Model A - dynamo chain cover

 I've mentioned the dynamo chain cover more than once and it's now risen to the top of the list for repair. I'm part way through the repair of the primary chain guard and I want to make sure that all of the items that affect its position are in place before I finalise the welding.

The dynamo chain cover is in pretty good shape really apart from the fact that the chain has at some time worn through one of the feet and it has disappeared.

It's a simple matter to make a new one out of a bit of 16 gauge steel sheet using the pillar drill and the linisher. More difficult is to drill out the old spot welds and release the remains of the original foot. Here's the new bit in place with 5/16" holes where the spot welds used to be:

It takes a surprising amount of material to make a plug weld into those holes. The tricky bit is to support the work on the copper heat sink and make the welds without burning the original material away. However it soon done and fitted back in place for testing prior to clean up:

Model A - crankshaft shock absorber 2

 Well the Lambretta cush drive spring has arrived and fitting it up you can see why AOMCC singles expert Peter said that it wouldn't fit with the '26-'27 pattern shock absorber, which is what I have here. There is no way that you can get the nuts on to start this compressing the spring.

Fortunately, the 1930 pattern shock absorber is available from Karol Burger of the Slovak Ariel Klub.

Even more fortunate is the fact that Karol stocks two types of sprocket, one with 19 teeth and one with 23 teeth. What I have here is a '26-'27 19 tooth engine sprocket which is obviously for sidecar use: 

We know from experience with both the Huntmaster and the Square Four that bikes of this era are usually low geared (even when specified for solo use) so we do not want to compromise our budget and our riding experience by buying the wrong sprocket. This makes me feel a lot better about having the wrong crankshaft shock absorber!

We won't do anything else in this area until we have the new bits from the Slovak Klub.

Model A - crankshaft shock absorber 1

 It's all go here. The latest investigation is to look at the crankshaft shock absorber, which it turns out is missing a few vital parts!

These are the sections of the parts book that deal with the crankshaft shock absorber. I had assumed, wrongly, that because there was a shock absorber in the clutch there would not be one on the crankshaft. However club member and black Ariel spares coordinator Lee, who is currently restoring a 1928 Model E (which has a Burman box) tells me that his bike has a shock absorber in the clutch as well. Therefore I am now given to believe that all the bikes have a crankshaft shock absorber.

I'm missing the spring and both the collars that it sits in. I'm told that a Lambretta spring maybe useful and I have a dimensions for that and I actually I have ordered one. 

The spring collar A6/714 is missing and I have no picture at the moment. However the function of these parts is fairly obvious so I'm confident that I can make something up.

This is the bit that Sturmey Archer call the spring retaining collar. It's listed at Draganfly but unfortunately out of stock at the moment. I'm sure we can make one of these.

This is the A6/712 sliding member:

As you can see, the spring sits on a 33 mm diameter. The Lambretta spring dimensions are:

• Free length = 37.5mm
• ID = 35mm
• Wire dimeter = 6.85mm

The diameter should fit nicely. It looks like this:

As you can see, there is only two wire diameters in that 37 mm length, so it should compress considerably - maybe to the 20 mm I have available!

Model A - jobs for the mini-lathe

 Like all vintage bikes, there are lots of bits that are broken or warm and that you just can't buy. For enthusiasts of the homework shop these bikes are great fun. 

I don't think I'd make much use of a milling machine but the mini-lathe, as usual, will get a bit of a workout - in fact I've made lots of bits on the lathe for this machine already.

• Stand bolts 
• Mudguard bolts and special nuts
• Chain adjusters and lock nuts
• Clevis pins for the brake rods and gear controls 
• Brake adjuster knobs
• Front brake spring box

There are many more bits to make, and the purpose of this post is to record them so that I don't forget:

• Crankshaft nut 
• Tank bolt 
• Gear change rod 
• Luggage carrier / mudguard stay bolts
• Footrest bar 
• Footrest spacer 
• Battery strap nuts 
• Parts for the crankshaft shock absorber
• Clutch spring screws
• Missing studs - for example for the front of the primary chain guard

That should keep us busy all winter!

Model A - dynamo engine plate covers

 There's a lot of splits in sheet metal components on this bike - not surprising after 95 years of corrosion & vibration. This is the top engine plate cover over the dynamo, and one of the bolt loops is missing. I'm replacing it with a bit of sheet cut from the side of a dead dishwasher - 0.5 mm thick:

One of the benefits of having quite a small TIG welder is that you can do tiny little things like this - this was set at 15 amps:

This is the front engine plate cover. Despite the fact that the one in the parts book is slightly different (it has four bolt loops) it appears Ariel modified this part without reflecting the change in the parts book illustration - I'm saying this because others I've seen are the same as mine - go and look at the one in this post, about the dynamo clamp.

Model A - the gearbox

 As part of the Preliminary Investigation season here on Amelia's Blog, today we are having a tentative look at the gearbox.

The reasons for this are threefold:

• I can't engage first gear 
• The kickstart shaft is wobbly 
• I'm concerned that the kickstart shaft is much too long

The gearbox is a Sturmey Archer LS type heavyweight gearbox, configured for Ariel. These are quite well documented though spares support isn't good. As you probably know, it's a 3 speed hand change box.

The end cover is easily removed when you have taken off the six neat little shouldered nuts, one of which is a special nut with a grease nipple that feeds through a hollow stud into the top of the gearbox.

What greets me is a robust and simple cluster, seemingly intact and free of damage - there's no hint as to why it doesn't select first. 

Here's the end cover and kickstart shaft from the inside. At the bottom of the picture is the main shaft and bearing and within that the clutch worm.

Here is a close up of the cluster just for the record.

Right after I took  this picture I discovered that if you engage first gear with the end cover off, the cluster goes flying across the workshop floor!

After a session in the parts washer, we can have a better look. This is the Kickstarter shaft - there were a number of alternative lengths of these available for different manufacturers but looking at the catalogues it appears that most of them must have used splines because the makers make special mention of the cotter slot for the kickstart lever that was used for Ariel.

The kickstart bush also comes in various lengths to suit the shaft. This is the 1 3/8" extension the Ariel parts book talks about:

With the kickstart shaft at the rest position and the lever fitted to suit the cotter slot, we can see the lever is in totally the wrong position. That shaft is not original, but would be more suited to the box in the horizontal position, like a Panther...

Here is another view which shows you the excess length in the kickstart shaft. Note that the silencer is further outboard than it should be by that stack of washers, so correcting the silencer mounting will leave even more clearance under the kickstart lever.

That spring isn't right either - there is a 45 mm ID spring used by Norton, and a 49 mm ID spring. Guess which one this is...

Model A - dynamo clamp

 As I may have mentioned, one of the first parts I found missing was the dynamo clamp, shown here in this screenshot from the parts book. I have a couple of bits missing including the stud, bridge, and the clamp itself. I have no idea what they look like.

Or rather I didn't until I kind club member pointed me at this set built up some years ago by a Czech member Karol. None of this is available now unfortunately, these things tend to get built in small batches and then sold and remain unavailable until demand rises again.

Another member sent me this picture - this is an original clamp I believe so I can use this as a pattern to make my own.

This is folded up from a piece of 3 mm thick 25 mm flat bar. It's supposed to emulate what I believe is a Mazak casting. I shall file it to shape.

Metalwork almost complete - just requires some form of finish, probably chemical blacking...

Model A - work faces

 The Model A has been on the bench a while now and I've been spending time investigating what I've bought and reminding myself of the parts I've made or acquired over the last few years. 

As a man who likes to tinker in his workshop - who doesn't - various work faces have opened up as I've investigated the machine. 

One is the broken dynamo and it's clamp. Removing the dynamo I realised that I didn't understand how it was held in place with only half a strap - pleas to other club members soon yielded a few photographs showing the bits that were missing. 

Taking the dynamo off showed me quite how bad the damage was. Both of the end castings appear to be broken - the drive end is in two pieces and I had to drill out one of the screws, but worse, the armature is actually bent. It looks like it's been dropped on the floor or had a whack from something at some point.

For the record, the armature is 157 mm long and you can get new ones - Feked have them.

The secondary of investigation is all of the tinware on the drive side. I started with the clutch dome but I have various repairs to do to the primary cover and the dynamo chain cover. 

This led to me looking at the clutch and the gearbox because of course the aperture in the primary cover dictates the movement of the clutch to some extent during the tensioning of the primary chain.

Thinking about the gearbox and it's range of adjustment led me to the gear controls, most of which I have already made. This leads naturally to the fixing of the fuel tank because of course unless the fuel tank is firmly bolted down (and I have new rubbers for that) the gear controls can't be set up. 

If that wasn't enough I've been looking at the front wheel and loosening the spoke nipples. I'm not going to go any further than that though - I was trying to establish whether the front wheel rim could be used or whether it was too far gone. 

The other area I've been looking at is the Lucas H52 headlamp, it's shell, and the mountings. The shell was quite bent and whilst I had the hammers and dollies out to sort out the clutch dome I knocked the dents out of the headlamp shell. It still wouldn't sit straight - it's aligned to the offside - because the mounting bars are also bent...

I think that's enough for now. I promise that I won't take anything else to pieces except perhaps for the gearbox outer cover - the kickstart doesn't seem to work and I can't get first gear!

Model A - primary chain case tinware

 Moving on from the clutch bowl, our tin bashing activities come to the primary chain case. This is all present and mostly correct but some of the brackets and appendages have been broken and repaired by riveting. 

One thing we mustn't forget when we view this overall shot is that the position of the gearbox rather dictates the position of the primary case in that the primary case aperture for the clutch must accommodate the full range of movement of the gearbox. 

We must also think about the bolt hole for the rear upper chain guard. 

Again this position is dictated by something else - in this case the rear bolt for the chain guard which is fixed to the luggage carrier.

However we can take comfort from the fact that the holes for the foot rest bar, the brake lever and the shock absorber grease nipple at the front are fixed positions, so we can probably weld up the lower rear bracket without too much worry.

 The secondary cover, which protects the dynamo chain is present and in more or less sound condition - it's only missing one of the feet.

The stripped 1/4" CEI stud in this position came out very easily. The bracket is a little bent.

Here's that missing foot:

There's plenty to sort out here!

Model A - Lucas H52 headlamp

The Model A is fitted with a Lucas H52 headlamp which was sold to the industry between 1930 and 1932. It's distinctly different from the lamps that succeeded it as you will see. 

Outwardly the lamp fitted to my Model A looks a bit bashed, and indeed it is. The rim has obviously taken the brunt of a collision, but the nearside mounting is pushed right in as well.

The shell is brass, deeply drawn or spun - it's likely to be hard, so we may have to normalise it to avoid cracking.

To straighten out the front end requires adjusting the headlamp mounting bars and I can't do this with the headlamp bowl bent out of shape. In parallel with the clutch dome I have got out the panel beating hammers and dollies and set about straightening the bowl.

It's a little better in this shot but the near side mounting is still not positioned correctly. You can see the connections panel on the back of the switch here - the H52 has no internal wiring for the headlamp and side lamp but uses this Tufnol panel with sprung copper leaves for connection to the bulbs and ammeter.

Here is the inside of the main switch - it's retained to the Tufnol panel by two brass posts and sleeve nuts. You can see the half charge resistance and the switch in the middle. It's interesting that this switch is clearly a predecessor to the later commonly seen Lucas U39 switch, and you can see how it connects to the Tufnol connector panel from four of the terminal screws and from that central brass plate.

Here is the wiring diagram for the H52 - indeed for the whole bike. I suspect that since the headlamp is the centre of all things electrical, Lucas would have supplied the headlamp with the wiring for the whole bike already installed:

Here's the shell again with the nearside mounting almost correct. I think that to get it much better I will have to remove the rivets, straighten it and replace it with new rivets - these are round head copper rivets quite easily available.

There's also a flat on the shell around 2 o'clock.

The view from above shows that it is a bit better than before. We will need to buy a new rim and a new glass, but we will keep the old reflector. We will probably use one of the LED headlamp bulbs with an integral lens which doesn't use the reflector at all - I've got one of these on the W/NG and they're quite effective.

These bits are available from Jiri Horace at https://www.vintage-replica.com in the Czech Republic, so when we have a better handle what everything we could buy from him we will send an order.

Model A - clutch dome

 The clutch dome from the Model A has been full of dents since I've had it, and is also split - it looks like someone put a screwdriver through it at some stage. Since I have the sheet metal working tools out today sorting out some of the dents in the Lucas H52 headlamp, we'll have a go at the clutch dome.

I took out the largest dent on the sandbag before I took this picture but essentially this is the before shot.

Half an hour with stakes, dollies and hammers had it at this stage, though I don't think it's very different, at least visually. We'll do some more.

Getting there?