I haven't spent a lot of time with this so I'm not certain what the issue is. I thought I'd toss this into the ring to see what happens.

I run, now and again a hybrid ( frankentank? ) KV-1. Mato upper, Asiatam lower with Asiatam road wheels. Mato tracks I believe if I remember correctly I
used Mato's tracks and Mato's sprocket and idler. I used the sprocket as it fit the gearbox shaft; I don't believe I'm using some other sprocket.

The issue is that even in a straight forward run the right hand track will jump the sprocket; not if just when. Even on a hard smooth surface. In reverse
it runs true and never jumps the sprocket even in loose dirt with the track jammed full of dirt- it's clearly not a happy tank but the tracks stay put and
the model toughs it out impressively which is what I was shooting for. I have Mato ( brass) gearboxes with speed reduction to give me power. And that works exactly
as I hoped. Slow crunching power- as long as I don't go out of reverse. In forward after a few feet out it comes.

I think I bench ran this thing with the gearbox running from an external power supply directly and while the sprocket might lose the track momentarily it pops back in;
I think that momentary situation turns permanent while actually running.

The sprockets both appear to run true, I believe the center line of the sprockets are where they should be. I've never modified ( sharpened? ) the sprocket teeth
to see it that has a positive effect.

Just curious if this is a artifact of the KV1's semi dead track ( my Tamiya Pershing rarely does this neither did the first T-34 I ran ) which I keep on the loose side; is there an issue with Mato KV tracks or is it that I need to research this more? Other than this bug the KV-1 is slow, powerful and deliberate just as I intended.



Jerry

Jerry, sorry to change the subject but I've just spent the last 30 minutes reading your webpage. Great stuff. Can I ask what became of the Hester?

thanks
Joel

I haven't worked on it in a while. It runs wonderfully and that's where I left it.

Jerry

If I recall there was an issue with the sprockets and tracks matching. I thought it was resolved though. How long ago did you get them? Although that's not a fact that they are the newest version,

FYI my Tamyia IS2 and Mato tracks don't have this issue. Nor does my PZ4.

Quite possible you have sticking pins that are just tight enough that the track doesn't follow correctly.

Jerry,

I had a stock KV1 and tried to upgrade it using Mato metal tracks and sprockets. I had the same issue. I tried several different tracks and sprockets (working with my local clubbie Phil Phfleuger) and we tried HL, Mato and Tamiya sprockets, but just couldn't get the Mato tracks to work. I eventually put the stock Tamiya plastic tracks/sprockets back on and it works fine. Sorry this is no help, but at least maybe you don't feel like a one-off here.

Jeff

I actually heard of this too surprisingly. I had a customer that was trying to put mato tracks on our sprockets, it turned out he was using the 58mm shaft gearboxes instead of the 48mm and it was making it jump. The stock HL shafts are 58mm, but asiatam and our chassis require a 48mm shaft with our drive wheels. I HIGHLY doubt this is your issue, but the only other issue I can think of is the drive wheels not being perfectly round. Have you tried watching them from the side instead of head on?

The behavior I observe is similar to what I've rarely encountered when the pitch of the sprocket doesn't quite match that of the track/ chain
or the spacing between the sprocket halves is marginally off. It's not enough to be obvious in a no load condition but at heavier demand it causes a problem

I don't yet understand the difference mechanically, dynamically between running forward / reverse - clockwise / counterclockwise but I'm sure there's
a clue there.

I thought of sticky pins but I've run the tracks enough to hopefully rule that out and that wouldn't quite entirely explain the forward/ reverse difference.

I'm going to run the model on my bench to see if I can spot something. I can use a break from my JagdPanther.

I'm not above buying another set of tracks/ sprockets for this model as I really like it. It steers well being slow and as I mentioned the power is great.
I may upgrade it to a Clark unit; I'm using a Dave BU I assembled and it's ok but the functions are not as granular as I'd like.

Jerry

So if you swap the drive wheels from one side to another does it run ok?

When I built my KV-2 a couple years ago there was a lingering issue with track & sprocket mismatching.. it's difficult to say without seeing up close though. Although with Taigen handling everything more or less from one source that seems to have vanished, but many moons ago Heng Long KV tracks would pop off the Asiatam metal sprockets like crazy, unless you also had the Asiatam tracks...