And the downside of model tanks

[Meter Rat]

Maintenance time on “Ya Bastard”. How come so much sand and grass can get so trapped in the drive line? Grease, new drive sprockets, replace transmission support bearings, lubricantion, and clean out the return idlers. Looking for some reasonably priced gear boxes and motors. Priced up red motors from Motion eu. Postage costs more than the motors.

[Meter Rat]

[cmdrcody]

Some gnarly vegetation you got there in Scotland.

[Sappo]

Ah yes the joys of tanks, one hours running and three hours cleaning. You oughta try running them in mud. But in saying that I don't know why but the challenger seems to be the most maintenance heavy tank I own

[Meter Rat]

Ah yes the joys of tanks, one hours running and three hours cleaning. You oughta try running them in mud. But in saying that I don't know why but the challenger seems to be the most maintenance heavy tank I own

I totally agree, regarding maintenance on the Challenger.
This is turning out to be more than maintenance. A full strip down is on the cards. Seized bearings and bolts, seized on wheels. All comes from running on a wet sandy beach.

[Sappo]

Oh hell, and that's why I don't run in salty conditions. Fresh water is bad enough

[Meter Rat]

Spent the morning pulling off and stripping each wheel, to assess the bearings and to clean out the vegetation. . Maintenance/rebuild on hold until I can accurately measure the size of the wheel bearings. Ordered a new vernier calliper as mine got damaged when we moved house. Also I have to workout how to repair the track adjuster, and a bodge I did, which has turned out to be more permanent than expected. All work is on hold for the time being.

[Meter Rat]

More work carried out on Ya Bastard. All wheels removed, taken apart, bearings inspected, and cleaned of debris.

Some neat little vegetation donuts.

Bearings not to bad. I need to replace 5, at £1.37 each. Happy, as I was expecting to need to replace more.
Suspension, stripped, cleaned, and starting to be rebuilt. I have one broken suspension arm, and a seized track adjuster to deal with.

[Meter Rat]

Part 2.
Took the Challenger into work, as replacement fixing and bearings have arrived.
I had to cut off one of the idler wheels at the front as the thread had stripped, so it had been fixed in with JB weld, and wouldn’t budge for love nor money.


The head of the fixing bolt was worn so needed drilling off to allow the track adjustment to be removed.



The track adjustment then required drilling out, with the drill preferring to take the path of least resistance. Of course I forgot to photograph this.

Next, I removed the seized track adjustment bolt. These are going to be replaced with 4mm stainless steel bolts. Need to work out properly how to do this, although I have an idea.



And lastly a start was made on a frame to install some rigidity following removal of the battery compartment. New red motors have been ordered from Ali express, so probably some Chineseum copies.


Regards Ian.

[Sappo]

I didn't completely remove the battery box, just cut one end out and changed how the leads lie in the hull. And I replaced the idler adjustment screws with stainless as well. To be honest I'm tempted to sell mine, went to use it the other day, started running and then stopped, wasn't the battery or controller for some reason it just died. I'm hoping the real thing isn't so finicky

[Meter Rat]

Part 3.

Sized bolts were either drilled out or cut off.



Then the seized track adjusters were removed and new 4mm stainless nuts were installed using some bodgery skills, along with stainless cap head bolts.




Next the idlers we’re installed also using 4mm stainless nuts and bolts.



Finally a frame was made out of 25mm x 25mm aluminium angle. This was bonded, bolted into place. Also installed were new red motors. This is turning into a test mule now.



The tracks were refitted, however there was a problem. They were too short. At first I thought it may have been due to an increase in diameter of the drive sprockets, but when measured against the old one they were the same size. Originally I had removed two links from the track to get the correct tension. I now had to add two links back in and they are still tight. I can only think that there was so much flex in the hull, that it was bending before it took up the slack in the track before the correct tension was put on them. Now with the frame fitted the hull is more rigid so the tracks became too short.
A couple of test runs have been carried out, on the bare hull, which have given me the confidence to refit the upper hull. Going out to do a comparison test with the unmodified Abrams.

[Meter Rat]

I think I may have sorted my running problems. Although I now have a noisy gearbox, but I think that is down to me, and my incompetence. This is my solution and my thoughts on why it was consistently shedding tracks. Mine runs metal tracks, road wheels, idlers and sprockets with guides. It also had drive shaft support bearings. It is rather a heavy beast. The track was constantly overriding the sprockets. Tension them correctly and if anything came between the track and the sprocket the sprocket would break where it went onto the drive shaft. It was completely stripped down, new wheel bearings were installed, the track tensioners were rebuilt with 4mm stainless nuts and bolts. The idlers were also installed with 4mm stainless nuts and bolts. Stronger springs were installed on the front pair of road wheels, and last two pairs of road wheels. This stops the rear end from squatting and helps to keep the track tension consistent. Finally a frame was made from 25mm x 25mm aluminium which was bonded and bolted to the lower hull. When installing the tracks back on I needed to add two links back in. Previously two links had been removed to get the correct tension.I believe that the chassis was being compressed before the track tension was able to take up the slack. This made the idlers, and sprockets out of alignment. By making it more ridged, the tensioner is better able to do its job properly. I put in new red motors, and over the last couple of weekends I have given it some serious abuse in the garden, which has a steep slippery bank with long grass which it would struggle to climb, and due to the grass it definitely would not turn with out either of the tracks coming off. It now climbs and turns on this bank in a lot more capable fashion. I also took it over the old golf course at the back of us and using a fresh charged battery it covered approximately 1km with out any issues with the tracks. Hope this helps and it is only my experience with mine. I now need to find more speed. This is an ongoing test, but so far the runs it has been given, seem to have worked. The Abrams I was comparing it with shed a track whilst trying to execute a turn on the first hill in the garden. The work carried out on the Challenger will be implemented on my Abrams and T72 for the same reason. All three of these model rip out grass, like nothing else, unlike my Tiger 1, which just seems to float over the long grass. This could be due to the track on the Tiger being plastic which allows the grass to slide through the links, where as the metal tracks seem to grip the grass and rip it out. In the new year I may try plastic tracks on the Challenger.