7mm MOK BR Standard 4MT Tank

Discussion in 'Area 51' started by P A D, 14 May 2018.

  1. P A D

    P A D Western Thunderer

    Here is the left rear step after fitting.
    20180706_191140.jpg 20180706_191046.jpg

    I then went back to the body and added most of the detail to the fire box. The washout plugs, mud hole clamps, safety valve base have all been added. Additionally, a boiler band cleat from Laurie Griffin was fixed to the front cladding band and the band fixings were drilled out and small brass rivets added to improve the appearance . All soldering was done from the inside with 145 degree solder. The exception was the etched safety valve base which was tinned with 145 and then sweated onto the fire box top.
    20180706_191520.jpg

    This view from the side shows the etched extensions to the sides
    20180706_191454.jpg

    And back together again.
    20180706_190937.jpg

    20180706_190956.jpg
    20180706_191017.jpg

    And a broadside view showing the all the recent additions.
    20180706_185948.jpg

    Cheers,
    Peter
     
    Last edited: 7 July 2018
  2. P A D

    P A D Western Thunderer

    Here's the bogie frames tabbed together before soldering. The formost of the spacers has a slot for the slider. I did not realise until much later, but it would be best to remove the cusp from the a slot in the flat, to ensure the runs smoothly.
    20180709_102010.jpg

    After soldering , adding the rod spacers and end castings and cleaning up.
    20180709_215948.jpg

    After adding the axle box castings, I discovered that the holes in the frames, the equalising beams and springs were all at different centres.
    20180709_220158.jpg

    To rectify this I first added the inner equalising beams, wedged them in place with strips of card and then soldered to the axle boxes. Then I drilled fresh holes in the frames, throuth the holes in the beams. This allowed me to add the rods to mount the springs and outer beams.
    20180709_220445.jpg

    To correct the hole centres in the springs, I opened the holes from the outside with a razor saw and file, to make them into slots. This allowed me to fit them over the wider spaced rods.
    20180709_220535.jpg

    Here is the spring after slotting the holes.
    20180709_210948.jpg

    After finishing and cleaning up.
    20180709_210917.jpg

    And with the wheels on. 20180709_210836.jpg

    Here's the bolster casting after fitting the grease lubricator. The etching just has half etched holes, so I drilled them out and fitted 0.5mm brass rod to represent the grease nipples. 20180709_210808.jpg

    And after fitting to the bogie. The pivot has also been added.
    20180709_221445.jpg

    And fitted to the chassis.
    20180709_220712.jpg

    This is the mounting point on the chassis.
    20180709_210700.jpg

    And from the topside. 20180709_220646.jpg

    And with the body on.
    20180709_221107.jpg

    Cheers,
    Peter
     

    Attached Files:

    Last edited: 10 July 2018
  3. P A D

    P A D Western Thunderer

    To finish off the bogie, the side control springs have been fitted to the slider. 20180710_230740.jpg

    The bogie is attached to the frames with a spring over the pivot that sits in the large bush in the rear spacer. It is retained with a C clip. The rear coupling hook can pivot from side to side via a 12 BA screw through the mounting point 20180710_202219.jpg
    Here's a view from the rear.
    20180710_202254.jpg

    Next the pony truck. After adding the coil springs to the bearing/side frames, I soldered these to the bottom etched A frame. I was then able to use this assembly as a jig to line uo and solder the two halves of the bolster.
    20180710_202454.jpg

    And after soldering the bolster to the side frames.
    20180710_202410.jpg

    And with the remaining parts added.
    20180710_202702.jpg

    A view from the underside.
    20180710_184056.jpg

    And with the wheels on. 20180710_184029.jpg

    Mounting to the chassis is via a bracket and 12 BA screws.
    20180710_183943.jpg

    Here's a view of from the front with the body on.
    20180710_183908.jpg

    And a couple of the complete loco.
    20180710_183805.jpg

    Starting to look the part now.
    20180710_183657.jpg

    Cheers,
    Peter
     
  4. P A D

    P A D Western Thunderer

    I noted in the front view that the guard irons were over hanging the rails when fixed as per the instructions. The wheel rims were also just touching the bolt detail so a correction was needed.
    After removing the irons, I filed out the half etch location to make a slot. Here's the right hand one after filing. 20180711_104750.jpg

    After refitting the irons, they no longer touch the wheels and are now in line with the rails. Just goes to show, that with this error and the missaligned holes in the bogie equalising beams, no kit is perfect. That said, they were easy issues to correct, so no complaints.

    20180711_104651.jpg

    Cheers,
    Peter
     

    Attached Files:

  5. P A D

    P A D Western Thunderer

    Next the cylinders. Two cast blocks with etched overlays for the wrappers. After fettling them up, the holes for the mounting screws need to drilled out and tapped 10BA. Here they are ready for the wrappers to go on.
    20180711_133641.jpg

    As per the instructions, I soldered the top edge first and the folder the wrapper around the block down to the bottom. To start with I held the block in the vice and lined up and clamped the wrapper with a suture clip.
    20180711_184130.jpg

    Here they are with the wrappers on and the inspection covers being fitted. I scribed a fine vertical and horizontal line and added masking tap to butt the cover against for soldering.
    20180711_154406.jpg

    This is the left hand cylinder after fitting the core plugs, snifting valve and cleaning up. Looks like there's a slight gap in the solder along the top edged of the inspection plate, that needs attention. These brass castings are excellent, but a real pain when they need drilling. In the case of the cylinders, that's 10 holes each side. Two for the screws, two for the core plugs, two for the lubricator pipes behind the core plugs, one for the snifting valve and three for the cylinder drains.
    20180711_171554.jpg

    Here's the right hand cylinder screwed to the frame.
    20180711_184313.jpg

    And from the front with both cylinders on. It's just possible to get a screwdriver into the slots in the screws and turn it.
    20180711_184345.jpg

    Here it is assembled again.
    20180711_184919.jpg

    There are not many etched parts left now but still bags of castings.
    20180711_184718.jpg

    Cheers,
    Peter
     
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  6. markjj

    markjj Western Thunderer

    Watch your wheels don't touch on the back of the front step it's a common problem if you have tight curves.
     
  7. dibateg

    dibateg Western Thunderer

    Your work is so tidy Peter... Note to self - must do better!
     
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  8. P A D

    P A D Western Thunderer

    Thanks Mark.
    Strangely, on the left hand side, the wheel just clears the step on the curves, but on the right side it just catches. I cannot for the life of me see why that might be as everything is square. I think the simplest thing to do is to move the pivot casting on the apex of the A frame forward slightly, which will move the wheels back to clear both steps. I could try take the steps off and move them forward, but then then they would be noticeably too near the buffer beam and it will also be more difficult.

    Many thanks Tony.

    I don't have to build to a deadline, so I can spend longer cleaning up. Whether that ultimately has any impact on the model after finishing is debatable, but it is how I prefer to do it. Do you recall having any issue with the pony wheels touching the steps on your build?

    Cheers,
    Petere
     
  9. markjj

    markjj Western Thunderer

    A guy at my local area group had the same problem running it on our club layout. It took ages and about 20 people watching it's every move to find the short. I think he just tweaked the step out very slightly I think Slaters thick wheel rims don't help.
     
  10. dibateg

    dibateg Western Thunderer

    No I don't recall a problem Peter - but there again - my memory. I'm recall it ran ok on Heyside ( 6 foot radius curves ) ok.

    Regards
    Tony
     
  11. P A D

    P A D Western Thunderer

    Thanks Tony,
    I adjusted the pivot bearing slightly and now the pony swings clear of both steps.
    Cheers,
    Peter
     
  12. P A D

    P A D Western Thunderer

    Here's the pivot bearing after removal. I have a round file the same diameter as the bearing hole, so it was a simple matter to file the slot to move the bearing forward slightly.
    20180712_193228.jpg
    And refitted.
    20180712_101950.jpg

    Now the wheel just clear the step.
    20180712_195431.jpg

    After having fitted the roof vents earlier, I noticed the two etched overlays that are not mentioned in the instructions. Also looking closer at the illustration, I realised that i had fitted them upside down.
    20180712_195602.jpg

    After removing and straightening the vents, I then laminated the overlays, curved to the shape of the roof and refitted. The one with the row of rivets goes to the front, although I have seen a picture of one preserved example where they are the other way round.
    20180712_195305.jpg

    And back in place on the cab.
    20180712_195054.jpg

    Next I turned my attention to the buffers. These are the parts minus the spring ready for assembly. Top left is the steel shank and etched retaining disc, that fits into the shank, with the lugs in the slot. This has to be soldered in place and the lugs filed flush. To the right is the cast buffer head and below is the stock. The dimple in the side has to be drilled through, as does the one on the other side. After fitting the spring and the shank, a piece of rod is pushed through the hole and the slot in the shank to retain it. The rod is filed flush and the tiny riveted discs are glued over the holes. 20180712_174527.jpg

    Here we have the heads and shanks assembled. One buffer is complete albeit temporarily.
    20180712_174406.jpg

    Here are the rear buffers added to the beam. 20180712_174303.jpg

    And front ones. It makes things really easy to do when you have sub assemblies like this. There are a number or other parts to go on this before it is soldered to the smoke box.
    20180712_174330.jpg

    I couldn't resist a preview with the heads placed in the stocks.
    20180712_194734.jpg

    20180712_194556.jpg

    Cheers,
    Peter
     

    Attached Files:

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  13. P A D

    P A D Western Thunderer

    The cab floor is designed to be fitted from below via two tabs at the front locating into slots in the cab front. It is supposed to be soldered but it clearly offers the opportunity to have it removable. To facilitate this I drilled and tapped a hole 10BA just behind the floor opening. A
    simple pivoting bar is then swung under the rear of the floor to retain it.

    20180713_184758.jpg

    The floor then slots in, the bar is swung in position and the screw tightened. There is just enough thickness in the metal to take the thread, but a better option would be to solder a nut on the other side earlier on.
    20180713_184712.jpg

    After that I turned my attention to the tank top details. The kit provides alternative castings for the water filler and inspection plate, one type cast and one type etched laminates for the latter.
    For the fillers I've gone with the screw locking type as soured to early LM locos and fire the inspection plates I used the cast ones. These are a bit on the thick side so a fair bit of rubbing down was needed to thin them down. The etched bases for the tank retaining brackets, lifting hooks and fire iron holders were also fitted. The instructions suggest fitting the breather vents later on to avoid the risk of knocking them up during handling, but they are secured with two lugs into holes in the tank tops plus a tab on the inside of the tank. I decided they would be robust enough so fitted them now while it is easier to do and clean up.
    20180713_185001.jpg

    And a view from the other side. The two small holes behind the inspection cover on the left hand tank are superfluous and will be filled.
    20180713_184935.jpg

    Here are some shots with the boiler and firebox back in.
    20180713_184519.jpg 20180713_184412.jpg 20180713_184454.jpg

    And a couple of the complete loco.
    20180713_184039.jpg 20180713_184107.jpg

    I wonder how Farnetti is getting on with his, over on the "What's on your Workbench" thread in the members forum. Last time he posted he was ahead of me, but I may have caught him up.
    Cheers,
    Peter
     
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  14. farnetti

    farnetti Western Thunderer

    Have been away for a couple of weeks and so not much so you getting slightly ahead of me. I have been wondering what those two half etched plates were for, I'll be putting them on the roof today.

    I have been having trouble holding the wheels firmly to the axles, the screw, although tight, is still proud of the wheel boss. Mine are from the S& stores rather than Slaters,, investigation needed. I also bought the additional crankpin set from MOK which involves drilling out the crankpin holes on the wheels and counter sinking them on the rear. Another job for today, hopefully enough time to finish the cylinders as well.

    Ken
     
  15. P A D

    P A D Western Thunderer

    Hi Ken,
    It will be interesting to see if any more "mystery" parts turn up. :)

    Can you clarify who's wheels are you using, as I don't recognise the name. Other than cast wheels, I was not aware there was another supplier of 7mm wheels.
    Cheers,
    Peter
     
  16. richard carr

    richard carr Western Thunderer

    Ken

    The problem with the wheels is that the screw doesn't seat properly, I have the same problem on the S7 stores diesel wheels.

    So 2 things you may need to do, shorten the screws and thin the neck of the where it starts to flare out, that has cured it witht he diesel wheels.

    Richard
     
  17. Dog Star

    Dog Star Western Thunderer

    Advice received from David White... ensure that there is no swarm or dirt at the bottom of the threaded hole in the axle.
     
  18. farnetti

    farnetti Western Thunderer

    Thanks Peter, Richard and Graham. The wheels are Slaters but via S7 stores. There is plenty of depth in the axle for the screws and I have just solved the problem by slightly counter sinking the ends of the axles.

    So on to the cab roof and crankpins. When the wheels are back in place I'll fit the brake gear and post some more photos then.

    Ken
     
  19. markjj

    markjj Western Thunderer

    I have both S7 and finescale wheels I believe the S7 ones are possibly slightly thinner I don't think the ends of the axles where adjusted to compensate for it.
     
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