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?
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.
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.
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?
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.
RE: Fun one trolley.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Fun one trolley.
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.
RE: Fun one trolley.
I'd love to use a VFD as the power control. That would be sweet. 5 or 6hp on single phase. Erk!
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.
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.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Fun one trolley.
Or look up electric trains for examples. Although I don't know of any one who has used electric and cog at the same time.
RE: Fun one trolley.
RE: Fun one trolley.
I usually don't recommend this site, but now and then they do a little explaining.
RE: Fun one trolley.
A generator may not be as bad as you think for this project.
RE: Fun one trolley.
RE: Fun one trolley.
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.
RE: Fun one trolley.
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.
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".
Just so you all know - it's a wine cellar..
Keith Cress
kcress - http://www.flaminsystems.com
RE: Fun one trolley.
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.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Fun one trolley.
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.
"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.
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.
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.
Love it! Totally true too. Absolutely. Of course it depends on what your definition of when "start" is.
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.
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