Thursday, August 29, 2013

LED Lighting: Circuit Board and LED's

The previous "LED Lighting" post covered preparing the original Sturmey Archer lamp housings and making "heat sinks" for the LED's.  This post will describe the circuit board and LED's.  The circuit board only contains two components, a Bridge Rectifier, and a Capacitor.  I ordered both components and the circuit board from Digi-Key.

The Bridge Rectifier converts the alternating current (AC) supplied by the Dynohub to direct current (DC) which is required to power the LED's.  The Bridge Rectifier has 4 leads.  The two center leads marked "AC" are used to receive the the AC input from the Dynohub.  The two outer leads, "+" and "-" are used to output the converted DC current to the Capacitor.

Bridge Rectifier 40 Volt, 2 amp, Digi-Key # 641-1213-1-ND
The Capacitor will receive and store the converted DC current from the Bridge Rectifier.  This will help smooth the current going to the LED's to reduce flickering caused by the 20 poles within the Dynohub which act like on/off switches.  The Capacitor has two leads "+" and "-', the negative lead is marked on the outside to the can with a Gold stripe and negative sign "-".  This lead will be connected to negative DC output from the Bridge Rectifier.  The other lead will be connected to the "+" output from the Rectifier.  Capacitors are rated by micro-farads, this is a 10,000uf capacitor, the high number the more storage capacity and a smoother current to the LED's; however, as the numbers increase so does physical size of the capacitor. This is the same size capacitor I used for the 1949 Comrade LED conversion, but it had a bigger lamp housing. Using a 10,000uf capacitor for the smaller 1953 Sports housing is really pushing the space available inside the housing.

Capacitor, 10 volt, 10,000uf, Digi-Key # P10241-ND 
Circuit board comes in many shapes and configurations.  This particular board is from Digi-Key, it's a extra piece from the Comrade conversion.  The original board was 3" x 3.5" and has a "common bus" configuration.  This means any component leads that are connected to a common row on the board will be connected electrically.  As an example, to connect the "+" Bridge Rectifier output to the "+" Capacitor input the leads must be positioned on the board in the same row.  The board has two sides, the leads are inserted on the plain side, and are solder into place on the printed side.

Circuit Board (plain side), Digi-Key V2018-ND
Circuit Board (printed side), component leads are solder on this side.  Any leads solder in the same lettered row will be connected electrically.

This is the circuit board and mounted components.

This is the board after adding the leads for the input from the Dynohub (Blue) and output to the LEDs (Red (+) and Black (-).  I also trimmed the board to better fit within the housing and added Velcro to hold the board in place within the housing.

This is the board positioned within the housing.

Next I mounted the LEDs onto the heat sinks.  I'm using the same type of LED as the Comrade conversion, they are Luxeon Rebels (neutral white) pre-mounted on a 10mm base.  They produce 230 lm @ 700mA.  It is much easier soldering the leads to the LED if they are mounted on a base which contains a separate soldering pad for each input.  I'm also using 10mm adhesive pads to mount the LED and base to the heat sink.  I centered the LED and then marked the holes to drill for the leads that will be connected to the circuit board.

Front heat sink, LED, and adhesive pads 

Mounted LED and solder  leads

Front LED and heat sink mounted in original reflector.

And the same for the rear LED.

Rear heat sink and mounted LED

Heat sink and LED mounted in original rear bulb housing.
I wanted a quick test to make sure the circuit board and LEDs were working up to this point.  Using some alligator leads I connected the front and back lights to the Dynohub and gave the front wheel an easy spin. Let there be light!

The next step will be mounting the light housings and running wire from the Dynohub to the circuit board mounted in the front light housing, then running wires from the circuit board to the rear light housing.

Please share your comments and experiences.

Saturday, August 24, 2013

LED Lighting: Preparing the Housings

While waiting for the brake and shifter cable housings to arrive, I'm going to start preparing the light housings for conversion to LEDs.  The Sturmey Archer Dynohub and lights were an option on the 1953 Raleigh Sports Tourist.  This particular bike has the smaller front light housing, I believe the larger housings were used only on the Superbe models.  I previously converted the lights on my 1949 Comrade Roadster to LED's; however, it used larger housings.  Hopefully; I will be able to squeeze the circuit board into the smaller housing.

These are the housings before any prep work, there are some dents in the front housing, and someone drilled a hole through the side of the housing to install a switch.

I will wire brush the housings, try to fix the dents and extra hole, and repaint as necessary.  First I need to remove the internals and prepare them for LED lighting.  I'm going to use the same approach previously used on the 1949 Comrade.  Its been installed for over 3 years and I know it works with the Dynohub.  There is a wealth of information and opinions on-line for LED bike lighting.  The circuit I used for the Dynohub is a simple variation of more sophisticated options.  In addition to the LEDs, it uses only two components, a Bridge Rectifier, and a Capacitor.  Also needed is a Heat Sink for the high powered LEDs. From browsing the web, these seems to come in many variations, from commercial products to DIY versions using a bolt and some washers.  According to the "experts" a heat sink is needed to draw heat away from the LEDs to prevent damage.  I will make some heat sinks similar to what I used on the Comrade, but made smaller fit the Sport housings.  In addition; they will provide a mount for the LED's within the vintage housings.  These are the heat sinks made from aluminium rod to replace the bulbs, they are sized to be a friction fit within the original bulb housings.

Rear light heat sink.

Heat sink for rear light inserted into bulb holder.  The LED will be mounted to the face of the heat sink.
Front light heat sink

Front light heat sink inserted, the LED will mount to the face of the heat sink.

This is a patch to repair the hole that was drilled into the lamp housing by a previous owner.  With a little Bondo and some sanding and it will be unnoticeable.  I also had to shorten the screw that fits into the rear of the housing because it was interfering with mounting the circuit board.  I will use J-B Weld epoxy to affix it to the housing.

After Bondo and sanding

Shorten screw, will be epoxied to rear of housing

The next "LED Lighting" post will cover building the LED circuit board and mounting.  Please share your comments and experiences.

Saturday, August 17, 2013

Model GC2 Trigger Control

The Model GC2 trigger control was produced from 1948-1953, it was used for both 3 and 4 speed hubs.  The printing on the face plate of this control was intended for below the bar mounting, but the letter in the gear window was inverted for above the bar mounting.  These are pictures of the trigger control before disassemble and cleaning.

Notice how the face plate and sides of the case have are bent.  There was no movement of the trigger, the lever and ratchet were rusted together and insects had build a mud nest inside the case.  In order to fix the bent case and faceplate, and to free up the internals I decide to drill out the case rivets and disassemble and clean.

Once apart I was able to straighten the case and faceplate.  I also wanted to try restoring the paint on the faceplate, so I painted in the depression and then used steel wool to clean the excess paint.

Now that the case was straight and paint restored I was ready to reassemble.  I originally thought I would make pins to replace the drilled out rivets, that would  use a small 2-56 threaded nut on the small diameter of the pin to retain the internals to the case.

Original drilled out rivets on top.  On the bottom are the steel pins I made on the lathe to replace the rivets, I was originally going to thread the small diameter of the pin that  protrudes from the back of the case and use a small 2-56 nut to retain it.

I did not have a 2-56 die on hand, so instead  I decided to try and peen over the pins like the original rivets.
Worked good and looks original.

This is the 60 year old Model GC2 control back on the bike, ready for duty again.

Tuesday, August 13, 2013

Homemade Brake Parts

I spent some time at the lathe experimenting with making some parts for the 1953 Raleigh Sports brakes. This picture shows the cable knarp, levers washers, and brake arm washers I made.  Below I will show how I intend to used these parts.

The cable knarp will allow me to use modern brake cables with the 1953 Raleigh brakes which do not have the cable anchor.  These brakes were intended to be used with the special Raleigh brake cables that were a predetermined length, had soldered cable fittings on both ends, and all the fittings already attached, barrel adjuster etc.  This is a picture showing the cable knarp fitted to the 1953 brake arm.  The knarp was made from 1/4" brass rod which was turned down to fit the brake arm fitting, and drilled and tapped for a 3 x 48 set screw.

 Next are the washers I made to remove all the play in the brake levers.  As I stated before this bike appears to have been ridden a lot.  The brake lever bolt was worn as well as the levers.  There was a lot of slop between the levers and clamp when they were pulled.  These washers were made from Teflon filled Delrin, I cut them very thin (.005 - .008) to fit the space between the lever and the clamp.  They made a big difference in how the brake levers felt after installing, very smooth and precise, no slop.

Cutting the brake lever washers on the lathe.

Washer fitted to brake lever, one on each side.

Next are some Teflon washers made for the brake arms.  The 1953 brakes did not have any washers between the brake arms like the later versions.  The picture below shows the latter type (top of picture) brake arm bushing and and red plastic washer the sits between the brake arms.  The lower bushing is from the 1953 brake, the white washer (Teflon) is what I made to replicate the washer found on the latter brakes.  I do not know if it is necessary but seem like a good idea to reduce the metal on metal contact.  The brakes do not feel as notchy when using it.


I've notice a significant improvement in how the brakes feel with these extra parts, only when I get it back on the road will I know for sure.

Friday, August 9, 2013

I Need A Brake

These are the very rusty brakes removed from the 1953 Raleigh Sports.  Initially I thought the easiest approach would be to find some good used replacements instead of spending time trying to clean them up.

 Apparently; Raleigh used two different types of brakes on their Sports model.  The earlier versions (pre-1965) did not use a anchor bolt to secure the cable, instead special brake cable with all barrel adjuster fittings attached, and a "pear" shaped cable end that fit a slot on the brake arm.  In addition these earlier brakes used a different center bolt, unthreaded bushing and packing washer then the later version.  The holes in the brake arms for the center bolt bushing were also larger then the later style brake arms.

Once I had both sets disassembled, I noticed the center bolt, bushing and packing washers were different between the front and back sets.  Not knowing which was correct I checked one of the on-line Raleigh catalogs available at the Three-Speed Hub site (1960 Shop Manual).  According to the catalog parts diagram the front brake had the proper fittings, the rear brake had a center bolt, bushing, and packing washer from the later style brake.

The hardware on the left was installed on the 1953 rear brake, according to the Raleigh Service Manual parts diagram this hardware is incorrect for the earlier brakes, this hardware is from a later brake.  The hardware on the right is from the front brake and is correct for the 1953 Sports.

The top bushing is correct for the 1953 brake.  The bottom is from a later brake, notice the smaller diameter ( .338" vs .407") of the shoulder the brake arm pivots on.

Using the smaller latter style bushing with the original 1953 large hole brake arm caused a very loose fit at the rear brake arm pivot point.  I'm currently trying to find proper 1953 replacements for the rear brake parts, anyone have extra's? 

Another point concerning these brakes is the threading used.  You will not find replacement nuts and bolts at your local hardware store.  The center bolt is threaded BSC (British Standard Cycle) it is 1/4" x 26tpi.  Since the brake arm bushing is not threaded on the earlier brakes a UNC/UNF 1/4 x 20 or 28 bolt and nut could be substituted. The lever and handle bar clamp are threaded 1BA (British Association) the clamp bolt also uses a special nut these 1BA parts are difficult to replace so do not lose them. 

These are the 1953 brakes after wire brushing and buffing.

While I'm trying to source some rear brake parts, I'm going to install the handle bar and brake levers and try to run new brake cable to the old style brakes without the anchor bolt, using a fitting called a knarp.

Please share your comments and experiences.