Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Help with gate opener / roof

  • Please log in to reply
8 replies to this topic

#1 TheFinePrint

TheFinePrint

    Lift Off

  • -----
  • topic starter
  • Posts: 23
  • Joined: 01 Dec 2020

Posted 12 August 2021 - 02:49 PM

Hi folks,

I'm wrapping up my observatory build, but the last major hurdle (getting the roof working) is proving quite problematic.

 

Observatory is a 11' square ror built from the CJE1 plans, but not built by them.

I do not have 110v AC available - I'm using an off-grid solar system.

 

The roof rolls well by hand (I guess? I have never rolled any other observatory's roof) - it's heavy, but it rolls freely and doesn't seem to be binding anywhere.

 

My plan was to use an Aleko gate opener to move the roof - they make a model specifically for use with solar applications, the AR950.

I mounted the motor sideways - with the gear sticking straight up - as I have seen others do, and I mounted the gear rack on a 2x6 that runs the length of the observatory and is braced in a few places.  This seemed to work well at first, and I was able to open and close the roof a couple times, but then the motor started slowing way down and seemed like it was struggling.  eventually the motor stopped moving the roof at all.

 

I thought the motor was simply under-powered (it's rated for something like 900 lbs) so I bought a similar, larger motor - a Topens DK1000, rated for 1900 lbs.

Much like the first motor, this one worked great for one or two openings & closing, then started slowing down like the first one.  Eventually this motor stopped running in one direction at all, even with the clutch disengaged.  I replaced the circuit board and the motor worked again, but after a couple more attempts, it started slowing down again and I'm sure I'll burn out another control board if I keep trying.  I'll attach a video of what's happening.  Weirdly it seems like the motor is slowing down even with the clutch disengaged - it definitely runs faster in one direction, and it didn't do that when it was new or after I replaced the control board.

 

Maybe I'm just overloading these motors?  It seems like a motor rated to move a 1900lb gate should have no trouble with this roof (if I had to guess - it weighs maybe 800-1000 lbs?).

 

For those that are using gate openers - what is the rating of your motor & what size is your roof?

Anyone running a motor off 24v DC?

How easily does your roof roll?  Do you have to plant your feet and use both hands?  I do.  Can you roll it with two fingers like a skateboard?

 

Pulling my hair out and running out of ideas...

I welcome your assistance.

 

 

Here is a video of the roof in motion - as you can see it starts out moving just great then slows down for no apparent reason.  There's nothing binding the roof in that spot and that behavior - slowing and stalling - can happen anywhere in the roof's travel, not at any particular spot, so I think it's the motor, not the roof.  I stopped the motor with the remote in the video - it didn't click off on its own, so it isn't detecting a stuck condition or anything.

https://drive.google...iew?usp=sharing



#2 John Fitzgerald

John Fitzgerald

    In Focus

  • *****
  • Posts: 10,598
  • Joined: 04 Jan 2004
  • Loc: near Elkins and Pettigrew, Arkansas

Posted 12 August 2021 - 03:02 PM

I have a 16 ft x 16 ft roll off with approximately 18 x 18 roof that weighs about 1,400 pounds.  It rolls on ten 4-inch V-groove wheels on inverted angle track.  It was built in 2008.  One person can roll it off by hand.  The easiest way to roll mine is to use a strap tied to a double eye bolt at the north end of the roof, and pull on that.  But, it can be pushed off / on with two hands and a "lean into it" stance.

 

I think, with the small wheels, you may have too much friction there.

 

I've rolled gates by hand.  They roll easily with one hand.  You need a winch motor.

 

I think you are overloading those gate motors.



#3 scadvice

scadvice

    Mercury-Atlas

  • *****
  • Vendors
  • Posts: 2,588
  • Joined: 20 Feb 2018
  • Loc: Lodi, California

Posted 12 August 2021 - 03:06 PM

What is your peak power draw The motor spec sheet should tell you? I suggest before anything else see how much current your drawing. Maybe buy one of these rated above your predicted current. This way you know what is happening.

 

https://powerwerx.co...YRoCvnEQAvD_BwE


Edited by scadvice, 12 August 2021 - 03:09 PM.


#4 kathyastro

kathyastro

    Soyuz

  • *****
  • Posts: 3,802
  • Joined: 23 Dec 2016
  • Loc: Nova Scotia

Posted 13 August 2021 - 10:32 AM

Have you tried disconnecting the motor and rolling it by hand since the motor installation?  Does it still feel like there is no resistance?  Maybe something has settled and there is now resistance that wasn't there before.

 

Have you measured the force required to open it?  Use a spring scale to measure the pull required.  Does the motor have the necessary torque?  Foot-pounds of torque, divided by the radius of the drive gear in feet, will tell you the force it can deliver. 


  • vrotondi, Raginar, scadvice and 1 other like this

#5 John Fitzgerald

John Fitzgerald

    In Focus

  • *****
  • Posts: 10,598
  • Joined: 04 Jan 2004
  • Loc: near Elkins and Pettigrew, Arkansas

Posted 13 August 2021 - 03:38 PM

Of course, this is simple physics, but it takes much more force to start my 1,400 pound roof moving, than it does to keep it in motion. 

 

Gates that I have seen have large wheels, and low friction. 

 

Many small wheels make for more track contact, therefore more friction, than fewer, larger wheels.  This almost has to be a case of burning the control board out, from overload.  Have you tried lightly greasing the track?  Did the plans call for all those small wheels, or for fewer, larger wheels?



#6 archer1960

archer1960

    Viking 1

  • *****
  • Posts: 912
  • Joined: 26 Jul 2011
  • Loc: Southern New England

Posted 13 August 2021 - 06:19 PM

I wonder if the roof is flexing (racking) just a bit and increasing the load. When you open it by hand, do you push on the side where the motor is, or in the center?



#7 TheFinePrint

TheFinePrint

    Lift Off

  • -----
  • topic starter
  • Posts: 23
  • Joined: 01 Dec 2020

Posted 21 August 2021 - 10:25 PM

After all that it was just simply that the motors were underpowered. I bought an Aleko 5750 (so named for its rating in lbs) and it moves the roof with authority every time.
Frustratingly, it’s AC only which means I also had to get an inverter which I will have to add to the roof automation eventually so it doesn’t waste power (about 25W at idle which may not sound like much, but when you’re off grid, you care about every watt). Thanks for all the input! This was the last big hurdle to getting the observatory up and running!
  • Scott123 and OldManSky like this

#8 Phil Sherman

Phil Sherman

    Soyuz

  • *****
  • Posts: 3,530
  • Joined: 07 Dec 2010
  • Loc: Cleveland, Ohio

Posted 22 August 2021 - 11:14 AM

I wonder if you could have used a DC motor. Asphalt trucks have a DC motor that opens/closes a canvas cover that covers the load. If the motor itself isn't powerful enough to move the roof, you could always introduce an intermediate gear assembly to increase its torque and accept a lower movement speed. DC winches intended to be mounted on the front of a jeep are another source of geared down powerful DC motors. Unfortunately these rarely have standard sized shafts to which you could attach a gear.



#9 Stozhary

Stozhary

    Vostok 1

  • -----
  • Posts: 100
  • Joined: 18 Jan 2017

Posted 25 August 2021 - 05:10 PM

This message a little bit too late but it may help. I would try 12V winch as a powerhouse and feed from car type battery if your solar system can be connected to 12V DC. There are plenty winches from auto parts suppliers or store like Harbor Freight Tools. Winch usually has wired remote controller. You may need to modified your pulley/rope system and "integrate" winch into it.

 

  https://shop.harborf.../7/57365_W5.jpg

 

I hope it will help

Stozhary




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics