Can anyone here help me with a problem I have with a 1980's bump n go robot,
the bump n go is purely mechanical and I don't have a very good mechanical
mind so I am not quite sure how this works, I have spent an hour searching
the net but have had no luck finding any info on how this mechanism works or
what to do if it has a problem. Anyhow the problem is that the robot mostly
spins on the spot, I presume it is suppose to go straight until it hits an
obstacle. I can see how everything else works but can't figure out how it
achieves the bump n go. So if someone could either point me in the right
direction or help me out directly it would be much appreciated. I would
really like to find a webpage that describes how this works.

Don't know the specific design...but-there should be a spring loaded
contact ring around the base or a set of inertia switches internally
that momentarily reverse one of the drive motors on impact. However it
is configured, the offending device is stuck 'ON'. Perhaps a broken
spring, or the unit was dropped and an inertia switch is stuck. Or, no
fault with the sensing circuits; one of the drive motors is dead, thus
it only spins.
JR

trigon wrote:

Can anyone here help me with a problem I have with a 1980's bump n go robot,
the bump n go is purely mechanical and I don't have a very good mechanical
mind so I am not quite sure how this works, I have spent an hour searching
the net but have had no luck finding any info on how this mechanism works or
what to do if it has a problem. Anyhow the problem is that the robot mostly
spins on the spot, I presume it is suppose to go straight until it hits an
obstacle. I can see how everything else works but can't figure out how it
achieves the bump n go. So if someone could either point me in the right
direction or help me out directly it would be much appreciated. I would
really like to find a webpage that describes how this works.




--
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Home Page: http://www.seanet.com/~jasonrnorth
I

"trigon" fsdfsd@dsdsffds wrote in message ...
Can anyone here help me with a problem I have with a 1980's bump n go
robot,
the bump n go is purely mechanical and I don't have a very good mechanical
mind so I am not quite sure how this works, I have spent an hour searching
the net but have had no luck finding any info on how this mechanism works
or
what to do if it has a problem. Anyhow the problem is that the robot
mostly
spins on the spot, I presume it is suppose to go straight until it hits an
obstacle. I can see how everything else works but can't figure out how it
achieves the bump n go. So if someone could either point me in the right
direction or help me out directly it would be much appreciated. I would
really like to find a webpage that describes how this works.


To clarify, I am talking about a very simple toy robot, not really a robot
at all but a toy that looks like a robot, there are no fancy electronics,
just a dc motor, lights and wires, everything else is done by mechanics.
Here is a link that shows the toy I am talking about
http://members.aol.com/robotoys/botoy.html

Thanks, the toy i am talking about is even simpler than that, I have
described it further in a reply to my original post. There are no
electronics involved in the bump and go mechanism. Sorry I did not describe
this as a toy in my original post.


"JR North" wrote in message
.. .
Don't know the specific design...but-there should be a spring loaded
contact ring around the base or a set of inertia switches internally
that momentarily reverse one of the drive motors on impact. However it
is configured, the offending device is stuck 'ON'. Perhaps a broken
spring, or the unit was dropped and an inertia switch is stuck. Or, no
fault with the sensing circuits; one of the drive motors is dead, thus
it only spins.
JR

trigon wrote:

Can anyone here help me with a problem I have with a 1980's bump n go
robot,
the bump n go is purely mechanical and I don't have a very good
mechanical
mind so I am not quite sure how this works, I have spent an hour
searching
the net but have had no luck finding any info on how this mechanism
works or
what to do if it has a problem. Anyhow the problem is that the robot
mostly
spins on the spot, I presume it is suppose to go straight until it hits
an
obstacle. I can see how everything else works but can't figure out how
it
achieves the bump n go. So if someone could either point me in the right
direction or help me out directly it would be much appreciated. I would
really like to find a webpage that describes how this works.




--
--------------------------------------------------------------
Home Page: http://www.seanet.com/~jasonrnorth
I

trigon wrote:
Thanks, the toy i am talking about is even simpler than that, I have
described it further in a reply to my original post. There are no
electronics involved in the bump and go mechanism. Sorry I did not describe
this as a toy in my original post.


These kind of toys usually have a simple mechanism driven by a single
motor, it`s not easy to describe tho. Usually, a vertical motor drives a
pair of wheels in a free turning cage. It`s a kind of differential -
imagine the solid back axle of an old car with the prop shaft vertical.

The whole toy balances on these wheels, stabilised by a couple of
protrusions on the underside of the toy. Because of the design of the
bottom of the toy, when there`s little resistance, the robot moves
forwards, but if it is stopped by an obstacle, the resistance on the
wheels causes the the cage to be spun by the motor, thus steering the
toy in a different direction - Imagine how a dodgem (bumper) car works
except the steering wheel is turned by the motor when the driving wheels
are obstructed.

So, I think the chances are either one of the wheels is loose on it`s
shaft, or the cage is somehow jammed. Maybe you can post a link to a
photograph of the underside?

Ron(UK) (Old Toy Collector)

"Ron(UK)" wrote in message
...
trigon wrote:
Thanks, the toy i am talking about is even simpler than that, I have
described it further in a reply to my original post. There are no
electronics involved in the bump and go mechanism. Sorry I did not
describe
this as a toy in my original post.


These kind of toys usually have a simple mechanism driven by a single
motor, it`s not easy to describe tho. Usually, a vertical motor drives a
pair of wheels in a free turning cage. It`s a kind of differential -
imagine the solid back axle of an old car with the prop shaft vertical.

The whole toy balances on these wheels, stabilised by a couple of
protrusions on the underside of the toy. Because of the design of the
bottom of the toy, when there`s little resistance, the robot moves
forwards, but if it is stopped by an obstacle, the resistance on the
wheels causes the the cage to be spun by the motor, thus steering the
toy in a different direction - Imagine how a dodgem (bumper) car works
except the steering wheel is turned by the motor when the driving wheels
are obstructed.

So, I think the chances are either one of the wheels is loose on it`s
shaft, or the cage is somehow jammed. Maybe you can post a link to a
photograph of the underside?

Ron(UK) (Old Toy Collector)


Thanks a lot Ron, that's how I thought it worked but still cannot quite
understand how it accomplishes this but it seems that there is too much
resistance on the wheels most of the time so it ends up spinning when it
shouldn't, I can get it to go forward and back a little but then it seems to
get stuck in a spinning motion even though there is no obstacle, I thought
it might be the joins in the wooden floor but it does the same thing on a
smooth table. Anyhow thanks for your confirmation on how it works, this
makes me confident that i least understand that part right. I will post a
reply when I get time to take it apart and look at it, hopefully it is not
just wear and tear that cannot be fixed, the rest of the mechanical
mechanism is in very good order, I have another of these robots and it seems
to have the same problem so it looks like wear and tear, which maybe a bad
thing for me.

"Ron(UK)" wrote in message
...
trigon wrote:
Thanks, the toy i am talking about is even simpler than that, I have
described it further in a reply to my original post. There are no
electronics involved in the bump and go mechanism. Sorry I did not
describe
this as a toy in my original post.


These kind of toys usually have a simple mechanism driven by a single
motor, it`s not easy to describe tho. Usually, a vertical motor drives a
pair of wheels in a free turning cage. It`s a kind of differential -
imagine the solid back axle of an old car with the prop shaft vertical.

The whole toy balances on these wheels, stabilised by a couple of
protrusions on the underside of the toy. Because of the design of the
bottom of the toy, when there`s little resistance, the robot moves
forwards, but if it is stopped by an obstacle, the resistance on the
wheels causes the the cage to be spun by the motor, thus steering the
toy in a different direction - Imagine how a dodgem (bumper) car works
except the steering wheel is turned by the motor when the driving wheels
are obstructed.

So, I think the chances are either one of the wheels is loose on it`s
shaft, or the cage is somehow jammed. Maybe you can post a link to a
photograph of the underside?

Ron(UK) (Old Toy Collector)


Thanks for your help Ron, your advice gave me the confidence that i at
least knew what I should be expecting from the robot, it turns out the
weight and balance of the robot is very important to it's operation, it
seemed a stretch that this would be the case but i tried putting the front
of the robot casing and arms on and now it works fine, obviously the weight
of these extra parts is important, I had not put them back on because I
still had more electrical work to do on it so exactly how this bump n go
mechanism works is still a mystery to me, I have seen it referred to as a
mystery action, now i know why, kind of cool that it remains a mystery
really.