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Fun one trolley.

Fun one trolley.

Fun one trolley.

(OP)
Here's an odd one. I need to move a 2000 pound (payload) trolley up a 200 foot 17º grade in about 2 minutes. The track is curved.... So I'm thinking DC. Battery powered. Needs about 5 or 6hp.

The batteries are going to add significantly to the 2000lb payload.

I'm looking for any comments or anecdotes on this subject you folks might have.

Your thoughts on hydraulic drive verses gear chain. I need to consider the down slope here too! The hydraulic would provide speed limiting easily.

Motor supplier suggestions? Voltage 24V? 48? 90?

Keith Cress
kcress - http://www.flaminsystems.com

RE: Fun one trolley.

Grade is usually measured in percent (10' rise in 100' horizontal is 10%). So do you actually mean 17 degrees or percent?
Hydraulic systems are not very energy efficient so I don't think that would be a good choice for a high power battery application. To me this sounds like a perfect application for a DC motor. That way you can use regeneration for braking and energy recovery. At 5 hp you probably want to use a standard 180 vdc motor and simply hook enough batteries in series to get your voltage.

RE: Fun one trolley.

(OP)

Quote (Compositepro)

Grade is usually measured in percent (10' rise in 100' horizontal is 10%). So do you actually mean 17 degrees or percent?
Hmmm. Good point. That would be a 31% grade. I was told degrees. I'll confirm that.

Quote (Compositepro)

Hydraulic systems are not very energy efficient so I don't think that would be a good choice for a high power battery application. To me this sounds like a perfect application for a DC motor. That way you can use regeneration for braking and energy recovery.
Efficiency was my first thought too, but then what happens if a fuse blows on the way down? With hydraulics you can be limited by an orifice. Perhaps, an electric brake?

Quote (Compositepro)

At 5 hp you probably want to use a standard 180 vdc motor and simply hook enough batteries in series to get your voltage.
Hadn't thought of 180V.
15 lead acid batteries.. Wow.

I can't think of a good way to feed AC to a curved track. If it was straight, I'd just use some sort of coiled or reeled lead.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Fun one trolley.

The rails to the wheels make a perfectly good power delivery system. Third rail with return through the the running rails is more common. Look at some of the airport trams, they have a three-phase sliding contact rather than a single third rail. No need for batteries.

RE: Fun one trolley.

A DC supply via a third rail, an on-board inverter and standard AC induction motors may work well. Normal braking would be by regeneration with spring applied brakes for parking and in the event that the third rail connection is lost.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Fun one trolley.

Friction of wheel on rail, or wheel and tire on any surface, is not going to get you up that grade. Whether the winch is stationary or mobile, 200 feet of wire rope can be tough to roll up reliably. You could use a funicular, cable with counterweight, but cable is practical only if the lateral curve is very limited.

So, you need a rack railway.

The rack gives you the option of dropping a sprag for emergencies.

You need to wrap something partially around the railhead so the pressure angle of the rack can't separate the rack and the pinion. All the design issues were worked out more than a century ago.

It's time to visit a rack railway, schmooze the staff, and take a lot of pictures.

Bridge cranes use sliding contacts on a partially enclosed conductor bar, typically 3 phases plus ground. I haven't seen it done, but I'd guess the conductor bars could be warped around a gentle curve.
See, e.g., the Insul-8 product on this page:
http://www.conductix.us/en/products/conductor-bar-...



Mike Halloran
Pembroke Pines, FL, USA

RE: Fun one trolley.

For a 200 ft run, using a steel winch cable from the top of the hill does seem the best solution.

RE: Fun one trolley.

(OP)

Quote (davidbeach)

The rails to the wheels make a perfectly good power delivery system. Third rail with return through the the running rails is more common. Look at some of the airport trams, they have a three-phase sliding contact rather than a single third rail. No need for batteries.
I like that idea. This is for a residence so 3ph is not probably an option.

Quote (waross)

A DC supply via a third rail, an on-board inverter and standard AC induction motors may work well. Normal braking would be by regeneration with spring applied brakes for parking and in the event that the third rail connection is lost.
I'd love to use a VFD as the power control. That would be sweet. 5 or 6hp on single phase. Erk!

Quote (MikeHalloran)

Friction of wheel on rail, or wheel and tire on any surface, is not going to get you up that grade. Whether the winch is stationary or mobile, 200 feet of wire rope can be tough to roll up reliably. You could use a funicular, cable with counterweight, but cable is practical only if the lateral curve is very limited.

So, you need a rack railway.

The rack gives you the option of dropping a sprag for emergencies.

You need to wrap something partially around the railhead so the pressure angle of the rack can't separate the rack and the pinion. All the design issues were worked out more than a century ago.

It's time to visit a rack railway, schmooze the staff, and take a lot of pictures.

Bridge cranes use sliding contacts on a partially enclosed conductor bar, typically 3 phases plus ground. I haven't seen it done, but I'd guess the conductor bars could be warped around a gentle curve.
See, e.g., the Insul-8 product on this page:
http://www.conductix.us/en/products/conductor-bar-...
Great info Mike! Thanks for the link too. Yes, a gear rail of some sort will be needed for either 17° or 17%. I'll be talking with them directly later today and I can get more definitive info.

Quote (Compositepro)

For a 200 ft run, using a steel winch cable from the top of the hill does seem the best solution.
I would totally agree. Including a nice counter weight, except for the curve in the path, which pretty much sinks a cable/winch method.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Fun one trolley.

Consider idler pulleys or, if the winch is on-board, hooks between the rails to control the cable on the curves.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Fun one trolley.

The Swiss have electric cog railways. Logging operations in the early 20th century used cable/wench over some pretty adverse terrain, including around curves with track side sheaves to guide the cable. There would also be sheaves between the rails and the occasional overhead hold down sheave. It's all been done before if you can just find the right examples. There were lots of examples of these "inclines" in the Sierra's, all gone now.

RE: Fun one trolley.

Years back a friend of mine bought a futuristic train from an amusement park, a couple engines and about 20 cars. The park had scrapped the track earlier along with the insulated 3 phase crane buss. I was invited to a meeting of how to get this thing going again. Just the electric buss was going to cost about $150K. I told them to just buy a propane generator and put it in the cab. They didn't like it. The project was tabled for a few years and then another friend was tasked with building the track. At a meeting he was told their electrician came up with the idea of putting a generator in the cab. He reminded them that I had come up with that idea 5 years earlier.

A generator may not be as bad as you think for this project.

RE: Fun one trolley.

why don't you just take a trip to san fran and look how the trolleys there do it? Just write it off as a business trip.

RE: Fun one trolley.

That wouldn't be the trolleys, that would be the cable cars. They require a very knowledgable and skilled (not to mention incredibly fit) Grip to get them up and down the hills. Great idea if you want lots of cars on a single rope, making independent stops but far too complex for a single car only stopping at the ends of the line.

Consider a four railed track, a low slung counterweight car riding the inner pair of rails with the payload car riding to outer pair of rails and able to pass over the counterweight car. One rope, balanced for half the projected load, like an elevator tilted over on its side. Remember, an empty elevator cab (traction, not hydraulic) requires power to decend and regenerates when ascending.

RE: Fun one trolley.

What about an overhead feed line as trams use?

RE: Fun one trolley.

Is the grade of the track equal all the way or does it vary as it goes up the hill? Is this curve one direction?

If you answer yes to the above then I'm really liking David's idea of using 4 tracks and a counterweight trolly. Keep the cable connection low and beside the inside track for each trolly and let the inside curve of the track guide the cable around the curve.

RE: Fun one trolley.

(OP)
Great stuff here! The grade is pretty uniform and 17°(31%). Curve is one direction.

I also think I'm not going to have anything to do with it as the lead guy seems to "have it all figured out". spineyes

Just so you all know - it's a wine cellar..

Keith Cress
kcress - http://www.flaminsystems.com

RE: Fun one trolley.

Yeah, let the expert do it.

Jostling the wrong bottle could get ugly.

If you get forced into it anyway, I would amend my earlier suggestion somewhat.
Instead of a cheap rack comprising a pair of angles with sleeves and bolts between them and engaged by a sprocket,
I'd use real gear rack and engage it with a worm pinion. That requires mounting the motor at an odd angle (basically the helix angle), it will drive smoothly enough to not bother the wine. You can probably get away with bending the rack around a gentle curve.



Mike Halloran
Pembroke Pines, FL, USA

RE: Fun one trolley.

(OP)
Nice idea Mike. Done right, would that also provide the safety of not moving without power? A wee bit of drag is added on the worm side?

Keith Cress
kcress - http://www.flaminsystems.com

RE: Fun one trolley.

The helix angle determines whether the worm can be backdriven.
Once worn in, and liberally greased, it probably can, so I'd use a brakemotor.
Ordinary motor bearings won't take the thrust from a worm pinion, so it needs to be mounted on its own set of tapered roller bearings, or radial bearings plus thrust bearings. Then a longish intermediate shaft to get the motor far enough away from the rack to clear the rack.



Mike Halloran
Pembroke Pines, FL, USA

RE: Fun one trolley.

Here's the same requirement with the restrictive word "trolley" removed.

"I need to move a 2000 pound (payload) up a 200 foot 17º grade in about 2 minutes."

What entered my mind is how automobile components are moved through a manufacturing plant
on a link chain drive system driven over head, similar to a "ski lift" for example by a Sumitomo drive.
(As sibeen hinted at in the 20 Nov 13 5:34 post.)

A project started right, is half finished.
Being restricted by the trolley rail system really limits the best method to achieve a necessary result.

This reminds me of the trick question asked in the Marine Corps about what's the most efficient method
to travel over snow? Early answers say, "Snowmobile, Snow Shoes, Skies" etc.
And of course the best answer is helicopter.

Chiming in from the gallery, enjoying the forum.

John

RE: Fun one trolley.

Funny how the ideas keep coming even though you've tried to call it off. :)

I don't think anyone's mentioned a capstan yet. If you want to try the cable, but can't carry the 200' spool along with you (or don't want the stationary winch system) then the capstan can do the job without holding more than (I guess) 10 wraps of the cable on the drum. Both ends of the cable attached at the ends of the circuit to be traveled, and it just feeds on and off the capstan as the trolley goes along.

Also (not very 21st century of me to say this, but) have you considered a briggs & stratton solution? It could be the cheapest option.

STF

RE: Fun one trolley.

(OP)

Quote (MikeHalloran)

The helix angle determines whether the worm can be backdriven.
Once worn in, and liberally greased, it probably can, so I'd use a brakemotor.
Ordinary motor bearings won't take the thrust from a worm pinion, so it needs to be mounted on its own set of tapered roller bearings, or radial bearings plus thrust bearings. Then a longish intermediate shaft to get the motor far enough away from the rack to clear the rack.

Jeez you've given this some good thought with shaft thrust and motor diameters. Neat. I can see this perfectly. I've rebuilt a couple BIG truck winches built around worms.

Quote (dArsonval)

A project started right, is half finished.
Love it! Totally true too. Absolutely. Of course it depends on what your definition of when "start" is.

Quote (SparWeb)

Funny how the ideas keep coming even though you've tried to call it off. :)
Yeah, but we're all still learning and having fun at the same time. Heck, half of what we all do is solve 'thought' problems.


Quote (SparWeb)

I don't think anyone's mentioned a capstan yet. If you want to try the cable, but can't carry the 200' spool along with you (or don't want the stationary winch system) then the capstan can do the job without holding more than (I guess) 10 wraps of the cable on the drum. Both ends of the cable attached at the ends of the circuit to be traveled, and it just feeds on and off the capstan as the trolley goes along.

Also (not very 21st century of me to say this, but) have you considered a briggs & stratton solution? It could be the cheapest option.

Ah, a capstan. Simple. Effective. I actually fleshed out one for a truck winch. It would allow one to 'rig up' quickly to whatever is available and to pull from both directions as needed. It could also be used at a fixed location instead of a winch. Dragging the 'trolley' fixed to the cable somewhere.

As for the B&S I was told "no noise". It makes the most sense. Toss on a silenced propane powered engine and voila!

Keith Cress
kcress - http://www.flaminsystems.com

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