Vantex 1/6 scale M4 Sherman tank, RC, electric power

Well after keeping an eye on these for about two years I finally broke down and bought one. NOT CHEAP! But none of the 1/6 tanks are except maybe the 21st Century Toys M5 Stuart tank if you can find one.

It took about a week to arrive from China and made the journey without any damage. They used FedEx as the carrier.

Upon first opening the crate the tank looks huge! It’s a fiberglass body but still quite heavy. It’s packed well and you’ll need a electric screwdriver to take the crate apart unless you want your arm to fall off from unscrewing it manually.

I bought the version without the radio and servos so I needed a six channel radio & receiver, two 1/4 scale servos for steering and three standard servos for speed control, turret rotation and gun elevation.

It’s a unique setup where one large 24 volt motor, controlled by an electronic speed control, drives a geared transmission. Steering is done by control levers that engage, disengage and reverse the gearing.

There are three lever switches that control the turret rotation and gun elevation and these are controlled by two standard servos. These can be replaced by ESCs and I probably will go that route later, for now I’ll operate it as it was designed.

For the two 1/4 scale steering servos I needed to be able to supply more current than what a normal receiver would provide. The tank has two 12 volt 5 AH batteries, these are for the motors so a power source for the receiver is needed. Since most receivers operate around a 5 volt supply I decided to use a 7.2 volt NiMH 6 cell pack and use regulators to get three separate 5 volt supplies, one for the receiver and  one for each 1/4 scale steering servo. This way the servos can draw the high current they may need and the receiver will have its own dedicated supply. So from the NiMH pack I wired three low dropout regulators and put heat sinks on the two for the steering servos.

I decided to use a separate battery for the servos and receiver rather than tap off the 12 volt batteries to keep the motor supply separated so if it dies down quick from that huge 24 volt drive motor the receiver would not be affected.

Here is the transmission, the sprocket on the left came loose after about an hour of run time. The set screws on the hub were not tightened all the way down. On the right the control arm had play in it that allowed it to move vertically, this allowed the gears to disengage. To fix that I added a collar that prevented the shaft from moving vertically but allowed the horizontal movement for gear shifting.

It’s hard to see but this control horn is secured from moving vertically by a makeshift aluminum collar held in place with a plastic tywrap.

Put a couple of Joes in and ran it around the back.

Click for VIDEO

More to come . . .