The "Fell Diesel".....hornblock help required.

Discussion in 'Kits, Kit bashes & Scratch builds' started by Keith M, Jun 12, 2019.

  1. Keith M

    Keith M Staff Member Moderator

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    Whilst I was 'on a roll' having finally completed the DJH "Merchant Navy", I thought I'd follow on and make a start on my 'Judith Edge' Fell diesel kit. I cut and cleaned up the inner frames, frame spacers and suspension arms (I'm intending building the chassis 'compensated'), soldered the bearings to the suspension arms and filed the bearing outers flat as per the instructions.I have the "High Level Kits" hornblocks, so made these up ready, then looking at the instructions, it says "cutouts for High Level hornblocks are also marked on the inner frames". I've previously only built one 'Compensated' chassis and this was my "English Electric GT3" one, which had the hornblock cutouts etched into the frames and only required cutting out, but I can't for the life of me see where these "cutouts for High Level hornblocks are marked on the frames".

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  2. Keith M

    Keith M Staff Member Moderator

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    Now I may not be the sharpest knife in the box, but I just don't see any markings relevant to the hornblocks! Chris Gibbons "High Level" site gives complete instructions for using hornblocks with his CSB (Continuous Springy Beam) suspension system, but I'm not using that, and I'm unsure of how to mark out the chassis frames to make sure things work correctly. Can anyone throw any light on the way to mark these out accurately, as the only markings on either side of the inner frames are for the frame spacers (shown), and holes for suspension pivot points, brake shoe wires etc. This pic is a closer up view of the frame markings.
    Keith.

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  3. jakesdad13

    jakesdad13 Staff Member Moderator

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    I haven't built a sprung frame for a long time but if I remember right, when I built my 1F (scratchbuilt) frames I marked as accurately as I could the centres of the cutouts relative to the axle centres then using the hornblocks as patterns, marked out where the cutouts should be, cut them out, then using the coupling rods and jig axles to hold every thing in line, soldered the hornblocks in place.
    Obviously you have 4 axles to contend with, and am I right in thinking it is a 4/2/2/4 loco? On mine I used one axle fixed for the motor to drive but the other 2 axles were sprung and used the screws on top of the hornblock to set the ride height.

    Pete.
     
  4. Rob Pulham

    Rob Pulham Staff Member Administrator Feature Contributor

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    That's pretty much how I would do it too Keith.
     
  5. Keith M

    Keith M Staff Member Moderator

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    Hi Pete (and Rob).
    You're correct in that the Fell (as I'm building it in later form) is what you might call 4-2-2-4, though I'm using the "High Level" gearbox and linked drive unit which drives the centre two axles of the four pairs of driving wheels simultaneously. The drive unit is not fixed, so the two centre axles can move up and down independently and parts are provided on the etch to allow all four pairs to be in suspension. I can't use my usual box to set the axles as they are only 2mm diameter and the box is only suitable for up to 3 pairs of wheelsets (the kit uses bogie wheels which means smaller axles, so I'll need to be very accurate with measurements), but really it's a matter of my marking out and cutting both sides of the frame together, probably by bolting them back to back to make sure each side lines up perfectly. On these hornblocks, being 00 gauge, there is no height adjustment screw, and I guess I'll need to check the up and down movement of the hornblock bearings and cut out the frames to allow them to be fixed so that mid travel corresponds to the centres of the existing holes for a rigid chassis build.........am I correct assuming this?
    Keith.
     
  6. Rob Pulham

    Rob Pulham Staff Member Administrator Feature Contributor

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    Hi Keith,

    Yes you have it right. To create the adjustment for the screw would it be possible to solder a nut edge on above the cut out so that you can then use a screw for the adjustment/end stop?
     
  7. Keith M

    Keith M Staff Member Moderator

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    Hi Rob.
    At the "A" end (visible in the first pic), there is a frame spacer mounted directly above the intended cutout, so it's not possible to fix a nut there. Perusal of "High Level's" hornblock instructions states that on most models, the tab at the top of each hornblock frame should be 4mm above the axle centre, so I've marked out the frame accordingly, ready for cutting out, as in this pic. Unfortunately I don't have any 'Engineers blue', so I'll use felt tipped pen to show up the lines before any cutting takes place, and handily I had some 5BA screws & nuts which are a snug fit to fix both frames back-to-back for cutting.

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  8. Keith M

    Keith M Staff Member Moderator

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    In between times, I set to and built up the "High Level" gearbox, assembled it to the Mashima motor and then built the drive extender box, both being a little fiddly (for someone like me with "Sausage fingers!). You can see Chris Gibbons novel approach to driving two sets of axles in synchronisation.

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  9. Keith M

    Keith M Staff Member Moderator

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    You can see in the pic below that the second axles drive is completely 'swivellable' around the first axle through over 180 degrees, thus allowing for any vertical suspension movement.......clever stuff!

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    Rob Pulham, jakesdad13 and Toto like this.

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