Last night after butcheri... I mean disassembling the donor, I went into "brain-ramble"-mode. This involves a glass of good whisky, some nibbles, a bit of distraction by a semi-entertaining movie (Last nights choice; Goldeneye. Awesome tank chase...) and a pad and paper.
Pretty soon the pad and paper were traded in for my computer, Tinkercad and more whisky.

A bad movie, a small cheese and sausage platter and some measuring later I ended up with this. I took the 3-piece cover of the Grant model I found online and based on the dimensions of the HL Sherman like the general width, the diameter of the axle-support thingy and several key distances like the gearbox and whatnot I arrived at this. Popped into my slicer program it gave a print time of about 2 and a half hours. Coulda been shorter if I had noticed one of my settings made my printer build a raft to print on... *sigh* At least I had the rest of the settings set to "fast prototyping".

And indeed, 2 hours and 22 minutes later... It looks rough because of the prototype settings, but it's all there.

Not too bad, with all the supports removed and the raft pried off. Not the greatest print in the world. This is just a tribute... I mean it's just to check my general dimensions.

So close... in my attempt to stay true to the dimensions of the 3-piece on the Grant, I came up short in the space department by about 5mm. When designing parts to fit on existing models, you (almost) always end up with a compromise. The Stug gearbox and the gears are as small as I can go (well, not quite true... my 3-dram whisky brain did consider adding an extra gear wheel and getting the space that way...) But the sensible thing to do was a small tweak to the design. The various aftermarket 3-piece covers must have done the same...

So, a little tweak to the design, as you can see the new part (here in orange. The green one was attempt #1) moves out the minumim I (think) I need to clear the gearbox. And in about an hour I will know for sure...
To Be Continued...
TTFN,
Rob
Sherman M4A3/Stug III/Panzer III/Panzer IV/Tiger/King Tiger/KV-1/T34-85/Leopard 2A6/Abrams M1A2/Walker Bulldog/Pantiger
Under construction; Sherman Firefly IC - M3 Grant - Sherman BARV
... No, I do not have a problem....