Lucas SM5 switch panel spare parts

[Stuart Giles]

At the moment I'm doing up a SM5 switch panel to fit in my Ulster replica/special. As well as the 80 something years of wear and tear, it came to me with one of the bakelite levers snapped off as in the photo. Does anyone know of a source of a spare, or indeed any other spares for the SM5 panel.



Thanks for looking. Stuart.

[Bruce Nicholls]

How about trying 3D printing?

[Nicholas B]

I had exactly the same problem a few years ago before I had a 3D printer which I would definitely attempt now.  I used the good lever to make a mould with plaster of Paris.  Then mounted the broken end in the mould with a strengthening rod inserted into a drilled hole in the stub.  Resin mixed with a bit of fibre glass for strength was poured into the remaining gap.  The cured and finished item was rubbed down and painted and it is difficult to tell the difference.

[David Cochrane]

I can supply the grub screws for these if you need any.

[TomHunt]

Stuart, 
Someone was asking for replacement knobs on facebook a few months back. I made a silicon mould tool to make them a few years back for an incomplete panel I had. I think Steve Hodgson said that he had some spare originals, he would be a good place to start. 

Personally I would say a rapid protoype wouldn't be a great way to go, mostly the prints aren't very robust and breaks down in UV. Surface finish would also be a bit rough. Moulding over a brass insert gives a good strong result that comes out as a finished product. Here is a picture of a moulded one I did. 

   

[Stuart Giles]

Personally I would say a rapid protoype wouldn't be a great way to go, mostly the prints aren't very robust and breaks down in UV. Surface finish would also be a bit rough. Moulding over a brass insert gives a good strong result that comes out as a finished product.

Hi Tom, I've just seen your post, very interesting regarding the moulding -looks impressive. Your comment does confirm my experience with the surface finish of 3D printing, that could certainly be fixed with some fine abrasive, don't know about the potential longevity with UV; there seem to be a bewildering range of filaments available nowadays.

A good mate who does a lot of CAD stuff at work offered to have a go at replicating the lever by drawing it up and 3D printing. Here's a couple of photos of the first print -as it's just a try out he used whatever filament was in the printer.





Fortunately, while that was going on, a member on here (thanks so much) sent me a lever. Identical to the SM5 lever at the front but turned out to be different at the rear, the 'london transport logo' dimensions were both larger and further forward on the lever. Quite an interesting machining job to reproduce the SM5 register without using CNC equipment.



Very pleased with the result, just need to build up the rest of the car now!



BTW, Mark, who did the drawing/3D printing did the drawing on a publicly accessable site -TinkerCAD- so if anyone wants to print one or edit the drawing and print, let me know and I'll get you the URL

[Ivor Hawkins]

Loving your work!

It never ceases to amaze me how resourceful Seveners can be...

[TomHunt]

Stuart, 
Nicely done, I can imagine it was a tricky thing to machine. I figured you had got something sorted out as the thread went quiet. The moulding does work well, and can be applied to other things. Such as ML Magneto Caps.....
   

We have a similar rapid prototype machine at work it is great for making casting patterns but I haven't found many more home uses for it.

[Dave Mann]

Necessity is the mother of invention. Many years ago My RN SM5 had only one knob from which the previous owner had removed the the split pin and moved the knob from ignition to light switch as required. The knob was removed and put in his pocket when it was parked up. I put up with that for a while before I found another knob.

[JonE]

Just re-assembling and I could have sworn there was a good how-to on one of the owners clubs. Cornwall just concentrates on the lettering for the switchpanel. Any suggestions?

1. The two "bobbled" rotating brass terminal selector plates I think used to be symmetrical but the wings appear to wear on the side where the contact the centre sprung terminal/post. Is it thus sensible to swap these so the long one is reused to the centre?

2. I also have large (but thin/flexi) insulating washers which fit the bakelite knobs (internal diameter) somewhere but I'm not sure where. Do they go just under the faceplate? or?

here is the asymmetric selector. If they are physically different from the start, then what is the other side actually for? Are they to be used in different ways for each side of the SM5?
   

I've just found an old Friends forum post here may also be helpful to some: http://pub25.bravenet.com/forum/static/s...4&cmd=show