Making some controllers in 7mm/ft Part 2

I decided it was going to be easier to make the controller handles in one long strip instead of trying to shape them individually as in the first photo.

I then cut them up and glued a short piece of rod on to represent the wooden knobs. The switch for cutting out a faulty motor was done with another short piece of rod as was the reversing levers. This was a mistake when I look at the finished controllers. The reversing levers would have been better done with a couple of pieces of flat section to closer represent the keys as they are basically flat anyway, reasonably thin where you grab them with your hand and broader where they connect to the controller.

I think I will sand the current ones off and do them properly but having just finished 14 controllers over the last two days I'm not full of enthusiasm to do that right now. I will have to correct two though so I can get back onto my droppie model.

The last photo shows them ass together on the bench. There is some variation which is normal when each one is made individually but as they will never be seen together I don't think is really matters.

I need some brake leavers as well so I hope to mass produce some of those as well. I think that they will have to be in brass so a visit to the hobby shop will be next on my agenda.

Making some controllers in 7mm/ft

I needed a pair of two motor type controllers for my new model so it seamed like the time to batch produce a few. I'm making a generic type controller but I'm basing it on one that was common to the drop centre trams. The first photo shows a top view and this type had an extra switch on the top plate to switch out a faulty motor. Others used in Brisbane required the front cover to be removed as the motor isolation switched were in the bottom of the controller.

I laminated a number of strips of styrene to build up the size required for the body of the controllers and let them thoroughly dry before sanding to shape with my new sanding sticks. The two smaller strips are for the top plates which on the full size controller overhang the sides by a good 1/2". When originally built these trams had open driver's compartments and I suspect this overhang was to protect the internals from rain.

I expected trouble snapping off the individual pieces because of the thickness and allowed extra material for the rejects but it went without any problems at all and I ended up with enough pieces for 14 controllers.

In the last photo the top have been glued to the bases and most of the sanding done. I can see a few problems to fix up. It's amazing what shows up in a photo that is not apparent when you are holding the piece in your hand.

So some more sanding and then onto the detail on the top. Handles etc.

Sanding sticks

I had to go to the museum this morning to measure up a couple of controllers as I am going to mass produce enough for six or seven trams. While I was there I made good use of the bench saw as, now I am back using styrene, I needed to make more sanding sticks. My old ones seem to have become "dispersed" over the years.

I sliced a 1" strip off an old piece of pine then cut that into a number of strips 5/32" thick. I cut the strips down to 12" long and a quick hit with the belt sander to put finger grips into the wood and with my controller dimensions I was off home again.

I laminated a number of pieces of styrene together to build up to the size I needed for the controllers and had to put them aside to dry. So I thought I would get on with making the sanding sticks.


I use wet and dry emery paper for these things which I buy in the 11" x 9" sheet size. I cut off a number of 1" wide by 9" long strips of 80, 180 and 800 grit because that is what I had in the cupboard and glued them on with a very thin coat of contact adhesive. Ideally they should be ready to fall off when they are worn out but it doesn't always work out that way. I made plenty of sticks and when I'm out next I will get a couple of more different grits to give me a better range.

I find the home made ones are sturdier, last longer and are much cheaper that anything from the hobby shop.

A early version Drop Centre in "O" scale part 4

While I have been working on the trucks I have been starting on some of the detail on the body. The area below the driver's window is curved. I find the easiest way to do that is to make a full front which is flat. Then I add curved ribs to that and finally the curved styrene.


It's not prototypical because the curve is visible from inside the cab of the full size tram as it is only a single skin. But for a model I find my way easier and stronger and by the time I install the controller and brake handle you can't really see it. All the outside trim and the bumpers have been fitted as well. The first two photos show the before and after.

With the trucks finished I have been able to fit the cabin floors. I like the tram to "sit" properly and I don't mind if, as a result, the cabin floors are at the incorrect height. The drawings show that the drop centre floor as being 25" above the roadway although this is a bit of an iffy measurement. We have wheels at the museum that due to wear are 2" less in diameter than a new wheel and with a full load of 100 people the weight on the springs could easily increase by 8T taking the tram from 14.2T to 22.2T. So I decided to set the height at about 23" to 24".

So I cut out the two floors and mounted them on to the trucks and then eased the floors into the cabins without gluing them. With a couple of spacers positioned under the body I set the body the correct height above the bench. Now the floors have to be at the correct height and after checking that they were level with a depth gauge I ran a bead of glue around the joins and left it all for an hour or so.


The last two photos show the tram on it's trucks. The last photo shows how the pony wheels swings outside the body line on curves. A typical characteristic of these trams. There is sufficient clearance with the trucks to allow a radius of 6" to be used. Well within my requirements.


I still have some detail on the outside to complete plus all the roof detail. Fortunately I made a batch of trolley poles awhile back so that is one job out of the way. Then I can start on the interior.

Making maximum traction trucks. part 6

Just a short post with a couple of more photos. The side frames and the lead weights are in place. So the trucks just need painting and the wiring finished to the motors.


Now that the side frames are in place I can see just how open they are. So I shall paint the side frames grey and everything else in mat black.

These diamond frame trucks date back to the private company days. Recently we have been refurbishing a pair of Brill 39E trucks in 12" to ft scale which are also from the private company days. We found their original specifications for the Brills and one of the requirements was for the trucks to be supplied, painted with hot bitumen. Obviously for protection against water damage. So, I'm quite happy to use black on the internal framework of the trucks. In my time period, the 1960s, everything could be seen by the public was was painted grey.

The important thing is I can now get back onto the body of the tram.

Making maximum traction trucks. part 5

I finally got back to working on the trucks and they are very close to being finished now. I just have to mount the side frames. The brass lugs to hold the side frame spreaders are soldered on to the ends as well. I did decide to mount the pivot point close to the driving axle as per the prototype as can be seen in the photos.

As this was a change of plan, I had to solder on a brass rubbing plate that would overhang the gears. A good thing none of this will be visible in the finished model. The phosphor bronze pick up springs were soldered to small pieces of printed circuit board which were glued to the side frames with epoxy. The pony wheels always cause a problem for me if the pick up spring tension is too high. The wheels won't rotate or only do so intermittently. I have about 1mm side play in the axles and I like to adjust the tension so that the spring barely makes contact when the axle is to that side. Then when I get both springs with the same tension they will centre the axle in the chassis and with luck the wheels will rotate.


The wire from the pick ups to the motors aren't terminated yet because these motors have no markings to indicate which lug should be positive or negative. I could have tested them before assembly but decided to leave the leads long enough to reach either lug and I will figure that out later.

It's not particularly obvious in the photos but the brass cover that holds the motor in place is itself held by two pieces of copper acting as straps. They are soldered lightly with the end of the wire bent outwards so it can easily be unsoldered if I ever need to replace the motor. The backlash is about what I think it should be and I can rotate the motor with a finger with no obvious binding of the gears. So I am happy with the results so far. I have left a space above the pony wheels where I can add some lead weight which I think will be necessary because of the position of the bearing point. So now I just have to mount the side frames and some lead and then I can get back onto the body.

A early version Drop Centre in "O" scale part 3

Assembly is well under way with all of the main components glued together. The first photo is an overall shot of the model so far. No attempt has been made to clean any of it up. I still have to fit a lot of the smaller detail, the timber mouldings and the rounded noses to the tram.

When the rounded noses are in place I shall have to put it aside for a few days for the glue to dry properly so I can sand what I have so far Much easier to sand joints etc without all the fine detail in place.

I use ultra thin styrene cement and I have a theory about this stuff. I have noticed if you sand a joint too quickly you often tear out pieces of styrene and leave a groove or at least a series of holes that have to be filled. My theory is the liquid wicks inside the joint softening the styrene and making the bond then the outside sets hard and then it's like screwing the lid on the glue bottle. The solvent is trapped inside and can't evaporate. This leaves one with an apparently hard joint but it is actually soft inside for some days.

I need to finish the trucks for this project anyway as I can't glue in the cabin floors until I know how much clearance I will need. So another day on the body then back on the trucks for awhile.


The last two photos are either side of the driver's compartment. These early trams did not have the full metal skirt and timber battens were used to provide some safety for the public.