BRAKE LIGHT SWITCH

My scooter never had a stop light switch fitted as I guess this was fitted to the later models in response to legislation.  I had a look through various web sites and Blogs in the hope of finding how best to fit a switch.  The best I found was at billy192.blogspot. There is a picture of the switch mounted to the frame.  I particularly like the switch that was shown as it had a metal body. 

 I looked everywhere (if you Google "motorbike brake switch" using images you pretty soon get fed up with the options available) and couldn't find a suitable one with a metal case.  In the end I had to settle for a switch with a plastic body but with two lock nuts so that I could adjust the position of the switch in its mounting.

The switch can be bought for under a fiver and comes complete with the coupling spring 







Having found a switch the next problem was how to mount it.  Billy192 had gone for a bracket secured to the center tube using a couple of pipe clips.  I fancied a different approach.  I even considered welding a bracket to the frame but discounted this on the grounds it would be permanently altering the frame.  

 I decided that I could design a bracket that would only need a single hole to be drilled in the existing rear brake cable bracket.  This proved much more difficult than I had anticipated.  Having no right angle drill (something for next Christmas) I couldn't get a conventional drill into position.  In the end I managed to use a chuck and turn it by hand.  Starting with a 2.0mm drill I progressively opened the hole to the 5.0mm I finally needed.  It's a very slow process!

Trying to visualise a bracket can be difficult.  I have found in the past that the process can be speeded up by using paper or card.  This allows me to change things quickly before I attempt using metal.

In this case I used a scrap piece of paper and cut and folded it until I was confident that it would work.  It showed me where the critical dimensions were and allowed me to think how I was going to make it.

 This is my final bracket.  Its a bit different from the paper version but then that is the point of the paper prototype.  It allows you to see where things need adjustment.

The 5.0mm hole allows the the bracket to be "pulled" into the bracket on the frame.  The top flange prevents the bracket from twisting.  It is difficult to obtain a tight fit with two bends especially since the top bend is not parallel to the bottom bend.  To overcome this I made the bracket in two parts and welded them together.  In this way I could I could adjust the fit before welding.






The next task was to find a way of connecting the switch to the foot brake.  My switch required a pulling action for the contacts to be made.  There are no obvious attachment points and I didn't want to modify the actual pedal lever itself.  (I guess I could have found a different switch which would have been operated by the pedal lever pressing against it.  The switch would then have had to be mounted in front of the lever in a more exposed position.)
The actual movement of the brake cable is about 3.0mm.

My solution was to modify the inboard of the two cable clamping plates.  Welding a strip of steel to the clamp plate provided a point to attach the brake switch plunger.

This how the components are configured

The final installation

Using a buzzer across the switch leads I adjusted the two securing nuts until the switch made contact after approximately 1.0mm of cable movement.  Once the switch contacts have made further travel of the cable is taken up by the spring section. 






In Conclusion?  I think it will work as a stop light switch.  It's reasonably protected by the brake lever assembly both mechanically and environmentally.  How could I have improved the design?  Looking at "billy192's" configuration he has mounted his switch above the brake cable bracket so that it is less vulnerable.  I think this is a better position but at the time I did not fit the legshield to check clearance, perhaps I should.

THE BATTERY TRAY

For no particular reason I fancied moving on to the battery tray next.  It was obvious that I was going to need new battery straps as these had been cut off at somepoint

Before I can decide how best to replace the battery retaining straps I need to know what battery I am going to fit.  I have two alternatives, fit a genuine Lambretta battery or a modern alternative.

I contacted Lee at Scootopia, (was Casa Lambretta) (they really are so helpful) and he went away and measured a real Lambretta battery for me, W 125 - D 35 - H 127.  I trawled the internet and found a number of reasonable alternatives despite them being larger in most cases.  I liked the YUASA battery at Allstyles-scooters for £30 ish with a size of W 122 - D 46 - H 125 and a capacity of 7Ah.  I could now make some decisions.

Non standard tray with straps cut off

I was suspicious of the plate at the back as it was made of much thinner material than the rest of the tray.  The tray was a lot wider than the Lambretta size and when I removed the rubber mat in the bottom of the tray I could see why.

The tray had been modified by bending the back flange down and attaching a thin plate.  I guess to accommodate a non standard battery.  I can see the sense of this as Lambretta battery is very expensive at around £70.  


I need to decide what standard I'm trying to achieve.  If Concourse I will have to have the correct battery, if not I can use a cheaper alternative.  I think the non concourse route is the one for me.   

My original concern to have any welding completed before I filled the tank with fuel included fitting new battery straps.  This problem was solved when I discovered that the battery tray is removable, I had thought It was welded as part of the frame. It is in fact attached to the frame by two screws.  With the paint removed I was able to drill out the rusted screws and release the tray.

I have subsequently been able to buy from Terry, a contact, an original battery tray so I now have the opportunity to revert to the correct battery and tray configuration if I change my mind at a later date.

The top tray is from my scooter.  The original battery strap can be seen in the base of the tray where it has been cut off what was the side.  Even the extended back plate has evidence of a strap that has been removed. 

The lower tray is an original  that I bought  just in case I ever wanted to fit an original battery.





I intend to rebuild the extended tray to make it like an over sized original.  This has the advantage that it gives me a wider selection of cheaper batteries.  I eventually ordered the battery from Allstyles Scooters (B396-6) at £29.95 (I was subsequently told that a similar battery should be available for around £15, do I feel gutted?).  With the battery available I was ready to work on the old tray and the battery restraining strap.

I first I removed the tall back plate and the old ends of the retaining straps. The backplate was replaced with a strip of material the same width and thickness as the other three sides to complete the tray.  With this welded into position I could start work on the retaining straps.

I had previously looked at as many pictures of the original strap configuration as I could find.  There seemed to be a number of options.  I liked the idea of replicating them as far as possible but once I found that there  appeared to be no definitive solution I decided to develop my own.  I liked the idea of being able to fold part of the outside strap down to allow the battery to be more easily removed.  (a bit daft actually because I'm unlikely to ever remove the battery once the scooter is running but it was a good idea at the time).

I hate using tin shears to cut thin sheet.  It always results in the bit you want being twisted like a piece of apple peel.  Despite trying to flatten the material it is never quite right.  So without access to a guillotine I resort to my other favorite technique - the hacksaw.

This may be a bit slow but with the sheet securely clamped and using a fine toothed hacksaw blade at least you end up with a nice flat strip of material.  

The finished battery tray and strap.  the folded down section makes for easy fitting of the battery.  The original straps are spot welded to the tray.  I had visions that if I ever wanted to transfer my straps to the other tray welding was not an option.  I therefore elected to tap M3 threads into the tray sides and secure each strap with two M3 roundhead screws.

The tightening of the strap uses a pair of trunnions and tray screw purchased from Allstyles Scooters.  The trunnion on the right has a clearance hole whilst the one on the left is tapped M5.  The spacer between the head of the screw and the trunnion is because the head rubs on the strap.  I'm not too sure I like that but I can always turn down the head of the screw if it continues to offend me.

The final assembly fit well inside the scooter frame and does not touch anything.   I have to say that the actual "clamping" of the battery is adequate but not exceptional.  The battery will not fall out and should not move too much but I may have to adjust the trunnion position so that I can further tighten the strap.  If I apply this to the outer trunnion I may be able to dispense with the spacer which would be nice.



 i think I need to start thinking about the harness soon.  I seem to have a lot of wires in place where I wasn't expecting them.  I also need to find a way of providing a stop light switch.  Still more fun to come.

SEAT SPRINGS

I had trawled the internet to search for replacement seat springs for an LD 150 Mk 2.  There appeared to be new ones available for dual seats as fitted on the later models but nothing for my front and rear seats.

The original springs are 8.0mm diameter with a wire thickness of 1.6mm, 13 for the front seat and 11 for the pillion seat 

Whilst searching I came across a really good blog, "Lambretta LD Restoration" which had a very useful entry on seat restoration ( http://billy192.blogspot.co.uk/2011/11/stage-3-with-lambretta.html ).  He also had the problem of sourcing springs and had read of someone else making his own using a flexible drain cleaning spring from B&Q.

B&Q 6ft Spring Spiral Drain Cleaner  
Length 6ft  (1.8m)
cost about £7 
Spring diameter 5.5mm
wire thickness 1.2mm

Having looked at the B&Q spring I felt that it was too weak.  I discovered that WICKES have both a similar version and a heavier one.  This time I took my vernier calipers with me and found  the size to be closer to the original seat springs.

WICKES Adjustable Drain Cleaner
part No  W500594W
Length 4.7m
Cost approximately £15
Spring diameter 7.4mm  
wire thickness 1.4mm.

Note:-  this provided sufficient for all 26 springs and some left over.

 

With two options for the replacement springs I couldn't resist the temptation to check the spring rates, I didn't have much choice but I wanted to know where they were compared to the originals.  My test was simple, I fixed one end of the spring in a vice and attached the other end to a spring balance.  I stretched the spring 0.5 inches and noted the load on the balance.  Not very accurate but the results were as follows:-

                          ORIGINAL       11 lbs

                          WICKES          21lbs

                          B&Q                 8lbs

Despite the higher reading the WICKES spring felt best so I went ahead and started making the springs for the pillion seat. 

 The spring is supplied with both ends terminated ready for drain clearing.   Firstly cut off one of these ends in readiness to form the hook end for attaching to the seat frame.  I used a Junior hacksaw, whilst the spring material is hard it was possible to make one blade survive all the cutting.

 It's virtually impossible to form the hook with the material cold.  I used a small Servert gas flame which heated a limited area.  Firstly grip the end of the spring with pliers and pulling to start to open the coils.  Now apply the heat to the first couple of coils.  As the coils become red hot the coil opens out easily.  You can unwind as many coils as necessary to make the hook.  The only problem is how to stop without distorting the last turn in the spring.  With a little practice I got better (after 52 ends you have to).

Making a neat end also takes a little practice.  At first I did it freehand.  Later on I made a simple jig that allowed me to bend the wire more consistently.  The other end of the spring is made in the same way but it is necessary to look at which way round you want the hook to face.  This depends on how they are attached at each end 



In most cases the hook ends are at 90 degrees to each other so that when assembled the spring is not in torsion, only tension. I think there were only two positions where the hooks were in the same plane.


I was concerned that heating the end of the coil would result in the wire being left too soft. So much so that it would straighten out under tension.  I didn't want to have to re temper each end so I was relieved when this proved not to be a problem.  It will be interesting to see how the springs respond to use.

I noticed that whilst there were thirteen holes in the back frame there were only eleven holes in the front fixing.  There was an obvious space in the front fixing to accommodate the addition two holes so I went ahead and drilled them.  I have no idea why they were missing.

Pillion - Rear fixing

Pillion - Front Fixing - missing holes

The completed Pillion Seat

The Completed front seat

 

The Choke

Is it just me or is it difficult to remove the slack from the choke operating cable?  When I received the engine unit back from Scooter Surgery it had a choke cable attached.  I had previously bought a choke operating button that fits on the nearside of the frame under the front seat.  I assumed that it was a simple matter of connecting this to the cable.  Not so for me it appears.

The choke barrel in the carburetor is held closed by a spring and when the choke button is pulled this lifts the barrel and opens the choke.  The choke is held open by rotating the choke button 90 degrees so that it aligns with detentes in its mounting.  

I would have thought fitting the cable would have been simple.  Well it was really but once installed I discovered that when the choke barrel was fully closed there was slack in the operating cable and the choke knob had to lifted a long way before the barrel started to move.

This shows how far the choke button could be lifted before it started to lift the choke barrel.  Well above the detent in the mounting, obviously no way of keeping the choke open.



 
 It seemed to me that the inner cable needed to be reduced in length by some 20mm.

  I tried to unsolder the nipples on the ends of the cable but had no luck, they must have been swagged and soldered.  The only solution was to cut off one end and make a replacement, I went for the choke knob end.

The only bit of brass I could find was a screw which enable me to have just enough material to make the replacement nipple.  This was soldered to the end of the cable and the surplus material cut off.

 

The new nipple in position

Flushed with my success I reassembled the choke operating cable only to find that I couldn't lift the choke knob high enough to engage with the detent.  Now the inner cable was too short!  

(NOTE:  when fitting the carburetor end of the assembly take GREAT care not to cross thread the cable end mounting in the carburetor body.  It's difficult to align because the  choke cable wants to fight the alignment and the body is very soft material.)

How could I have got it so wrong? What to do now?

Reduce the length of the outer to increase the length of the inner protruding beyond the end of the outer.  Having done this on a previous occasion I knew to be careful not to damage the inner cable when cutting through the outer. I reassembled everything with the new length cable only to find the slack back again, as I should have expected if I had thought about it.  At this point I gave up.  I will need to consult the experts to find out what I have been doing wrong, apart from cutting the cable. (When I find out how to make the choke work I will add it to this section).   I will also have to add a new choke cable to my next order.

WHAT NEXT?

I've been thinking about this for a while now.  I guess the next logical step is to think about getting the engine running since it would be a great boost to the project.  I know that some point in the future I will need to do some welding to the chassis and this could have an impact on what I do next.

To run the engine I will not only need to sort the electrics, hopefully not too difficult, but also put fuel in the tank.  Here lies the problem.  I don't fancy welding when there has been fuel about.  I know that its contained but I also know that welding produces a lot of sparks and I don't fancy the two coming together.

I know I should have done any welding before I started refitting the engine.  My excuse is that I was so impressed with the paint finish I overlooked the fact that there were bits missing.  I have accepted that I will end up with the reworked areas touched up to prevent it looking too much of a mess.  I now realise that I will have to strip the scooter once it's completed if I want to make a good finish of the paint and chrome.  I tell myself that this phase will be a doddle compared with getting it to that stage, I hope I'm right.

The bits of welding I have in mind are the fixing lugs that secure the side panel sealing strips to the body and the battery carrier.

This is the fixing point at the off side rear of the scooter, just below the panel latch fixing.  The dealing strip is at the top of the picture.

The securing finger has been broken off, probably because it had rusted through.  I will have to weld a short length to what is remaining.  It will have to be long enough to bend round the edge of the sealing strip.  There is not much of a flange to the sealing strip so there only needs to be sufficient to trap the flange and yet not wrap too far round to become involved with the side panel.










There are four securing points in total, two at the back and two at the front.  These secure the ends of the sealing strip, the rest of the length is held in position by the shape of the strip.

This is the front securing point.  All four points are similar to this and will require a section welded.

This is the battery carrier.  Again I guess it was in a rough state either due to battery acid or rust and so the securing parts have been removed.

I don't think I will go to the expense of fitting a batterysince they were only used to provide power for the parking lights.  It would be nice to have the parts fitted, just in case I change my mind.








This is a section taken from the parts list showing the battery assembly.  This gives the impression that the support tray is a piece part where as mine is welded to the frame.  I can see where the two arms have been cut off, and I do have item 14 - the felt for the battery only mine is rubber!


















Whilst I know I can replicate the parts required to secure the battery I have no idea of the size.  Another little challenge I think.

During the welding process it will be necessary to protect the units already fitted e.g. the engine the tyres the cables.  Perhaps wet cardboard will do the trick.  I will also have to establish a good earth for welding so more paint will have to be removed.

So how do I see making progress?  I think I will investigate the battery situation with a view to making the necessary parts and sort out extending the seal clamps.  In the mean time I can start to think about fiting the engine cowling.  A Plan?