Model A - kickstart spring cover: 3rd and final part!

 Honestly, this will be the last post about this kickstart - it's gone on far too long! To be fair though, making the shaft was probably the most complicated machining job I have ever done and I had no idea what the spring cover looked like - so forgive me three blog posts on this subject.

We are at the end though, the cover has been raised a little bit to reduce the clearance between the distance piece and the gearbox end cover and it's been cleaned up and painted.

Once I got a couple of coats on the spring cover I fitted the spring and gave it another blow over to cover over any damage.

And that's it, fitted and finished.

Apart from greasing it... might need another blog post?

Model A - Kickstart spring cover 2

 After lots of input from the Ariel community, I now understand how the kickstart spring cover is supposed to work. 

There are four parts in play, illustrated by this page from the parts book:

• LS254, the kickstart lever. I think I have the right one
• LS262, the kickstart bush. This comes all the way out of the end cover up to the end of the shaft, LS253. The bush is 1 3/8" OD
• LS263, the distance piece. Andrew H of the AOMCC tells me that this is 1 1/2" OD, so the wall thickness must be something like 1/16".
• LS264, the spring cover

The big reveal is that it is the distance sleeve that keeps the spring cover in place, and that it is itself kept in place by the kickstart lever. This means the spring cover, LS264, must fit tightly enough around the bush LS262 to be retained by the 1/16" thickness of the distance piece LS263. 

The other thing I've seen is that the top of the spring cover is not flat, but follows a nice radius. The former has been back to the lathe for reshaping:

I've prepared another bit of sheet, by cutting it to size, squaring the ends and removing the paint:

Before we start on that, I found a piece of exhaust pipe the perfect size for the distance piece. I made a wooden former so I could cut it to length in the lathe and form a short radius on the end.

The radius prevents it sliding towards the gearbox quite successfully and it fits rather well behind the kickstart lever.

I formed the spring cover in the same way that I did last time but there was no way it would shrink far enough to get to the required inside diameter for the kickstart bush, so I ended up cutting darts in it and welding them up

There is a bit more work to do, but all the bits fit together. I think the spring cover is too long but I always knew I would have to trim it and I need to finish the welding. Lastly there will be a hole for the spring to pass through.

Before we get into that though - this is my latest invention for welding - an arm rest! Makes controlling the torch so much easier:

The arm rest made finishing those tiny welds much less stressful. The welds were backed with a curved copper strip which as I have shown before minimises the dressing required on the back side and gives you much more control when welding this thin material. It's been welded, ground out inside, straightened, ground outside and so on...

Next job is to drill a 1/4" hole near the edge, and file it oval:

Then I've used a drill to form the material such that the spring can pass through:

The spring is wound in from above:

In the video, the spring cover has been trimmed to length and fitted:

It's not perfect but it's nearly there. I shall raise the edge of the cover a little more since the whole assembly has to account for end float in the kickstart shaft, and there is a bit more clearance than I would like.

Model A - Kickstart spring cover

 When you have a few old bikes, and you use them, and especially if other people use them, you must expect a few diversions from your ongoing project whilst you fix the other bikes in the fleet. The Square Four has absorbed a bit of time recently and it's now become the daily rider again while the hunt must have takes a little holiday in Norwich.

Therefore, the Model A has taken a bit of a back seat but it's time finally for the next job. This is the tin cover for a kickstart spring.

To start the job off, we can measure the machined register that it fits on the kickstart cover and then we can work out how long it needs to be by measuring the spring.

I'm going to fold the cover up from a strip of 0.9 mm thick steel around a wooden former which I will turn on the lathe from a chunk of sapele, part of an old door.

I've screwed and glued this former to a suitable piece of timber such that I can hold it in the vise

Here's the first try, cut from a bit of sheet with the aviation snips to a suitable width and rough length. With it held in place on the former some tie wraps, I can mark the end and trim.

We'll do a little trial fit on the job:

We need to bear in mind that this cover is supposed to turn with the spring. The spring fits nicely inside it but I suspect it's rather tight on the gearbox end cover.

The only way to find out to tack it together. A couple of tacks show that it fits nicely will turn on the register on the gearbox end cover, so I fully weld it and dress it on the linisher.

The next step is to work out how long it needs to be. I believe that I will need to fold it over such that the inner diameter just fits the kickstart shaft bush.

A little session with the Wiss snips sees it cut to approximately the right length.

Attempting to spin the end over on the lathe was an abject failure - the wooden former just flew out of the chuck so I returned to doing it with a hammer.

That worked reasonably well, and it fits:

There's something fundamentally wrong though:

With a lot of help from the AOMCC, I've learned that LS263 holds LS264 in place and is itself held by the kickstart lever.

Time to try again.

Model A - getting into the gearbox

 I've now completed the footrest and brake pedal area and I have the lathe up and running again after the feed gear upgrade so it's time to get back to the gearbox and particularly the kickstart shaft. 

I've not had the gearbox out before so given that the clutch is off I'll go in there, clean it up and do a few jobs. The first step is to remove the oil tank and the battery tray, then you can remove the four nuts under the gearbox and lift it out.

It's in pretty good shape externally - there's no major damage and aside from the kickstart shaft nothing missing. There are a couple of little jobs: 

• One of the 5/16 studs retaining the frame bracket is missing, 
• There is some damage around the gearbox casting for these studs 
• The gearbox adjuster bolt is broken

First, a couple of general views:

With the gearbox out, we can attend to the bent bracket that the adjuster locates in. Somebody has obviously forced the gearbox adjuster without undoing the nuts underneath, bending the plate and breaking the adjuster - it's astonishing how ham fisted some people can be!

Five minutes with a hammer sorted that out.

The outside is a little bit grubby, but more worrying is the state of the bearings on the main shaft and the sleeve gear. I'm told that the sleeve gear bearing is available, but expensive - I doubt if you can get the bushes for the mainshaft though...

The next job is to remove the broken adjuster bolt. Fortunately it drills easily:

The bolt is not seized in place and comes out quite easily with the EZ-Out:

I have a new bolt available from AOMCC Black Ariel spares and after I have run a tap into the hole it fits back on with some Copper-Ease:

Apparently there is supposed to be a spring under that screw adjuster.

The next job is to sort this out. All we need here is a new stud - 1-in long with a 5/16 BSW at one end and 5/16 CEI at the other. 

What is a bit more puzzling is that the lug on the gearbox does not line up with the engine plate so perhaps there is a thick washer in here:

And as if by magic, a new stud appears courtesy of the mini-lathe and some 5/16" round bar:

And later, a 1" diameter, 1/4" thick spacer:

All I have to do now is sort out the mixed-up 1/2" diameter engine studs - or 'tie bolts' as Ariel call them and we are done with making & mending on the outside of the gearbox. 

Investigation showed I had three 3 5/8" studs, instead of two and one 4" stud. I made a new stud on the lathe, cleaned all the others and built it up again:

The spacer went in the spares box. According to the combined wisdom and photographic evidence provided by the AOMCC FB Group, there should be a half nut there - Ariel would have listed a spacer in the parts book but not a half nut - standard nuts are never listed.

We are calling that area done.

Model A - Making the kickstart shaft

From the features and dimensions in the previous post, we have some idea of what we have to make - if we are to avoid cutting the excess length out of the old shaft and welding it up again, with the cotter flat in the correct orientation.

This would be a waste of an original part and wouldn't be half as much fun, but it is worth remembering that what we are trying to here is produce a replica of the 'Panther' shaft we have, but shorter and with the kickstart lever cotter in the right orientation.

We'll start by defining a list of features, so we can talk about making the shaft sensibly and without getting confused. Here we go:

• A - the pawl carrier minor diameter
• B - the hole for the pawl spring
• C - the holes for the pawl pivot pin
• D - the larger 'stop flat'
• E - the smaller 'stop flat'
• F - the bore for the layshaft bearing, and the bearing itself
• G - The flat the pawl sits on
• H - The kickstart lever diameter
• I - The main shaft diameter - 1 1/8"
• J - The flat for the kickstart lever cotter
• K - The pawl carrier major diameter, 2"

Of course the key question is in what sequence do we machine these features?

This is what I'm thinking at the moment:

1. Face and centre both ends of the 150 mm chunk of EN16 round bar (diameter 55 mm) that I've bought from eBay.
2. Holding the stock in the 3-jaw with the end supported in a live centre, machine away the material to make diameters H, I and K
3. Reverse in the chuck and machine a flange on the waste end, with a 5mm hole to register with the pin in the centre of the rotary table.
4. Hold feature I in the milling vice and use the vertical slide and an end mill to machine feature G.
5. Clamp the waste flange to the rotary table and use an end mill to machine features D and E.
6. Use the rotary table to machine feature A.
7. Use a slot drill to machine the tangential hole B.
8. Hold feature I in the chuck and machine off the waste flange.
9. Machine feature F holding feature I in the chuck and supporting the shaft with the fixed steady.
10. Hold feature I in the milling vice and drill feature C.
11. Last job will be the flat for the cotter, J. We'll assemble the shaft into the box and then work out where the lever wants to be.

The blank we will have after step 3 will look like this:

Excuse the mixed units, and remember that these are approximate dimensions for roughing out only!

Model A - Kickstart Shaft

 The Model A arrived with a complete gearbox, apart from the kickstart spring, cotter, and spring shroud. The kickstart shaft was also strangely long and fitting the lever left the kickstart pedal very low, since the flat for the cotter was in the wrong place.

What we are trying to do here is produce a replica of the 'Panther' shaft we have, but shorter and with the kickstart lever cotter in the right orientation.

A close up of the pawl, the pawl spring with it's plunger and the two-diameter pawl pin:

This is the flat for the kickstart lever cotter. The shaft I show here allows the kickstart to sit too low - it's for a bike that has the gearbox fitted horizontally, rather than at the angle used by Ariel and Brough Superior. The shaft is possibly from a Panther, who used these boxes horizontally in 1929.

The flat will have to move for the new shaft.

This is the flat where the pawl sits, with the axial holes for the pawl pin and the tangential hole for the pawl spring:

These two flats engage with the two plates in the gearbox that stop the pedal travel and disengage the pawl:

This is the bore for the layshaft, with it's bush:

A few dimensions to help us choose the stock for the new shaft:

We see here that the total length of the 'Panther' shaft is 164 mm or thereabouts.

This is the 'Panther' shaft fitted to the bike. This is the excess length - just over 47 mm. That means the total length of the new shaft will be 164 - 47 = 117 mm. Our blank is 150 mm long.

Lastly, here are a few pictures from AOMCC member Michael, showing the original arrangement: