Vosper MTB 1/72
Boats
Tamiya Vosper MTB 1/72 kit
Converted to radio control
The model runs on two small electric motors driving short prop shafts via silicone tubing used as a universal joint. Two electronic speed controllers supplies each motor.
Upgrades - the model floats quite low in the water when at rest but looks quite realistic when running, the weight of the batteries needs to be reduced, when I converted this model a Sub C nicad was 1200mAh at 50 grams, now you can get a NiMH AA size cell with a capacity of 1500mAh at 25 grams.
So my next job is to make a new battery pack and then make a new speed controller to control both motors rather than the two large ones that are in it at the moment. I have decided to use a cheap six cell spring loaded battery holder, but I will solder the power leads to the terminals rather than use the clips provided.
The exiting battery pack (5 x Sub C cells) weights 250g, the new NiMH (6 x AA - 2100mAh) weights 180g.
It can also be removed through the top hatch which was not possible with the old pack.
It can also be removed through the top hatch which was not possible with the old pack.
Showing the inside of the hull with the upper deck removed, the deck screws on (see white brackets either side of hull, these are under the torpedoes) and is sealed with a silicone gasket. Notice the motor, silicone tube universal joint and prop shafts.
This is all the old electronics removed from the hull, receiver is in the middle, two speed controllers either side and a small 5v regulator at the back right.
I have completed the update on the electronics, as you can see below. The receiver is the same but I have fitted a small dual motor speed controller. Also added some boyancy in the form of polystrene block at the front and back. The battery has been swopped for a small 7.4v Li-Po which is even lighter than the NiMH's I was going to use (120g).
When the deck is fitted you only have access to the battery which sits much lower in the hull and makes the model even more stable.
July 2018 : I have removed the 27Mhz receiver and replaced it with a 2.4Ghz FrSky unit.
May 2024: After replacing the LiPo battery and taking these videos the motors are starting to burn out and need replacing.