7mm GP TRAMM scratchbuild

InvernessTMD

Western Thunderer
As some of you may have realised I have a penchant for these things!! I have two GJH kits which have been much hacked about.
I am doing a pair of them, one powered the other a trailer, through wired for pickups and cab lighting.
I used one of my GJH ones as a reference for dimensions and came up with the following design...
GPT_scratch2.jpg
The left hand vehicle has the crew cab and crane and will be the powered end, the right hand vehicle has a driving cab and a tool store, along with a slightly shorter load area (though that may change yet as the build progresses and I finalise a few bits). Both vehicles will be fitted with pickups and wired together.

It is a basic line drawing but I am able to work from it, and have already made a start on the two chassis..
GPT_scratch1.jpg
The left hand one is going to be the powered unit. Both bufferbeams/deflector plates are now attached and both have the cut outs for a Kadee coupler. Buffers are from GJH, as will be the axlebox/w-irons. Everything else will be made by me...

Inter unit couplings will be via a bar link in a pair of Gutzold HO NEM close couplers. (if it works of course!)
 

Ian G

Western Thunderer
I built one of these a few years ago and used sprung W-irons on both wheels, I didn't like the model once finished so will go down your route of scratch building, I will enjoy your build.

Ian G
 

InvernessTMD

Western Thunderer
I have one that has a rocking unit on the front axle only and that holds the track quite well. Not going to bother on these as they will be through wired with pickups on all wheels
 

InvernessTMD

Western Thunderer
I actually have a question regarding the inter-vehicle coupling... Would there be standard buffing gear or could I get away without it? From what I can gather from photos they had the usual arrangement, which even the MPVs have. If the MPVs weren't going to have wagons between the cab units would they have had some form of special coupling in lieu of buffers and screwlink?
 

InvernessTMD

Western Thunderer
That has confirmed what I thought, buffers it is then! They are useful photos as well regarding the outriggers for the cranes!
 

InvernessTMD

Western Thunderer
Some more progress on this, Both vehicles now have wheels and sit flat, the powered vehicle now has the solebars attached
Below shows the wheelsets in place, with the powered axle having the final drive gear on as well to save pulling it apart later.
GPT_scratch3.jpg

One side of the solebar fitted and the flanges started.
GPT_scratch4.jpg

Both sides done. The vero board is not fixed in yet, once I have the electrical connectors I will solder it all up and wire the pickups
GPT_scratch5.jpg

I need to make two more solebars for the other vehicle and wire it up for pickups, then I can make a start on the topside
 

InvernessTMD

Western Thunderer
The electrical connectors I ordered have arrived... BUT of course I have gotten ones that are small and they have a pin pitch of 1.25mm (ie, about half that of the veroboard spacing). I have looked but haven't found anything yet, can you get veroboard with that spacing?
 

Pugsley

Western Thunderer
I'm fairly sure that Veroboard only really comes in one spacing. I've spent ages looking for different spacings but have never managed to find anything.
 

InvernessTMD

Western Thunderer
I am coming to that conclusion too... Spoke to a friend last night who said it used to be available in half size but he hadn't seen any for years.
I am considering getting my own pcbs done, as I will use the same connectors on my MPV when I evenutally build it, so there are 4 boards straight off!
 
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