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Everything posted by andypugh

  1. It seems that the faceted punch works just fine, which simplifies things:
  2. It might need to be pointier. I think that, ideally it would be a double-action, where the square and inner ring is punched first,, then the spike comes up through the clamped, shape-locked ring and bursts it. But I don't know how you would do that. Possibly with a spring, but a spring stiff enough to punch the initial hole?
  3. Ironically the tin with contents would probably have listed at a lower price.
  4. I wonder if it is really as simple as a pentagonal pyramidal spike inside a square hole? (ie. like this https://a360.co/3pagTbb ) And would a hexagon work?
  5. If you can find them at a decent price, this style of threading tools make a lovely whitworth-form thread in a single operation. https://www.ebay.co.uk/itm/284087318863
  6. They would cut the thread that they had tooling for. In 1934 that would have been BSW / BSF. They wouldn't have randomly chosen (pre-ISO) metric or UN / Sellers just because it is theoretically cheaper to single-point. They might well have chosen to forego the crest rounding for the reasons you mention, but the thread angle is still rather more likely to be 55 than 60 (or 47.5, or 80).
  7. Or you are under-thinking it when you suggest that an 1"-16 UN thread is an option. I am saying that it is unlikely that the thread form is UN, it is very likely to be Whitworth, and the two are not compatible. This has nothing to do with any of the standards, it has to do with the basic shape of the threads, which differ significantly.
  8. I found a YouTube video of someone making their own: https://youtu.be/lw1b58kITxQ I was wondering if the lead angle of a thread affects the apparent thread angle when projected, but after a bit of 3D modelling, I have decided that the answer is "not enough to cause confusion"
  9. But would a 1934 British car be using Unified threads? (Unlikely, Unified threads were invented during WW11) I just finished an M77 x 1 thread. I chose that size as I had a 76mm recess that needed a thread, and the 1mm threading tool was the one in the holder. If it had been the 1.25 insert then it might have been an M77.25 x 1.25 thread instead.
  10. Or, indeed for fun. I made an M14.75 x 0.95 thread pair once. Just because that satisfied a mathematical optimum.
  11. Looking at the thread crests might be informative. Flat crests would indicate that it is _not_ Whitworth form. Rounded crests, unfortunately, just mean that it _might_ be Whitworth form at that time period.
  12. It's probably worth trying to figure out the thread angle. There is a fair chance that a British car of that age would be using 55 degree Whitworth profile threads. Not that measuring a thread angle is particularly trivial.
  13. Ben has a Singer too: https://hmvf.co.uk/topic/30968-1914-dennis-lorry/?do=findComment&comment=461079 There is no requirement that any thread conform to any standard. Especially if LH. What you have was probably called out on the drawing just as "1in x 16 LH" and left at that. Possibly with a reference to a matching gauge. I don't see any candidate threads in this list here: http://www.bodgesoc.org/thread_dia_pitch.html
  14. You can order 3D printed aluminium online. But it's horribly expensive: https://www.shapeways.com/materials I looked at having an inlet manifold for a motorcycle cast, and it would have been £1200. However, I think that the main part of the cost is the overall volume (and especially height) so the pump parts might be worth investigating. 3D printing a pattern for conventional foundry casting is probably worth considering, though. We have a couple of Aluminium printers at work, but sadly I have not found a way to sneak my parts on to them.
  15. Arguably https://www.alexander-dennis.com https://www.dennis-eagle.co.uk/en/ You can still buy a vehicle with “Dennis” on the front.
  16. I visited the Dennis factory in the late 1980s and it was much the same then. I think that low-volume truck production might have changed less than you think.
  17. I had the inverse problem. After I finished my course at university I hung around for the rest of the summer taking the fire engine (which has a central accelerator pedal and hand-operated brake) to rallies. When it was all over I rented a transit van to take all my stuff back North to start a PhD. It was as I was heading down my road, which runs straight out into the A4 near Heathrow, that I suddenly couldn't remember which pedal was the brake on a modern vehicle....
  18. I don't know if you were replying to me, but you quoted my post so I assume so. I would never (well, almost never[1]) dream of using anything but an exact replica thread and fastener. What I was pointing out was that a correct imperial coach screw can be found inside the metric one if you peel it carefully. [1] The flywheel bolts on the 1916 Dennis currently have metric heads, but as they are prevented from rotating by machined flats rather than a spanner this is not a concern for assembly/disassembly. I used metric washer-faced bolts as a source of high-tensile steel of the right type and heat-treatment.
  19. It is, but stated the way I did I feel it makes it clearer that an M16 bolt has 1/16" of extra diameter to work with. (If I ask you what the difference is between 5/8 and 9/16 isn't the first thing that you do to double the 8ths?)
  20. When we needed some feather-edge coach bolts for the wings of the fire engine one of the club members (a famous loony) re-machined metric bolts. He used MNC, Manual Numeric Control, for the heads. He had a table of coordinates and dialled them in by hand on the lathe handles. M16 is 10/16" so I would imagine that you could find some 9/16 coach bolts hiding inside metric 16mm ones. M14 is slightly undersize for 9/16. And I rather expect that M14 coach bolts are rarer than 9/16. However M16 coach bolts are likely to be 2mm pitch, so I imagine that you would need to cut all the thread off of over-length ones to get a good thread. Alternatively, perhaps try the US, but again buying over-length and re-threading. https://www.fastenersclearinghouse.com/fastener-search=carriage-bolts&size=9/16-12&Cat1=PRM460D65E02814;&Cat2=FL3DCA0E45011;
  21. At first I thought that the counterweight on the sledge wasn't moving (it moves forwards through the pull in competive pulling) but on a re-watch it is. So that's quite impressive.
  22. "We have a pressure lubrication system, but you can turn it off once the engine is run-in as it is clearly a silly idea which will never catch on"
  23. You might find contemporaneous oil paintings, I suppose. Colour photography was available at the time, so I would not want to rely too much on colour fidelity. Especially this long after the fact. There is a 1917 photo of a French Soldier on the Wikipedia page, interestingly: https://en.wikipedia.org/wiki/Color_photography
  24. Maybe, I remember an Enfield Pageant in the 80's where the field was like a mud pudding, with a dry layer of turf over a squidgy base. Low gound-pressure vehicles didn't even notice, but those of us on narrow solids were completely stuck. But: The simple application of a Landrover was a lot less bother than putting chains on. Not that seeing chains in action isn't an end unto itself.
  25. Just an opinion, but they are original, and you are unlikely ever to need to use them, so I would keep them, patina and all.
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