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The 'Yamaha Enduro'

1975 Yamaha DT125/175MX Hybrid

Monday 23 January 2012

Holey Head-Lamp!

Well, a busy week. And lot's of 'little' tasks tackled. With the new head-lamp lense, and the HID kit, I could try and get that fitted up so I could see what space I had for the wiring and dash panel.

This required a little adaptation; the HID Headlamp is 'just' a little longer than a standard H4 and connector, and an 'nth' too big to be squeezed into the headlamp shell! So I cut a hole in it!

It needed to be a rather big hole, much larger than any drill bit I have, so I started by marking the 'rim' of the hole I wanted, and drilling lots and lots of very little holes around the edge.


Next step. is 'Dirty-Drilling'.. using a larger drill to open each of the little holes up and make the gaps between them nice and small, and deliberately 'laying off', waggling the drill from side to side to make them a bit oval and break through between some of the holes.

Then a good smack with a hammer, and the middle of the hole 'breaks out', just like tearing out a tax disk! I have to confess to some 'guilt' here, 'permenantly' modifying parts of the bike; BUT, it's a mongral ANYWAY, and far beyond any sensible restoration to original 'concourse' condition, and the intent is to make a 'useful' practical classic out of it.


Edges were then tidied up to make a fairly round hole with hand-file and Dremmel


Some of that plastic pipe was split to make an edging for the hole, and the lense and HID assembled into the bowl.


And the assembly could be trial fitted to the bike.

And you may notice that the tank has been 'finished'. The Decals now lacqured in under 'professional' two-pack Lacquer.

HORENDOUSELY expensive stuff in a rattle can. 14 for a 200ml can! BUT supposed to be 100% 'Petrol-Proof' unlike the celulose 'Petrol-Proof' Laquer we have been using, that has proved to merely be slightly more 'Petrol Resistant', provided you dab any spill off fairly fast!

Funny can. Has a grenade pin thing on the bottom! You have to take a plastic cap off, pull the ring and twist, to release the 'activator' then shake like fury for three minutes to mix it before you can start spraying. AND you only get one 'shot' from it. The stuff goes off like epoxy resin, once mixed, so you have about half an hour to get all your bits painted with it, or the stuff sets inside the can! But with only 200ml... only 'just' enough to do one coat on the tank and side-panels anyway!

Dash for Cash!

Right, with the head-lamp 'sorted', and in position, I could set about making the Dash-Panel. The electrics sort of centre around this and the head-lamp, and with the HID filling a large chunk of the head-lamp bowl where the standard wiring would collect, and a few add-on's planned, a lot would have to be gathered under the dash-panel, including the ballast box for the HID Headlamp.

The basics ingredients for the dash are the Speedo, Rev-Counter and ignition switch, and a bit of aluminium plate to bolt them on. Mentioned before, that ALL I had to start with was the Speedo. The Tacho, was a second hand e-bay bargain I snaffled for 15 delivered. The Ignition lock was brand new for just under 10, and the bit of aluminium plate, another 10. So this is almost all 'bought' bits.

The first job, was to rip the tab off a corrugated cardboard box, and make a rough template, and cut the plate to the aproximate outside dimensions.

Next the holes for the Tacho & Speedo Drive were marked and drilled. The boses are about 14mm in diameter, and the largest drill I have is 10.5mm, so after drilling these had to be opened out with a round file. The holes are 'just' that tad too small to do by the small hole trick.

With the holes for the bosses made, then the clocks could be aligned on the base and the mounting peg holes marked and drilled.

With mounts for both clocks made in the plate; I needed to cut the relief's around the mounting holes where the plate will bolt to the fork yoke. Again the 'Dirty Drilling' technique was used to get the 'rough' of the curve.

The reliefs broken out and then dressed with a hand-file.

Drilled, it could be trial fitted to the Yoke to check clerance around the fork-caps and handle-bar clamp bosses.

The Clocks Dropped in to see what they look like. They are possibly a little far ahead of the bars. Because I'm tall, and possibly because I come from trials, and used to riding 'stood up' I tend to always have the bars rolled quite 'forwards', and I placed them 'ahead' so that they weren't obscured by the brace bar when I was sat the bike, and to allow some 'space' behind the clocks to fit any extra switches, LED's and a cigarette lighter/accessory socket.

The 'balence' isn't helped by the Head-Lamp brackets having been shortened in a former life, and the lamp, when fitted does seem to be 'hiding' under the dash somewhat! But as yet, I'm not sure. When the bracket is finished and trimmed, it may be less obvious, but I do have some scope to trim the back of the bracket a bit, to bring it in closer to the bars.

Meanwhile, next job was to make the mounting for the ignition lock, and the relief holes for the back-lights & tell-tale warning lamps. All done with the 'Dirty Drilling' Technique to rough out the more complex shapes, then dressed to finished shape with hand files.

And there you go. NOT finished yet; but it bolts to the bike, and the Clocks and Ignition Switch bolt to it, and it has holes in the right place for lamps. I have yet to work out where the alarm & auxilliary LED's are going to go; or the hazard warning switch, or the Aux-Socket. AND there is the matter of attaching the HID-Lamp ballast box underneath. But for NOW, it's done 'enough' to let me get on with some wiring... and... well, it JUST needs 'something' to go between the bracket and the clocks... stop them wobbling around....

Easily LED!

Right, time to get experimental. I need back-lights and warning lights for these here clocks. When we did Donna's 'Pup' we spent a horrendous amount on LED Peanut Bulbs for all her instrument lights, and I need holders and loom as well! So I decided to see what I could do with 'component' LED's and resistors, and ordered a few bags of them off e-bay.

I got a bag of red, a bag of blue, a bag of green, a bag of amber, a bag of UV/Purple and a bag of white. 50 LED's in each bag, which were about 3 each, on average, so 6p each or there-a-bouts!

LED's are Light Emitting Diodes, one way valves that light up. They give out light depending on how much current goes through them, so there needs to be a 'load' on the circuit to draw some, or you just create a short circuit through the LED and burn it out.

They also are rated at something like 3.5v and we have a 12v supply, so the simplest thing to do is wire them in series with a resistor to knock the voltage down and put a load to draw some current through them. So some more bags of 540K Ohm resistors were bought to go with them. Again 50 in a bag for about 2.50 so 5p a resistor. Soldered together one resistor and one LED makes a 'bulb' for about 12p!

This makes a 24 LED 'array' about 3. For comparison, I bought proprietary 'plug-in' LED indicator bulbs, with 24LED arrays in a conventional bayonet fitting. 6.27 a pair, so the economics here can be a bit marginal for the effort; but the 3LED instrument 'Peanut' bulbs for 'The-Pup' were 4 each, and individual wired LED's on e-bay can be as much as 2.50 each. So for the instrument lights I need to make, made economic sense, AND I can get to be creative with components!

Turning Components into a 'Bulb'

First thing to do is make the components into 'Bulbs', which simply means soldering a resistor to each one. Convenient wiring diagram that came with the LED's said to solder the resistor to the negative, or 'short' lead of the LED. Easiest way to make a joint between the two leads here is to wind the resistor lead around something similar diameter to the LED lead. I used the snipped off lead from a diode, or a thick sewing pin, and did a 'bunch'. Then the coiled bit could be slid down the LED lead, and a dab of the soldering iron; joint made.


The unwanted bit of LED leg under the resitor can now be snipped off, AND, tip of the day; if you save the insulation stripped off the ends of wire when you joint it; you can often use it to sleeve the legs of LED's (and other electronic components!) to avoid short circuits! I now have an LED light bulb I can put on a 12v supply and that will light up! So time to do something with them.

Making up Dash-Lamps

After a bit of fiddling, this is what I came up with. Three LED's mounted in a bit of 6mm braided fuel hose! The hose is 'just' the right diameter to plug the hole in the back of the Speedo or Rev-Counter, where a peanut bulb holder would have been, so this saves buying a separate holder. GETTING here though took a lot of messing to find out a good length and fit, and way to get the LED's to stay in the hose.

First task was to get a bit of clear plastic and prick holes in it to push the LED Legs through in a sort of tri-pod shape, with the common + legs in the middle and the - legs poking out at 30 degrees, so that the resistors could be soldered to them. After a couple of tries, soldering the resistors on at different heights to the legs meant that they could be folded in 'tightly' to fit down the slightly bored out hole in the cut length of fuel pipe.

Lead wires soldered on, and dome heat shrink around them and the leads, and with a little 'fettling' of the fuel pipe to make it fit, the LED assembly could be slid into the rubber mounting, and all glued in place with superglue.

Clear support for the LED's could then be trimmed to flush with the rubber, and the assembly tested! This is the Amber One for the Indicator tell-Tale. A green one for the Neutral warning; a Blue one for the Hi-Beam warning and two white ones to do exactly the same way for the rest of the instrument lights.

Getting Funky!

Well, getting a bit carried away here, having made up my dash-lamps, I was 'pondering'. The Speedo & Tacho were designed to mount on a plastic or pressed tin tray, and I have a flat aluminium plate, and with the screws and bumps and 'stuff' they don't sit 'flat' on it. I needed something 'squashy' to support them and hold them snug. The speedo had been packed out from the plate bracket that held it when I got the bike with what looked like the rubber drive band off an upright hoover. I was thinking of something like medium density closed cell foam... but then I spotted that PVC hose pipe I had bought for the oil line and had an "Um!?!" Moment.

I made a ring out of a piece of PVC pipe, but discovered it wasn't really tall enough to support the body of the clock. So I made another and glued them together, so that they fitted around the 'step' in the clock body. I then notched them and poked LED's down the ends... hi-tech experimentation here... reminds me of my time developing missile guidance systems!

The result was not particularly spectacular. four bright blobs of light right at the front and none diffusing around the clock body as I had hoped. Modifications were called for!

The kitchen was 'raided' and a roll of tin-foil and a roll of grease proof paper looked 'promising'! I cut a strip of each, covering the tin-foil with celotape as 'insulation', then sandwhiching them, so that the paper was to the front and the tin-foil to the back, I dragged them through the pipe with a thread of solder. The tin-foil at the back to reflect light out and around, the paper to act as a diffuser to spread the light out a bit. THEN I poked the LED's back into the middle, and glued up the ends of the pipe.

I was STILL not happy. They looked a 'bit' better when lit up, but unlit, they looked like a piece of clear plastic pipe with some sweet-wrappers stuffed down the middle. So I painted them!

Better. Much better, AND the paint helped diffuse the light some more.

So that's my little 'custom Feature'. LED lighty Up Instrument bezels!





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