Friday 27 April 2018

Another evening run

Another evening run out around Norfolk, some shots from me but most taken and tweaked by John Harris. Find John at https://www.facebook.com/JohnHarrisPhotographyandTours/.

This week, we took a tour around RAF Matlaske, RAF Oulton and the National Trust's first property at Blickling Hall.







Saturday 21 April 2018

Another lathe job

I made a trip out the other day, with a mate on an MT350, to look at the Dome Trainer at RAF Langham. Great run out, lovely weather and all that, some shots from me but most taken and tweaked by John Harris. Find John at https://www.facebook.com/JohnHarrisPhotographyandTours/.




Back home I found the clamp screw from my float bowl had disappeared - mainly because I had changed the cap for a better one, with a tickler of the correct length to reach the float (!) and hadn't screwed the clamp up at all...

So, unable to find one on eBay and too mean to buy one from Amal (they are over a tenner!), I checked the thread and found it to be 1/4" BSF. Rooting about in the 1/4" screw box, I found an Ariel clutch centre screw which has the correct thread AND the reduced hex head, or something like it, that the real Amal screw has. Adding a small sleeve out of a bit of round bar yielded something that will do the job:


Here it is in place, with the new float chamber lid:


It will do the job until I can find a real one at a reasonable price.

Sunday 15 April 2018

Tommy Bars

Genuine Ariel tommy bars are another rare item, and typically (of the tools at least) are rather confusing - not helped by the aforementioned rarity:
  • 6612-27, Dwg # G1/57 appears in the 1940 singles parts books as a single diameter bar 
  • The W/NG workshop manual shows a dual diameter bar
  • 6612-27, Dwg # G1/57 (yes, the same part number) appears in the 1947 singles parts books as a bar with three diameters. This also appears in several parts books until 1956, so we can assume this tommy bar was now considered a mature design (!)
    • the 1948-1949 twins parts book
    • the 1949 SQ4 parts book
    • the 1953 singles parts book
    • the 1954 Huntmaster parts book
  • The 1956 Huntmaster parts book lists a 'Tyre Lever and Tommy Bar", 6625-55. Parts books (prior to Leader/Arrow) ceased to be illustrated in 1951, so we have no idea what this looks like.
  • Leader/Arrow parts list include tube spanners with tommy-bar holes, but no tommy bar. One assumes that you were intended to use the screwdriver as a tommy bar...
Once again courtesy of a few members of the Ariel clubs around the world, I have these pictures of three examples of the later 6612-27 three-diameter, two step tommy bar, and a W/NG tommy bar from Ray Tolman's genuine W/NG tool kit which has yielded so much interesting information.

Part of Scott Williamson's 1949 SQ4 tool kit

Close up of some of the tools from David Andersen's 1949 VH toolkit
We can see a few interesting points from this last picture:
  • the tommy bar appears to be about 0.375" in diameter and is overall about 7 1/2" long
  • the tommy bar has a section reduced to maybe 5/16", and this is about an inch long. This is to pass through the holes in the various box/tube spanners and the QD wheel nut spanner.
  • the tommy bar has a further section reduced to maybe 1/4", and this is possibly 3/8" long. This is to engage with the smaller box spanners and the hole in the telescopic fork wheel spindle: this is probably the reason this third, smaller diameter was introduced
Ray's pictures give us some proper information. Ray kindly measured these for me and allowed me to share the pictures so we can all use the information.


You'll notice Ray's tommy bars are a little shorter than David Andersen's later tommy bar. Here's a close up of the stepped ends; Ray confirmed that there is a 0.31" section on both bars:


I'm planning to turn each of these up from EN16 steel round bar. First cut two 7" lengths from a bit of 3/8" round bar:



Face and round the ends:


And as if by magic, some tommy bars appear:


Hub Bearing Locking Ring Spanner

This is a rare item indeed, but courtesy of a few members of the Ariel clubs around the world, I have these pictures. I've been using this modern version:


It's mostly fine, but you have to remove that handle to remove the non-brake side retaining ring since it is recessed in the hub and you cannot get the pins (which are 5/32" diameter, by the way, and about as long) to engage safely in the ring.

Recessed locking ring
The one on the brake side is easy - its not recessed at all. Making a replica of the original will make it easier to get the non-brake side locking ring screwed in, as well as completing the tool kit.

We can see from this next picture that the original locking ring spanner is cast. I'm not going to be able to emulate that - I will be making one on the lathe, welding and using the pillar drill. We can see that the disc is not much thicker than one of the pins - the pin diameter is of course dictated by the holes in the locking ring.

Part of Scott Williamson's 1949 SQ4 tool kit
We can see from this picture that the drive pins on the locking ring are very close to the edge of the disc:
Part of David Andersen's 1949 VH tool kit

Close up of David Andersen's tools
We can see a few interesting points from this last picture:
  • the lock ring spanner is about 1.75" in diameter
  • the lock ring spanner has a 0.820" hex - 7/16" BSF by scaling from the picture which will match the hub nut tube spanner
So, the plan is to find a suitable bit of hex bar; then use a slice of 1 3/4" round bar or a bit of 3/16" plate (which I have in stock). I've been thinking about how to make this and I've come up with the following sequence, which will probably get modified as I think more about it:

  1. Cut a rough shape from the 3/16" plate, suitable to fit in the 3 jaw chuck
  2. Fit the external jaws to the chuck, chuck the plate and face one side with a minimal cut.
  3. Flip the plate in the chuck and face the other side.
  4. Centre drill, drill 6 mm, open out to 10 mm and then 13 mm. Bevel the hole slightly.
  5. With the plate still in the lathe, mark off the PCD of the pin holes.
  6. Chuck the 0.820" bar and face off.
  7. Turn a journal to an interference fit for the 13 mm hole and to a length equivalent to the thickness of the plate.
  8. Bevel side first, push the plate onto the journal using the tailstock to keep it square.
  9. Saw the 0.820" bar to a suitable length - about 0.5"
  10. Put the hex in the vice with the flat side of the plate upward
  11. Weld the plate to the journal
  12. Put the hex back in the 3 jaw and turn the face flat again, dressing the weld
  13. Turn the plate to a suitable diameter
  14. Round the side of the plate with the hex
  15. Ensure the PCD of the pin holes is still clearly marked.
  16. Flip the plate in the chuck and face off the hex; bevel the edges.
  17. Drill the pin holes somehow... ideally indexing in the lathe and using a tailstock drill?
  18. Use the tailstock chuck to push the pins in square
  19. Test
  20. Paint
Step one, saw out the plate:

Almost there
Step two, change the jaws of the 3-jaw chuck for the external jaws, and chuck the plate. Then clean up the face with a minimal cut:


Step 4, centre drill the plate:


Next step, drilling the hole 6 mm, then opening out to 10 mm and then 13 mm. I managed to stall the lathe for the first time!


The plate prepared for welding, and the hex cut to length to go in the lathe. The 0.800" hex does not fit through the chuck...


Step 6 done, and the beginning of Step 7: turning a journal for the plate to fit on.


Step 8, the two parts together:


Step 11, welding. Remembering that the only hex bar available is EN1A, it's no surprise that the weld is porous. I'm not sure what the plate is, but that is probably EN1A as well...


Step 12, facing off shows the porosity nicely...


Step 13, turning the plate to a suitable diameter - part way through:


Marking the pin pitch circle diameter:


Ready for drilling:


Some of those voids are actually in the 1/4" plate. Great quality steel...

Dykem applied, ready for marking out:


Before we start machining the holes, we have to set the lathe up for milling. this involves removing the compound slide, bolting down the adapter plate and fixing the vertical milling slide to the adapter plate.


Before we start, we have to make sure the milling vice is perpendicular to the spindle axis. We can do this with a piece of round bar in the chuck, and a small square to set the vice up to the axis.


To drill the six holes at 60 degrees to each other, we need to index the disc. I'm indexing on the hex, welded to the back of the disc - I machine one hole to 5/32" deep, index, then machine the next.


When I've drilled all the holes, I cleaned up the disc with emery. The pins are 4 mm dowel, which provides a slight interference fit on the holes in the disc which are drilled 5/32" (about 3.96 mm) - they are pressed in place in the vice with Loctite 243 (medium strength threadlock - not very appropriate):


The holes in the hub locking rings are flat-bottomed. To provide maximum engagement, I ground the ends of the pins flat:


Next job is to turn the tool to the proper diameter, but first I need to test it:


It's not too bad, but a quick test reveals that I must deburr the pins.

Now finished. The hexagon and the disc have been turned to shape to mimic the cast original, and I have deburred the pins.



Friday 6 April 2018

QD Wheel Nut Spanners

QD rear hubs need a special spanner to reach the hub nuts through the spokes:


This is the 1938 version, as shown in the 1938 singles parts list. Drawing number G1/126, PN 6608-38


I'm not sure what that hole on the LH end is doing - there are no dimensions?


Note that the LH end hole does not appear in the assembly drawing:



Access to the gearbox bolts are a problem with the oil feed pipes on the SQ4, and I have found that something like the QD wheel nut spanner is useful to get at the top nut, and to drive a small socket in the top nut


Looking in the 1939 SQ4 parts list, it seems Ariel had a similar idea. 6608-38 now has something like a roll pin in one end, and drives an extension (6611-38), with a slot to receive the roll pin in the other:

1939 SQ4 Parts List

1939 SQ4 Parts List
Now, my mission is to be able to replicate the QD wheel nut spanner and the gearbox top nut extension for my own SQ4, which is 1951. Here's the parts list:


And here's the problem - the part numbers are different. This may be extra length associated with Anstey springing, but that would not explain why the gearbox top nut extension was changed...

Fortunately, and this is yet another 'AOMCC to the rescue' story, I have been sent this picture of a 1950 Pattern Spanner sent to me by Klaus Gerhard in Germany. It's a tool that came with his 1951 NH:


I guess that the gearbox nut extension 6649-50 is just a hex tube to fit over the front of the spanner.

Reproduction 1938 Pattern Spanner

So, I have purchased some 0.600" EN1A hex bar with which to reproduce the QD wheel nut spanners and since I have no drawings of the later spanner my 1951 SQ4 needs, we will start with the older one. Another job for the brilliant new mini-lathe!

Starting with the handle component, part no. G1/126A we chuck the steel bar, face off, centre and chamfer the end:


Changing the chuck for the revolving centre, we can start turning the reduced centre section


Turning the radii with a specially-ground form tool:


Finish turned and ready for parting off:


After parting off, I faced and chamfered the cut end.

For the extension, I will use a section of my most-damaged 5/16" BSW box spanner. This is the Moore & Wright type made from hex tube - very useful for this job. Here I am parting off a 1 1/2" section for part G1/126B.


The two components, ready for drilling the tommy-bar hole and welding up.



Best try it out before we spend any more time on it! A small test reveals there is plenty of length, even for my Anstey frame SQ4:


Drill and de-burr the hole for the tommy-bar:


And welded up:


Welding is looking OK - 2.6 mm electrode, 60 A:


Let's try it out:


U-Pol etch primer, U-Pol Matt  Black and a little oil for mock Parkerizing...


Good job.