Giles' misc. Work bench.

Discussion in 'Workbenches, including workshop techniques.' started by Giles, 2 June 2019.

  1. Giles

    Giles Western Thunderer

  2. simond

    simond Western Thunderer

    “thank Heavens for collets!”

    I suspect GJC said something similar

    :)
     
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  3. Osgood

    Osgood Western Thunderer

    The cranks look good, but the coin looks excellent. How long did that take - and did it cost more than £1 to produce?
     
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  4. Giles

    Giles Western Thunderer

    Ah.... the green things with the regulator's on the wrong side..... :)

    Sadly, I've always found it takes rather too long to make those things..... I've never perfected it....:(
     
    Last edited: 26 September 2021
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  5. SimonT

    SimonT Western Thunderer

    Er Giles, the regulator is in the middle. The regulator handle is on the correct side:p
     
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  6. Giles

    Giles Western Thunderer

    Indeed..... I only drove one GWR loco as I recall, a Pannier of some description I was rostered for, though it went well!

    (I confess, nearly all the industrials I used to drive were RH drive as well...)
     
    Last edited: 26 September 2021
  7. Giles

    Giles Western Thunderer

    Bearings are made (CNC'd again)

    [​IMG]

    And another set of frames, rods, cranks etc., as someone expressed an interest should I build a second loco. So I may as well make a start on one and see how far I get!

    [​IMG]
     
  8. Giles

    Giles Western Thunderer

    Blackened, dipped in very dilute gun blue, and with the printed spring assemblies epoxied in, one set of power bogie now starts to look something like.

    [​IMG]

    And both sets done and with etch primer, with one axle test-fitted

    [​IMG]
     
  9. Giles

    Giles Western Thunderer

    [​IMG]

    The first two bogies assembled. Only one motor in place, and the motors gear not yet fitted. The gear motor is one of the erstwhile useless 8mm 40rpm gearmotors with one planetary stage removed to give a very useful 150rpm.

    [​IMG]

    The bolster is printed in PLA for strength, and includes a hole through to accommodate the gearmotor at the correct diameter, position and angle for meshing. On top is a sphere for pivot and snap fixing.
     
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  10. Yorkshire Dave

    Yorkshire Dave Western Thunderer

    Hi Giles,

    Having seen your drive mechanisms for road vehicles could you have used a similar drive for this diesel?

    Mount the motor in the body and drive through a gearbox to the propshafts.


    718ydnls.jpg
     
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  11. Giles

    Giles Western Thunderer

    Hi Dave,

    Yes, I could have done - it was a toss-up! That of course is precisely how the real thing was done, but they found the had to fit a diff in the centre between the bogies, as they were getting 'wound up'!
    The idea of short shafts and sliding couplings together with a fixed gearbox on each bogie made me plump for dual motors!
     
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  12. Osgood

    Osgood Western Thunderer

    That is quite - well, actually very - surprising. I guess they tried without one first and had some transmission breakages.
     
  13. Giles

    Giles Western Thunderer

    They supplied the first one to the customer, who loved it, but reported problems. The second and third were supplied with integral diff, and a another diff was shipped out to be fitted to the first loco, which sorted that....
     
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  14. GrahamMc

    GrahamMc Active Member

    Was it that a bit of wheel slip on one bogie would mess everything up?
     
  15. Osgood

    Osgood Western Thunderer

    I'm really not sure, Graham - wheel slip at one end would just mean the torque to that end would be lost, but the torque to the other bogie would remain smooth and constant.

    It is essentially the same mechanical layout as a double drive truck bogie (albeit simplified by the omission of axle differentials - not required).
    In the 40s and 50s not many heavy double drive trucks had an inter-axle diff - albeit any variation in 'wheel travel 'between axles could be absorbed by the flexible tyre.
    But virtually all variation occurs across the axle, very little between axles.

    One might imagine with the locomotive that any variations that might occur (and which would surely be very minor compared to the truck application) would be relieved by the initiation of wheel slip on one bogie.
    The evidence however shows that significant wind-up occurred, necessitating the use of a diff.

    Im sure if I had designed the transmission I would have fallen into the same trap - neatly avoided by Giles.......:D
     
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  16. Giles

    Giles Western Thunderer



    And to prove at least one of the works!
     
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  17. simond

    simond Western Thunderer


    Tony,

    it’s not necessarily the case, it might be that the uj’s, splines, or the shafts themselves, simply were not up to the torque that was necessary to break traction at one or the other bogie (which would cancel any inter-bogie wind-up), in which case the spines would wear, or jam, or the uj’s would shred themselves. All of which might be cheaper to correct with a diff, than by beefing it all up to the required capacity.

    that said, the diff can’t have been cheap…

    atb
    Simon
     
  18. Dog Star

    Dog Star Western Thunderer

    I think that I have related this snippet before; in the early 1970s Old Oak had need of tyre turning for a Hymek... for expediency the engine was sent to Stratford for the work. Nobody at Stratford had encountered one of these beasts before and nobody on the WR thought to advise of the correct procedure. Stratford turned the wheels and returned the engine. The damage was done by the time that Old Oak received the loco. A Hymek requires that all wheels are of the same diameter to a fine degree and that was not done in this instance. Whether the damage was to a gearbox or to one/more cardan shafts is lost in the mists.

    Suffice to say, the fitters at Didcot enjoyed discussing the finer points with the GWS volunteers as at that time there were several Hymeks which "shared" shed space with 6998, 6106, 1466 and several industrials.

    regards, Graham
     
    Last edited: 8 October 2021
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  19. Giles

    Giles Western Thunderer

    Mounting the bogies..... my profuse apologies for simply recording this on my phone!


     
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  20. Yorkshire Dave

    Yorkshire Dave Western Thunderer

    Could haberdashers press studs/snap fasteners have been used for the truck/bogie mounting or do they require more force than the wire system you've designed?
     
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