Garage door following truss..... Again

[cstmg8]

I've read a few threads on here regarding this situation, but none that are at the point I'm at.
I've installed the doors:
10x10 insulated with one panel of windows
Standard rise but immediately following the trusses.
Two springs per door.
I have high lift drums on them.
With the sprigs wound, the doors will spring open at full close, and will not lift much over half way.
What is my fix? I'm putting in jack shaft openers, are they strong enough to overcome this in both directions?? My current springs can't be adjusted to work correctly and hold the doors up.
I'll probably call a local professional, but is there an easy fix for this??

 

[wssix99]

I'm putting in jack shaft openers, are they strong enough to overcome this in both directions?? My current springs can't be adjusted to work correctly and hold the doors up.

No, you have to get the springs right. All openers are not that powerful and need the springs to be balanced and doing their job.

Where did you get the springs? Are they matched specifically for the door and your follow-the-roof tracks? (Springs specified for regular tracks will not be strong enough for the weight of the door on follow-the-roof tracks.)

 

[The Cobbler]

as said for openers tow ork properly the door needs to operate properly .something's wrong with your set up .

 

[Jogyver62]

I’m running 600# springs on my 16’w x 7’T composite door with windows. It’s best to call A reputable garage door company.

 

[like2wheel]

I had a similar problem, but noticed my cables were too long & weren't spooling to the larger diameter of the high lift pulley. When I shortened the cables, the problem was solved.
Long shot, but worth taking a look.

 

[cstmg8]

I'm struggling a bit with the physics of a spring that will be strong enough to lift at the bottom, (without pulling it open) and still able to hold the weight of the door unsprung at the top. That's what the pros are for ( I hate paying for something I could do)
Thanks, I'll definitely check the cable on the drums. It makes sense that it would struggle if it wasn't switching to the mechanical advantage of the larger drum.

 

[Viper98912]

That's the magic of a well designed spring/drum/cable length setup. The spring provides the right force/torque to lift the door from the bottom, but provides less force as you raise/unwind. High lift drums with different diameter grooves help increase or reduce the amount of torque depending on if you're high or low and how many winds/length per revolution you get. And the amount of weight being lifted gradually changes as the weight of the door goes horizontal and ends up being held by the horizontal track/ceiling and not the spring anymore.

It really is a nifty physics calculation (in a dynamic system) if you really think about it...

 

[firebirdparts]

I'm struggling a bit with the physics of a spring that will be strong enough to lift at the bottom, (without pulling it open) and still able to hold the weight of the door unsprung at the top. That's what the pros are for ( I hate paying for something I could do)
Thanks, I'll definitely check the cable on the drums. It makes sense that it would struggle if it wasn't switching to the mechanical advantage of the larger drum.

I understand how it works, but we just don't have enough info here to really appreciate what went wrong. There is a fundamental science to it. The size of the drum, which in a high lift is variable, determines how many turns the spring will get from open to closed. You can't change that. The spring has to give the desired force at that number of turns.

What you describe is that you don't have enough movement. The door won't open and it won't close. So that's telling you the springs are too short for the drum diameter, but I don't want to get into a debate with somebody that doesn't understand how it works.

My point is there is no easy answer if I take what you posted at face value. You have mismatched components.

 

[CraigStu]

Yes it is a really neat physics challenge. A standard garage door gets lighter on the way up as more of the door moves onto the horizontal part of the track. And that works out just fine since the spring is getting weaker also. OTOH I imagine that a door that never goes horizontal needs close to the full force all along it's travel. Some day I need to look into how that can happen just to satisfy my curiosity.

 

[racecougar]

What you describe is that you don't have enough movement. The door won't open and it won't close. So that's telling you the springs are too short for the drum diameter, but I don't want to get into a debate with somebody that doesn't understand how it works.

Bingo!

 

[andyvh1959]

Yes it is a really neat physics challenge. A standard garage door gets lighter on the way up as more of the door moves onto the horizontal part of the track. And that works out just fine since the spring is getting weaker also. OTOH I imagine that a door that never goes horizontal needs close to the full force all along it's travel. Some day I need to look into how that can happen just to satisfy my curiosity.

Yup. I built a 12x16 shed back on 2005 that has a loft. I wanted a 4' wide OH door so I could park the lawn tractor inside. I used two 16' flush door panels cut down to 4' wide, and modified the tracks so the door tracks up at a slight angle from closed. Came up with a cable/pulley system using 75 lb of barbell weights to counterweight the door. Works great, door stops wherever I want it.

 

[jmdirk]

Yes it is a really neat physics challenge. A standard garage door gets lighter on the way up as more of the door moves onto the horizontal part of the track. And that works out just fine since the spring is getting weaker also. OTOH I imagine that a door that never goes horizontal needs close to the full force all along it's travel. Some day I need to look into how that can happen just to satisfy my curiosity.

That's exactly the point! That's why high lift drums vary in diameter. At the bottom, springs are at their highest tension from the most force they can. As the door rises they are unwinding and reducing the amount of force. But in the case of high lift, the door is necessarily getting 'lighter'. To compensate, high lift drums are a larger diameter at the start and as the door rises, the cable wraps around the progressively smaller parts of the drum, thus increasing the mechanical advantage of the system. Like lower gearing to increase torque.

It's critical to get the cable length right. If the cables are too long, you've already got too many wraps on the drum and you're going to provide too much torque. But as the door rises, you won't get more mechanical advantage and as the door rises and the spring unwinds, the door will 'stall'. Exactly what the OP is describing.

 

[jstroede]

Please post pictures if you can. That would help identify exactly what you have. If you only have roof pitch and no high lift, high lift drums are not a great choice. Standard lift drums work better for that arrangement. Do you have a bill of materials or packing list with the door since you were the one that put it up?

You say that the door won't open over half way. Are you saying that it goes up to that point and stops? What does the door do if you put it up another couple feet? With jackshaft openers, you want it to be somewhat heavy because the opener is not actually closing the door really. It is simply allowing it to close via gravity.

John

 

[cstmg8]

I understand how it works, but we just don't have enough info here to really appreciate what went wrong. There is a fundamental science to it. The size of the drum, which in a high lift is variable, determines how many turns the spring will get from open to closed. You can't change that. The spring has to give the desired force at that number of turns.

What you describe is that you don't have enough movement. The door won't open and it won't close. So that's telling you the springs are too short for the drum diameter, but I don't want to get into a debate with somebody that doesn't understand how it works.

My point is there is no easy answer if I take what you posted at face value. You have mismatched components.

Thanks. I do understand the general idea and mechanics of it all, I'm just not pretending to know more about the equations than some here. I'm an elevator mechanic, so I deal with similar physics at work. Not looking for a debate either, I'll gladly listen to any advice you may have.
The kit I ordered was for a high lift, so that's the drums I have. I'm going to check that the cables are actually coming off of the larger circumference grooves. That may help a bit, but after reading the responses here, I did some research on drum types. I believe I'll need vertical lift drums, so that the mechanical advantage continually increases as the spring tension is exhausted.
You're probably right about longer springs, but I'm going to try one solution at a time.
Thanks for the insight!

 

[jstroede]

Thanks. I do understand the general idea and mechanics of it all, I'm just not pretending to know more about the equations than some here. I'm an elevator mechanic, so I deal with similar physics at work. Not looking for a debate either, I'll gladly listen to any advice you may have.
The kit I ordered was for a high lift, so that's the drums I have. I'm going to check that the cables are actually coming off of the larger circumference grooves. That may help a bit, but after reading the responses here, I did some research on drum types. I believe I'll need vertical lift drums, so that the mechanical advantage continually increases as the spring tension is exhausted.
You're probably right about longer springs, but I'm going to try one solution at a time.
Thanks for the insight!

Please show pictures. The cables, springs, and drums all need to be sized together. Unless you are more steep than a 12/12 roof pitch, then you don't need vertical lift drums. How much high lift did you order this "kit" for? Some pictures and a couple measurements will help solve the problem.

John

 

[cstmg8]

To clarify my situation, the door springs open at the bottom, you have to force it down and latch it. About halfway up, the door gets very heavy. It can physically be opened, you're just not getting any spring assistance.
Hopefully these will help! Then, possibly, longer springs.

 

[cstmg8]

I'll grab some pictures today. The doors run up the trusses which are a 2/12 pitch, but get closer as they go up, so probably more like a 4/12. I don't think high lift drums will work, as my door never goes horizontal.
Pics will help. The order was high lift because Menards didn't carry a truss option. I ordered 12" high lift, but the curve actually starts right above the door.

Thank you for all of the help. The doors are sealing up my new shop so I can work inside, and are operational, so I'll take the time to figure out the correct solution.

 

[firebirdparts]

I'll grab some pictures today. The doors run up the trusses which are a 2/12 pitch, but get closer as they go up, so probably more like a 4/12. I don't think high lift drums will work, as my door never goes horizontal.

If you slope the tracks, there are infinitely many variations on the shape of drum you'd want, and they don't do that. They have to pick a geometry for which the drum is actually perfect. The cone ones you posted are for the door goes straight up.

This is the other available geometry. Maybe this is the one you already have?

These have a cone that comes into action toward the closing direction, and an ordinary door section toward the open direction. So these are intended to be "just right" when you have a door that goes straight up a little while, like let's say 3 or 4 feet, and then breaks over into horizontal tracks. What that 2/12 you have, these ought to be pretty useful with a well sized spring.

 

[firebirdparts]

To clarify my situation, the door springs open at the bottom, you have to force it down and latch it. About halfway up, the door gets very heavy. It can physically be opened, you're just not getting any spring assistance.
Hopefully these will help! Then, possibly, longer springs.

Your initial post was very very clear, I thought.

 

[jstroede]

To clarify my situation, the door springs open at the bottom, you have to force it down and latch it. About halfway up, the door gets very heavy. It can physically be opened, you're just not getting any spring assistance.
Hopefully these will help! Then, possibly, longer springs.

I can guarantee that those drums will not work with your current springs/cables.

How many turns are on your springs?

John

 

[jstroede]

I'll grab some pictures today. The doors run up the trusses which are a 2/12 pitch, but get closer as they go up, so probably more like a 4/12. I don't think high lift drums will work, as my door never goes horizontal.
Pics will help. The order was high lift because Menards didn't carry a truss option. I ordered 12" high lift, but the curve actually starts right above the door.

Thank you for all of the help. The doors are sealing up my new shop so I can work inside, and are operational, so I'll take the time to figure out the correct solution.

The problem is that you didn't order the roof pitch part. If you ordered it with high lift, you should have gotten track with high lift. Regardless of the issue, most likely a new set of springs is what you are going to need to fix the problem. We just have to figure out what those need to be. I can probably make the high lift drums work, though I want to see what your track looks like exactly first.

The other thing we need to figure out is what the weight of the actual door is.

John

 

[jstroede]

Also technically, most standard lift track with 15" radius already has 7" of high lift built in. If someone were to actually want 12" of high lift, the best way to do that is with 20" radius track and standard lift drums.

John

 

[wssix99]

Sorry I forgot about the different drums. The drums required are hybrid and tapered. This thread shows an example of that they look like: https://www.garagejournal.com/forum/threads/follow-the-roof-garage-door-problem.140601/

The cable starts on the conical of the drum, where the spring gets leverage help to start lifting the door and then as the weight becomes less vertical and has a horizontal component, (resting more on the rollers) the cable moves outward and the spring exerts less power on the drum and cable. This shape and the windings are matched to the profile of your track.

^ I suspect the shape in the thread above is for a high-lift door and the drum you would need for a follow-the-roof track would look more like a traditional cone.

I'm struggling a bit with the physics of a spring that will be strong enough to lift at the bottom, (without pulling it open) and still able to hold the weight of the door unsprung at the top. That's what the pros are for ( I hate paying for something I could do)
Thanks, I'll definitely check the cable on the drums. It makes sense that it would struggle if it wasn't switching to the mechanical advantage of the larger drum.

With changing forces on the cable wrapped around the cone and a moving center of gravity (of the door) with changing horizontal/vertical components, (the changing vertical components are what the springs does the most work on) one would need calculus to figure out what size spring is required.

If I recall correctly, the site Admins have a no calculs rule...

Either way, I haven't seen any online calculators to do this. The door manufacturer should have standard tables to look all this stuff up and would hopefully be able to supply the additional parts needed. (If you want to cut out an installer/middle-man.)

 

[jmdirk]

If you've got any kind of tapered or high lift drum, how many wraps of cable are on it in the closed position? If your cable is too long and you've got one or two wraps on it already the drums aren't working as intended

 

[cstmg8]

If you've got any kind of tapered or high lift drum, how many wraps of cable are on it in the closed position? If your cable is too long and you've got one or two wraps on it already the drums aren't working as intended

Too many!!!

 

[FMB4]

The door manufacturer should have the info you need. I'd start there.

 

[racecougar]

Too many!!!

 

[cstmg8]

Which type of cable termination would you trust to shorten the cables?

 

[FredWanaker]

edit: Generally it is one turn on the spring per foot of door height. The door should then balance manually when open about a 1/3 to 1/2 of the way up. This is what an online pictorial shows for the cable on a high lift door when it is being installed. You might want to talk to the garage door company where you bought those to be sure you have the correct length cables for that arrangement. They should have a chart for the height, door size, angle and drum type. I don't know and could not find that definitive chart online but looking at your photograph and this one my GUESS is that your setup isn't taking full advantage of the roller.

 

[cstmg8]

Generally it is one turn on the spring per inch of door height. The door should then balance manually when open about a 1/3 to 1/2 of the way up. This is what an online pictorial shows for the cable on a high lift door when it is being installed. You might want to talk to the garage door company where you bought those to be sure you have the correct length cables for that arrangement. They should have a chart for the height, door size, angle and drum type. I don't know and could not find that definitive chart online but looking at your photograph and this one my GUESS is that your setup isn't taking full advantage of the roller.

You are correct. It's because the kit was made for a typical high lift, where the drum would be mounted 12"+ higher.

 

[FredWanaker]

a local garage door company should be able to recrimp those for you to a custom length if they have the tool and crimper. You can also order custom cables online at really reasonable prices.

 

[like2wheel]

Too many!!!

What do I win??

 

[cstmg8]

What do I win??

A multiple hour drive to help me fix it!!

 

[like2wheel]

Great, I'll bring my Chineseum crimper that I bought when I couldn't get anyone interested in shortening my cables for me

 

[jstroede]

Too many!!!

Well since you have no idea what you actually have, how do you know it is too many?

 

[jstroede]

Generally it is one turn on the spring per inch of door height. The door should then balance manually when open about a 1/3 to 1/2 of the way up. This is what an online pictorial shows for the cable on a high lift door when it is being installed. You might want to talk to the garage door company where you bought those to be sure you have the correct length cables for that arrangement. They should have a chart for the height, door size, angle and drum type. I don't know and could not find that definitive chart online but looking at your photograph and this one my GUESS is that your setup isn't taking full advantage of the roller.

This is incorrect. People get hurt following advice like this.

John

 

[FredWanaker]

This is incorrect. People get hurt following advice like this.

John

John - the general rule is one full turn each side per foot of door height. That means a 7 1/2 foot door is 7 and 1/2 turns. Each hole is a quarter. If someone is uncomfortable being on a ladder with the bars, then they should stay off. I paint a line on the coil before starting, my door guy uses chalk. I am 71 now and pay them to do the work replacing springs every 4 or 5 years. FWIW usually they don't even get the balance right and only when I mention to them to check it do they correct it. That usually means adding or removing one quarter of a turn, sometimes 1/2 on a new spring. If you see danger in the way it reads in all the instructions then you should point it out to the manufacturers and people who sell doors. The real danger is that people install the wrong springs. Even my garage company guy has tried to pull that one off on me because he didn't have the correct springs with him, and didn't want to make a trip back with the correct ones.

 

[racecougar]

Well since you have no idea what you actually have, how do you know it is too many?

Did you look at the photo the OP posted? The cable isn't utilizing the tapered part of the drum.

 

[racecougar]

John - the general rule is one full turn each side per foot of door height. That means a 7 1/2 foot door is 7 and 1/2 turns. Each hole is a quarter. If someone is uncomfortable being on a ladder with the bars, then they should stay off. I paint a line on the coil before starting, my door guy uses chalk. I am 71 now and pay them to do the work replacing springs every 4 or 5 years. FWIW usually they don't even get the balance right and only when I mention to them to check it do they correct it. That usually means adding or removing one quarter of a turn, sometimes 1/2 on a new spring.

I think he was stating that your previous post was incorrect because you had said one turn per inch rather than per foot.

 

[jstroede]

Ok, so seeing some pictures, what exactly is your track pitch, and what is the measurement of the floor to center line of shaft? Do you know the weight of the door? Or size and model? It is often listed on the paperwork. If not, tell me what springs came with it and I can probably back into it.

Just FYI, you have no high lift there.

John