This page last updated: December 21, 2012 as of Jan 2017
rotary dumper positioner
- Building the positioner
- Assemble : Must have a moving arm range of 8" to move a coal car, 9"+ for a pulpwood, 10"+ for an aluminum bottom pulpwood car.
Left front is one the moves the rail and the servo on a truck along the rails.
Left back is the beginning of the one that will be used - as it takes up a LOT less room : the servo and metal box moves along the rail rather than moving the rail.
The picture on the right is the positioner and dumper. Note the height difference between the 72' and the mini gons... after it was determined they will be used with pulp dumpers the additional height will be added to them. ...
rotary dumper positioner How To:
- Follow the VEX directions, then determine where it needs to go and glue and screw and connect wires... small wooden blocks were used to raise the positioner off the surface and to enable moving the contact switches.
- The Paper mill dumper will dump cars of different lengths so it has movable switch contacts on the positioner... Different per train NOT mixed together on one shipment... that would be too complicated to bother to solve :) Unit trains rule ! As of 2017 there will be two dumper-positioners as it gets to close tolerance to reliably use two different touch sensor sets. So there are 3 Vex positioners and 1 or 2 positioners made from renovated printer rails.
- There will be a remote electronic Kadee uncoupler beneath the rails .. at some point in time. ... or better yet is to use MTH locomotives that have working couplers!
- There will probably be another positioner at the front of the dumper to move the cars Into the dumper .. until the Exit positioner can grab the cars... this other positioner will determine where the electric uncoupler is. As of 2017 there will be one at the exit and the locomotive pulss and dumps the first car then hooks up to the positioner and self uncouples.
- Rotary Dumper Paper-plant... has information on building a dumper and positioner - the latest as of 2017 - when the need for another dumper-positioner was realized.
- Paul Mack modifies Kadee couplers to make them rotary. He is building a positioner that has pulleys w/wires that move the platform .. much more prototypical. Have not found good small ~1" pulleys that would be mountable and stand the stress that I imagine there would be. Bicycle brake-deraileur wires would probably be bendable enough and strong enough. or use belts and pulleys along a 8mm rail from multiple sellers. uhm except they are cylinders and what keeps it from rotating... i dunno
- The positioner is controlled by the Arduino controlling the dumper. It is a simple program that does one thing at a time : Move something untill a switch is closed and then move something else until a switch is closed... etc.
- The limits of the servos : contact point with the coupler and how far to raise to clear the cars when moving past them -( where it grabs the coupler and is raised to clear the car are determined using contact switches that are closed by the moving positioner)- Which way (greater or less than 1500) turns the servo to move the dumper and positionerin a direction are determined using a HPP-21.
Copyright © 1991..2017 by Ivan Lee Herring