IS2 Scratch Build

[AlwynTurner]

Hi Herman, yes I am one very lucky and grateful bunny, it is way beyond anything I would have bought, and now I have to make sure that the rest of the build lives up to the quality of these parts, and that's quite a motivation.

Alwyn

[c.rainford73]

Mr Alwyn The lower hull is coming along quite nicely. I have a question ( silly I'm sure) is the upper hull going to be a complete scratch build or can you utilize parts of a KV upper as a base to work with? I'm assuming the upper hull is also narrowed like the lower hull design. Is the turret going to be sourced from a vendor or somehow scratch built?

Just very curious and watching as this evolves.

[AlwynTurner]

Hi Carl, the upper hull will be scratch built, and the turret will be 3d printed. One reason for doing this build is that wibblywobbly found an stl file for the turret that someone had scanned and put on thingyverse, so all I have to do is find a way to chop it into pieces to print it. The upper hull is relatively simple compared to the nashorn, and is rather satisfyingly 'crude' as the Russians did not have time to pretty up their tanks, and left lots of rough edges and slightly messy welds. I can see me using lots of milliput and Mr surfacer to simulate that.

It is proving to be an interesting and challenging build

Alwyn

[c.rainford73]

Alwyn....always find your builds and determination to build the impossible exceed normal mortal standards so this one will be without a doubt incredibly built and designed

[AlwynTurner]

DOH......... Homer Simpson moment par excellence!!!!!

I was looking at the KV1 drive sprocket and thinking - That looks a bit big! And sure enough when I checked on the blueprint it was. In my scatterbrained state I had assumed for some reason that the KV1 drive sprocket and the IS2 drive sprocket would be the same Well they aren't, the IS2 sprocket only has 14 teeth to the KV1 16 teeth, 50.9mm vs 57.8mm.





Oh dear, but never mind because I have a set of IS2 sprockets. Then the fun started. The mounting depth for the KV1 sprocket was 15mm vs 6mms for the IS2 sprocket which meant that the drive shafts were sticking out by 9mms too much.





Given that there is insufficient space in the hull to move the gearboxes in by 9mm, plus the JS2 sprockets aren't fitting snugly to the drive shaft, the only solution is to cut 5mm from the end of the drive shaft and then move the gearboxes inboard by 4.5mm.

So that's today's job. Talk about one step forward and three steps back! All down to insufficient research, checking, and preparation so lesson learned.

Alwyn

[Raminator]

Before you get too carried away, are you able to get shorter shafts for those gearboxes? From what I've seen, there are two types of gearboxes; with ~23 and ~33 millimetre drive shafts. Since those are such nice-looking units, you might be able to find the shorter axles and swap them in. It might save you some headaches cutting and machining the existing ones to fit.

[AlwynTurner]

Thanks Raminator, I've already done the deed, but I needed to shorten the shaft anyway as the sprocket wasn't sitting properly on the shaft. I've done all the moves and it now is sitting perfectly - pics to follow.

Alwyn

[c.rainford73]

Thanks Raminator, I've already done the deed, but I needed to shorten the shaft anyway as the sprocket wasn't sitting properly on the shaft. I've done all the moves and it now is sitting perfectly - pics to follow.

Alwyn

Somehow I'm not surprised that you've already fixed the issue so quickly

[wyvern]

Interesting build - I have thought about doing the same myself and even have the same blueprint printed to 1:16 scale! Your progress so far looks good, I just had a couple of questions. The first is are you going to scratch build the upper hull and turret or buy tamiya parts ? The second question is are you going to use tamiya is-2 tracks or the heng long ones as my guess is that the tamiya IS-2 sprockets won't mesh with the HL tracks.

I'll be staying tuned in and good luck.

Guy

[AlwynTurner]

Thanks for the interest Guy, I am going to scratch build the upper hull and hopefully 3d print the turret, I don't have the budget to buy Tamiya parts. I have a set of HL KV1 tracks which seem to fit the JS2 sprockets that I was given, but I'm not sure where they came from. This whole build is a voyage of discovery so we'll see where it leads!

Alwyn