Friday, 12 April 2019

Little steps: Horn Bracket for the FH

Back in January, before I started work on the crankshafts and before my little Grandchildren laid us out with those pre-school viruses they love to share, I was assembling the toolbox and some bits around it. I wrote about it here.

Workshop time for bikes often occurs as a distraction from something domestic you are supposed to be doing but have become tired of - or maybe I have a short attention span; so it was that yesterday found me building shelves for my off-grid battery bank and making a horn bracket while the glue dried.

You'll recall that I have a toolbox which may be too early for my FH. The bottom bracket looks like this


Ariel do not list a separate horn bracket for 1958 and here's why - the horn bolts directly to the toolbox tab as shown in MickD's picture below. As you can see, I don't have those holes on my toolbox! The swinging arm toolbox carried a -54 part number through to the end of four stroke production, so I must have an earlier incarnation of the same part, designed to be used with an Altette and not the Lucas HF1441 horn used in 1958.


I needed to make an intermediate bracket, or modify my toolbox. I have the correct Lucas HF1441, which I think came from eBay. It has a right angle bracket, retained to the multi-leaf horn bracket with two 2BA hex head screws:


As always with any sheet metal work, we mock up the required part in cardboard and test it for fit:


Then, with some Dykem marking blue we can lay it out on a bit of 4mm sheet. It's hard to see with the lighting, but I have punched witness marks around the perimeter of the part to help me see the shape during the filing & linishing that will happen later:


Cut out commences with the hacksaw, and carries on with files and the linisher - a very useful tool that I acquired recently.


The holes were actually drilled while the part was still square - so that it could be clamped securely in the machine vice on the drill press:


Test fit - good to go to paint I think, though it's very close to the upturn on the toolbox bracket. I'll need to deal with that as the toolbox may get powder coated.



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