Forum Lockdown

[davemassam]

The lockdown and social distancing measures apparent on the forum lately have now been lifted.  Is there any workshop activity to report?  What plans are in hand for rebuilds?

I am in the process off making new cones for front wheel bearings to eliminate a dangerous sounding crack every time the wheel completes a revolution.  I am undecided what material to use and how to heat treat it, should I now wait by the computer in anticipation of a flood of responses?

If not, seasons greetings to all, and don't forget that social distancing on a bike is easy.  

[CC Rider]

Hmmm - hope you're not still waiting or it'll be a looooong repair!

Happy New Year - belatedly!

[CPR]

Hi Dave. Just seen your post. I’ve been rather busy in the shed recently, modifying a girder fork spring. The Post Office managed to loose the original spring and the fixing ‘claw’ (they generously compensated me with 6 first class stamps!!, but I used up most of them complaining to them!!) I have bought a similar spring from Paul Powell but this one is attached to the forks by bolts, so I had to cut 2 coils off one end to get it to twist in to the ‘claw’ on the forks. By removing the 2 coils, this has made the spring shorter, so I’m not sure if it will be strong enough. In the absence of a better one I think I will go ahead and try it. The next tasks are to make a friction damper for the forks and to patch the engine plates.
Anyway enough of my problems, back to yours. Have you seen the Vintage Workshop book by Radco? There is some advice in there on making cup and cone bearings. He recommends one of the case hardening steels EN 31, 32 or 36. After turning and finishing in the lathe with emery on the end of a bar, it needs to be case hardened and then re-finished again with emery. He recommends cyanide-hardening but I'm not sure if this is practicable. For the home workshop the 'casenite' process is the only one available and I'm not sure how effective this would be.
Hope this helps.

Chris

[davemassam]

Thank you Chris, I do have some EN32 and Casenite so that looks like the way to go. I'll try some tempering before case hardening provided that it doesn't become brittle, wear won't be a problem as mileage will be minimal.
I didn't think to open Radco, there's nothing so difficult to see as the bleeding obvious.
Progress with my own bikes has been limited as priority was claimed by the family Vincent, but a clearing is starting to show so here's hoping it's more straightforward than your spring. At least nobody else will be responsible for what goes wrong.

[johnc]

I have done a little in the past with Casenite.  usually I have done the casenite process, then quenched in oil to harden, then polished up, then used a blowlamp to temper it to light-straw colour (205 C I think), but is very easy to over-shoot, resulting it being soft.   However, i only recently realised that some normal ovens can go this hot, so 'cooking' it in an oven might be a good way to do it. 
I doubt if all members of the family would agree though!!!!!!   

[davemassam]

That process makes sense, the oven is the best way of evenly heating treating components at lower temperatures. After a season's use the Norton gears go in at 200c for one hour to stress relieve. It's always difficult to decide whether the post process aroma of gear oil, Jizer or brake cleaner would be most appreciated wafting through the house.
Thank you, I think I have a plan.

[cottonjo]

Hi Dave, Are you sorted now? Is it a pre-war machine? I have some ideas if you still need them.
Paul S

[davemassam]

Not sorted yet I'm afraid, I've been diverted onto a couple of other bikes but hope to get back to playing before too long.

[CPR]

Hello Dave.
How did you get on with the case hardening? Did you use the casenite method? I ask this as I have been refurbishing the tappets on my 1935 250cc twin port JAP engine. The exhaust tappet was badly worn on one side, and I had to stone it down to regain its profile. In doing this I have reduced the depth of the case hardening. So I am interested in knowing how you got on as I may have to re-harden the tappet surface.

Chris.

[davemassam]

I'm still completely bogged down in a Rapide starter motor kit, sorting out a bespoke wiring loom for the complete non-standard bike, and sorting the gearbox and a clutch conversion. Cotton maintenance is light relief in comparison.