Need speed switch for DIY funicular/hillside elevator

My dad and I built a homemade hill lift (in Europe refered to as
funiculars) in Eastern Tennessee. You can see a working demonstration
and picture of it at:

http://www.funimag.com/photoblog/ind...elf-funicular/

The tram works fine, but I am trying to figure out some kind of simple
safety mechanism in the event that the spools break loose from the
gearbox or shaft and start rotating freely. Since my wife and kids
ride this thing, I'd like some kind of backup solution in the event of
major catastrophe. We are using 2 cables instead of one even though
one can handle 5 times the max load, and we have a braking motor to
stop, but both of those would be moot if the spool spins out of
control.

I am thinking of having some way of measuring the outfeed speed of the
cable (or spool) and have some emergency brake apply if a limit is
exceeded.

Any suggestions? I thought about putting fan blades at end shaft of
the spool to have air slow it down, but that would be a little
unsightly. I'm looking for a simple solution, one preferably without a
computer since this is outdoors and needs to be functional 100% of the
time. I'll take any flames in stride on this point. I realize that
this group is about computer automation, but its the only one similar
to this kind of project I could find :-)

Thanks in advance.
Jeff

Since there is always tension on the cable, regardless if the car is going
up or down, can you fix a spring loaded brake to the car that is held off by
the tension of the cable?.

Doug

--

<astutesolutions@earthlink.net> wrote in message
news:1162061065.466027.213040@b28g2000cwb.googlegr oups.com...
> My dad and I built a homemade hill lift (in Europe refered to as
> funiculars) in Eastern Tennessee. You can see a working demonstration
> and picture of it at:
>
> http://www.funimag.com/photoblog/ind...elf-funicular/
>
> The tram works fine, but I am trying to figure out some kind of simple
> safety mechanism in the event that the spools break loose from the
> gearbox or shaft and start rotating freely. Since my wife and kids
> ride this thing, I'd like some kind of backup solution in the event of
> major catastrophe. We are using 2 cables instead of one even though
> one can handle 5 times the max load, and we have a braking motor to
> stop, but both of those would be moot if the spool spins out of
> control.
>
> I am thinking of having some way of measuring the outfeed speed of the
> cable (or spool) and have some emergency brake apply if a limit is
> exceeded.
>
> Any suggestions? I thought about putting fan blades at end shaft of
> the spool to have air slow it down, but that would be a little
> unsightly. I'm looking for a simple solution, one preferably without a
> computer since this is outdoors and needs to be functional 100% of the
> time. I'll take any flames in stride on this point. I realize that
> this group is about computer automation, but its the only one similar
> to this kind of project I could find :-)
>
> Thanks in advance.
> Jeff
>

astutesolutions@earthlink.net wrote:
> My dad and I built a homemade hill lift (in Europe refered to as
> funiculars) in Eastern Tennessee. You can see a working demonstration
> and picture of it at:
>
> http://www.funimag.com/photoblog/ind...elf-funicular/
>
> The tram works fine, but I am trying to figure out some kind of simple
> safety mechanism in the event that the spools break loose from the
> gearbox or shaft and start rotating freely. Since my wife and kids
> ride this thing, I'd like some kind of backup solution in the event of
> major catastrophe. We are using 2 cables instead of one even though
> one can handle 5 times the max load, and we have a braking motor to
> stop, but both of those would be moot if the spool spins out of
> control.
>
> I am thinking of having some way of measuring the outfeed speed of the
> cable (or spool) and have some emergency brake apply if a limit is
> exceeded.
>
> Any suggestions? I thought about putting fan blades at end shaft of
> the spool to have air slow it down, but that would be a little
> unsightly. I'm looking for a simple solution, one preferably without a
> computer since this is outdoors and needs to be functional 100% of the
> time. I'll take any flames in stride on this point. I realize that
> this group is about computer automation, but its the only one similar
> to this kind of project I could find :-)
>
> Thanks in advance.
> Jeff
>


I like Doug's idea of the automatic brake. I also think you should put
solid sides on it to keep people from "dangling their legs" through the
railing like I observed in one of the movies. I also think you should
employ some sort of gate, permanently mount the controller and
incorporate a safety switch that would prevent the device from moving
with the gate open.

> I like Doug's idea of the automatic brake. I also think you should put
> solid sides on it to keep people from "dangling their legs" through the
> railing like I observed in one of the movies. I also think you should
> employ some sort of gate, permanently mount the controller and
> incorporate a safety switch that would prevent the device from moving
> with the gate open.

Yes, all good points.

Solid sides, yes. The vid was from the weekend we first got it done.
I plan on finishing it with side pickets such as a deck. I also need
to put the rail back up on the deck with a gate so we can keep small
kiddies or dogs from falling off. I can put a limit switch to prevent
it from running when open on the main deck, but don't really have a
good solution for that on the cart since it is wireless. I think it
will eventually be more of an education thing. The legs dangling
although not prefered was actually not too worrisome at that point
since the front of the cart is 4 feet off the ground. But eventually
the sides would prevent that.

As to the slack, I was originally thinking of something like that, but
with the cable being so heavy, there is actually much slack midway down
in the cable when it is descending, and there will be even more once I
increase the speed of it (variable speed controller). That would work
well in the event of the cable snapped, but that is pretty unlikely
having 2 wires snap at the same time.

In the event of a free spool, there are 2 places I could slow it down.
Either up top at the spool with some kind of cable grapple, or on the
cart assuming a I had a fixed cable running from top to bottom that the
cart straddled and ran through some eyebolt/pulley scenario.

The trick is, how to determine when it is going fast. I almost need
some kind of centrigal device on the cart or at the spool that cuts a
cord or triggers something when it gets going too fast. I don't have
to worry about a a false alarm start surge because the motor controller
ramps up the speed when starting.

Thanks!

If I understand correctly, you want something that will automatically
activate if the spool starts turning too fast.

Could you adapt this idea?

http://www.msha.gov/S&HINFO/TECHRPT/HOIST/PAPER5.HTM

astutesolutions@earthlink.net wrote:

>My dad and I built a homemade hill lift (in Europe refered to as
>funiculars) in Eastern Tennessee. You can see a working demonstration
>and picture of it at:
>
>http://www.funimag.com/photoblog/ind...elf-funicular/
>
>The tram works fine, but I am trying to figure out some kind of simple
>safety mechanism in the event that the spools break loose from the
>gearbox or shaft and start rotating freely. Since my wife and kids
>ride this thing, I'd like some kind of backup solution in the event of
>major catastrophe. We are using 2 cables instead of one even though
>one can handle 5 times the max load, and we have a braking motor to
>stop, but both of those would be moot if the spool spins out of
>control.
>
>I am thinking of having some way of measuring the outfeed speed of the
>cable (or spool) and have some emergency brake apply if a limit is
>exceeded.
>
>Any suggestions? I thought about putting fan blades at end shaft of
>the spool to have air slow it down, but that would be a little
>unsightly. I'm looking for a simple solution, one preferably without a
>computer since this is outdoors and needs to be functional 100% of the
>time. I'll take any flames in stride on this point. I realize that
>this group is about computer automation, but its the only one similar
>to this kind of project I could find :-)
>
>Thanks in advance.
>Jeff


http://www.davehouston.net
http://tech.groups.yahoo.com/group/roZetta/
roZetta-subscribe@yahoogroups.com

Dave Houston wrote:
> If I understand correctly, you want something that will automatically
> activate if the spool starts turning too fast.
>
> Could you adapt this idea?
>
> http://www.msha.gov/S&HINFO/TECHRPT/HOIST/PAPER5.HTM
>
> astutesolutions@earthlink.net wrote:
>

Dave, yes, that is helpful. It demonstrates many techniques I can use.
Althoug I'm still limited as to how to build a similar system myself,
it should give me some more terms to google to see if there is an off
the shelf solution I may be able to adapt.

I especially liked the rope brake discussions. Although their solution
used compressed air, I could use some kind of spring powered mechanism
(on cart) to clamp down on a fixed cable that runs from top to bottom.
I'm still at a loss though as to how to easily trigger it on the speed,
although obviously a simple solution may be out of my reach.

Thanks for the link!
Jeff

Look here also for other general ideas...

http://en.wikipedia.org/wiki/Dynamometer

One possibility would be a small air compressor that would be driven by the
spool shaft with a discharge to the atmosphere through a fixed orifice. At
slow speed there would be little resistance but as the speed increases the
resistance increases, slowing the spool. You want to be sure that everything
is sized to be safe - you don't want the compressor or any associated pipes
to burst. You might even let the discharge drive a whistle to warm anyone
nearby.

astutesolutions@earthlink.net wrote:

>
>Dave Houston wrote:
>> If I understand correctly, you want something that will automatically
>> activate if the spool starts turning too fast.
>>
>> Could you adapt this idea?
>>
>> http://www.msha.gov/S&HINFO/TECHRPT/HOIST/PAPER5.HTM
>>
>> astutesolutions@earthlink.net wrote:
>>
>
>Dave, yes, that is helpful. It demonstrates many techniques I can use.
> Althoug I'm still limited as to how to build a similar system myself,
>it should give me some more terms to google to see if there is an off
>the shelf solution I may be able to adapt.
>
>I especially liked the rope brake discussions. Although their solution
>used compressed air, I could use some kind of spring powered mechanism
>(on cart) to clamp down on a fixed cable that runs from top to bottom.
>I'm still at a loss though as to how to easily trigger it on the speed,
>although obviously a simple solution may be out of my reach.
>
>Thanks for the link!
>Jeff


http://www.davehouston.net
http://tech.groups.yahoo.com/group/roZetta/
roZetta-subscribe@yahoogroups.com

Dave Houston wrote:
> Look here also for other general ideas...
>
> http://en.wikipedia.org/wiki/Dynamometer
>
> One possibility would be a small air compressor that would be driven by the
> spool shaft with a discharge to the atmosphere through a fixed orifice. At
> slow speed there would be little resistance but as the speed increases the
> resistance increases, slowing the spool. You want to be sure that everything
> is sized to be safe - you don't want the compressor or any associated pipes
> to burst. You might even let the discharge drive a whistle to warm anyone
> nearby.

Yes, something like that could work.

At the end of the drums is part of the 1.25" diamater shaft that
sticks out. I could increase the torque on it by using 2 different
gears (large one on shaft, smaller on compressor) connected with a
chain to increase the rotational speed.

When going downhill, even if it was in resistance mode, the motor would
overpower the slowdown, but in a freespool situation it could slow it
down as desired.

It would be nice if it was able to only apply torque in one direction
like a bicycle wheel. I wouldn't want it to torque on the trip up, but
just on the trip down. I suppose I could use a bicycle setup for
exactly that purpose, but I think my dad would scoff at the
non-industrial sizing of it, lol.

<astutesolutions@earthlink.net> wrote in message news:1162061065.466027.213040@b28g2000cwb.googlegr oups.com...
> My dad and I built a homemade hill lift (in Europe refered to as
> funiculars) in Eastern Tennessee. You can see a working demonstration
> and picture of it at:
>
> http://www.funimag.com/photoblog/ind...elf-funicular/
>
> The tram works fine, but I am trying to figure out some kind of simple
> safety mechanism in the event that the spools break loose from the
> gearbox or shaft and start rotating freely. Since my wife and kids
> ride this thing, I'd like some kind of backup solution in the event of
> major catastrophe. We are using 2 cables instead of one even though
> one can handle 5 times the max load, and we have a braking motor to
> stop, but both of those would be moot if the spool spins out of
> control.
>
> I am thinking of having some way of measuring the outfeed speed of the
> cable (or spool) and have some emergency brake apply if a limit is
> exceeded.
>
> Any suggestions? I thought about putting fan blades at end shaft of
> the spool to have air slow it down, but that would be a little
> unsightly. I'm looking for a simple solution, one preferably without a
> computer since this is outdoors and needs to be functional 100% of the
> time. I'll take any flames in stride on this point. I realize that
> this group is about computer automation, but its the only one similar
> to this kind of project I could find :-)

A centrifugal brake should do the job. Ideally, the brake engages as the drum starts spinning fast. As the brake slows the drum, it
eases up a bit, allowing a safe descent. ISTR they used something like this on the tram at a ski lodge in NH.

--

Regards,
Robert L Bass

=============================>
Bass Home Electronics
941-866-1100
4883 Fallcrest Circle
Sarasota · Florida · 34233
http://www.bassburglaralarms.com
=============================>

Hello,

Don't know if this has been suggested but here goes.

In your desire to keep this a simple system to control a loss of cable or
drum think about this.

Since it appears that your tram is straight on an incline you could affix a
single cable between the rails from end to end. This would be under your
tram. On the tram bottom have it pass thru a spring loaded clamp apparatus
that would have a pivot lever with a protrusion thru the floor. This
protrusion would have a foot pedal mounted on top. The operation would be
that a passenger would just stand on the pedal which would release the clamp
on the cable thus allowing the tram to move. If a disaster should happen it
would a matter of lifting your foot and the clamp would stop the tram.

Also your drive motor would or should have either a slip clutch or a
overload trip to protect the rest of the system. With all in place you
could use it to help stop and hold at the other positions you have
indicated.

In some applications it is called a Dead Mans Stick or Switch. Such as on a
train or trolley.

It may not work exactly as described above but it may start the seeds to
grow.

Good luck and great job.

Les



<astutesolutions@earthlink.net> wrote in message
news:1162061065.466027.213040@b28g2000cwb.googlegr oups.com...
> My dad and I built a homemade hill lift (in Europe refered to as
> funiculars) in Eastern Tennessee. You can see a working demonstration
> and picture of it at:
>
> http://www.funimag.com/photoblog/ind...elf-funicular/
>
> The tram works fine, but I am trying to figure out some kind of simple
> safety mechanism in the event that the spools break loose from the
> gearbox or shaft and start rotating freely. Since my wife and kids
> ride this thing, I'd like some kind of backup solution in the event of
> major catastrophe. We are using 2 cables instead of one even though
> one can handle 5 times the max load, and we have a braking motor to
> stop, but both of those would be moot if the spool spins out of
> control.
>
> I am thinking of having some way of measuring the outfeed speed of the
> cable (or spool) and have some emergency brake apply if a limit is
> exceeded.
>
> Any suggestions? I thought about putting fan blades at end shaft of
> the spool to have air slow it down, but that would be a little
> unsightly. I'm looking for a simple solution, one preferably without a
> computer since this is outdoors and needs to be functional 100% of the
> time. I'll take any flames in stride on this point. I realize that
> this group is about computer automation, but its the only one similar
> to this kind of project I could find :-)
>
> Thanks in advance.
> Jeff
>