|How NOT to build a kit - Part 1|
A Class 31 Diesel Locomotive - Rescue
This group of four pictures is of the inner bogie chassis.
Picture 1 – Top Left
It’s not an optical illusion, yes the right hand chassis is banana shaped – I checked it on a piece of glass.
Picture 2 – Top Right
The top chassis has not had the section removed where the motor sits, this would be a pig to remove without distorting the chassis, as it is the chassis is already distorted so it doesn’t matter at this stage.
Picture 3 – Bottom Left
This picture is a blow up of picture 1 and shows more clearly the seriousness of the situation. All of the brass bushes for the axels have been passed through from the wrong side, non of the lamination is correct and the most serious error is the floating frame for the centre and front axels which should be supported by a piece of 2mm rod passed through the outer frame with the arms free to swing about their centres. Here they are supported by a copper nail which is substantially less than 2mm diameter and is soldered off centre, the brass bush is also not soldered in square. Bottom line, there is no way this bogie would have ever run correctly.
Picture 4 – Bottom Right
Apart from the fact that the plate where the motor sits has not been removed, basically nothing is square, almost non of the folds are 90 degree, this is very important where the two plates slide in that support the motor, the degree of error here needs to be under 0.5mm. I don’t know what all this was soldered together with but flux does not appear to have played a part in the proceedings, this is actually an advantage to me because it means none of the solder has penetrated very deep into the laminated parts which are going to have to be completely stripped down, cleaned and reassembled. The whole thing is also coated in something greasy that resisted standard cleaning.
While it would be nice to strip it all down and flatten everything out this is not practical. The half etch lines that form the edges will probably not withstand being folded back and then folded again to the correct angle, we would then be in a worse situation because the basic geometry of the chassis would be lost.
So, 2 hours work with a 75 watt soldering iron, a small gas torch and several meters of desoldering tape brings us to the picture below
Some extreme heat was applied and as much solder removed as possible using desoldering tape, this was sufficient with some parts and they just fell apart. Some parts required direct heating from the gas torch and gentle prizing apart using a sharp knife blade. As you can see I have splayed the chassis sides slightly in order to do the final clean up before reassembly. The next step is to remove all the remaining solder using a glass fibre brush and fine wet & dry paper, then a final clean up in hot soapy water. The final picture in this section shows the end result.