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In lugnet.trains, Ted Andes wrote:
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In lugnet.trains, Reinhard Ben Beneke wrote:
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Hello after a long time!
I played around somewhat with the different train systems.
The result is displayed in this table:
And probably more interesting as a video:
Pulling power of different train
systems at YouTube
Only the step 4 is featured in the video.
Hope you enjoy + Leg Godt!
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Hi Ted,
thanks for your feedback.
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Very interesting experiment with plenty of variables to consider. It has my
mental wheels turning...
It would be interesting to see this done with a
pull type spring scale to measure the force...
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That would in fact have been favourable. My test rig suffered under the effects
of friction in the 3 wheels, which lead the wire. I have tried to minimize this
by using high diameters.
It would also be
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interesting to adjust the mass over the drive wheels to determine the impact
on gaining traction for a specific system (given the coef. of static and
dynamic friction)...
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Definitely. I am convinced, that in the first line the friction coefficient is
not depending (very much) on the weight. The different coefficients I measured
are basically due to different ages and types of rubber / silicon material.
If you look at the table the probably most surprising numbers are those of the
10153 motor without weight in contrast to the extreme weak 10020 engine. The
only explanation for this is the material of the rubber rings around the
driving wheels.
As a sidenote I may mention the 7898 engine, which has highly surprised me! I
had experiences with some 7898 type motors and those have been the lamest I have
ever seen. LEGO had addressed this issue by choosing a softer stickier type of
silicon. And they did this twice. First generation has been horrible. Next was
not very sufficient. But this last version offers fun. The engine still CAN slip
under overload, but pulling force is maximized. Well done LEGO!
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...when Ive met with design engineers at GE Locomotive in the past, they
always said the more weight in their deisel engines the better for pulling
power. I wonder how much that applies to the various LEGO systems?
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This is definitely one of the keys to higher pulling power. In real life you
have steel vs. steel. So your only chance for higher friction force is higher
mass on top. (Or use sand and live with higher wear on rail and wheels).
In Lego you can use higher masses or better rubber-rings. Too much of mass
will of course reduce the life span of your motor, which is not made for that.
Old trains 4.5V and 12V had ribbed rails for higher friction. That in
combination with good rubber and high weight is the reason for their good
results.
...
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Hmmm... That could be a great next experiment - to see how varying mass over
driving wheels can maximize the pulling power of an LEGO system engine....
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Once you reach a mass that the motor wheels do not spin through, you are at the
theoretical limit.
Leg Godt!
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In lugnet.trains, Reinhard Ben Beneke wrote:
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In lugnet.trains, Ted Andes wrote:
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In lugnet.trains, Reinhard Ben Beneke wrote:
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--snip--
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This is definitely one of the keys to higher pulling power. In real life you
have steel vs. steel. So your only chance for higher friction force is higher
mass on top. (Or use sand and live with higher wear on rail and wheels).
In Lego you can use higher masses or better rubber-rings. Too much of mass
will of course reduce the life span of your motor, which is not made for
that.
Old trains 4.5V and 12V had ribbed rails for higher friction. That in
combination with good rubber and high weight is the reason for their good
results.
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--snip--
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Leg Godt!
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Great video, Ben :) I watched it all the way through which is a bit rare for me.
An interesting test would be the new motor with the old ridged tracks (since
they are compatible). You may get really high traction.
Tim
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In lugnet.trains, Reinhard Ben Beneke wrote:
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Definitely. I am convinced, that in the first line the friction coefficient
is not depending (very much) on the weight. The different coefficients I
measured are basically due to different ages and types of rubber / silicon
material.
If you look at the table the probably most surprising numbers are those of
the 10153 motor without weight in contrast to the extreme weak 10020 engine.
The only explanation for this is the material of the rubber rings around
the driving wheels.
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The quality of the rubber is definitely a critical factor for friction, but it
is not the only factor. Ive found with a normal 10020, one motor, pulling a few
Santa Fe coaches, the wheels will spin excessively (especially if you have a
slight grade). So I wasnt encountering stalling so much as spinning. Some coins
in the battery compartment helped the problem. You need enough weight on the
motor to prevent spinning. My heavier locomotives seem to do a better job
pulling. I have some loaded with pennies, others that are built solid. The ones
with too many pennies are definitely too far (though it is fun to hand one to
someone at a show and watch their eyes bug out as they nearly drop it). I think
just building a solid locomotive with plenty of plates is a good target for
weight.
With the move back to battery trains, I dont know why they didnt resurrect the
toothed track. I suppose in an effort to match the 9v track as much as possible.
Benn
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