Subject:
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Re: Shay Chassis (Uni Joint Mods for Trains)
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Newsgroups:
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lugnet.technic, lugnet.trains
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Date:
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Tue, 11 May 2004 18:48:04 GMT
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Viewed:
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384 times
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In lugnet.technic, Rob Hendrix wrote:
> > I had it working at a pulley ratio of 1:4 last night - about realistic Shay
> > speed at 9V with the 12:20 bevel ratio. I'll have to synchronise it so that a
> > 9V train motor on 1st notch moves the same speed as the Shay at the same
> > voltage. That probably means gearing up the Shay to motor speed for a 43362
> > motor.
>
>
> I'd like to see a mod (still trying to come up with it myself too), to
> eliminate the need for the train motor altogether. That would work great
> one your Shay. I wonder if we can get someone to manufacture metal wheels
> the same size as train wheels with a technic axle hole in the middle? Let's
> start a new thread and see where it goes!
>
> -Rob
I experimented with using paper fasteners as pickups with the 12V railway a few
years ago. I wrapped each one round a toggle joint and rested it on the
conductor rails. This would probably be a bad idea for 9V track as scratching
it would wear it out.
I think metal wheels or flanges are a job for Big Ben Bricks!
The 9V motor wheel flanges are quite soft to the touch - softer metal than the
track. Coating a couple of BBB wheels in conductive paint might work, but
they'd melt if you applied molten metal. I saw single motor wheels advertised
on Bricklink, but we really need the pickup wheels to also be the driving
wheels.
You could do worse than using a 3482 wheel hub with tin-foil stuck on it and a
contact resting on the top! That's no worse than using sellotape as an
insulator between 9V track pieces to create isolating sections - it actually
avoids a mod! However, we're getting too close to the problems railway
modellers have with pickups and tolerances on metal parts.
If you have a broken 12V train motor you could suspend the copper pickups
between the two BBB wheels on each Shay bogie, since the 12V motor pickups were
designed for that. Cut a 26cm or longer 9V wire in half, separate the two wires
for 5cm to give 6 studs spread at the wire ends, bare 1/4" of the wire ends and
solder the two wires to two copper pickups. Then suspend them cunningly in the
right places. Do the same with the other half of the wire at the other end of
the engine, connect both wires to the motor(s) and voila! redundant pickups on a
Shay!
I say motor(s) because you'll probably need two, due to the reduced torque per
motor at low speed and the fact that a lot of our 9V locos have two train
motors, due to the power required. Ideally the Shay would move at a similar
speed to a train motor at a given voltage, and would normally operate on 1st
notch on a 9V controller (20mph or so).
Another problem is traction though. The 9V train motor has rubber tyres and BBB
wheels don't. You could apply a rubber coating of some kind as long as you can
do it evenly (whilst rotating the wheel?) and without damaging the plastic. I
wonder if bicycle puncture repair rubber solution would work? Does anyone know
if it would damage the plastic?
Phew! that's a lot of fairly random ideas for mods with non-Lego contributions!
Do them at your own risk!
Meanwhile, the third bogie for the Shay will be more difficult due to the
smaller space available for the transmission parts between the 2nd and 3rd
bogies. I think there's less flexing of the uni joints though - maybe a piece
of pneumatic tube would do the flexing?
Mark
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Message has 2 Replies:
 | | Re: Shay Chassis (Uni Joint Mods for Trains)
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| (...) the (...) advertised (...) Maybe a plaster mold could be made to pour liquid metal into. I was actually thinking someone with a milling machine could step in for the challenge of producing a metal one. (...) and a (...) actually (...) I have a (...) (21 years ago, 11-May-04, to lugnet.technic, lugnet.trains)
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Message is in Reply To:
| | Re: Shay Chassis (Uni Joint Mods for Trains)
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| (...) Shay (...) that a (...) 43362 (...) I'd like to see a mod (still trying to come up with it myself too), to eliminate the need for the train motor altogether. That would work great one your Shay. I wonder if we can get someone to manufacture (...) (21 years ago, 10-May-04, to lugnet.technic, lugnet.trains)
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