Subject:
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Re: motors for the handy board
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Mon, 4 Nov 1996 20:34:02 GMT
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Original-From:
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rabbit <G-WEBB@STUDENTS.UIUCavoidspam.EDU>
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Viewed:
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1619 times
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On Mon, 4 Nov 1996, Scott Sherman wrote:
> Handy Board Users:
>
> I took the LEGO Super Car (#8880) and scrapped everything but the four
> wheel drive with the differentials, the front and rear wheel steering,
> ...
This is exactly what I wanted to do! Had I only the cash...
> could drive each one. As you might guess, there is not enough torque to
> drive the wheels - even when the axle is geared down 4 times over using
> LEGO 8 tooth and 24 tooth gears and the vehicle is held off the ground.
> And even if it did drive the wheels they probably wouldn't go that fast.
Are you driving each wheel with a separate motor or driving the
front wheels with one 9v motor and the rear with another?
> I want to get a different type of motor that would be able to drive the
> vehicle but am not sure what I should get or where I could get it at.
I have been fooling around with them since I was young. While legos are
marvelous building materials they nevertheless suffer in the tradeoff
between ease of use and strength. I started to make wheeled lego base
for my handyboard which was simply one motor geared down to drive the
wheels and one geared down to steer the front wheels. I had suspension
for front and back wheels. The performance was not impressive; either
the steering mechanism was not powerfull enough or the drive motor could
not move the car at any reasonable speed.
Additionally, with a handyboard strapped on the back there was
considerable strain on the legos which only superglue would have helped.
In your case not only do you have to move a greater mass (that super car
is pretty big), but you have the additional friction of those universal
joints which allow you to have both steering and suspension.
Adding bigger motors to your model will put more strain on the
legos which may require more structural strength than legos have. What I
advise is this; rebuild the car from the ground up taking only what is
necessary (the steering and suspension). Make it smaller and simpler.
When you get bigger motors try to get ones which already have gear
reduction on them. Lego gear reduction takes up tons of space and adds
quite a bit of friction (reducing the benifits of gearing down!). If you
cant any motors with gear reduction I would use either the lego reduction
boxes (if you dont know that I mean let me know), or use lots of worm
gears. Use some sort of spray lubricant which will dry (teflon?) on the
gears and axels. I woulnt use anything petroleum based.
What I ended up doing is abondoning the whole suspension thing and
using treads. One motor for each tread. That move solved steering and
locomotion since there are two motors working together for both
operations. Its not as cool as 4x4 type car with suspension but it
worked with so little fuss and let me get on with what I really wanted to
do.
Currently I am trying to build a robot to compete in something
called "Wastelands II" which is sponsered by the University of Illinois,
and I think I am going to totally abandon legos for this. Legos are good
for getting working designs but I dont think my poor lego bot would last
2 minutes in the ring with the other robots, or survive a 2 foot fall
should it be knocked off the platform. On that note, does anyone have
any treaded RC vehicles they would recomend? Pickings at radio shack and
toys-R-us are slim and I am thinking about getting used parts from a
hobby store. Any suggestions?
Garth Webb
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Message is in Reply To:
 | | motors for the handy board
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| Handy Board Users: I took the LEGO Super Car (#8880) and scrapped everything but the four wheel drive with the differentials, the front and rear wheel steering, and the suspension. Then I shortened the frame sllightly so that the distance between (...) (28 years ago, 4-Nov-96, to lugnet.robotics.handyboard)
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