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Are these cases salvageable

Posted: Sun Sep 23, 2012 3:23 pm
by Haggis
Has anyone experienced the problem in the picture attached. It looks as though the kickstart support boss has failed, presumably because of some over enthusiastic kick starting. The bottom half of the boss has snapped off (( picture has ben taken "upside down" incase the resolution is not good enough to see.

Are the cases salvageable? I don't know anything about welding.

I have managed to get some replacement cases, so these would become spare if they were salvageable.- I am not anticipating needing them but it seems that there is so much enthusiasm for Ducati singles that it would be a waste to bin them if they are salvageable.

As an aside, are there any guides on sizes of attachments? I have been reducing them from about 2 Mb. -

Any comments very welcome.

Thanks

Chris

Re: Are these cases salvageable

Posted: Sun Sep 23, 2012 10:40 pm
by Jordan
That looks very fixable. A good welder will build up the missing portion, and milling operations will restore the bore/face.
The challenge is to do the boring accurately. Before welding, a fixture should be arranged to locate the casting on the milling table. The existing hole provides location, not easy once it's welded. A fixture might be a dowelled plate with a removable machined bar for the hole.

For forum type use, I use a graphics program to reduce image size to something like 800x600 ish DPI, and compress as JPG at about 70%. Irfanview is very quick at this job.

Jordan

Re: Are these cases salvageable

Posted: Mon Sep 24, 2012 5:24 pm
by double diamond
Pretty common failure and repairs have been made. Usual problems with welding an oil saturated casting. After welding, you can put the clutch cover back in place and indicate the bore off the kickstart shaft hole in the clutch cover. If that's all that is wrong with the cases, they're well worth keeping. Matt

Re: Are these cases salvageable

Posted: Tue Sep 25, 2012 12:15 am
by Haggis
Thanks Jordan.

Although I have replacement casings it might be better to use the originals. I will ask if anyone locally can weld the cases. My main concern was that the boss is in a high stress zone and I didn't want stray lumps of metal rattling around the cases. It is pretty reassuring that Matt says this is a common failure and repairs have been made. - I am a bit baffled about why the boss failed in that place given that the shaft is supported between the back of the boss and the outer cover. One of life's little mysteries.

I will investigate further and report back. Thanks guys.

Chris.

Re: Are these cases salvageable

Posted: Tue Sep 25, 2012 12:15 am
by Haggis
Thanks Jordan.

Although I have replacement casings it might be better to use the originals. I will ask if anyone locally can weld the cases. My main concern was that the boss is in a high stress zone and I didn't want stray lumps of metal rattling around the cases. It is pretty reassuring that Matt says this is a common failure and repairs have been made. - I am a bit baffled about why the boss failed in that place given that the shaft is supported between the back of the boss and the outer cover. One of life's little mysteries.

I will investigate further and report back. Thanks guys.

Chris.

Re: Are these cases salvageable

Posted: Tue Sep 25, 2012 5:12 am
by Jordan
Matt's suggestion on bore location sounds like a goer.

Jordan

Re: Are these cases salvageable

Posted: Sat Oct 06, 2012 2:11 am
by DesmoDog
Been there, done that. Mine was the result of a less than brilliant moment tearing the engine down, but I have heard they can/do break in use.

Here's a post-fix picture
Image

It's worked fine ever since though I have to admit the bike doesn't see much use.

Re: Are these cases salvageable

Posted: Mon Oct 08, 2012 8:17 pm
by Haggis
Thanks Craig.

I have found someone who thinks they can weld the cases. Do you remember much about how it was done? - Better if I can pass info on to the guy who is doing the work. I will take the other suggestions from earlier replies as well.

Chris.

Re: Are these cases salvageable

Posted: Tue Oct 09, 2012 9:42 pm
by DesmoDog
Sorry but I don't really know much about the specifics on this. I sent it off to Rich Lambrechts and he did the welding/machining for me. I assumed he indexed the bore off the back of the hole but never put much thought into it. He may well have a template to do it from the front for all I know.

Hmm... that might not be a bad idea for when I rebuild my 350 - bring the bare cases in to work and have the holes mapped out on a CMM, it'd be pretty easy to make a jig from that info...