How To.. 1939 RH rear numberplate and Torpedo lamp

Post by **alan.moore** » Thu Oct 01, 2015 10:11 pm

As I now know...in 1939 the rear numberplate and light was a bit of an oddity. Repro number plates do not appear to be readily available, Draganfly quote about £70 but have not had any in stock for a while. Repro Lucas MT1130 rear lamps just don't appear to exist. I found an 'origional' one sold on Ebay in 2013 for £300!!.

I had been told that a Lucas 1130 car sidelight, as fitted to fifties MG cars, was similar with some modification.These are readily available either new repro (about £50) or on Ebay. I would like to thank Andrus for providing me with a lot of information on how to modify the lamp. I will include all this later in the series of posts which follow.

Adrie provided me with a newly stamped rear numberplate, which is spot on and a great deal at £25.

I will do a series of posts to cover the topic.

Post by **alan.moore** » Fri Oct 02, 2015 12:02 am

Here are a few pics of an original Lucas MT1130. Note it has a slot underneath to illuminated the numberplate and a red plastic 'tell tale' insert in the top.

: Side view; .......jpg (8.25 KiB) Viewed 5811 times

: Inside view; ..-.jpg (12.25 KiB) Viewed 5811 times

The repro lamps you can buy have a few options:

chromed pressed brass bodied
chromed die cast 'monkey metal' bodied
plastic lens with no chrome bezel
glass lens (clear or amber) with a chrome bezel.

There are plain bodies with a red 'tell tale' insert in the top and ones without. Although the Draganfly site says that no tell tale was fitted the pictures I have seen, and other info on this site, would support that they were fitted.
Prices vary, just Google Lucas 1130, about £50 each.

I got two used lamps on Ebay for £50. One was brass bodied and one cast. The shape is identical, and the glass lens from the brass one fitted the cast one.

: Brass left, cast right

: Brass

: Cast

Post by **alan.moore** » Fri Oct 02, 2015 12:28 am

I used the cast body as the brass one has a few dents and a split that will need repairing. As it was going to be painted I abraded the chrome finish with a scotchbrite wheel on my bench grinder but a good rub over with wet and dry would be OK.

Here are the relevant measurements:

: Dimensions

: Cut out height

I cut the 'slot' out with a junior hacksaw and a small cutting disc on a 'Dremel' finishing off with a file.

: The cut

Post by **alan.moore** » Fri Oct 02, 2015 1:09 am

(continued)
The 'foot' of the casting is solid and having been cut it can be leveled with bodyfiller or just left. If you use a brass one then the front of the cut in the 'foot' will need closing using solder:

: Brass bodied modified

The four small holes are there in order to rivet the plastic 'window' inside the slot. I am using a 'circle of clear plastic (from a plastic bottle) with a slit in it glued in place. The natural curve of the plastic holds it in place. The rivets will just be glued in there for show (not riveted in).

You then need to drill hole D3 which is used to mount the lamp to the numberplate with a clamp bracket similar to that used to hold ammeters in headlamps. I just used a strip of metal bent to suit which I heated to red hot and quenched in old oil. This gives it a bit of 'spring /resistance to bending' which helps it keep tension on the lamp

: Hole D3 drilled

: Clamp bracket

My lamp came with a bulb holder that will take a twin filament bulb so you have tail and brake lights. You can get these from the same places the lamps are bought from if the lamp does not already have one fitted. All you need to do is shorted the mounting plate, which means removing the original forward mounting hole and then drill a new mounting hole to line up with D3. I welded a nut onto the holder for the D3 bolt to screw into.

: Bulb holder (right modified)

Post by **alan.moore** » Fri Oct 02, 2015 11:32 am

Adrie sent me mine 'flat packed' so the two sections need to be butt welded together. I used a series of small 'Mig' welds to reduce the chance of any distortion. Not that pretty until it has been ground back.

: Pre assembly

: Welded

: Weld cleaned up

: Weld cleaned up

: A thin coat of filler will sort this out

Post by **alan.moore** » Fri Oct 02, 2015 2:54 pm

Next job is to cut the aperture for the lamp.
There is a template which should help with size and positioning (thanks Andrus). The jpeg picture image is not life size if you print it out, but the measurements are on there. I have converted it to a PDF which, if you print it out on A4 using Adobe Reader and select 'Actual Size' it should print out very close to actual size. If you open it in a browser window and print from there do not tick the 'Fit To Page' box. Please check with a ruler before you start cutting!!.

: Will not print at actual size

Template.pdf: Should print out actual size..check; (339.29 KiB) Downloaded 223 times

I actually marked around the base of the lamp itself rather than use the template as I could always remove a but more. I cut it with a small cutting disc in a Dremel (took about a dozen discs but mine were cheap ones).

: Aperture cutout

I then kept filing and shaping, using the template as a guide, until I was happy with the fit. As it worked out the final aperture was very close to the template.

: Final Aperture

: Template for comparison

Post by **alan.moore** » Fri Oct 02, 2015 3:06 pm

There should be a rubber gasket between the lamp and numberplate. Andrus informs me that Draganfly can supply, but you may have to wait. Part number is 6130-39 and it is £23. I suspect it may be moulded to shape. I settled on using a piece of 'U' shaped rubber channel from my Dad's greenhouse door (sorry Dad, all in a good cause) which does the job. It is easy to replace with the correct part when I get to 'the bikes finished I can now start fiddling' stage.

: Rubber gasket

: Fitted

: Fitted

: Fitted

: Fitted

Post by **alan.moore** » Fri Oct 02, 2015 4:23 pm

The glass lens I had was an opaque white colour with a smooth outer and dimpled inner surface. It is 'crimped' into the chrome bezel so not really removeable.

: Lens

My mum once had a thing for painting flowers on glass. The paint is translucent and once it has dried properly is very wear resistant. I borrowed the darkest red she had. It needed painting onto the outside of the lens otherwise the 'white' colour was still present. It looks like it will do the job but obviously not as good as an actual coloured lens. You can get proper stuff for painting car lenses on the Web.

Anyway with one coat here is what it is like compared with a MT110

: 1130

: MT110

Post by **alan.moore** » Fri Oct 02, 2015 4:28 pm

Here it is fitted. It may not be exactly as original and it still needs a bit of fiddling to get it aligned just right but, for about £50, I am very chuffed.

I hope this will be of help to others in the future

Post by **alan.moore** » Fri Oct 02, 2015 4:34 pm

Realised I had forgotten to include this diagram. It is not to scale but shows the relevant measurements

: Numberplate dimensions; n_a (4).jpg (24.19 KiB) Viewed 5756 times

I am waiting for a red 'King of the road' tell tale to arrive. I will post it's fitting when I get it.

: Tell Tale; tell tale.jpg (3.3 KiB) Viewed 5752 times

Cheers
Alan

Ariel Owners Motorcycle Club

Ariel Owners Motorcycle Club