried hammering (tapping then walloping) it but it would go no further.

At this point a rational man would've stopped, sliced the sleeve off and started a fresh, but of course not me, in the end I smashed the splines on the end of the shaft and bent the end trying to get the sleeve off. Learning curve continues....
I know why it got stuck, there was 2thou taper on the area of the shaft which I turned down, I thought in my ignorance that wouldn't be an issue. Still I know for next time.
Going to set to and make a new shaft over the coming months.