7mm MOK BR Standard 4MT Tank

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

  1. daifly

    daifly Western Thunderer

    In the second of Mike's links, I've measured the angle as 4deg. Peter's appears to be approx 6deg. I blame the photographer for my earlier photo!
  2. P A D

    P A D Western Thunderer

    Hi Richard ,
    Looking at the photo, I have to agree. I will check if out to find out why it's misaligned and how to correct it. It looks better in this image so maybe it's just the camera angle???

    3 LINK, chrisb, Scanlon and 5 others like this.
  3. farnetti

    farnetti Western Thunderer

  4. P A D

    P A D Western Thunderer

    Hi Ken,
    Good to hear you've got it running smoothly.

    Thanks to Richard for the heads up on the slide bar support and to Dave and Mike for their input. Having looked at it in the flesh, the support was at the wrong angle. There was also a slight bend at the upper slide bar, towards the front which added to the miss aligned appearance. I don't know why that has occurred, as the cylinders and slide bar support have dimples at the rear to drill and tap the holes for the fixing screws. None of the 4 holes appear to be off centre and the holes in the frame are pre etched. The slide bars have pre etched holes as do the mounts on the cylinder and support bracket through which 0.7 mm rod is inserted, so I'm at a loss to explain it.

    In any case I have straightened the bent support, which required unsoldering the fixing point at the rear of the lower slide bar. I also elongated the mounting holes in the frames which has allowed me to "twist" the cylinders/slide bar unit slightly to reduce the rakish angle. I also noticed the the outer support for the expansion link was slightly miss aligned so that has been corrected. Here's the unit before correcting. The wrapper to the rear of the steam pipe is also adrift in this photo, which probably occurred when the valve guide was being soldered on.

    Here it is after correcting and cleaning up. I'll post some photos of it back in place later, but it looked OK when I trial fit it before cleaning. I have also made a start on the right hand slide bars and valve gear.

    The lifting links are meant to be mounted on 3/32 silver steel rod. However, that is also used for the pivot on the rear axle, so there is now not enough left for the lifting links. I could contact MOK and I'm sure Dave Sharp would send me another piece, but I'd rather use nickel silver rod and have ordered a length from Eileen's.

  5. Dikitriki

    Dikitriki Flying Squad

    Hi Peter,

    That immediately looks a lot better!

  6. P A D

    P A D Western Thunderer

    Thanks Richard.
    That's one of the benefits of being on forums like this. Some eagle eyed member will always point out the errors you have not seen yourself, even as in this case when they are blatantly obvious.
    In the last photo, the pin between the union link and combination lever is missing as it came adrift during cleaning up. I seem to have made a lot of cock ups, all in the same session.
  7. P A D

    P A D Western Thunderer

    Having adjusted the slide bar bracket on the left hand side, and added the valve gear etc on the right, I turned my attention to the lifting link and weight shaft. As the weight shaft brackets need to be demountable when the valve gear and cylinders are removed, there needs to be some way for the weight shaft to separate. First the lifting links were fitted to suitable lengths of NS rod and fitted into the weight shaft bearings. The kit provides a brass bush to solder to one end of one side of the rod, with the other end loose so that when the brackets are unscrewed, they can separate with the valve gear. Following the instruction, would mean the valve gear on each side could be set independently, when what is required is that both sides are set the same. I chose to replace this with some suitable brass tube, soldered to the right hand side, but with a slot filed at the other end. The shaft on the left side was drilled to take some 0.7mm NS wire, cut and filed to locate in the slot in the brass tube. Here they are before fitting to the frames. The two tiny castings are the blocks that slide in the slots in the ends of the radius rods. After fitting in the slot, they are connected to the ends of the lifting links with 0.8mm NS wire.


    Here they are linked together.

    And a view of the left hand side after fitting. There is a slight issue with the reversing shaft which is provided as to short etchings that are laminated (Ken, these are parts 159, from the list of unidentified parts that you posted). The problem is whether to leave loose it to pivot, or solder it in a fixed position. After faffing around trying various options to get it to work, I decided it did not bring enough to the party to warrant further time and effort and soldered it. However, in forward gear it sticks up like this. No problem as there is room behind the tank and it does not foul anything.
    In reverse gear it looks like this. It just clears the wheel, but potentially can touch when the axle rocks in the compensation.

    So I set it like this when in mid gear, and cut it short so that there is no chance of touching the wheel in full forward gear.
    Here's a view of the weight shaft from above. 20180806_233823.jpg

    So, nearly there with the under pinnings. I just need to fit the sanding gear, injectors and plumbing and await the arrival of the motor and gear box. It's running pretty freely, but I will run it in further by pushing it up and down on a meter of track for while.

    Most of the plumbing will be on this side with the injectors and of course there is still work to do in the cab, plus the steam and break pipes to be added.
    I think the slide bar bracket angle is OK now. As I mentioned earlier, with the body on, there's not a lot of the reversing shaft that can be seen. There are 7 oil pipes that need fitting to the cylinders, valve chest, the valve slide bars, the upper main slide bars and the oil pot next to the stuffing gland. The ones from the valve slides would go up to the lubricator, so the question will be how to secure the upper ends so they are not flopping loose. Before that, I will straighten the regulator rod which I seem to have bent.

    And the other side.

  8. P A D

    P A D Western Thunderer

    After further consideration I decided to replace the weight shaft, as I was not happy with the central brass tube. After removing it and cutting it shorter, I refitted it with longer lengths of NS rod. Here it is ready to go back on.


    The brass linking tube does not now rub on the curved plates at the sides, giving a freer movement.

    I've now made a start on fitting the injectors and pipework . Here the injectors are in place and a start made on adding the pipes . The drain pipes and unions are separate brass casting and the pipes will be painted copper and weathered. 20180808_223919.jpg

    To improve the appearance of the drain pipes, I drilled out the ends 1mm to make them look like tube. It looks the part, but can't be seen when the loco is on the track.

    Here they are after adding the two main pipes plus the operating rods. The main pipes are soldered to the large bracket, but I have added two cosmetic brackets from waste fret, to represent the brackets under the side tank.

    On the real thing, the control rods pass through holes in the bottom of the tank (pressumably in tubes) into the cab. The rods ars soldered to the pipes and the tops pass into holes drilled in the tank casting. 20180808_223153.jpg
    Here it is with the body back on. The are still 2 more pipes to fit at the front, that loop down and back to the water filter.

    And another view of the plumbing with the body off. The kit includes the splasher for the curve of the frame over the rear wheels, but I'm leaving them off, as they can't be seen and will get in the way of the pick ups. I "ran in " the chassis on a meter of track by pushing it back and forth and it's now very smooth.

  9. adrian

    adrian Flying Squad

    Thanks for posting - it's looking superb and the rate of progress is impressive.
    What are you planning for the pickups then? Some back of the wheel phosphor bronze scrapers?
  10. P A D

    P A D Western Thunderer

    Hi Adrian,
    Yes, pick ups will be phosphor bronze wipers. I think the clearance for fitting to the back of the rims may be too tight, so I'll go for wiping on the tops of the flanges. Richard Lambert mentioned that he has had good results doing that, so I will give it a try. I think it may be possible to screw some narrow copper clad strips to the top of the pipe brackets for the rear and middle drivers. The front ones I need to think about, but should not be a problem.
  11. Lyndhurstman

    Lyndhurstman Western Thunderer

    This build is a thing of beauty, and testament to your skills and artistry. I am in awe (and in love with that beautiful beast).


  12. P A D

    P A D Western Thunderer

    Hi Jan,
    Many thanks for the kind words. I'm glad you have enjoyed the build.

    It has been a joy to build this kit, as it was building the Finney A3. I hope to build more models from these brands in the future and have the Finney 7 A4 to do next. I'd been wanting one ever since seeing Tim Watson's excellent build in the MRJ many years ago. It was beyond my budget then and I ended up with the Acme models kit designed by John Ennis. It turned out OK and I'm very pleased with it, but I hope to do better with the F7 version.
    mswjr likes this.
  13. Martin Shaw

    Martin Shaw Western Thunderer

    I would echo Jan's comments, it really is marvellous, and done seemingly very quickly. It captures the spirit and look of the prototype exceedingly well. I take it you would recommend the kit? On a full size note the driving wheels returned having had the tyres turned, and in one case the replaced due to a crack, so we are a bit nearer 105 steaming again.
  14. P A D

    P A D Western Thunderer

    Thanks Martin.

    Yes I would highly recommend it. You pay a premium for these kits (and Finney 7), but as with most things, you get what you pay for. The design approach is different, but they both produce kits where the etch parts fit together with a high degree of precision, that you don't find with any other brands. It doesn't mean you can necessarily produce better models with these kits, it is just easier to do so.

    On balance, the mini slot and tab design of the MOK kits probably gives them the edge over the Martin Finney kits, allowing subsections to be assembled and lined up before soldering. The all cast valve gear is also a bonus, provided the castings are high quality, which they most certainly are with MOK kits. The Finney castings are also superb although a mix of brass, nickel silver and white metal. Personally I don't mind white metal for non vulnerable parts and don't see that as a negative.

    However, it's difficult to make a direct comparison between these HiFi brands as they do not have any prototypes in common. It will be interesting to see how Finney 7 develop the Finney range and we've seen a preview of the shape of things to come on Mickoo's threads which are very exciting. As I said before, I hope to be able to build more kits from these manufacturers in the future, with the F7 A4 next in line.
  15. Martin Shaw

    Martin Shaw Western Thunderer

    I've just noticed something, there appear to be no water feeds to the injectors, or sieve box, are they going on after painting?
  16. P A D

    P A D Western Thunderer

    Hi Martin,
    As mentioned earlier, "There are still 2 more pipes to fit at the front, that loop down and back to the water filter". I'll be adding these shortly, along with the sieve box and plumbing on the other side.
  17. P A D

    P A D Western Thunderer

    One thing I forgot to mention is that support bracket for the pipes running under the tanks, have two fold down sections on the outside as seen below on the left hand side. They are not prototypical and I will snap them off before fitting the outer pipe.

    On the other side, I didn't realise until after they pipes were soldered in place so I had to file them off, and chamfer the visible edge above the pipe to disguise it.

  18. Scanlon

    Scanlon Western Thunderer

    Hi Peter,
    Superb build, makes me want to do one as well. As a matter of interest what number will the loco be? This could have a bearing on the coupling rods and location of tank vents, but I'm sure you have thought of this.
  19. Martin Shaw

    Martin Shaw Western Thunderer

    Sorry Peter, I should have read your previous posts more assiduously, still a stunning looking thing though.
  20. P A D

    P A D Western Thunderer

    Hi Roger,
    I haven't decided on the number yet, but it will be one of the early ones allocated to the LMR, so the rods, return crank and vent position are appropriate. But as you say it does have a bearing. So much for standardisation.

    No worries. Sometimes the wood is obscured by the trees. Good to hear that 80105 is "on the mend".