FH - Lucas HF1441 horn

While waiting for bits for the QR50, I took the opportunity to refinish the horn for the Huntmaster. It tests OK in that it pulls a current and deflects the diaphragm, so some adjustment will have it working.

Lucas catalogues are very useful. This is catalogue 716A, section F - six pages of horns and horn pushes. The application page tells you which part number you should have:

In the case of my 1958 Huntmaster, it's a HF1441 model horn, part number 70048. The spares list tells us a bit about it:

It's black, and looks like this:

So, I had the correct horn (bought from eBay I think - it was missing from the kit) and all I needed to do was strip it and give it a coat of paint.

First up was the various bits of bracket:

It’s good to clean the points in these horns, but this nut is usually very tight and it retains the diaphragm to around the moving point. I had it soaking in Plus-Gas for a few days but I couldn't shift it:

Since the horn worked I gave up and cleaned the old paint off with emery tape. 

I painted it with the usual U-Pol etch primer and gloss black. I know the tone disc is supposed to be black, as is the nut, but it looks nice like this: 

Rusty metal

While it doesn't look too bad from this angle, the battery tray on this MZ TS125 is falling apart due to acid damage. There is a crack from one of the hooks for the battery retaining strap which means that that tab, with the M5 hole for the side panel is quite floppy.

Since it was only going to cost me a few minutes, I tried to braze it up but in practice it is all too thin to have any strength, so the easiest thing to do is cut it off and make a new one. The bracket used to mount the battery tray on the frame is sound, so we can cut the tray away from it retaining as much as possible of the old tray to provide a pattern for a new one.

I have some 18 SWG cold rolled sheet in the shop, which is a good deal thicker than the original which looks like 22 SWG. You can see the extent of the damage in these pictures.

The new one is very simply folded from sheet, cut out with the jigsaw & hacksaw and with 5 mm holes drilled into the corners for clearance and drainage. We'll tack the corners together with the MIG welder.

Here's the hooks folded down and around the old strap.

So now I have transferred the side panel tab to the new tray, and brazed it in place in case I have to move it again. Next, to weld up the corners and finally weld the tray back to the frame:

Welding the outsite of corners is tricky if you are not to blow the material away completely; my welding needs a lot of dressing! Corners done, we'll tack it in place using the old one as a guide:

We'll need to fit some other parts around it to confirm that the side panel mount is in the correct location, and then we will complete those welds underneath. Removing it with those fully welded would probably destroy my new tray.

Just a little U-Pol etch primer to avoid rusting...

A few days later I have the cast aluminium rear mudguard and the coil bracket to mount up and test my new battery bracket. I'll put the lot in the vice and mount the rear end with some 10 mm pins, that are a close fit in the holes and don't allow any wobble:

You can see the three M6 mounting holes for the side panel - one in my battery bracket, one on the coil bracket and one in the mudguard. Here's the side panel mounted up:

Perfect! now we can weld up and apply some paint.

And that's it, ready to be returned to its owner.

Battery Carrier

This is about the carrier I am using to mount my gel batteries. Here are the batteries:

Now these will happily fit in the box, indeed they were chosen to do so. But because they are so short they will be a pig to get out, and I want to hide a fuse box and maybe some other wizardry in there. So, I have come up with this:

It's a simple carrier made from 18 swg cold rolled sheet; the batteries enter from one side and it is lifted out of the battery box by the two handles on top. The top deck is to carry the fuse box. I plan for the cables to exit through a slot in the upper inboard edge of the battery box:

So, now I have identified where the cables are going, I can cut a slot in the box. A coping saw and a half round file does the job nicely:



So next, final wiring and painting. I have used closed cell neoprene foam to cushion the batteries; painted with U-POL etch primer and black gloss, and wired in accordance with the diagram on the wiring page.

All that remains is to put the lid back on and look at sealing the lid.