Landships II

I have been working on designing and printing parts to correct, as far as possible, the venerable Airfix ‘Mk 1’ tank.  There is plenty of threads on the why’s and wherefores of errors apparent in the kit and my parts aim to correct those.

I thought I would start this thread to give you some idea as to the work required to produce the various parts starting with the tracks:

Initially I thought I could use the track plates produced by Arie Dijkhuis and re-scale them.  Unfortunately it proved ‘too difficult’ to rework them so I started afresh:

This drawing was based on dimensions available and modified very slightly to be acceptable in 1:76 scale.  That was the easy bit, it was now necessary to put 90 of these around the rhomboid.

each plate has a semi circle and associated concave section underneath, these equate to the track connection pivot points and allow me to align each track correctly - important when following the tight curves of the ‘horns’.

And so it began, a single plate at the front end of the straight section of the upper section.

I had measured and drawn the profile of the track run of the Airfix model and imported that into the 3D design:

With that in place, I started to add the plates individually (there is a ‘follow a path’ option in Fusion360 but I couldn’t get it to link the plates properly).  Thats 90 plates remember!  This is one of the lesser changes in angle:

getting the plates around the horns was moderately challenging:

The end result being much more effective than the ‘rubber band’ type.

The design of the tracks was time consuming but no less so when it came to printing the track.  Normal practice is to set the track at a nominal angle (say 5 or 10 degrees) but I couldn’t persuade the printer to create full prints at those settings.  I eventually tried horizontal.

As you can see, every plate lip has a print support (so 90) and every other plate has 2 additional supports - fortunately I can ‘mirror’ the end result.  It is a salutary thought that the various different support angles I tried required individual print supports so ‘fails’ were very frustrating.