Modifications

These are some modifications to try on your tanks that hopefully improve the performance or enhance the appearance.

Suspension Play Elimination

To reduce the play in the torsion bar suspension system some people have used hot melt glue to attach the torsion bars to the chassis mount. The bars are glued while the tank is supported on a stand so that the suspension arms are in their lowest position. This modification makes the suspension stiffer & quieter. Also, it slightly raises the ride height of the model.

Another option is to install shims. Here is what Steve Malikoff has to say about his shim installation. I've been putting together my KT today, and while only on step (3) of the instructions I have made what I consider to be the following improvements. I was a little disappointed at the large slop in the suspension arms once they had been assembled. They had almost 8mm travel at the shaft before the torsion plate started to touch. I wanted to reduce this so I cut some 20mm x 5mm strips from an aluminum soft drink can. Anyway, I folded these pieces in the middle, bent out the outer 2mm or so, and placed one at the fixed end of the torsion spring and a similar one in the suspension arm groove. The slop was now 1mm, almost completely eliminated! I also cut a 5mm strip of Teflon gas tape, 0.1mm thick, to wrap around the suspension arms where they mate against the inside of the cast brackets. This tape is similar to the standard PTFE pipe tape except that it is a lot thicker and can be cut easily with a pair of sharp scissors. It can be obtained at most hardware stores. Anyway, the result is that the suspension arm is nice and firm, pivots beautifully with no binding or scratching and does not have that nasty rattling noise.

Finally, some have suggested replacing the stock torsion springs all together with either new flat spring steel plates or even music wire with the ends bent into hooks. I know Small Parts Inc. carries spring steel in 1/4" wide strips in various thicknesses from 0.005 to 0.032. It comes in lengths up to 24".

Dual Motor Conversions

I am going to expand on this in the dual motors section.

Realistic Antenna

I essentially took a 1/16" diameter brass rod and soldered a small spring (about 3/4" long w/ a 1/16" I.D.) to one end. Then, I soldered a short piece (approx. 1" long) of 1/16" brass rod to the other end of the spring while leaving a small gap between the two rods. You need to be careful during this step since it is very easy to solder the entire spring to it's self. Next, I drilled a 1/16" diameter hole through the actual antenna location on the tank (it is located just behind the KT Henschel turret on the right side). Finally, you insert the antenna through this hole and attach your receiver antenna to the inside. Note: it may be a good idea to remove a portion of your receiver antenna equal to the length of the new antenna piece. I would just test it first before cutting it to see how it works.

Speed Reduction

This modification will provide for more realistic speeds and better climbing ability. I have outlined a few different methods to do this in the gear reduction section. Note: The August issue of R/C Car Action after reviewing the KT and the new Sherman stated that the KT could not climb hills as well as the direct drive Sherman due to the clutch slipping. I am curious to see how my KT's clutch holds up after this modification. I am sure that it will be able to climb steeper hills, but will the clutch hold?

Sprocket Hub Set Screw

The set screw that holds the drive sprocket on to the drive shaft on my KT seemed to be a little on the short side. This screw travels almost entirely through the brass hub before seating on the shaft because the shaft's milled flat is half of it's own diameter. This does not provide much support because only the last few threads of the screw are in the hub. Therefore, I got a hold of some set screws that were about 5mm long and after completely tightening them they end up about flush with the outside of the hub and not the inside. This setup is stronger and the new screws don’t work free as easy as the shorter ones. Note: loctite is a must here even though the manual does not say it.

Gear Box Shims

The gearbox in the new Tamiya KT comes preassembled from the factory. However, depending on how the gearbox in your model was assembled, it may require a little bit of help. Mine appeared to be loose on one side and tight as hell on the other. Therefore, I purchased a set of 4mm shims for R/C car axles and went to work. I completely disassembled the box and reassembled it with the shims and it makes for a much better setup. The bevel gears mesh much better and the play has been eliminated.

Dirt Shields

If you have ran your model in loose dirt you already know how much dirt fills up the inside of it. This includes all over the open gearbox as well. Therefore, I created dirt shields for my Tamiya KT that run the entire length of the chassis. They are super glued to the top flange of the the chassis and fit snuggly against the body when it is attached. Also, I added small triangular pieces over the openings by the idler wheels. All of these shields were made out of lexan plastic and were attached with super glue. I have completed a drawing that shows the dimensions I used. I made a template out of cardboard first to check the fit. You may have to slightly rework the small notches a couple of times so that the shields do not catch on the body bolts.

Chris Walker had another way of keeping out the dirt. Basically, instead of installing horizontal dirt shields, he installed vertical ones. It looks like they will work great. Here is what he had to say:
I added additional hull plates to the sides of the lower hull which bring them up flush with the lower side of the deck plate. These were made from double wall plastic board (a house for sale sign) and attached with double sided tape. Next, the joint between the metal hull and plastic add-ons was hot glued to stop dirt & water penetrating into the sticky tape. Then, I added a divider in the lower hull that separates the motor/gearboxes from the main hull compartment to stop the grease from the gears being thrown back into the rest of the hull. Finally, I added fine net curtains to the undersides of the radiator and fan vents as sand & dry dirt would come up through the track side & then fall down in the inner hull side, as my extended hull sides pass along the middle of the radiator grills. The net was blacked out to reduce its visibility from above.

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