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Re: Primary chaincase disaster

Posted: Sun Apr 14, 2019 8:54 pm
by paul.jameson
You have a good point on the re-manufacture. Although the numbers of 1936-38 singles primary case outer sales may be low, the extremely similarly shaped Square Four primary case outer is also in short supply and probably rather more demand. The singles outer is of course rather longer than the Square Four version but the two cases were obviously designed to be as alike as was possible.

Re: Primary chaincase disaster

Posted: Sun Apr 14, 2019 10:45 pm
by roland robinson
Paul,
A pattern is already in existence for the square four primary outer case.
Roland.

Re: Primary chaincase disaster

Posted: Mon Apr 15, 2019 9:25 am
by Dave.Barkshire
I did email Roger Gwynn and he sent me the following reply...

Niether Draganfly not the club have any plans to get these made at the moment but it is something that perhaps we should be looking at. nPattern making can now be done for about £500 by laser scanning and 3d printing. The casting is not expensive, perhaps £30 but machining is still not cheap, perhaps £70 - £100 each, based on a qty of 10. Higher quantity of course = reduced costs. Primary cases for Slopers have been made in recent years by at least 4 parties, so we ought to be able to make some of the more common ones. Presumably the inners are required as well. Doug Walker has made a pattern and a prototype casting for the 1937-58 SQ4 case but I don’t have any costings for that. Really it needs someone desperate enough to pick up the ball and run with it…..


I seem to remember that there was a list of candidate re-manufacture projects in the club, does anyone know who keeps this list?

Re: Primary chaincase disaster

Posted: Mon Apr 15, 2019 5:54 pm
by volker.halbach
Count me in. I have been looking for an outer cover without any success and found only later covers.

Re: Primary chaincase disaster

Posted: Sun May 26, 2019 1:29 pm
by brenton.roy
Me too. I could do with 2 sets.

Re: Primary chaincase disaster

Posted: Mon May 27, 2019 9:24 am
by ian.scott
There seem to be quite a few on eBay of various types and conditions. They do tend to be expensive though.

Ian

Re: Primary chaincase disaster

Posted: Mon May 27, 2019 1:21 pm
by john.whiting
if a pattern is to cost 500 quid,then I would have a case CNC machined from a solid lump of ally.....the upside being the holes would come as part of the job.....of course ,you would have to glue the old one back together,so it could be digitized..........its probably easier to take good care for your primary drive......I dont like belts,but there is no way a belt is gonna bust your primary

Re: Primary chaincase disaster

Posted: Mon May 27, 2019 2:01 pm
by Mick D
john.whiting wrote: there is no way a belt is gonna bust your primary


In my opinion, if a belt, or any other form of drive, carries debris larger than the chain case can accommodate it will break the chain case - a better approach in this case would be to prevent the screw from being able to fall out, an extended head would achieve this.

Regards Mick

Re: Primary chaincase disaster

Posted: Sat Jul 27, 2019 4:12 pm
by jj.palmer
To lock the subject screw in place I drilled 2 small holes in the casing adjacent to the screw and wired it through the screw slot, see attached.

John P.

Re: Primary chaincase disaster

Posted: Sat Jul 27, 2019 4:28 pm
by jj.palmer
A better view, also a lock washer on the cush drive nuts.

John P.
002.JPG