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.

Lessons learned

- Use support bars under clamper rails and cut out ALL the floor.
--Or use a servo to raise clampers - but how to lift all 8 clamps.

-Move Positioner farther away from Dumper and leave 1 car un-dumped - could not push it in correctly anyway. Dump the last car by pulling string of cars though from other end with a locomotive and stopping in the dumper.

-Positioner top rails act as a brake since the bottom rails are rolling the wheels.

Coal Load: 3/4 cup to fill 1 car
Perlite weighs 18 grams per 1/4 cup :54g = 1.9oz
Walnut shells weigh 22 grams per 1/4 cup :66g = 2.3 oz
Plastic aquarium gravel weigh 42 grams per 1/4 cup :too heavy
Sand weighs 78 grams per 1/4 cup :too heavy

Even after soaking in paint wash Perlite seems to break very easily.. too dusty?
Still crunching walnuts i bought at grocery store to get the shells.
10 grams = 0.351 oz
1 oz = 28.47 g

Rotary Dumper Rotates

The Rotary Dumper with all covers removed. Flapper switches were used to signal when to reverse direction and stop the servo. (rather than photo diodes as planned) Step one: Rotate the Dumper can be viewed. How can i be so happy about something so cruddy looking ? The Brake is too simple to show, so the Positioner will be the next adventure ... actually the Brake will be part of the Positioner. It will move a car into position and Brake it- hold it in position.

Rotary Dumper

The major parts are assembled here. On the right; under the track, is the servo and gear to drive the 12 tooth Tamiya (metric 48) pinion gears i replaced the little red ones from the kit with. The dumper has a hole cut in the bottom with reinforcement styrene added to guide the coal towards it. A light has been placed inside the back bottom edge of the dumper to illuminate a photo resistor. There is a servo under the left side track to hold the car axle in place. On the far back left is the car positioner. It is a styrene box with 2 pieces of track (1 above the other) to hold a 2 wheelset cart that supports a metal rail which holds the servo that drives the little cart and another servo (not on the cart yet) which will raise-lower an arm to push the cars into position. The box itself is 8x24 inches and designed to 'drop' into a hole in a 'standard' 2x8' module. A photo resistor will be placed on the side of the dumper to sense the start and end points of rotation. Another photo resistor will be placed under the track to sense the end of the train. (actually the last car will not be dumped ... keep reading) Switch(es) will be used to turn on/off the controller, 'reset' the servos into starting positions, and whatever ends up being needed. Another servo might be placed across from the positioner at the end of the next car to add a last little push, as the cart pusher can only push to the edge of the dumper and the car needs to be about half an inch inside the dumper so the coupler will be at the correct place for rotation. Gee, it was easy to make it rotate, when i scratch build the wood chip dumper it will be a non-rotary coupler, shove it into the middle of the dumper with a locomotive operation.

HO train projects

The following are several of the HO train projects i am working on.
RC Helicopters on flatbeds that take off. You've seen the copters, i am sure. This is a simple : add sideboards to a flatcar project. The sideboards actually help the helicopter take off without spinning in circles. The first one I did was from an 89' with a shack from a crane helper on the back, but changed things all around since then. That flat now carries a SD90 shell.

This is a picture of several missile launchers using servos to lift the tube. You can see the several versions on my You-tube channel: http://www.youtube.com/user/HOtrainHobby
The servos glitch, which is why i changed from using the auto carrier and now have servo modules that go inside 86' boxcars. The roof was raised by 2 servos in tandem and the tube was raised by a retract servo. When the retract servo glitched with the roof down it would bend the raising arm. Now the servos raise the tube and the tube pushes the roof open. The roof closes using a piece of elastic string. Next i will make a flatcar to launch the red missile sans tube.


A 72' wood chip Bethgon with tub floors (Freightcar America) i bashed from some Coalgons. This and its follow on cars will be used with a rotary dumper i will scratchbuild... someday. One of the Coalgons i broke fixing something i glued together wrong. Being careful with the second, you will notice (well, its actually not visible here) i still managed to glue the brake wheel to one end and the cylinder to the other. Since 'kits' are not made anymore, it will be a while before i 'break' any other Coalgons and feel no loss at bashing them into something else. This car is almost ready for the 'paint shop' as AAR type J314 class GT Plate F is used by 'International Paper Corporation' with the reporting marks FPBX of 'old' acquired Federal Paper Board company, not BNSF. The cover is similar to one i saw on woodchip cars, seems a lot better than having to crawl across the load to place netting over the chips to keep them from flying off and away.













The (Walthers) Rotary dumper i am working on. It will use Bethgon Coalgons. The rotary couplers are made by Paul Mack and the command-control will use Parallax controllers with servos and light sensors similar to Wayne Roderick's . Similar yet different, this dumper will have a horizontally adjacent train positioner to move the cars into position. The positioning will be critical as there is no room for error with the couplers connected. Subtle adjustment to the position will be made with an under car 'brake'. The coal will probably be the 'dyed in the wool walnut shells' as other bits i have tried are too heavy ( gravel, aquarium gravel, aquarium? plastic beads, etc). Now to find the shells and try them... Cabela's size is 1/32", too small to be coal... Meanwhile i will be transporting transparent coal that will fall through the bottomless pit into the invisible conveyor.

First day

Today i started this blog to display my efforts in the hobby of HO trains. Current projects include Minuteman missle launcher cars, a Rotary Dumper for Coal gondolas, a conversion of 2 Coalporters into 1 Wood Chip Bethgon. Pictures to be posted next day.