Witness the birth of a new monster...the IS-4

[Herr Dr. Professor]

Am I correct that the IS-4 is an unusually wide tank in proportion to its length? The electronics seem to confirm that I am correctly seeing it as just so. And on the workbench I see a familiar detail sander and soldering equipment, but is that a home-made belt sander?

[tankme]

Am I correct that the IS-4 is an unusually wide tank in proportion to its length? The electronics seem to confirm that I am correctly seeing it as just so. And on the workbench I see a familiar detail sander and soldering equipment, but is that a home-made belt sander?

It is a pretty wide tank, but not as wide as say an IS-7. It's dimensions are about on par with an IS-3 as they were developed around the same time. Tracks are wider than a KV-1. The belt sander was a spur of the moment purchase from AliExpress I think. I've used it a ton and has a standard 775 motor on it so if that motor ever dies I can just buy a replacement. It's nice and small to have on the desk. It has an external power supply that is variable, but I rarely need to slow it down.

Mine is very similar to this one minus the reverse switch which I'm not sure why you would need that.

https://www.aliexpress.us/item/32568101 ... in_prod%3A

[Herr Dr. Professor]

Thank you, tankme: I have that one bookmarked now.

[tankme]

Been a little while since the last update, but more progress has been made. The provided straps for the unditching log were rather basic so I used some of my fabrication skills to fashion some new mounts out of some left over brass and aluminum can for the straps. See, I don't have to 3D print everything. The log is just some 5/8" dowel rod I picked up at Walmart one night. I also decided that I didn't like the solid tow shackle holder and made a new one out of brass.




Then I did print some tow cable ends and added some steel cable to make my own tow cables. I used some more of that brass sheet and some square styrene bar to fabricate the tow cable tie down points on the front and rear of the tank. Each one is held to the tank with a small brass bolt. I also added the mounting angle iron on the front fenders that would be used to locate the stove/heater thing that I'm not going to mount there. Didn't really care for how it looked and the part wasn't that detailed regardless.




The tow cable mounts wouldn't be complete without the guide pins and holders fabricated out of brass rod and some spring steel rod leftovers.



On the rear end, I added some resin printed tools, resin printed smoke dischargers and mocked up the location of the resin printed supplemental fuel tanks. The first pic shows the lack of detail on the parts that came with the STL files for the tank and the second pic has the more detailed resin pieces depicted.





I had heard of quality issues with these plastic Heng Long PDSGB type gearboxes, but my Kranvagn gearbox was running great so I bought a few more. I also figured they were so cheap at $60 when I bought them that I would take a chance. I bought like 4 of them so I figured that I could keep at least two of the running with parts from the other ones. All was going well until I got the main wiring done. I fired up the tank for a test drive and the gearbox was acting weird and making some strange noises when I tried to turn the tank. I ripped the gearbox out and found that the first stage of the reduction was missing teeth in one spot and the teeth in an another area were worn down.

gear marked pic.png (1.61 MiB) Viewed 86 times

At this point, I wanted to QC what was in the other plastic gearboxes. Upon opening the 3rd plastic gearbox I found that the second stage gear in that gearbox was actually the completely wrong gear from the HL factory. The bore was oversized so it wobbled on the shaft and it was supposed to be a double gear. Instead it was a single gear with a smooth hub. Before even installing it I found out that it would never turn the tank. A metal replacement gear for that one has been found, but not at an economical price so the search continues to get that one running. I doubt I can log a complaint to Toucan as I've had these gearboxes for a very long time before using them. Since I had a metal version of this gearbox in my stash, I opened it up and stole the first gear reduction out of it and installed it in the plastic gearbox. I did this because I found a replacement gear on AliExpress and ordered enough of them to replace all the plastic first stage gears in all my gearboxes and a few extras just in case.



Anyway, after replacing the failed first stage gear with a metal one, the tank ran great. I'm still waiting for the metal first stage gears to arrive, but they should be here in time to install in my other projects. The gears I found for the first stage are these in case anyone else has had a failure of that stage on one of these plastic HL gearboxes:

https://www.aliexpress.us/item/32568085 ... pt=glo2usa

first stage gear.png (1.14 MiB) Viewed 86 times

That's all for now...

[tankme]

In case anyone is wondering why I didn't just put the metal version in the tank...it's kinda heavy for the suspension. I didn't really want to push the 3D printed torsion bars or have to add another set of larger ones to the rear to support the weight of the metal version. Plus I have heavier tanks I wanted to use the metal gearbox in. Anyway, just an FYI on that.

[Stormbringer]

The detailing is coming along really well mate

[Panzermechaniker]

A good adversary for my Conqueror

[ColemanCollector]

All of that brass, steel and plastic detailing is impressive. Really makes it come to life with all of the tiny bits and pieces. Dang!

Mike.

[tankme]

It is pretty amazing to me though that there is very little in the way of pics and information about the IS-4 even though they produced like 250 of them. There is only like 2 or 3 IS-4 tanks still in existence today which makes it a pretty rare tank.