Engine Mounting Plates 500 Singles

[spookefoote1956]

Morning groovy cats. I've had a brain wave. As you may know I'm currently building a Lecky Leg for the 18s. Looking at Joker Bones post I realised that the that the later rear engine mount plates don't have a big hole in them for a dynamo so would be ideal as they wouldn't require strengthening plates. So this led me to a thought.

There has been some interest in the article from folks who are considering doing this to their bikes but maybe the alterations to the plates are beyond their skill base. If folks could send me a tracing of a range of rear mount plates through the ages I could convert them to CAD so that they could be cut out of 4mm stainless etc ready to go. Obviously I couldn't provide the final made item but it would be a file that could be handed over to a manufacturer to produce it for you.

Just a thought. If anyone's interested then PM me

Chris

[spookefoote1956]

See what I mean?

plates.jpg

[shaunstaples]

Could do with an area or library to make things like that accessible to the club, so the same ground isn’t being covered over and over again?

[SPRIDDLER]

Could do with an area or library to make things like that accessible to the club, so the same ground isn’t being covered over and over again?

Christians Archives would be the place which has many hundreds of techy articles and factory manuals.
There are already un-dimensioned drawings of the engine plates, plus sizes of spacers, mountings and studs etc. in the Archives here:

http://archives.jampot.dk/technical/Gen ... 6-1964.pdf

[shaunstaples]

Thank you Neville, yes another folder on there would do nicely
That’s another afternoon taken care of…
Beats shovelling snow anytime!

[spookefoote1956]

Cheers Nev. The drawings are OK for bolt sizes but sadly lack anything to to help with the plate dimensions themselves which was why I was looking at tracings of real ones which I could then vectorize. Apart from the bolt sizes I can't see much else of great use there.

[Joker_Bones]

Does the club have the factory drawings for the engine plates?
In another thread about lightweight side stand brackets IIRC someone posted the factory drawing. The drawing was fully dimensioned and a cad vector drawing could have been produced from it.
I have the engine plate that I scribed round to cut out the plates in the photo and I'll happily draw round it for you...
I imagine the most accurate method would be from the original dimensions.

[Joker_Bones]

Just seen your post in the 'shock absorber' thread, I'll answer it here...
The plates in the above photo I cut out using a plate that was described as being from an alternator model heavyweight as a template. The duplex frame they are fitted in is a '61 M31
The black plates in the other photo came with the bike, the frame is a '64 CS frame.
Comp models without lights and alternator models didn't need the hole in engine plates for the dynamo. How universal that style of plate is across all the other models... I don't know.

[SPRIDDLER]

Cheers Nev. The drawings are OK for bolt sizes but sadly lack anything to to help with the plate dimensions themselves which was why I was looking at tracings of real ones which I could then vectorize. Apart from the bolt sizes I can't see much else of great use there.

Indeed, sadly the sketches of the plates don't have any dimensions.

Does the club have the factory drawings for the engine plates?

Factory drawings are rare and most are fragile in very poor condition.
Word on the street is that Russell Motors took a great many drawings, (apparently from skips), when they cleared van loads of parts and factory tooling when Plumstead closed. I believe that Les at Russells has been approached but is unwilling to let them out of his possession.

[RichardS]

I have a similar requirement for a slightly different reason and I'd be happy to collaborate - I do plenty of CAD and was intending to get some alloy plates water-jet cut once I can get the dimensions accurate - I have no correct plates at present. I have plates for a rigid single with a CP box and for a twin I thought in a duplex frame, but it doesn't match a AMC box which is odd.

A quick and reasonably effective way to CAD-ify them is to take a decently high resolution photo (modern phone is easily good enough) straight/square on and then vectorise that, but a tracing works fine too of course.

My actual requirement is that I have a twin tube Comp frame, a long stroke comp. motor and an AMC gearbox. It shouldn't be too hard to match them up, but without knowing the shape I'm looking for when trawling fleaBay or autojumbes the part numbers in the Parts Manual don't really help.

Chris, do you have CAD for the plate in your photo? Looks to be just what I'm after

Richard