Genghis's 7mm Workbench

Discussion in 'Area 51' started by Genghis, 28 April 2015.

  1. Genghis

    Genghis Western Thunderer

    My next 7mm build will be the Gladiator Scottish Director. I have just started by cutting out the cab glazing - much easier to do when the etches are still on the fret, but a job I usually forget to do - and have fitted crankpins and blackened the wheels. No pictures of these, but in true Blue Peter tradition, here's a few I made earlier. The DJH/Piercy B1, A Martin Finney A4 (painted by Paul Moore) and a Connoisseur J36 (awaiting naming and weathering).

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  2. dibateg

    dibateg Western Thunderer

    Ah news from Bangkok! welcome to WT David. I'm sure you'll find plenty of interest here.
    Genghis likes this.
  3. Genghis

    Genghis Western Thunderer

    Slow progress, but the frames are nearly ready for assembly. The frames had to have some cutting out for clearance for the rear bogie wheel, and a bit of rivet embossing at the front end. I have also made up the coupling rods. I have to decide where to fit the plunger pick ups and how the gearbox will be secured.

  4. Peter Cross

    Peter Cross Western Thunderer

    I liked the job you did of Maude I look forward to seeing this one develop.
    Donald Campbell likes this.
  5. Genghis

    Genghis Western Thunderer

    It has been slow progress as I have had a welcome trip home. I should have a completed chassis this weekend.
    BR Tony, P A D and Len Cattley like this.
  6. Genghis

    Genghis Western Thunderer

    Sorry: not had much time for posting but progress has been made. The chassis is complete bar sand pipes and finishing the crankpins: I'll do that when I am sure that there is no further requirement to take things apart.


    The main elements of the body are complete.


    And the cab brasswork done.


    The tender chassis is also finished bar fitting of pick-ups. I will probably change the centre axle to be sprung rather than rock around the 6BA screw.

    BR Tony, P A D, BrushType4 and 6 others like this.
  7. Genghis

    Genghis Western Thunderer

    A business trip at the weekend stopped any modelling but last night I was able to do a little. The reverser - which I had fitted previously - was repositioned.


    I also realised that I had forgotten the step on the cab splasher, so I fitted that. I have yet to finish cleaning up the excess solder. Once done, the loco will be ready for the cast details. I will fit the steps just before painting as I know that I will bend them if I don't!

    I made a start on the tender body by adding the valances, drag beam and buffer beam to the base. It is resting loosely on the frames below: I was in a hurry to take the photo and didn't set it down square.

    tender base.JPG

    I am going to fit pick ups to the tender as I am not comfortable with using just the four driving wheels. It looks like I will be able to fit wipers to the tops of the tender wheel treads: if I can then I will also be able to use them as the springs for the centre wheels.
    BR Tony, P A D, Peter Cross and 2 others like this.
  8. Genghis

    Genghis Western Thunderer

    A few hours at the weekend saw good progress on the tender.



    Not much brasswork left to do: the end is in sight!
    BR Tony, LarryG, P A D and 4 others like this.
  9. Genghis

    Genghis Western Thunderer

    I have now added the tender frames and spring detail. This proved much more troublesome than it should have been, entirely down to me forgetting to check that the spring castings were symmetrical (they weren't, but easily rectified). Nevertheless progress has been made.

    Lifting eyes and fall plate also added.


    BR Tony, P A D, Peter Cross and 5 others like this.
  10. Genghis

    Genghis Western Thunderer

    Sorry not had chance to post in a while. Anyway Malcolm is finished and will be at Telford.
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  11. OzzyO

    OzzyO Western Thunderer

    If all goes to plan I'll see you at Telford.
    Genghis likes this.
  12. Genghis

    Genghis Western Thunderer

    So safely back from Telford - which I enjoyed very much, it was great to meet so many people there - it is time to start on the next addition to David Allan's fleet of Haymarket locos. This will be Vera the V1, from a DJH kit.

    The etches are superb and the instructions interesting, relying mostly on photos of part assembled sub-assemblies. I tend to be suspicious of instructions to 'fit the remaining parts' unless it is obvious what they are and where they go. There are lovely pictures of the individual parts to help identification but I would have liked a parts list and description as well.

    The etches are excellent.
    050.JPG 051.JPG 052.JPG 053.JPG

    The first job is to build up the coupling roads. These are formed from a total of 13 parts on each side! While I was at it I did the connecting rods as well. I have a business trip to Japan for the next 10 days so nothing more will be done for a while. I used drills to align the parts, taking care not to get flux near them and tack soldering the bits in the middle before using loads of phosphoric acid and 188 solder to glue it all together, followed by a good filing and sanding to finish.

    I have cut out the frame assemblies and embossed the rivets on the frame overlays. I am hoping to get them assembled before my trip.


    BR Tony, P A D, Rob Pulham and 3 others like this.
  13. Genghis

    Genghis Western Thunderer

    After a couple of weeks of travelling I have been able to make good progress. Frame assembly was straightforward: the only minor issue I had was one of the detailing plates that fits at the rear of the frames. You need to ensure that the drag beam is clear of the frames to let the detail in. I hadn't done that and had to use a razor saw to gain clearance.


    And the tricky bit:


    Even though this is being constructed as a rigid frame model, I used the axle spacing jigs and coupling rods to check that the bearings are in the correct position.


    Pleased to find that all wheels sit on the ground at the same time!


    By way of a small distraction I built the leading and trailing pony trucks.


    I will be using the Slaters motor/gerabox, which is not what the kit was originally designed for. I decided to start on the body work to check for space so I can get the orientation of the gearbox correct and make arrangements for the reaction arm at this stage. The instructions are not wonderfully clear especially for the initial stages of body construction. Now I know what to do it is easy to understand what the written word is trying to say, but the lack of an exploded diagram makes things a little tricky. I do like the photos of the part built stages though. I would also have liked a full parts list to check that nothing is forgotten at each stage.

    Here are the unformed tank and bunker etches located on the footplate with the cab former and spectacle plates.


    The tank and bunker etches were bent around a silver steel rod held in a vice. There are half etched lines to facilitate this.


    The tank was tested and checked for squareness: phew - OK!


    Similarly with the bunker. None of the parts are soldered yet.

    I am happy with progress so far. I need to solder up the tank/cab/bunker assemblies and then form and solder the footplate and valence assemblies. That will be enough to do a test fit to the frames and determine how the gearbox will fit.
    BR Tony, P A D, Jon Nazareth and 4 others like this.
  14. Len Cattley

    Len Cattley Western Thunderer

    On my Samsung 5 phone the picture's won't load, don't know why as they load on my IPad :(

  15. oldravendale

    oldravendale Western Thunderer

    The first two pics come up on my PC but not the remainder. Is anyone else apart from Len and I having the same difficulty? I can't check the IPad as I don't have one.:)

  16. Genghis

    Genghis Western Thunderer

    They all show on my iPhone. I loaded them on a laptop.
  17. oldravendale

    oldravendale Western Thunderer

    Don't understand this, but the photos are all there now.

    Looks a good build too!

  18. Genghis

    Genghis Western Thunderer

    Getting the body dry assembled showed me how the motor gearbox has to fit, so it has been back to the chassis. I discovered that the holes in the cylinder front and rear etches are smaller than the size of the cast parts that fit therein. No surprise of course, but like an idiot I didn't check and open them out before soldering the etches in place. Not an issue for those parts that fit outside the frames, but for the whitemetal castings that form the middle cylinder slidebar assembly and valve chest cover it's a bit of an issue that may require me to file down the locating lugs on the castings.

    The slidebar/crosshead assembly has taken time to get right, but time well spent I think. It took about 3 hours of careful filing and polishing to get the excellent lost wax castings sliding nicely together. The time taken was mainly me not wanting to rush it and taking a only little off at a time before trying again. I did have one issue: the distance between the square hole on the cylinder plate and the centre of the hole for the piston rod is not quite the same as the distance from the lug on the slidebar assembly to the piston rod. I had to open out the hole for the piston road gland and file the lug down.

    If I have read the instructions correctly - and I did misread them once already - DJH supplies a 1/8" 10BA cheesehead screw to hold the con rod in the crosshead, but the cross head is 1/4" thick. I countersunk the rear of the crosshead and substituted a 1/4" countersunk screw, which will help with clearance to the leading wheels.

    Here are the crossheads, con rods and piston glands.

    DJH notes that the inside rear of the slidebars need filing to give clearance for the con rod. To get an idea how much would be needed I set about fitting the wheels and coupling rods in place first. The leading and trailing wheels use 12BA screws, but I replaced the Slaters ones with countersunk steel screws loctited in place. DJH supplies a set of reduced height crankpin bushes to fit on the leading axle. DJH also supplies a special crankpin for the centre axle which requires the wheel to be tapped M2. I had a slight problem with the thread on one of teh crankpins being bent slightly, but hand on heart I cannot say that it wasn't me being ham fisted when trying to clean up the thread on the pin with an M2 die. For some reason I just couldn't get the die to start and resorted to using a steel M2 nut a few times until I could run the nut on and half by hand. The crankpin can be seen in the following photo.


    It was very pleasant to find that with the coupling rods on the chassis rolled freely first time without any binding.

    I was concerned about fitting the slidebars to the cylinders. With the crosshead captive in the bars, the whitemetal piston gland casting has to be in place as the slidebars are soldered in place. I was concerned how to do this without melting the whitemetal and getting the alignment correct. In the end it was far far easier than I could have wished for. The slidebars are actually held in place by the motion brackets, both of which are formed from two etches, one of which represents a piece of metallic origami.


    I used a piece of 1mm wire to align the eccentric pivot rod holes and soldered to the frames.


    The slidebars and gland were placed in position in the cylinder etch and then the pre-tinned slidebars soldered to the motion bracket. Finally the slidebar locating lug was quickly soldered to the inside of the cylinders, the alignment of the gland checked so that the crossheads still run freely in the bars and then soldered in place from the inside of the cylinders. There isn't much clearance between the con rod and the bars, but not much is good enough!



    So next is the remaining cylinder furniture and brake gear, then off to the paint shop.
    BR Tony, P A D and richard carr like this.
  19. Genghis

    Genghis Western Thunderer

    After fitting the cylinder wrappers it became obvious that these and the drain cocks should have been fitted before adding the whitemetal castings. I put these on first deliberately as I thought access would be difficult with the wrappers in place, but there is sufficient room. I managed to dislodge the left hand piston gland while adding the wrapper but was able after to get in and relocate it.

    The drain cock castings are a delight.


    The springs and brake gear presented no problems at all. The brake shoes are a close fit to the wheels but are tapered so that the outer face is the widest part of the shoe.

    When I took those pictures I hadn't fitted the brake cylinder and pull rods. Those and the rest of the chassis detail have been added and the frames are now going through the paint shop.

    This has enabled me to start soldering the body together. First the front spectacle plate to the cab former.

    Followed by the rear.


    And then the cab sides and tanks. I haven't fully made the joint for this yet: I want to get my big iron (80W) out for this job.


    I am using the running plate as a jig as it has cut outs for the locating tabs on the front spectacle plate, tank sides and bunker.
    BR Tony, P A D, Rob Pulham and 3 others like this.
  20. warren haywood

    warren haywood Western Thunderer

    Here's one I finished earlier, only problem I remembered was the valance overlay being to thin, ok if BR lined black as they are not lined but a pain if doing lner

    Brocp, BR Tony, LarryG and 7 others like this.