KV-2 de-tracking issue rendering tank undrivable

[TheCoastalGhost]

Hello! I've made a couple first posts in the photo gallery, but the short story here is I'm building a fictional styled KV-2 inspired by the KV-2 (R) inside World of Tanks.







The KV-2 is meant to platoon with my fictional built Sherman X, which I've posted about in the photo gallery.

My problem is, the KV-2 has a severe de-tracking issue at the sprockets. I can't turn the tank on any surface to either direction more than an inch before the tracks walk right off the sprockets. The KV-2 is brand new, freshly painted, and the Pro Edition with metal roadwheels, return rollers, sprockets, and idlers.

I also have a KV-1 with this issue, but that tank is so worn from so much use that I don't know if it's the same problem.

How do I fix this issue permanently? It's highly irritating and makes my brand new Soviet fridge basically undrivable! :(

[RichJohnson]

Make sure your track is tight enough. They are rear drive so the track needs to taut.
make sure that the sprocket is seated on the shaft all the way. If it is not centered and lined up with the road wheels it will throw easily.
I’ve seen a lot of kv1 tanks driven hard and they have not had track issues so your missing something.

[Sappo]

And definitely make sure the last road wheel is tight on the swing arm, mine wasn't and drove me crazy for a while

[TheCoastalGhost]

Make sure your track is tight enough. They are rear drive so the track needs to taut.
make sure that the sprocket is seated on the shaft all the way. If it is not centered and lined up with the road wheels it will throw easily.
I’ve seen a lot of kv1 tanks driven hard and they have not had track issues so your missing something.

I sure must be missing something...I've tightened all the screws and made sure it's centered. From driving it, it just happens when the tank turns and the ground pressure pulls the inside track out to one side. Both my KVs have had this issue since brand new...

If I tighten the track that might fix it but I know it won't be perfect, also, I know these tanks are supposed to have that sloppy track look and most do, so yeah, more proof that I'm missing something.

[TheCoastalGhost]

And definitely make sure the last road wheel is tight on the swing arm, mine wasn't and drove me crazy for a while

Done, and it's got bearings and all that in it too, so it shouldn't move too much but apparently it does enough to let the track walk.

[tank_me]

The only time I've ever seen an issue with the KV track and sprockets is if they are mismatched. Mismatched as in Torro/Taigen/Mato sprocket with HL track or HL track on a Mato/Taigen/Torro sprocket. The Torro/Taigen/Mato sprocket is a slightly different pitch than the HL counterpart. I run my Taigen and Tamiya KV tracks pretty loose and never had a detracking issue, but I don't own a HL version. I would turn the tank over, look down the track path, and make sure all the wheels/sprockets/idlers line up. If you turn it over and the track has a bow in it, then the running gear needs to be adjusted to compensate.

[TheCoastalGhost]

The only time I've ever seen an issue with the KV track and sprockets is if they are mismatched. Mismatched as in Torro/Taigen/Mato sprocket with HL track or HL track on a Mato/Taigen/Torro sprocket. The Torro/Taigen/Mato sprocket is a slightly different pitch than the HL counterpart. I run my Taigen and Tamiya KV tracks pretty loose and never had a detracking issue, but I don't own a HL version. I would turn the tank over, look down the track path, and make sure all the wheels/sprockets/idlers line up. If you turn it over and the track has a bow in it, then the running gear needs to be adjusted to compensate.

Thanks. I might try adjusting the sprockets outwards with washers to see if that helps any.

[Rubicon99]

Thanks. I might try adjusting the sprockets outwards with washers to see if that helps any.

I was going to recommend that approach. I used nylon washer on mine and the problem more less went away. My washer set up actually work similar to having a larger "hub" surface for the sprockets which helps keep them aligned. It does not 100% stop the issues but does make a substantial difference.

[TheCoastalGhost]

I was going to recommend that approach. I used nylon washer on mine and the problem more less went away. My washer set up actually work similar to having a larger "hub" surface for the sprockets which helps keep them aligned. It does not 100% stop the issues but does make a substantial difference.

*sigh* Less results than I'd hoped for. I checked, and confirmed the sprockets are aligned perfectly from the factory without washers. I put washers on and now the track has to bow outwards a tiny bit to travel around the sprockets, which I dislike. And the problem hasn't really gone away. On pavement, it sort of helps, but on rough terrain it hasn't really made a difference. I'm gonna try to post a video to see if I can show you guys what's going on.

[TheCoastalGhost]

https://youtu.be/vNjsxCuU_kk

Here's a link to a short video of what's going on. The left side is a lot worse than the right.

Edit: this is after I put the washers on.

[Sappo]

Okay just watched your video, it's doing the same thing mine was doing before tighten up the last road wheels and swing arm. I forgot to mention I also moved the last set of springs to the higher setting, as for the tracks, as you can see I have quite a bit of slack in mine. I was gonna drop a video of it running but all my batteries are flat courtesy of the grandkids

[TheCoastalGhost]

Okay just watched your video, it's doing the same thing mine was doing before tighten up the last road wheels and swing arm. I forgot to mention I also moved the last set of springs to the higher setting, as for the tracks, as you can see I have quite a bit of slack in mine. I was gonna drop a video of it running but all my batteries are flat courtesy of the grandkids

What all did you tighten? I also prefer the slack-track look. The higher setting of springs is new to me...I'm guessing it's not the same thing as clocking the springs, correct?

[Sappo]

The last swing arms were loose, caused some movement in the road wheels and lead to detracking problems when turning, and yeah I should've said clocking the springs. If you look closely at the second picture you can see the road wheels are forced lower than the others, they're set at the highest tension setting

[TheCoastalGhost]

Ah, okay. Did you have to drill new holes to clock the springs or were there holes pre-drilled? I recall clocking the springs on my KV-1 and having to drill holes. I took a close look at the picture. How is the roadwheel arm able to sit lower than the others? They have stops on them that go into slots in the hull...did you remove the ones on the last two roadwheels?

[TheCoastalGhost]

I took it apart some. The four rear roadwheels are already all clocked to the highest setting, as well as the two in front. Everything is firm and sturdy and doesn't give when I stress it in different directions. Not entirely too sure what's the best fix...I'm gonna try adding another washer to each side but it's making the tracks have to bend to go around the drive sprockets which can't be good...

[sclui56]

I took it apart some. The four rear roadwheels are already all clocked to the highest setting, as well as the two in front. Everything is firm and sturdy and doesn't give when I stress it in different directions. Not entirely too sure what's the best fix...I'm gonna try adding another washer to each side but it's making the tracks have to bend to go around the drive sprockets which can't be good...

I had issue with the suspension on my KV-2 (full metal) when I bought her new in Feb last year, even after clocking the springs, she would squat and dive, springs were simply too soft. I ended up get a set of stiffer springs and that made a world of difference. The tracks continue to be noisy, but I also never experience any de-tracking, whether I run them loose or tight.

[TheCoastalGhost]

I had issue with the suspension on my KV-2 (full metal) when I bought her new in Feb last year, even after clocking the springs, she would squat and dive, springs were simply too soft. I ended up get a set of stiffer springs and that made a world of difference. The tracks continue to be noisy, but I also never experience any de-tracking, whether I run them loose or tight.

Yeah, I'm not entirely sure why it always happens to me but I think I have it fixed now. I had to put a thick washer on the right sprocket and two washers on the left sprocket, and it seems to be solved.

[Durahl]

I don't own a KV so I'm just suggesting into the wind but did you perhaps paint the Tracks / Sprocket with a Paint that a) behaves sticky or b) increased the Sprockets Tooth width / reduced the Tracks hole clearance thus perhaps promoting the track from getting thrown? 🤔

If ANY of that is the case I'd have a look at removing the paint ( at least of the Sprocket Wheel Teeth ) and maybe even consider sanding the cross-section profile of the teeth from a straight Profile to an angled one thus promoting the Teeth from sliding into the holes instead of getting caught on the edge:

⬆️ The blue marked surfaces

Other than that there's probably only the possibility of creating a Track Centering Guide that gets attached in-between the Sprocket Wheels:

⬆️ From my Tamiya 56016 M26 Pershing

[TheCoastalGhost]

I don't own a KV so I'm just suggesting into the wind but did you perhaps paint the Tracks / Sprocket with a Paint that a) behaves sticky or b) increased the Sprockets Tooth width / reduced the Tracks hole clearance thus perhaps promoting the track from getting thrown? 🤔

If ANY of that is the case I'd have a look at removing the paint ( at least of the Sprocket Wheel Teeth ) and maybe even consider sanding the cross-section profile of the teeth from a straight Profile to an angled one thus promoting the Teeth from sliding into the holes instead of getting caught on the edge:

⬆️ The blue marked surfaces

Other than that there's probably only the possibility of creating a Track Centering Guide that gets attached in-between the Sprocket Wheels:

⬆️ From my Tamiya 56016 M26 Pershing

That is a great thought. I did spray paint the tracks and sprockets and the paint likely did cause a lot more friction between the now-painted metal parts vs before painting. It seems to work fine now but I like the idea of sanding down the inside edges of the sprocket teeth like you've shown. I just live in a really sandy environment and I've watched my tanks get worn down to the point of falling apart by the endless combination of heat + sand + friction, so since it looks like it works now I might save the sanding idea for later in case something else goes wrong.