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Parallax BS2 control of an HO scale rotary dumper and train positioner. — Parallax Forums

Parallax BS2 control of an HO scale rotary dumper and train positioner.

BS2ILHBS2ILH Posts: 9
edited 2010-03-17 12:33 in Robotics
Parallax BS2 control of an HO scale rotary dumper and train positioner.

A locomotive positions a unit train at the gate servo arm. Either a button on the hardwired control box or the IR remote control (from a Sony DVD) is pressed to activate the sequence. The positioner lifts its arm and moves to the rear of a car and lowers the arm to grab the coupler. The gate arm is turned to clear the track and the brake servo arm is lowered. The positioner pushes the train cars forward, the the gate is swung and the brake arm raises to grab the leading car axle. The sequence is repeated and thus 1 car is inside the dumper. The dumper rotates to unload the coal from the car and back to upright. The sequence of moving a car and dumping it is continued until a light detector mounted under the tracks signals that there are no more cars to dump - a car is not over the detector when it is checked prior to the positioner moving another car in the sequence. When the sequence is complete the Siren sounds and 'Frere Jacques' plays thought the piezo speaker.

The servos, switches, buttons, LEDs, light-photo detector were connected to 3-pin servo connections. The speaker and IR detector are mounted on the board. The IR detector has a 3 pin connection for future mounting off the board. Each servo has a 3 pin connector with input, power, and ground. The 3 button inputs are connected to a 3 pin connector with a separate wire for the Vdd power. Ditto with the 3 switches. The 2 LED and a ground wire are on a 3 pin connector. The light-photo detector uses 2 wires of its 3 pins.


An HO scale Walthers rotary dumper kit was used with a Parallax continuos rotation servo. The positioner has a continuos rotation servo as movement and a standard servo for the arm. An old Futaba servo is used for the car brake under the track and a Hitec retract servo is used as the gate servo. The unit train is from Walthers and the Control box gondola is an E&C coalporter kit-bashed leftovers. The track is mostly Atlas and sundry other railroad manufacturers. The rotary couplers were made by Paul Mack. The positioner was built by me.


Other than to model railroaders this project probably has little significance. Portions of the code might be interesting in providing 'squashed' versions of the sound and IR detector used with the Remote control providing use of 10 buttons.

Attachments : the BOE and Homebrew code and photos, circuit schematics pdf, zipped blog of the daily progress during construction, a link to my U-Tube Videos.

http://www.youtube.com/user/HOtrainHobby


well, the photos will have to be redone to a much smaller size as they are all way over 2M... actually not a very big size for a photo these days [noparse]:([/noparse]

Will try to make a schematic in that program... else, will draw one and photo it and then shrink the photo and have it... well, later...

Post Edited (BS2ILH) : 1/4/2010 2:22:57 PM GMT

Comments

  • SRLMSRLM Posts: 5,045
    edited 2010-01-03 19:02
    Interesting project. Your youbube video link didn't work for me, so I assume that this is you: www.youtube.com/watch?v=vb8_sJLmrgY. Fascinating project, and thanks for sharing it.

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  • BS2ILHBS2ILH Posts: 9
    edited 2010-01-04 00:06
    thanks. i dont know how to do the url link thing, i guess.

    that is one of them, the latest with IR control is

    http://www.youtube.com/user/HOtrainHobby#p/a/u/0/6SB-Rjzs1KY

    the channel is http://www.youtube.com/user/HOtrainHobby
  • BS2ILHBS2ILH Posts: 9
    edited 2010-01-04 00:14
    some images as atttachments :
    Overview of the dumper, board, and positioner
    image of the BOE connections
    image of the Homebrew connections

    and my attempt at a schematic ... will post a hand drawn one later.
    800 x 600 - 892K
    800 x 600 - 899K
    800 x 600 - 858K
    2040 x 1540 - 79K
  • James LongJames Long Posts: 1,181
    edited 2010-01-04 00:31
    BS2ILH said...
    Parallax BS2 control of a rotary dumper and train positioner.

    A locomotive positions a unit train at the gate servo arm. Either a button on the hardwired control box or the IR remote control (from a Sony DVD) is pressed to activate the sequence. The positioner lifts its arm and moves to the rear of a car and lowers the arm to grab the coupler. The gate arm is turned to clear the track and the brake servo arm is lowered. The positioner pushes the train cars forward, the the gate is swung and the brake arm raises to grab the leading car axle. The sequence is repeated and thus 1 car is inside the dumper. The dumper rotates to unload the coal from the car and back to upright. The sequence of moving a car and dumping it is continued until a light detector mounted under the tracks signals that there are no more cars to dump - a car is not over the detector when it is checked prior to the positioner moving another car in the sequence. When the sequence is complete the Siren sounds and 'Frere Jacques' plays thought the piezo speaker..

    LOL, when I first saw this post, I was thinking real locomotive application. I worked for a company which did this kind of thing full scale (one of many jobs I have had in the automation and electronics industry). We did intelligent locomotives, and remote control. I always wanted to work on locomotives when I was younger, but I have no desire now to do so. I'm glad I'm not still working on locomotives. It's cold, hot, very dirty work, and is a job with very few kudos for going beyond what is required.

    You did a nice job of replicating the actual operation of a dumper. I would love to see if you ever get to the point of using a locomotive to position the cars for dumping. It would require a sensor to see the space between the cars, and being able to DCC control a locomotive. It would be complicated, but would be real cool.

    Very nice.....hope you plan to go further with the design.

    James L

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    James L
    Partner/Designer
    Lil Brother SMT Assembly Services

    Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!

    Post Edited (James Long) : 1/4/2010 12:36:45 AM GMT
  • James LongJames Long Posts: 1,181
    edited 2010-01-04 02:42
    BS2ILH said...
    thanks, should have said HO scale in the title, i guess...

    -using a locomotive to position the cars for dumping

    uhm, well, that is why there is the train positioner. from my limited-null knowledge : they use the positioners because it is so difficult to use a locomotive - due to the couplers having too much 'play' they spend all day pushing and pulling... never getting it positioned right on a long train.

    -hope you plan to go further with the design.
    uhm, well, no. i thought this included everything AFAIK. Hiding the wires underneath the train board and general clean up and decoration ie landscaping will be done, but i dont consider that part of the 'design'

    Design Suggestions ?

    I think if you used a system to see the space between the cars, it may be possible to do with a locomotive. You could use a sensor on each end of the dumper to see if the car is located correctly. The slack in the train may be somewhat of a problem, but should be manageable. The system would probably need a few sensors to see how long the train actually is. The longer the train, the more slack to consider. Or you just have an input to the system to tell it how many.

    I didn't mean to say it wasn't complete. I was just trying to inspire you to possible take it further. This is based on the fact that your system has a DCC controller or something similar. It would be hard to do without one.

    If you want, I would try and find out the DCC specifications, and one day (maybe never), you could possibly update the system to be locomotive power.

    I am still impressed. You did a fine job of scaling the dump operation down. I would love to know more about the couplers. I haven't seen rotational couplers in HO scale before.

    James L

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    James L
    Partner/Designer
    Lil Brother SMT Assembly Services

    Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
  • James LongJames Long Posts: 1,181
    edited 2010-01-04 17:49
    BS2ILH said...
    rotational couplers i used are made/modified Kadee#5 by Paul Mack. Sergeant Engineering makes some too.. but they are basically just round sticks in a hole and only couple to other couplers made by them. the zipped blog has more info as well as the comments in the code.

    i searched the forums for DCC .. much confusion but nothing really there. there is a propellor spin dcc system that does 4 trains or something... but could not tell how or why. NMRA DCC specs : http://www.nmra.org/

    -system has a DCC controller
    uhm nope not yet, Digitrax seems to be my choice, but the DCC makers leapfrog each other and not all are going in the same direction... and the NMRA (spec maker) is not necesarily going in mine...

    i -someday- will do a Coal loader.. now THAT would be something to do using a Locomotive controller... along with controlling the release of the 'coal', moving the loader 'funnel', moving the 'coal' inside the loader for the next cars load, ... AFAIK the Propellor would be used for its multitasking ... checking-doing many things at once... but the hardware of cogs, gears, tracks, pulleys, drivetrains the cogs to cog along, etc is not available without a CNC machine shop apparently.

    Understood. I did the research on the DCC, and is pretty easy to do. The only problem is the voltage control. The signal is a +/- dc control wave form. It is really pretty easy once the negative voltage problem is overcome. I do think a DCC control would be possible. With a Stamp you would need an accessory processor to control the pulse (continuous). The nice thing about doing it this way would b the nice true scale layout you would have afterward, but I do understand the overwhelming complexity of it all.

    As for the coal loader. The coal loaders I worked with were nothing but a large funnel, with a track under them. The locomotive actually pulled the cars under for them to be loaded. The train moved at a certain speed to load the cars correctly. The "chute" was close during the gaps in the train. Another pretty easy system is DCC was used with some kind of sensor to detect the gaps between the cars.

    Maybe I'll design just such a system.........

    James L

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    James L
    Partner/Designer
    Lil Brother SMT Assembly Services

    Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
  • James LongJames Long Posts: 1,181
    edited 2010-01-05 03:19
    BS2ILH said...
    -The signal is a +/- dc control wave form
    PWM pulse width modulation i think
    yeah, thats where i gave up on DCC, as it is actually AC with the commands added on top... to drive dc motors. they now have the AC frequency prettty high to alleviate some of the AC driving a DC motor wailing .. but sheesh, no thanks... why i have not gone drooling for DCC

    -the nice true scale layout
    well i guess we still see things differently... AFAIK the trains are hooked up to a train positioner, not spotted by a locomotive... in rotary dumper unit train operations. When unloading wood chips or single cars at other type plants, they actually use a forklift to ram the cars into position...

    -the coal loader
    a train backs under the loader and they check each car (-no leaks and in good condition (if it breaks down when it gets loaded-that causes a MAJOR problem- so they go through an inspection phase first)) till they get to the locomotive, then it pulls forward as they load the cars... the locomotives are usually the loaders locomotives.. remote controlled from the loading office- which also controls the coal flooding.

    seems like making a DCC controller to run the locomotive might actually be very complicated as you would have to drive it back and forth to get it into the line under the coal loader.. simpler to just use your DCC controller you would already have. The coal loading could have a DCC 'reader' that opened-closed the chute - etc... that part makes a LOT of sense to do with a Stamp-Propellor controller.-rather than just a DCC switch to operate an open-closed gate. Physically making the coal loader is more of a problem.. the ones i have seen-read about get choked a lot when they close the chute... i saw one that had a funnel connected to a semi-horizontal pipe that was 'vibrated' to shake the coal along and down into another funnel that deposited it into the car. that looked workable. Pin-point light detectors or IR detectors would need 'cones' to see the exact change of a car end-beginning... but seemingly doable.

    after the cars are flood loaded they go over a scale that adds coal-tops them off - if required.

    -design just such a system
    seems like you would need some kind of DCC reader - i dunno of it is even required.. i have a Sony IR remote control (stamp sensors) that has enough 'buttons' to control the loading.. just need a Start and Stop AFAIK... once the cars move under the loader they get dumped on when they block the light sensors. Keeping the coal moving internally would require interactive control and a servo-motor to shake the coal along and down. And then when the train is completely loaded and gone a little drone comes out and vacuums up the coal spillage... [noparse]:)[/noparse]

    I looked at the DCC signal, and it is pretty simplistic for communication. The voltage driving on the other hand would be a little more difficult. As I can tell.....for locomotives there are very few commands. All having to do with speed (or stop). The controllers themselves do all the fancy work (inertia).

    A member here helped me find a driver, so it would be real easy to put together a simple control. But it is not really cheap. The one chip to drive the voltage is about $15.00. So......it was a nice idea.....maybe in the future.

    Interesting there are places which do not use a locomotive to spot cars. I learned something. Since I worked on locomotives, I didn't know there was anything else. I knew there were people using other things, but not anything made for it besides a locomotive. Scary the things people do.

    James L

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    James L
    Partner/Designer
    Lil Brother SMT Assembly Services

    Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
  • James LongJames Long Posts: 1,181
    edited 2010-01-05 21:08
    BS2ILH said...
    sometimes you do what you gotta do.

    here is a link to a PE that designed his own DCC and hand controllers... before there was DCC...

    http://www.tslrr.com/index.htm

    you might also consider looking at his simple handheld controllers of normal DC trains... the Stamp-propellor controller could maybe do that kinda thing... as this would be on a siding it could be standard DC rather than DCC - even on a DCC system.

    the way i understand DCC:
    there is 1 DCC controlling system (Command Station).
    -it receives packets from 'throttles' : the locomotive handsets to drive the train
    - it sends commands mixed with the AC power to ALL things - locomotives, switches, etc... on the rails.
    - switches, locomotives etc 'listen' to ALL commands and react to commands that have their 'code' address

    Throttles do NOT need to- should NOT do power things.. simply send packets on the 'communication line' - normally something like a telephone cable that is hooked into the Command Station

    Having multiple Command Stations is NOT possible... you use throttles to send packets to the command station on the commo link and IT sends OUT the commands on the rails.

    All in all i think this thread was NOT about DCC and i am tired of it.

    goodbye.

    Wow....I'm sorry.....I didn't mean to offend.

    Consider the topic on my part closed.

    You did a nice job on the dumper.......

    James L

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    James L
    Partner/Designer
    Lil Brother SMT Assembly Services

    Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2010-01-05 22:12
    Gentlemen,

    This forum is for both the support of our products and the sharing of knowledge. It is a community forum and as such contains members with different points of view and ways of looking at things. It is often times the nature of people to offer their thoughts and sometimes even suggestions on a project when they see it. They will often think out loud, if you will, about what they might do differently. This often inspires others and sometimes gives the OP ideas he may not have thought of. I do not believe James was trying to upset you with what are generally accepted comments and suggestions. By posting a project here you do open yourself up to that and in some cases constructive criticism. You have to accept if for what it's worth. I hope this helps. Take care.

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    Chris Savage

    Parallax Engineering
    Check out the new Savage Circuits TV!
    ·
  • BS2ILHBS2ILH Posts: 9
    edited 2010-01-05 23:28
    why dont you and your buddy go back to running your leaf blower on the desk.
  • James LongJames Long Posts: 1,181
    edited 2010-01-06 00:14
    BS2ILH said...
    why dont you and your buddy go back to running your leaf blower on the desk.

    Interesting twist on a thread of which I feel you will probably revisit.

    I appreciate you enthusiasm about my project with the blower. Although not a real leaf blower, that is a good idea.

    I am currently working a system which will separate dried peas from their hull. (My father loves to farm). Sorry for being so OT.....but........

    James L

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    James L
    Partner/Designer
    Lil Brother SMT Assembly Services

    Are you addicted to technology or Micro-controllers..... then checkout the forums at Savage Circuits. Learn to build your own Gizmos!
  • Gary M. ReeseGary M. Reese Posts: 5
    edited 2010-03-17 12:33
    Actually I found the discussion quite helpful, from both points of view. I'm into garden railroad and was looking for just such a discussion. Yes they are two different systems. However, I think I can get them to interact indirectly. Seeing how easily some people are distracted, I'll keep it to myself. Hmmmmm, leaf blower huh? Interesting. smile.gif

    GaryR



    I respect those who admit their limitations, And if I had any, I would certainly admit to them.
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