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| Type: |
T-34-85 |
Armament: |
85mm |
| Built: |
January 2004 |
Armor: |
90mm |
| Builder: |
Pat McCarthy |
Rating: |
40/4 |
| Status: |
Under Construction |
Battles: |
0 |
| Owner: |
Pat McCarthy |
Points Earned: |
0 |
| Call Sign: |
??? |
Points Given: |
0 |
| Notes: |
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Homemade wooden drive cogs and tracks Drill motor and V-belt drive system Drill motor trigger speed control
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Click Photo For Enlargement (140 Kb) |
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These are the drill motors that power
the tank are arranged in an over-under
configuration.
The drill motors are 14.4 Volt Dewalts model 991 and a
1/2" ID pulley fits the shaft that the chuck screws into.
The 1/2" pulley also has an allen set screw to help hold it on
the chuck shaft. The drive shaft of the tank is 1/2" all
thread and the 1/2" pulley fits the drive shaft also.
You need to file a flat spot on the drive shaft to keep
the pulley from turning on the shaft.
The rear axle is in two pieces
(although it looks like a single piece) sharing
a bearing block in the middle of the tank.
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Click Photo For Enlargement (110 Kb) |
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The track system is built using a treadmill belt sandwiched
between an inner and outer wooden tread. Although the are only
secured with glue, they are quite sturdy. The inner tread has
a single center tooth which, when combined with the slotted
wheels, keeps the track in line.
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Click Photo For Enlargement (145 Kb) |
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A closeup of the track shows that a little bit
of cleanup work is in order, but everything lines
up nicely and seems to work.
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The drive cog (gear) is a 12-pointed star
that was made by chance and common horse
sense. The points mesh with the gaps between
the track treads and it works quite well despite
the fact that not all of the treads are
installed.
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Click Photo For Enlargement (118 Kb) |
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Click Photo For Enlargement (145 Kb) |
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The speed control consists two drill motor triggers that
are actuated by two servos.
The 1/4 scale servos could be just a tad of overkill but they
were fairly cheap. The servos are so strong that they need
their own power supply, so the servos are supplying the power
for the receiver now. You only need one servo doing this the
other one runs off the other ones power.
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A closeup of the motor mount shows a simple clamp made
with a piece of flat bar and some bolts.
I'm running the Dewalts on the number 2 setting and
they seem to have plenty of power.
The Dewalt literature says that the 14.4 volt motors
can pull higher voltages and should be good for models
up to 60 pounds.
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Click Photo For Enlargement (92 Kb) |
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Click Photo For Enlargement (117 Kb) |
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Some temporary (hopefully) wiring is installed to
get the radio and motors working. Four D-cells
run the receiver and speed control servos, while
a relatively small gell-cel runs the motors.
During it's initial field test, everything held together,
although the drive belts needed to be tightened.
It ran to the end of my drive way and back without a problem.
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