Heng Long Panzer III detracking issue

[quitcherbitchen]

So I have had two HL Panzer IIIs and of course they suffer from the same issue. Both had metal tracks and idlers/sprockets. My early version from 2015 didnt have adjustable idlers, so I added aftermarket Mato. It would still detrack occasionally. The newer H version from 2023 has the HL version of the track tensioner/plastic. It will detract every time I use the tank on the left side only. My older L version with the Mato adjuster same side. I have carefully looked at all the fittings and fitment and have tried to take out much of the play as I could to ease the situation without any effect on the detracking. The only observation I can see is that the Idler is out of alignment with the rest of the drive train. It has a noticeable angle that looks impossible to remove without modify the arm or the side of the tank. I thought the side flexed but it doesn’t. Any ideas or advice? image widget

[DavidN]

The last wheel before the idler is what guide the track teeth into the idler. If that wheel is loose, your tank will de-track. You need to tighten that wheel almost to the point that its arm becomes unmovable.

[quitcherbitchen]

I'll give that a try

[quitcherbitchen]

Found the problem. Small crack allows the idler to shift left and detrack

[MrChef]

Interesting. I've heard of the Pz III/Stug III having de-tracking issues. I haven't had that pleasure yet for either my Stug or PZ III though. I wonder if I'm just lucky or my install of the Taigen idler adjusters on both made a difference? H'mmm...

[quitcherbitchen]

So I replaced the stock adjusters with the Taigen. Still no joy. I noticed it will detrack immediately no mater the tension on the tracks. Always the same left side will detrack. I tried shimming the idler arm out to make it more inline and even filed the metal idler wheel so that there are no sharp edges where the track guides go in. I looked at the real Stug rear idler that theAustralia armor museum refurbished and noticed it had a very large bevel in the track guide that these heng long metal idler wheels dont have. I didnt want to modify too much so I just cleaned it up with a metal file The whole issue does have a lot to do with rocks getting in between the tracks and the wheels/idler. The fact that the right side will only detrack once in a while Vs the left side which is immediate has me baffled. The wall flex is almost nil. The only thing I can see is that the wheels especially the one closest to the idler that has a shock on it is very loose at the bearing. Mine you these are the stock plastic wheels and swing arms. Also I have read on RC Tank warfare that the shock stiffness is important, but both sides the shock stiffness is the same as I checked. I think I am going to attempt to sleeve the swing arms with brass tubing to get some slop out of the wheels or just buy the metal wheel set. The brass tube is cheap and will give that a try first. I might also limit the swing arm travel for the wheel with the shock.