Sign my
GuestBook

AD60

1.2 Chassis drive units (continued)

Instructions [22] to [61], page 8-10 of the instruction manual

 

[17] and [23]
Now follow two tedious jobs: fiddling eighteen washers and eight teen counter withes out of the etch, filing off the etch tabs and sanding them flush. Nice piece of music in the background and your mind in infinity....

 

These jobs can be done during final assembly, but why procrastinate? Better have the job done and have the parts safely stored in sorting boxes. To my experience the final assembly stage should comprise as few construction jobs as possible.

It avoids the "nearly there" syndrome.

The counterweights were glued on the spokes.

[23] I used a dab of epoxy glue to glue the counterweights. I avoid CA superglue and will only use it as a last resort. CA is sensitive for thinner and leaves you almost no time to correct. Five minutes before setting is just enough to work one side of both units. Allow to set for two hours, turn the units and do the other sides. In hindsight I better could have trial fitted the counter weight first. Especially the large counter weights on the driving axles have too small a radius on the outside, leaving parts of the spokes uncovered, but the kit has proved to be very accurate so far, so I was taken by surprise.

When mounting the wheels on their axles remember that they should be quartered. The right hand wheels should advance over the left hand wheels by 90 degrees when running forward.

 

[ 24]
I always enjoy the sight of turned pieces like these turned brass crankpins. I took this photo just for the very fun of it. Fitting them is a piece of cake. The manual says to use a Romford axle nut driver. I don't have it, I converted an old screw driver to drive the axle nuts home (latest: I have ordered it when I needed spare crankpins anyway). But these crankpins can be fitted simply by turning with your fingers until tight. Before painting that will do. After painting they are to be tightened by the encouragement of a non-grooved set of pliers.

 

[25] De-cusping the main drive rods is again necessary, but you can really tell the difference!!

Identical? NO!! The coupling rods are handed, and the manual does not mention that. Above the left, below the right coupling rod.

Do not remove the cusps from the crank pin holes as they are way too large anyhow

Disturbingly large in fact

I'm afraid this will give sloppy performance. The manual optimistically orders you to check for any binding to occur.
Well with this kind of craters in the rods chances of binding are remote.

[28-29]
I hope later in the manual there is an instruction to shorten this screw as is clearly interferes with the railhead! But cutting it will be one of the last things you will do in the final assembly stage.

 

[30-31]

The buffer beam's top side is being cleaned from casting lines by rubbing it over grain 400 emery paper. Other side are scraped and filed.

One done, one to go

When drilling, 2 mm for the buffer and 1 mm for the brake pipes, as per [30], keep in mind that the indicated locations for the buffers are definitely off centre. You'll have to position the drill by your own judgement.

 

[32-33]

The description on this site may seem detailed but in fact I do not elaborate very much. To demonstrate how many things you must do I have detailed what it takes to complete one set of steps, so you might appreciate why it takes about an hour to makes all four sets

  1. Cut main step out of etch
  2. File main step
  3. Fold main step left side until almost 90 degrees
  4. Fold main step right side until almost 90 degrees
  5. Position exactly in vise and close vise until folded square and fair
  6. Flux main step
  7. Cut tiny lengths of 188C solder
  8. Put solder on main step
  9. Touch with the soldering iron and let solder flow into the folds
  10. Cut step tread out of etch
  11. File step tread
  12. Fold step tread left side until almost 90 degrees
  13. Fold step tread right side until almost 90 degrees
  14. Cut tiny lengths of 188C solder
  15. Put solder on step tread
  16. Touch with the soldering iron and let solder flow into the folds
  17. Remove any excess solder
  18. Position exactly in vise and close vise until folded square and fair
  19. Put step tread trough the hole of the main step
  20. Position assembly in your vise, using the protruding part of the step tread to hold the assembly in place (photo)
  21. Check for squareness, reposition if necessary
  22. Flux step tread
  23. Cut a length of 188C solder
  24. Put solder on step tread
  25. Touch with the soldering iron
  26. Remove from vise
  27. Final check for squareness, resolder if necessary
  28. Fold top part of step assembly backwards
  29. Flux new fold
  30. Touch with the soldering iron, holding the assembly with a piece of wet kitchen paper to prevent the assembly from falling apart
  31. Rinse flux
  32. Dry assembly
  33. Scratch residue and superfluous solder away
  34. File remaining rims and impurities away
  35. Clean and smooth with glass fibre pencil
  36. Sand with 400 and 800 grain paper
  37. Repeat all instructions three more times

Done!!

[35]
The guard iron is best checked against a square. The tinyness of the guard is demonstrated here. Do not forget to solder the fold.

 

To solder the buffers in the buffer beam I put the entire frame upright. The rear was clamped between pieces of wood (paint stirring sticks) to prevent damage by the vise.
TAKE GREAT CARE NOT TO ACCIDENTALLY ENTANGLE YOUR CLOTHING AROUND THE FRAME, you'll tear the whole thing to shreds, the frame that is.

My vise can turn, which makes it easy to work from two sides without having to reclamp the frame again.

The buffer beams after [36].

The brake pipes are loosely fitted for the sake of the photo. I will store them so I can still get to the buffer beam during painting of the chassis. I could attach them after that but as they are in a vulnerable position I won't attach them before final assembly and no sooner.

Oh boy, again a lot of tiny particles. Decusp on all edges, sand smooth on both sides. 12 times if you please.

[38]

Cutting the hand grips to size was made easy by a little tool. I cut a piece of rod to 7 mm and soldered it on a scrap piece of brass. I used it to position the flush cutter exactly to 7mm and then cut off the hand grip. Measure once, cut four!

Note that the pilot front plate between the frames already has been fitted as per [41]

Snip!! O yes, and sand the top flat

[38-40]

Lamp iron, hand grips and buckeye lifting brackets in place. The order and size of the holes to be drilled is:

0.7 - 0.5 - 0.6 - 0.5 - 0.5 - 0.6 - .0.5 - 0.7

 

Note that the buckeye lifting brackets are positioned under an angle of 45 degrees.

As to placing solder: apply the good practise of cutting a tiny piece of solder and place it onto joint and in the flux before working it with the iron. DO NOT pickup solder with your soldering iron and than solder. The quantity of solder you pick up will be uncontrollable and usually way too much. This invariably means a lot of rework for removal of the excess solder. The "cut and place beforehand" method is more laborious but you'll get predictable and mostly clean results. Take care not to place too much solder. Better do it over than cause the need for rework. You'll be amazed how little solder you actually need!!

Here you see both bearing washers presented on one unit.

[44]

Fixing the sandbox bearing plate to the frame presented no special problems. Scrape, file and sand excess white metal flush with the frames.

[45]

I had considerable trouble identifying the bearing washers. The hint is: look for the washers with the threaded holes.
The one with the shorter bearing pin should be fitted to the rear unit, that is the unit with the pickup on the left side when looking towards the buffer beam, remember?
To assure a wear and tear free movement of the boiler cradle make sure the bearing plate is carefully sanded and free of burs. In this particular case I left the etching cusps on to add some detail to an otherwise dull bearing plate. But who cares, no one is going to see it anyway ;-)

[46-50]

Taking up the assembly of the power clip, I could not find the insulated washer no 200. I made it from 0.75 mm styrene sheet. I put it in my drill and "turned" it to the desired size

AD60 showing her parts for a model photo shoot ;-)

Easy. The assembly has not been fitted permanently yet as I have to solder the electric wiring during final assembly after painting.

 

This setup is required if you make the bogies electrically live as per the instructions of the kit. I decided later to make my own current wipers as I had no confidence in the DJH standard approach. Making my own wipers is described in Making the electric Pickup chapter. If you follow that road, insulating the bogies as describes above is not necessary. Simply do not short out the bogie wheels as per [104]

Whatever you do the DJH manual does not take the painting process into account. My advice is to install the wipers, [43], only after painting the chassis.

 

[51-61] Now comes another terrible job. Turn up the radio an have a pot of tea at hand and slowly work your way through de-cusping this lot. Over a 100 sides to do!!

The whole brake rigging.

It is a bit mysterious that the brake rigging comes with only one brake rod per drive unit which is located definitely off centre. Either there are two off centre brake rods or there is one in dead centre, otherwise the brake rigging will not work well.

 

[51-53]

If necessary drill the holes to match the 0.7mm wire.

A 0.7 mm wire of 25 mm length  is passed through the holes in the frame. I made a small tool from scrap brass to push the wire in to exactly the right length, although in hindsight this needn't have been so accurate.

I soldered the wire with 140C solder to prevent the axle bearings to loosen. The brake shoes were also soldered with 140C solder. This would often cause the solder joint through the nearest frame plate to flow again. This is no problem as the joint through the furthest frame plate will keep the wire in place.

 

Ready for soldering (after [54])

[56-58] Done.

Work carefully. See to it that every single brake shoe is perfectly vertically positioned. Any deviation from vertical will show up as soon as you try to fit the lower four brass rods with the brake actuator rod. You do that all at the same time and then solder all 12 connections on the lower set of rods in one go.

Instruction [59] tells you to cut the protruding wire flush. But I held a piece of 0.3 mm brass in between to retain just a little of the wire so...

 

... after cutting and filing a little bit the wire stands proud just to add a little detail mimicking the hinges of the brake gear.

 

Also take a good look how clean and straight the brake gear is after all the hard labour of removing the cusps from all sides. Also note that the upper rear wire is left untouched. It will be cut back to 2 mm (somewhat more than advised in instruction 59) to fit the brake tanks.

The completed brake gear from below

Same from top