Alloy front LED indicators

[Old indicators. ]

For some time the front indictors, which were just the stock items that had been shortened have been bugging me.

Wondering round the net Id found some ultra bright diodes (http://www.ultraleds.co.uk) in amber which set me thinking again. I had found four pieces of aluminium lying around in the garage already cut in to rounds so decided to tackle making the indicators. Unfortunately this meant I had no extra pieces to experiment with before doing for real.

First I fastened the front and back bits together, then trued the pieces up on the lath and marked out the diode holes. I drilled the holes first with a 2.5mm drill and then opened them out to 5mm. This usually gets you a rounder hole than drilling in one operation.

[drilled holes ]

I had hoped that drilling the holes first, would make the turning easer (my lathe only being a small model maker’s lathe of low power) but unfortunately the holes caused the lathe bit to judder (probably du to wear as the lathe is older than me ) leaving a ripple mark on the metal that showed up terribly when polished. This was only the first wrong turn in this project, but the best way to learn is by experience.

[iner turning ]
[3 fastenings ]
[1 fastener ]

I next turned out the inside. I had fastened them together using three 3mm counter sunk bolts taped into the front piece. Unfortunately once the inside was turned there was not enough metal to take a thread especially as I only had a middle tap and no bottoming tap. So I drilled out the centre diode hole and drilled a tap hole in the back for a single 6mm bolt for which I have a proper tap set of 3.

[3 holes filled ]

I then had three holes which I didn’t need in the back piece which had to be filled. I drilled them out to 6mm and turned up 6.1mm rod which I fitted with an interference fit and could then treat as solid. For some reason two of the holes on both piece disappeared completely wile the third showed up terribly when polished.

By this time the diodes had arrived, so I inserted them all, glued them in with epoxy and wired up. A long tedious job, wiring them all in parallel. First I wired in the positive connections and painted them with some nail varnish. This does two things, both insulating the solder joints and marking which is positive as once earth connections are wired in it is very crowded. The earth leads were trimmed off slightly longer than clearance so as to make contact with the body of the indicator and subsequently to the earth of the bike.

I then turned the outside fronts and another problem surfaced. When I had drawn up the planes for the indicators I had used a stock diode for measurements as I had to order the bight ones and wanted to get started on the turning. Unfortunately this meant the wall thickness I’d arrived at was to thin, the workings of the bright diodes being a 1mm higher up the body. Something which was not apparent until Id don the turning and removed some of said workings. When I tested the indictor 9 were dead and needed replacing.

[replacing diodes ]

Its times like these I’m glad I used the nail varnish as unwiring so close together is a bitch. Of coarse I had to re turn the front face to clean of the replacement diodes (which Id put in slightly lower to protect the workings)

After I'd turned the backs, and done the polishing I started to wire to bike. I had to use a test set up to work out how much resistance I would need to get the right currant for the diodes. Alas whilst I was doing this fate through in a hand, and the resistance got shorted out resulting in full currant getting to the diodes. This resulted in a very brief, bright flash from the diodes in one indictor and killed all 30 diodes. (The resistance of 50 ohms ended up wired internally where the short shaft enters the indicator.)

[diodes removed ]

If I'd had more metal I'd have given up and started again at this point as the finish isn’t what I would like it to be, and ill probably remake in future anyway, but I didn’t, so all 30 had to be removed carefully with a punch so as not to damage the alloy ( I write this as I’m waiting for more diodes to arrive as replacement, sometimes you could just kick your self %$**!! )


Flasher Relay

As I have replaced all my indicator bulbs on the bike with diodes that draw a lot less current than a filament bulb, the flasher unit wouldn’t operate correctly. The one fitted to the bike was a two pin metal strip type which can’t be adjusted. Fortunately my box of bits supplied a newer 3 pin flasher unit using solid state components to make the flash. If you want to fit one of these you only need supply the earth to the third pin and insure the other two are connected the right way round to get it working. If the pins have numbers on them the 49 pin should go the positive and pin 49a goes to the indicator switch, leaving pin 31 for your negative. It will however flash rather quickly as the circuit detects that there is less currant flowing than should be and ‘thinks’ a bulb is blown and indicates it thus.

[chip pin out ]

This can be sorted easily if the relay uses the U643B chip (shown in picture). You only need to sever the connection going to pin 7 as this is the detection circuit. I did this by cutting the track with a craft knife. My pictures will give you some idea, but please be sure your relay unit is lade out the same before you go copying me.



[U643B chip ]
[cut trak. ]

Once all finished they look lovely and discreet. The effect is great and the LED’s are clearer to see than the original indicators. Ill probably remake them sometime, as during the making I thought of one or two design improvements, apart from the finish not being up to a standard I’d like.

[finished indicator ]
[finished light. ]


Update

The new diodes arrive

[Cork inserts finished. ]
[Second wiring. ]

Not taking any chances I put two layers of 1mm cork to make sure the workings are well out the way. It also meant I could wire a bit tighter with it also insulating the body.

[indicators on bike. ]

On the bike they are so neat they almost disappear giving the bike a much cleaner look.

More Update

Whilst tidying the garage up from making the above, I found some more metal suitable for turning, so I found something to make with it.

[Side flasher. ]

A nice set of side flashers that also break up the rather square lines of my bottom yokes. Should hopefully stop myopic drivers from not seeing me.

[Flashers light. ]

[Initials monogram  A R T]

This page updated. 13/08/06

Reproduced in 100% Biker ..... Issue 88, March 07