Stephen's 7mm Workbench - J68 (starts p.23)

[ozzyo]

When I've used them I've bent one of the legs of the spring to follow the other one (that is so that both of them are running in the same plane), I also use some plastic tube to line the PCB and the frame.

 

OzzyO.

[The Nth Degree]

Stephen, what gauge of wire is used on the rear buffer beam on the J68? I can't find it mentioned anywhere in the instructions, only that it has to have the wire set into pre-drilled holes.

[stephenashton]

When I've used them I've bent one of the legs of the spring to follow the other one (that is so that both of them are running in the same plane), I also use some plastic tube to line the PCB and the frame.

 

OzzyO.

 

Thanks OzzyO. Bending the spring wire as you suggest makes sense. I hope to be able to install these without the need for plastic tubing to line the PCB and frame, but I can always drill out the pickup holes to take some if the frames have a tendency to short out. Thanks again.

[stephenashton]

Stephen, what gauge of wire is used on the rear buffer beam on the J68? I can't find it mentioned anywhere in the instructions, only that it has to have the wire set into pre-drilled holes.

 

If I recall correctly it was 0.9mm wire. I don't think I got this from the instructions, but I have a few good images of the prototype taken from the back and could pick something that looked right. These photos also showed that the installation had to be rather less than perfect if it was to look as battered as the prototype! ;-)

[C2CFenchurchStreet]

Any updates? 

[stephenashton]

Any updates? 

 

 

If only. Work and family have taken priority. I hope that with the long winter evenings I might back into this model ...

[The Nth Degree]

Hello Stephen, any news on the build? I managed to snatch a quick couple hours over the weekend after almost exactly a year buried in the cupboard.

[stephenashton]

Good morning

 

This thread - and the work on the J68 - has been dormant for a while. I'd become a little disheartened by the problems with the plunger pickups. However, I've laid that problem aside and refocused on the bodywork. So here are some pictures of the progress made over the last day or so:

 

First I've fitted the front sandboxes, including handles and operating rod:

 

 

 

Then I fitted the Westinghouse brake cylinder and its associated pipework:

 

 

 

I've added the clack valves, left and right:

 

 

 

Finally, I've formed the smokebox handrail from 0.7mm wire and soldered it into place:

 

 

[stephenashton]

And now for something completely different!

 

I've been working on a small OO Gauge layout for my seven-year-old son and wanted to create a 'proper' signal box. So we're going to use purely mechanical point (and perhaps signal) operation with microswitches for swapping the polarity of the frogs, all controlled from a lever frame. So I've picked up the Shropshire and Herefordshire Area Group level frame kit and started the build.

 

First up, here's what you get:

 

1) The packet as it arrived in the post:

 

 

2) The etch:

 

 

3) Springs and turned handles:

 

 

The first stage is to assemble the frame itself. Here are the parts:

 

 

And here are the 90 degree bends being formed. The instructions suggest that it's easier to form the bend on the lower edge first. Seems like this is good advice as folding the sides first would make folding the bottom much harder. As it was this was all relatively straightforward:

 

 

 

 

Here, then, are the parts ready for assembly:

 

 

And here is the frame assembled ready to take the curved top:

 

 

The next step is to borrow a rolling pin from the kitchen to form the curve and to fit the top.

[JeffP]

Hint: if you are going to borrow things for your modelling, from the household authorities, DO NOT post on a public forum before doing so........

 

"Monty Python voice on": I'll no tell yr wife for a poond!. "Monty Python voice off".

[stephenashton]

Hint: if you are going to borrow things for your modelling, from the household authorities, DO NOT post on a public forum before doing so........

 

"Monty Python voice on": I'll no tell yr wife for a poond!. "Monty Python voice off".

 

 

Rolling pin borrowed and returned last night. The whole operation was carried out in full view of the relevant “household authorities”. I hope to solder the top of the frame into position tonight.

[stephenashton]

I fitted the curved top plate onto the lever frame tonight. The instructions say to tack some brass scraps to the side to help get the top aligned. That seemed too much like hard work, so I've done it my own way using six coffee stirrers and a couple of rubber bands:

 

 

This made the process of aligning the top so much easier:

 

 

Once I'd tacked the top in place, I took off the coffee stirrers and ran solder down the length of the join. Here we are after cleaning up:

 

 

The next job is to make the pivot for the levers and the support for the microswitches. This involves a lot of precise tube cutting. Hmmm ... 

[stephenashton]

I've prepared the tubes to support the pivot bar for the levers and the mounting bars for the microswitches. This is formed from 1/8" OD brass tube and the bars themselves are 3/32 brass rod. Once I'd cut all the parts to length and marked where they should be located, I started tacking them into place. The rod (lightly oiled) held everything in line:

 

 

Here are all the tubes in place. I've made these over length, as per the instructions, this made it easier to keep everything straight and true:

 

 

I then then cut them to length. On the other side (sorry no photo) they're cut flush, but on this side they've been left long enough to mount a second back of five levers. Also note that I've also attached the mounting feet:

 

 

This final photo shows how the microswitches will be mounted. Note the spacers I've prepared to correctly locate the next switch. I now have a bag containing twelve of these spacers in two lengths ready for when I assemble the frame with the levers:

 

 

Now I can progress with constructing the levers themselves. They're made from three etches which will need laminating together. The process will be similar to assembling coupling rods. This is something I've enjoyed in the past so I'm quite looking forward to this next stage. 

[raymw]

Hi Stephen, can you give the dimensions of the lever frame, and length of levers and spacings.

 

Thanks, Ray

[stephenashton]

Hi Stephen, can you give the dimensions of the lever frame, and length of levers and spacings.

 

Thanks, Ray

 

 

Hello Ray. Yes, I can provide the dimensions of the lever frame. I’m away for the weekend and will measure it when on my return ... Stephen 

[stephenashton]

Ray – The lever frame is 50.5mm wide and 45mm deep. The overall height to the top of the levers (inc. the turned handles) will be about 129mm. The levers and rodding are at 10mm centres. Does this provide the information you need?

[stephenashton]

Time for another quick update. I constructed the main shaft of the five levers yesterday evening. These are formed from three layers of the etch. The central one has a hook for the spring:

 

 

I held these together with a couple of wooden clothes pegs then ran flux and solder around the edge, relying on capillary action to draw the solder between the etches:

 

 

Here are all five completed. I had to widen the slots in the frame to get these to slide smoothly, so I've numbered them so that everything can be reassembled in the correct order later on:

 

 

Here are all the levers in the frame complete with the spacers I cut to length last week:

 

 

 

This view from the back shows how the spacers hold the levers in the correct place in their pivot:

 

 

 

I've cleaned up the sides, but not yet the edges. Once this is done I can fit the turned handles.

[raymw]

Hi Stephen,

 

Thanks for your answer wrt dimensions. I was wondering what size it would be, in order to have working lever latches, etc.

 

Best wishes,

 

Ray

 

ps I replied last night, but seems i forgot the 'post' button...

[stephenashton]

Hi Stephen,

 

Thanks for your answer wrt dimensions. I was wondering what size it would be, in order to have working lever latches, etc.

 

Best wishes,

 

Ray

 

ps I replied last night, but seems i forgot the 'post' button...

 

No problem. Happy to help.

[stephenashton]

I've done quite a bit of work on the lever frame on and off over this week, but it feels like there isn’t much to show for it!

 

First I prepared the top of each lever to receive the turned handles. This involved filing some tabs to fit into a 1.4mm diameter hole in the bottom of the handles. I then soldered the handles in place before I realised that they shouldn’t be fitted until later in the build because they prevented the fitting of other elements. Never mind, that’s the beauty of soldering; a little heat from the iron and they came off easily. Here’s a shot of the handles in place before I removed them:

 

* At this point I hadn't cleaned up the edges of the levers at all. They look a *lot* better now!

 

 

I then started forming the drop boxes. These are easy to form into shape but have to slide freely up and down the shaft of the lever and slot into the tabs in the frame. Here they are in various states of construction:

 

 

In order to get the drop boxes to move freely, I had to clean up the levers. After some (read: lots) careful filing and polishing, this was the result:

 

 

I now need to prepare the five triggers and the five lifting rods. I can then do a trial assembly before painting the frame and lever arms. I plan to leave the turned handles, trigger, lifting rod and dropbox all unpainted.

[stephenashton]

Good morning. Here's an update following some work on the lever frame yesterday evening. I've discovered that everything takes a little bit longer than I expect as I have to carry out each operation five times!

 

First, I started work on the five triggers. These have a few holes which needed opening out to 0.7mm. This was done while they were still on the fret:

 

 

Each of the lifting rods had a hole to opened to 0.7mm as well. Once this was done they were all removed from the fret and the tags removed with a quick pass of the file:

 

 

The triggers have quite a few folds, but nothing that causes any problems. I think the photo below shows the sequence relatively clearly:

 

 

Here are the triggers fully soldered up and ready to be cleaned up with a fine file and a bit of wet'n'dry:

 

 

The lifting rods needed a twist about 10mm from one end and a hook for the spring forming at the other end. To keep things consistent I marked them all up together:

 

 

And then twisted and folded them into shape with a small pair of pliers:

 

 

Finally, I assembled each arm -- twice. The first time was to mark up where the lifting rod needed attaching to the drop box and then the second time was to check that everything was working properly:

 

 

Each numbered lever arm, with all its own parts, is now wrapped up in a separate sheet of kitchen roll waiting to be cleaned up. I've done it this way because I want to be sure that I don't start mixing the various components between the arms. It might all be fine, but I know everything fits alright at the moment and there's no point making things harder for myself.

 

I'll soon have to paint the lever arms and frame. I hope that, even with a layer of paint, everything continues to work smoothly. The test operation of each lever arm last night was very satisfying!

[stephenashton]

Good morning. I took the opportunity of a nice warm evening to paint the levers. I've simply used Halfords red primer for the home signal levers and Halfords black primer for the point levers. Here they are just before I covered them over to protect them from dust:

 

 

 

I've only put a few fine coats of primer on these because I'm worried that too much paint will prevent the drop boxes sliding properly and will mean that the levers themselves are too tight in the frame. After the paint dried put everything together to see how it worked:

 

 

 

The drop box on lever #1 was too tight. So I took some width off the lever and repainted it. It moves smoothly now. Levers #2 and #4 work really well, but the trigger mechanism for levers #1, #3 and #5 need some slight adjustment. The lever handles haven't been fixed in place yet but I'm really pleased with how this is all coming together. A little time spent adjusting everything now before I fix everything in place will make all the difference to how it works on the layout.

[stephenashton]

Good morning.

 

After a few evenings adjusting the trigger mechanism and soldering the parts into place, I've pretty much finished the lever frame now. I have a few photos of my progress to show you. 

 

First, here is one of the levers ready for the trigger to be soldered into place with a piece of tin foil preventing the solder creeping into the mechanism. This was so fiddly that I did the rest without the tin foil and (thankfully) managed to complete all of the levers without creating a problem.

 

 

I then cleaned up the stubs of wire with a fine file. As you can see, this made a big difference:

 

 

 

I then used some JB Weld (steel-reinforced epoxy resin) to reattach the turned lever handles. As you can see I found that a standard 3A 'choc block' connector has the right spacing to act as a support for this progress. On a side note that means that I can use one of these as a support for the rodding as it is routed into the layout.

 

 

Here are a couple of views of the (virtually) finished lever frame:

 

 

 

I still need to attach the numbers to the lever frame ... and build another one. I need ten levers overall, but wanted to be sure that I was happy with how this one worked before splashing out on two etches. I think the next will be quicker to build than this; we'll see!

 

Finally, here's a photo of the rear of the operating mechanism so that you can see how everything works:

 

[HarryP]

Stephen, any update on the J68?