A little more looking at Class 47s today,

One of the plans I have been considering recently is to rebuild the majority of my Heljan class 47 fleet with Vi Trains bodies, while this does involve a lot of work, it does appear to be the most cost effective method given the very low value the Heljan locos currently have (both due to the release of better models, the fact all couplings have been removed, P4 Chassis and finally in some cases a lack of hand rails...

Now I havent yet been able to take measurements off the Vi Trains body, and for the time being have been making use of a Bachmann shell, but it appears that approximatly 1mm of metal needs to be removed from each side, along with the removal of the buffer beams. My intention is to chop the buffer beams back behind the cab doors so that the Vi Trains inertia can be retained, along with removing 1mm of metal from each side and taking 2mm out of the underframe tanks.

I have got a small milling piece that fits in the mini drill that might be a bit easier than fileing off that much materiel, but will see how I get on with the first chassis. There are a couple of areas that I am a little worried about with this method, firstly I worry that the two out riggers which will support the bogie will be suspect to bending over time (I've already had one chassis block fail and I am a bit worried that once the ends have been chopped off there is going to be a weak spot at the joint between the sides supporting the bogies and the centre section. To try and combat that I plan on fitting a brass plate over the top of each bogie tower.

Again unfortunately because of the amount of materiel that has to be removed this will not leave enough metal left to screw into, so this plate would have to be glued into position.

The other option I plan to consider is to build a new chassis block to support the Heljan motor/bogies. I have attached a sketch outlining how I intend to build the prototype,

It would be of brass construction, forming a long U shape out of 3 pieces of 2mm thick brass sheet. Along the length of the chassis are 2 square tubes, these serve a duel purpose, adding much needed strength along the chassis length along with giving the correct hight for the bogie pivots. There are also extra benefits in that they can be filled with lead to help increase the chassis weight and will also aid in the alignment of side pieces. the sides will require the most complicated part of the fabrication, ensuring that they are identical. these will require cutting out the holes in which to mount the bogie pivots along with the recesses to hold the body retention clips that will hold the Vi Trains body in place.

Once thats finished it will be a case of glueing on the underframe takes (using the Heljan part with 2mm removed from the centre) and adding extra lead in order to bring the weight back up to that of the original Heljan chassis

While this does sound quite a long way round of doing things (part of me does just say sell off the unfinished Heljan bodys are a price to clear them and then buy complete Vi Trains locos...) the new chassis option does involve a good number of skills that I havent used before so it should be an interesting experience. The CAD file will now be redrawn to accurate dimensions (based on what thicknesses of brass I manage to source and the internal width of the Vi Trains body. Once thats done its out with the saw and the soldering iron......