Model A - kickstart shaft

 We're making chips! After a few test cuts, I've settled on a spindle speed of 750 rpm using carbide with oil mix cutting fluid and I'm getting a great finish. 

Depth of cut is 0.5 to 0.75 mm, and the feed is probably something like 0.002"/rev. The lead screw gives you 0.004"/rev and it's much slower than that, but unfortunately I have to manually feed at the moment.

There are a couple of upgrades you can do to reduce the feed rate, but they both need 3D printed gears which I don't have...

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:

Collecting bits

What do we have here? A camshaft, in much better shape than the one in my SQ4:

Dealing with teething trouble...

So this week, I've been out and about for another short ride, but first I refitted the Morgo pump. I did about 8 miles as usual, out of town and up to 40 mph. The lubrication job I did on the speedo seems to have stopped it sticking at full range.

The Morgo obviously provides more oil flow than the plunger pump, and I finished the journey with about 10 psi on the oil pressure gauge.

I also finished the journey with a completely flat rear tyre, which looks like it might be a valve failure. I wobbled along the road, complaining about the tramlines the council left when they resurfaced, only to keep my wobble, rapidly turning into a squirm from the rear end, when I ran out of tramlines. I recovered the puncture with a handy can of tyre weld I had in the pannier.

Of course, the low oil pressure problem is not sufficiently improved with the Morgo to use the bike in anger. Lifting the rocker covers with the engine running (rather dangerous - they are very hot) you can see little jets of oil coming from the rocker oil holes. I've fitted three new old stock rocker shafts to deal with the wear I found in the shafts last year - one was already fitted due to a damaged thread:

A thought occurred to me, corroborated by AOMCC forum members - retarded ignition causes overheating. Checking accurately revealed that the ignition was indeed retarded: I moved the distributor about 10 degrees, equating to about 20 degrees at the crankshaft, to get it right (thanks MikeN!).

So we will have to see what happens. Just waiting for a new inner tube...

Loose Ends

Well, its been an active and enjoyable weekend tidying up loose ends. Thanks go to Patrick Huthwaite who came by yesterday to do the inspection for the Dating Certificate - nice to meet you Sir.

On with the oil tank - the secret to fitting it, is to get it inboard enough to allow the clearance built in the top of the tank to accommodate the frame tube; the secret to allowing this to happen is to remove the nut on the gearbox top bolt.

Next problem is getting the oil lines in. I've realised that most of the struggle I have with this is down to the fact that the strainer I made is way too long, with the result that you have to bend it to get it in and it always catches on the threaded boss in the tank. I cut it down and re-soldered it:

So now, the oil lines go in easily.

I've also fixed the rocker feed oil lines:

And the rocker shafts are sealed:

What else?