Rotary dumper completed...

Rotary Coupler in action. Old Accurail dummy coupler turning a rotary coupler made by Paul Mack
Positioner arm grabbing the coupler.
Parallax BOE controller, currently changed to a hardwired Anderson Homebrew board.
Overview of the Rotary dumper, Positioner, gate servo, brake servo, controller board and all the wires. Have added an IR remote controller, a gate servo, lights, hardwired a Reset button to the BN control gondola, and Frere Jacques plays when the train has been emptied. All 16 pins are used and there are 3 bits of Ram and 2 Bytes of EEProm left. Someday i will move the controller board and all the dangling wires underneath the track area in front of the dumper... See it all in action on a U-tube video.

Rotary Dumper Christmas

The Rotary Dumper is installed in the module and somewhat decorated. The tracks are aligned and a rerailer is installed after the dumper to catch the wheels that fall off the track when they are turned upside down. The positioner seems to be working precisely, although there is a pause in movement - the servo wires apparently are very strong, and do not turn with the positioner all the time. A few grains of coal still manage to find places to cling - big chunks that do not fall through small cracks.
Summary:
The positioner is working precisely, there are still slight problems with de-railing and couplers uncoupling. Need to install a secondary rerailer and spray powdered graphite on things.

Have a Merry Christmas and a Happy New Year !

Rebuild Version 3

The positioner push bar is changed to a coupler grabber - semi-prototypical AFAIK, no push bars are used... they would smash real train cars :) The dumper pit bottom is cut out more and the ramps are now supported with metal rods. Hopefully this will alleviate 'coal' residue building up on the edges, rather than falling into the pit.

Getting the grabber to actually work is a problem, as there seems to be a wide variance in what the servos actually do : sometimes the 'brake' lifts the car into the air and other times it does not rise far enough to correctly position the car. This (and the positioner seeming to stop at different positions) affects where the car(s) are and thus the coupler grabber sometimes misses that thin divide between the coupler and the box support behind it. Hitting the coupler - rather than its attaching rod, or the box support causes the servo to grind and not actually 'grab', thus when the car is moved it stops in a wide range of positions :(

i dunno, might end up going back to the push bar - it seemed to be doing ok after changing the code to jiggle the car after stopping. ... but the coupler grabber sure looks a lot more interesting and realistic.

will keep trying to adjust things, however, being this finicky leads to a lack of repeatability - having to adjust things (for hours?) every time a train is dumped does not seem practical.

Rebuilding and updates

Apparently NS also has Woodchip hoppers similar to FPBX, although they are filed under a different type-class. Type E707 Class GTS Plate F. Only the NS Plate F are similar. Longer than 61' but dunno if they are 72'.

Reworked the module and the drop-in dumper. Added 2 tracks in the module back area so a locomotive can go around-behind the dumper, and a box the trains would go through and the electronics and wires can sit on.. on the way to camoflage the wires and make it look industrial-ish.

After viewing videos of dumpers and positioners it seems the positioners are on the empty side of the dumper. Many things i do not know at all :) Real Coal looks a lot smaller than what i use. o well i like to see the lumps and do not want little grains getting into the works. Someday i will check out what Walnut shell gun cleaner actually looks like.

In the meantime i will be soldering parts onto a Homebrew protoboard to make a permanent controller and not worry that parts get joggled into a short circuit.

One Step Forward Two Steps Back

After editing the PBasic code so the positioner moves the cars forward - stops at the end limit- moves back a little slowly - then moves forward again slowly to the limit: the cars seem to get positioned correctly : the brake catches the axle. Other than that all seems to work ok ... the Perlite coal works ok .. it gets caught on any available ledge, so i guess i need to remove any ledges, huh. It piles up at the back edge of the hole, but not enought to go over the back edge i made... but that is after only 3 cars... Time will tell if it piles too high... once i get it running i will leave the 'trash' a while to see if it collects too high.

Rotary Dumper dumps 3 empty cars

The module is built and assembled. The dumper works for a unit train.. 4 cars long :) Next is to load the coal : paint-dyed Perlite and hope it does not get too messy. As usual the video is on my channel. The cars sometimes get uncoupled and or derailed while dumping. With all the gates open the cars roll though the dumper ok and I put in different dummy couplers. The problem is the cars are NOT positioned correctly : the result seems to be the derailments and uncoupling.

The rotary dumper works.

Still a little buggy : need to change out the dummy couplers to some that have a tighter grip. Sand down the exit ramp a little and glue some more sandpaper onto the far end of the positioner run. Actually the next step will be to build a 2'x8' module that the 8"x2' dumper can be placed into. This will allow a longer run of cars and will 'finalize' the entry - exit problems ... and any others that crop up once the dumper is actually 'fixed' into a suitable location. Decorating-landscaping-painting all will be done after the dumper is functional in the module. The video is on my U-Tube channel. Enjoy it, i do.