Blog posts these days seem to veer between a little part manufacturing, perhaps on the lathe, to reporting on something else that I found broken. This post is one of those.
Pulling off the primary drive and clutch to gain access to the area behind the engine where the footrest spacer lives revealed a couple of problems with the gearbox. There is a little plate with three holes which ties the gearbox to one of the frame studs - there are two 5/16 BSW studs in the gearbox, with CEI threads outboard holding this plate to the gearbox .
Or there should be:
In this picture you can see the 5/16 BSW hole for the top stud, but it looks like the bottom stud is broken. We would have to get the gearbox out to have a look at that properly and remove it, but after a clean and a poke around it looks like the stud was lost years ago and the hole was just full of gunge. They clean up good as new with a 5/16" BSW tap:
While we are at it, we can bend this bracket back into shape - it retains the primary chain adjustment bolt which moves the gearbox forwards and backwards to tension the chain. Guess what? Can you see a broken bolt in that hole? I do have a new chain adjustment bolt because I thought it was missing but now I can see the remains on the old bolt stuck in the gearbox housing...
Continuing the investigation and assessment of the Model A, combined with some repairs as we go along, leads us to the rear wheel. Both of the wheels are in a pretty poor state with pitting, missing spokes, and bends of one sort or another. As you will hopefully have noticed I have started posting a lot more YouTube videos on my channel and here is one of them:
As you can see this rim is really for the bin. Around the wheel though there are a few other things that need fixing or replacing; we'll deal with the brake later on in another post and possibly another video but for now there are some small things to be attended to.
First up is a small part which I hadn't really understood very well - the W/NG has one in a mangled state but it's not until I had a proper look at the Model A that I really realised what was meant to happen.
For long period Ariel wheels were fitted with taper roller bearings and these need an adjustment facility built into the design. As you might expect there are two thin nuts to adjust end play in the bearing but of course these require the spindle to be held in place at one end whilst the other end is free and to do this Ariel provided a flat on the right hand side of the spindle. The slots in the frame lugs for the rear wheels are the same on both sides so this flat requires some packing allow it to fit in the same slot. What they do is provide something like a thimble around the spindle to take up the space and to provide a flat, non-threaded surface for the rear wheel chain adjuster to bear on.
This was missing.
To determine the proper material thickness for this thimble or sleeve I tried a few pieces of scrap sheet in the space:
With the sheet selected I cut a strip to more or less the right size and folded it around the spindle:
This prototype is clearly too short!
As an aside, I also wanted to check the thread on the spindle since I had to buy a tap and die set to clean them up. I'm not particularly familiar with CEI threads in this size, so it's best to check with a thread gauge:
This proved it is indeed 9/16" x 20 CEI.
The next step with the spindle sleeve is to roll it up and weld it. Apologies for the terrible picture!
With some work on the linisher, some fine files and a small hammer we have a nice fit over the flats on the spindle:
This is what the finished piece looks like:
The next job is to make a couple of replacement wheel nuts. The kit of parts came with a couple of 9/16" nuts that had been forced onto the spindle. I recut the thread on the spindle just to clean it up but recutting the nuts revealed the fact that they weren't CEI at all - they were very loose. Since they were quite mangled new nuts are the best option.
Starting with the appropriate hexagon material we put a bit in the lathe, centre drill, drill in sequence 6 mm, 10 mm and finish with 13 mm which will do as a tapping size for 9/16" CEI.
We'll put a little radius on the corner of the nut to emulate the factory part.
After drilling, the next job is to cut the thread using a 9/16" by 20 CEI tap. With these big threads, it's easiest to start the tap on the lathe to ensure the thread is cutting concentric with the stock. You don't need to cut the whole thread on the lathe as it's a bit awkward.
What I usually do is take the work out of the lathe and finish the thread on the bench. This gives you a lot more space to operate the tap wrench.
There we go, a nice new wheel nut.
The only problem is that the hex I selected is bigger than stock. Good thing I like lathe work, but I can't find any 0.92" hex stock (other than stainless) anywhere...
These nuts are also a bit thick - for years I have been under the misapprehension that a nut thickness is equivalent to the thread diameter - it's not. BS916 tells us that standard nut heights are more of less equivalent to the thread diameter of the next size down, so these 9/16" nuts should be 1/2" high:
A chance look at marketplace on Facebook brought a new addition to the workshop yesterday. As many of you will know I've had this old pillar drill for 6 or 7 years and it's had a few modifications to stiffen it up and remove play from the quill - not entirely successfully.
This new one is much the same design but from a better manufacturer - it has a cast base, thicker pillar, and a cast table.
In common with several Ariels of this vintage, the Model A has a rear wheel sprocket which is integral with the brake drum. This in itself would not be a problem were it not for the fact that the sprocket teeth are worn out.
The whole assembly is far too big to go in my lathe so what can I do about removing the sprocket teeth? Some options:
Can I spin the hub in the rotary table, mounted on the workmate and remove the teeth with a fixed angle grinder?
Can I build a jig to carry the whole hub in the milling table, and remove the teeth with an end mill?
Get Draganfly to do it?
Find a local enthusiast with a bigger lathe?
Find a better hub?
One thing I have discovered - a BSA A50 chain ring has the required 47 teeth to suit the 5/8" x 3/8" chain I need. An Ariel 4305-32 looks similar.
We'll have to think about that a bit more. In the meantime, we'll have a look at all the other bits in that area so that we can work out what we are dealing with especially since I'm expecting to place an order with the Ariel Klub Slovakia shortly.
The brake plate is all present and correct.
The brake plate dust exclusion ring is a bit mangled - I have a feeling you can get these new as they are spot welded in place but since the 1930 Model A doesn't have a plated ring here I may repair it and paint it.
In the brake drum we have the 'new for 1929' ring that retains the spoke heads should they break off. Ariel must have had some incidents with brakes seizing or wheels grinding to a halt through loss of spoke heads. Not a pleasant experience to contemplate! It's all very greasy in there.
Equally greasy is the back of the brake plate but at least we have some shoes which are whole and a set of springs and a cam.
The cam bush is very worn indeed and will have to be replaced.
It's fitted through the brake plate and there is a nice little gas weld on the inside:
Here's the cam. I don't think there's any doubt that we will be buying new ones!
Something else that has caused much discussion on the Facebook group is what brake lever this machine should have. This part is definitely Ariel, but it may not be 1930 - however it's not much later, perhaps 32. Checking the parts lists doesn't reveal very much from any of these years - they all show a relatively short stubby brake lever. The various members that contributed to this discussion revealed quite a variety of brake levers including this long curved one - so go figure.
It did have a lot of bends in it. I've taken one out and this will probably sit better with respect to the mudguard stays - we'll have a look when it goes back together.
Moving on to the frame, we'll take the opportunity to clean out the threads for the chain adjusters
There's something odd here - this looks like a braze repair around the sidecar mount. The mounting should exist as a more or less complete ring without that lump of material between it and the frame lug.
The brake plate torque lug is present on the inside and both of the top hat washers are present.
Moving to the other side of the bike, this all looks good and the stand stops are in very good shape.
Missing from this side is the little flattened tube that's used to protect the wheel spindle thread from the chain adjuster. They are often mangled - we will have to make one of those.
At both ends of the spindle, the wheel nuts are not in the best shape. The left hand side won't run all the way down the spindle - it looks like it's had a hammering at some time.
I'm making these clutch dome screws, because whilst such screws are commonly available even as Ariel parts, they are usually 1/4" BSW to go into the later alloy primary cases. These black Ariels with tin primary cases use 1/4" CEI screws which I don't stock.
We'll make a set from this bit of 3/8" round bar:
I used the compound slide adapted for vertical operation to put the slots in the screws. They are cut with a 1/16" slitting saw.
Here are the first two. They still need the raised top shaping, but that will need the milling equipment removed from the lathe so we'll do all the others first.
A couple of days later, with the lightweight milling attachment removed we can put the radius on the screw heads using the form tool:
After that, I've used a piece of 240 grit wet & dry paper on a piece of wood to get rid of that copper plating - the bar I used to make these screws was an old earth rod. I don't think that the chemical blacking that I plan to use to finish these screws will work on the copper plate!
