How to setup a 110 volt, 1/2 hp, DC reversing motor with relays, timers, etc.

Discussion in 'The Projects Forum' started by DCLIFTMOTOR, Apr 27, 2015.

  1. DCLIFTMOTOR

    Thread Starter New Member

    Apr 27, 2015
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    I would like to use a 110 volt, 1/2 hp more or less, DC reversing motor to move and close a horizontal, heavy fabric, thermal, curtain blanket and then to move and open back the blanket in a greenhouse. There are very expensive commercial greenhouse systems that exist to perform this task. Since I have a hobby greenhouse that is 30 ft. wide by 80 ft. long, I need a much more affordable system. Horizontal wires that run the length of the greenhouse at approximately the 8 ft. height will be used to support the blanket and for it to slide along when mechanically closed and reopened. My idea is to use a boat lift type motor rig to perform this task with modifications to work in the greenhouse. The boat lift motor rig will consist of the 110 volt, 1/2 hp more or less, DC reversing motor, that will be connected to a small round pulley on the motor shaft, then a belt to a larger pulley. The larger pulley is connected to a large toothed round gear. The gear will be attached to an approximate 1 and 1/2 inch diameter, metal hollow pipe that is approximately 30 ft. long. This rig will be attached at one end wall of the greenhouse at 8 ft. high and at the other end of the greenhouse also will be an approximate 1 an 1/2 inch diameter, metal hollow pipe that is approximately 30 ft. long. This pipe also will be attached to the end wall of the greenhouse at the same 8 ft. height. Attached to these 2 pipes will be say 1/4 inch aircraft cable that will be approximately 160 ft. (2 x 80 ft. length of greenhouse) long. Initially 80 ft. of the cable will be wrapped around the pipe at the non motor end of the greenhouse. The remaining approximate 80 ft. of cable will run the length of the greenhouse and will be attached to the pipe at the motor end of the greenhouse. The curtain blanket will have a 30 ft. long horizontal bar attached to it. This 30 ft. bar will be attached to the aircraft cable at the non motor end of the greenhouse. As the motor turns the 2 pipes by wrapping and unwrapping the aircraft cable, the attached curtain blanket will be pulled the 80 ft. length of the greenhouse.
    What I want to accomplish is as follows:
    1. Be able to slowly, if possible, (say over 20 - 30 minutes) close (move forward) the blanket with the motor rig at a preset time in the evening and for the motor to stop when the blanket is fully pulled to the motor end of the 80 ft. greenhouse.
    2. Be able to slowly, if possible, (say over 20 - 30 minutes) reopen (move backward) the blanket with the motor rig at a preset time in the morning and for the motor to stop when the blanket is fully pulled back to the non motor end of the 80 ft. greenhouse. To accomplish this, this reversing DC motor will need to reverse direction to reopen the blanket.

    I tried to research on the internet how to accomplish the above, but everything described similar processes in vague and technical terms of using various types of electromechanical timers, electromechanical relays, limit switches, microcontrollers, MOSFET circuits, transistors, arduinos, bridge rectifiers, etc. I have zero knowledge of all of these devices and am totally confused.

    I need some very, very, specific steps, specific products and where they can be purchased to be able to accomplished this. Again, I have zero knowledge of all these devices. Thanks very much for your help!

    Alan
     
  2. Papabravo

    Expert

    Feb 24, 2006
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    You might start with where you are located since that will affect the answers we are able to give. Also, zero knowledge is just not going to cut it. Even if we gave you a specific bill of material you're going to have to educate yourself regardless of anything else that happens. We're not there and we can't anticipate and debug problems that might come up. You're the man in charge; it's really up to you.
     
    Last edited: Apr 27, 2015
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  3. #12

    Expert

    Nov 30, 2010
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    Search this site for the word, "chicken".
    Electrically, you are doing what a chicken coop door does.
     
  4. DCLIFTMOTOR

    Thread Starter New Member

    Apr 27, 2015
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    I have already done this, not specific enough information. Also I made an error in saying a DC motor, I meant an AC motor. Thanks.
     
  5. DCLIFTMOTOR

    Thread Starter New Member

    Apr 27, 2015
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    The reason I said zero knowledge is because I am not looking for some wiring circuit diagram that is on the internet, because I cannot understand them. I need specifics. I am located in Tennessee. Also I should have said AC motor instead of DC motor. Thanks.
     
  6. tranzz4md

    Member

    Apr 10, 2015
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    DC motor drives (a.k.a. controllers) are fairly cheap, like around the price of the motor or less. I found a couple dandy little timers on Amazon that would do. You may well find one with 2 separate outputs. You most likely will do best with a battery powered unit with LCD display; power interruptions won't affect it, and they're simple and easy to set and change.

    Your mechanism sounds viable, but unwind / rewind will most likely become troublesome with disorder and lapping jamming things up. A partitioned "spool" area with only a 360 - 540 degree wrap may well work better, and a well selected, low stretch rope may work as well or better than the steel cable.

    Keep us posted.
     
  7. tranzz4md

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    Apr 10, 2015
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    You changed your motor type while I was entering my preceding response. Let me say that a DC drive and motor has some strong advantages, particularly because simple "across the line starting" of that AC motor will shock your mechanism as much as your power circuit.
     
  8. Papabravo

    Expert

    Feb 24, 2006
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    Located in Tennessee is good because you have access to components and modules at reasonable acquisition and shipping costs. If you were on Tristan da Cunha it would be a different story. It is reputed to be the most isolated spot on the planet.

    https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=Tristan da cunha

    I am here to tell that that specific instructions won't do the job. A picture or a drawing is how designs are created, maintained and modified, and you need to learn it whatever it takes. I'm certainly not going to try to satisfy the requirements as you have stated them, but maybe somebody else will. I wish you good luck with your project, but I have little reason for optimism. Sorry.
     
  9. #12

    Expert

    Nov 30, 2010
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    Do you mean, "Get a piece of 18 gauge wire with red insulation. Connect one end to the pin labeled, '56' on the first relay and connect the other end to screw, 'A' on the motor"?

    I don't think that's going to happen.
     
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  10. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
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    Do you have the ac motor yet or any components to make the electric switching, how about something like a garage door opener circuit...
     
  11. Papabravo

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    I think that is exactly what he meant. What he doesn't realize is that if something doesn't work, there is no way on earth to troubleshoot or amend such a set of instructions.
     
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  12. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    First thing you need to accomplish is your curtain hanging structure. Instead of pipe for the curtain to move on, I'd use "powerstrut" or one of the similar products. http://www.powerstrut.com/channelps210.html Using this will allow the curtain to be hung from "trollies". http://www.mcmaster.com/#strut-channel-trolleys/=wy68ez The powerstrut and trollies allow the assembly to be supported from above and not get in the way of the movement back and forth.

    Then with a pulley at the far end and the motor at the other you would put a loop of cable or even good rope between the two. The motor would need to be a gear motor. And a "drive drum" on the output shaft. The cable or rope has to be wound around the drum by at least five wraps, this is the standard for a hoist or winch, to prevent slippage.

    Then with the curtain anchored at the far end and the other end anchored to the cable loop, the motor can be run to either pull the curtain toward the motor. Or by reversing direction of motor away from the motor. Like the old time "pulley clothesline". http://shop.woodwardcrossingscountr...Amish-Built-Clothesline-Pulley-System-250.htm

    Instead of an expensive AC gearmotor and the making of a drive drum I'd buy one of these for AC http://www.harborfreight.com/440-lb-electric-hoist-with-remote-control-60346-9096.html
    Or these for DC http://www.harborfreight.com/2500-l...winch-with-wireless-remote-control-61297.html

    Both are over rated for the load you'll be putting on them but they have the motor, gearbox, drum, and controls all ready made and in one inexpensive package. Can't do it yourself for that price, believe me. Hope this helps you.
     
  13. Papabravo

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    Feb 24, 2006
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    @shortbus It's not far from Youngstown to Tennessee. You could probably wire it up in a weekend.
     
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  14. Papabravo

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    Feb 24, 2006
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    Unless of course you want to write down the specific instructions.
     
  15. tranzz4md

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    Apr 10, 2015
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    If you really want to do it on the cheap, dodgydave's garage door opener comment will definitely get you into most bang for your buck territory. I made a remote contol gate opener for about $10 of stuff I already had in my stash and a discarded garage door opener. That saved me at least $700.

    Rolling and unrolling 30' is likely to have distinct advantages over the 80' movement method.
     
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  16. Papabravo

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    You're not giving him what he wants.
     
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  17. tranzz4md

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    Apr 10, 2015
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    Ok, Mr. DC lift motor, who probably doesn't know the actual, literal, technical differences between AC and DC motors or, more importantly, the controls for them, let me get more specific for you.

    You will have to put multiple points along one edge to apply force to, to pull that edge the length of your shaded area (80'), AND BACK again. This will put the opened shade in a bunched up state during the daytime. Your choice of horizontal support wires is a good one, depending on the characteristics of that blanket you may need several of them. I don't see the purpose for your 30' rollers, (except as cable rollers with each cable attached to the manipulated edge of the blanket) because your blanket will not be extended, or able to freefall when retracted. A 30' roller on the uncovered end would be useful for having multiple points to connect multiple pull lines. You should have no less than 2 pull lines placed and operating symetrically even if you have a perfectly stiff, straight manipulated edge.

    Now, you go onto Amazon or wherever, and get a battery operated timed switch with the capability of 2 or more setpoints, or 2 battery operated timed switches with single setpoints.

    Next, you get a garage door opener that uses a chain and sprocket type mechanism (not a "screw drive"). This unit should either use endpoint limits triggered by tabs on the drive chain, or have an integral "screw and nut" end limit mechanism that can be disconnected (mechanically) or modified -> BY YOU <- for what in your case will be equal to an 160' tall (or even taller) garage door.

    Now, you mount your rollers, static "support" wires - which are static and pass just above your 30'rollers before attaching to your endwalls.

    Your drive end roller will need to be fitted with a sprocket of the same pitch as the garage door opener, but 2 or 3 times the tooth count. The speed of the manipulated edge and the force required to move it will drop proportionately to the ratio of those 2 sprockets. The limiting factors that you will experience will be the weight and friction of your blanket, the weight of the door that the opener drive was designed for, and the endlimit mechanism. One of the substantial advantages of using a garage door operator is this endlimit mechanism; it does not require mounting and wiring of switches at the actual physical endpoints of your manipulated edge, or selection or fabrication and meticulous adjustment (and reliability issues) of actuators for those "limit switches". So, if you can figure out how the endlimit mechanism on your opener can be modified for your sprocket movement needs, and get 40x as much movement as the original settings, you can use a 4:1 tooth ratio on those sprockets, and get better power and slower movement of your manipulated blanket edge. You realize that 80' of blanket movement is about 10x the normal movement of a garage door, right? If the endlimit mechanism on your door opener uses tabs on the chain, as opposed to the screw and nut style mechanism, you'll need to have that chain be 80' long and attach to the manipulated edge, and you'll not be able to (very simply) reduce the speed and increase the torque from what that garage door opener uses on ordinary garage doors.

    There are commercial garage door openers which have the capability for long door movements, and lots more adjustability, but they're usually expensive to buy, and often are 208-240VAC or even 3-phase AC.

    Your blanket really should have brass grommets for the support wires along the manipulated edge, and probably additional 12" spaced pairs at 10' intervals over that 80' length. string it like a shower curtain. without those grommets you'll get a tangled heap of torn blanket and wire.

    Your timer with 2 setpoints, -> and MOMENTARY outputs <- will connect its N/O (normally open) and COM terminals of the programmed output to the terminals for connection of the pushbutton for your garage door opener. When your 1st setpoint is reached (at night for instance) it will momentarily act like someone pushing the pushbutton to operate the garage door, and your blanket will move until the setting of your garage door openers endlimit is reached, and stop. When your next setpoint (on your timer) is reached it will again momentarily act like the door operator button is being pushed, and the blanket will move opposite its last movement until the opposite endlimit is reached.

    Other integral mechanisms / systems in the garage door opener which you must have if you choose to use a different drive:
    - reversal interlocking
    -absolute endlimits for each direction
    - motor speed reduction/torque multiplication
    - load shock absorption including slip joint or clutch and /or shear pin
    - automatic reversal from last action.
    - automatic reversal or stop from overload
    - low voltage isolated control from power source voltage (and current)
    -120VAC power source utilization


    Of course there are other ways to do it too..........
     
    Last edited: Apr 29, 2015
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  18. tranzz4md

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    Apr 10, 2015
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    And delving into a couple of those other ways,,,,

    A DC "packaged drive" (and motor) typically has settings for minimum and maximum speeds, rate-of-change (to ramp up and down the speed when starting and stopping), maximum load (sometimes even "electronic shear pin"), and "dry contact inputs" for direction, start, and stop functions. These dry contact inputs enable the use of simple mechanically actuated switches ("limit switches"), for your endpoints (to shut off your motor once your blanket is fully extended or retracted), and pushbuttons or your little battery operated time switches to open or close your blanket. For your moving load, your mechanical horsepower and electrical power requirements units powered by 120V AC should be readily available.

    You can also purchase AC packaged VFD controllers which will perform many of the same functions with AC motors. These AC "Freq drives" are comparatively new devices and their prices may well compete with DC drives in todays market. I've installed and serviced many of them, but not purchased any in the last 10 years, so for all I know they're competing with DC drive packages on pricing too these days. Again, for your moving load, your mechanical horsepower and electrical power requirements, units powered by 120V AC should be readily available.

    I'm afraid that making the electrical connections and selecting and installing the limit switches, as well as setting the parameters in a packaged drive (control unit) may well be more than you're willing to learn and do however.
     
    Last edited: Apr 30, 2015
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  19. DCLIFTMOTOR

    Thread Starter New Member

    Apr 27, 2015
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    Tranzz4md
    Thanks very much for your help! The garage door opener idea seems like a much better idea. I will try to comprehend everything. Again thanks.

    DCLIFTMOTOR
     
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