High Lift Garage Door Question

[superskaterxes]

So i just bought a scissor lift for my garage and i now need to move my door out of the way so i can get maximum clearance for lifting. I bought the LM8500 opener to get rid of the door opener but i also want to be able to raise my door up a little more for some extra clearance.

I have about 10' ceilings right now and my current door tracks are approx 18" below that. ive been reading alot about the high lift kits out there but most of them are for doors that are raising up another 4-5 feet before going horizontal. If i only want to raise the door 14-16" more, do i still need to get new springs and a whole kit or can i just add 14" of vertical track and shift everything up that 14"?

 

[astroracer]

I would get two new, extra-long, verticals and cut them off as long as needed. I wouldn't splice them. That may be okay but I don't know what code is for that.
Mark

 

[77Mini]

I would think you would be fine with the same springs. I am planning on doing something similar for my 2 post lift I bought (10.5" ceiling). You will likely need longer cables and possibly larger cable drums to take up any extra cable from buying longer ones.

 

[Dakota00]

I had my tracks raised about 18" when I got the high lift done. Ceiling is just over 10ft high. Needed new springs, longer cables and larger drums.

 

[DUK]

http://ddmgaragedoors.com/index.php Call Dan, he will answer all your questions and sell you the right stuff.

 

[77Mini]

I had my tracks raised about 18" when I got the high lift done. Ceiling is just over 10ft high. Needed new springs, longer cables and larger drums.

Why do you need larger springs? You are moving the same weight.

 

[superskaterxes]

Why do you need larger springs? You are moving the same weight.

this is the part i diddent understand =P

 

[dave*99]

Why do you need larger springs? You are moving the same weight.

After installing the new tracks, the new springs will need to dead lift 100% of the doors dead weight an additional 16" before the door begins to lay over into the horizontal position.

 

[77Mini]

After installing the new tracks, the new springs will need to dead lift 100% of the doors dead weight an additional 16" before the door begins to lay over into the horizontal position.

Fair enough. Could you not tension the spring a little more to cary that additional weight? I have heard of other who have done this.

 

[superskaterxes]

After installing the new tracks, the new springs will need to dead lift 100% of the doors dead weight an additional 16" before the door begins to lay over into the horizontal position.

why does it take more force to lift the same amount of weight a greater distance? the door isent getting any heavier so unless the spring is just losing some preload during those additional 16" and cannot continue to lift the weight then it sounds like you could just tension the spring a little more? i would be surprised if they sold different springs for a door that was lifted 16" more....

 

[cspcrx]

I would think you would be fine with the same springs. I am planning on doing something similar for my 2 post lift I bought (10.5" ceiling). You will likely need longer cables and possibly larger cable drums to take up any extra cable from buying longer ones.

Same thing here. Now my springs were old so they needed to go. The company that did the install also stated that because the lift is higher the springs are seeing more weight, because the turn to horizontal takes place later in the doors travel.

I also did mine because I have a scissor lift and used the 8500 opener. Great setup and love being able to have the door open and the car at max height.

 

[Dakota00]

Why do you need larger springs? You are moving the same weight.

I never said larger springs. Being as the existing springs were about 12yrs old, made perfect sense to change them out when doing the upgrade.

 

[Pythong]

I'm in the same boat as you and asked the same question:

http://www.garagejournal.com/forum/showthread.php?t=315187

I haven't purchased my upgrades yet but that's the route i'm going. I figured after dropping $7k on doors whats an extra few hundred to do it right.

When i do get them upgraded i'm going to count how many more winds are on the springs out of curiosity. But it is true you will be lifting the doors dead weight for a longer distance before the weight gets offloaded onto the horizontal track. Probably will work at the expense of wearing out the springs more i suppose..

 

[dave*99]

why does it take more force to lift the same amount of weight a greater distance? the door isent getting any heavier so unless the spring is just losing some preload during those additional 16" and cannot continue to lift the weight then it sounds like you could just tension the spring a little more? i would be surprised if they sold different springs for a door that was lifted 16" more....

As a garage door transitions from vertical to horizontal, less force is needed to complete the lift. When you add more vertical track, the springs must dead lift the door further than the original installation. So the springs must be upsized accordingly.

Consider this hypothetical case:

An 8' high door with a 9' ceiling. Door tracks hug ceiling. Door almost immediately begins the transition to horizontal on the way up.

Now think of an 8' high door with a 16' high ceiling. Door tracks are completely vertical and are 16' long.

In the second case the springs must hold the entire weight of the door when fully open. In the first case the springs hold no weight when the door is fully open.

The door weighs the same in both cases.

 

[jstroede]

why does it take more force to lift the same amount of weight a greater distance? the door isent getting any heavier so unless the spring is just losing some preload during those additional 16" and cannot continue to lift the weight then it sounds like you could just tension the spring a little more? i would be surprised if they sold different springs for a door that was lifted 16" more....

Because springs produce less torque for each turn they unwind. Springs store energy are release it as torque on the shaft, inch-pounds per turn (IPPT). For instance a spring with 50 IPPT wound up 10 times produces maximum inch-pounds (MIP) of 500 inch pounds. Now if we are using a standard 4" drum, and the door goes up one turn of the shaft, that is about 13" for this discussion. Now the spring only has 450 inch pounds. If the door is high lifted, then effectively the weight of the door is still the same, but the spring can pick up 25 lbs less door.

I tried to simplify it a little since it would take me more than a couple minutes to type out all the math, but I think this should get you the basics.

And to answer your question about springs, there aren't really springs per weight like say 120 lb extension springs. Springs are normally cut to say the nearst 1/2" in length for the required size. Some places may stock springs for particular sizes and weights of common doors, and cut the rest.

John

 

[bjcouche]

And to take Dave*99 and Jstrode's explination 1 step further,
You need tapered drums (partially tapered, called high lift drums) because that first 18" of vertical lift takes the same amount of force fully closed as it does 18" up, but the springs have already unwound by the time they get to 18" and have less force. If you simply wound the springs tighter (with standard drums), now the door would sit at 18" from the floor and you'd have to force it closed if even possible. The door opener isn't really supposed to do any weight lifting, that's the job of the springs. Thus to fix this you use the tapered drums. The tapered portion of the drum is set up with the proper cable length, so the cable is winding up on the tapered portion when the door is going up from 0" to 18", thus changing the "gear ratio" and providing the door with the same up force even though the torque of the spring is reduced. At 18" the door starts to transition to horizontal, and the cable transitions to the flat portion of the drum. As the drum and spring rotate, less spring torque is needed but less door weight is vertical.

hope this helps rather than confuses. I high lifted a 16wX12h insulated shop door and the springs were required to be WAY bigger.

 

[77Mini]

And to take Dave*99 and Jstrode's explination 1 step further,
You need tapered drums (partially tapered, called high lift drums) because that first 18" of vertical lift takes the same amount of force fully closed as it does 18" up, but the springs have already unwound by the time they get to 18" and have less force. If you simply wound the springs tighter (with standard drums), now the door would sit at 18" from the floor and you'd have to force it closed if even possible. The door opener isn't really supposed to do any weight lifting, that's the job of the springs. Thus to fix this you use the tapered drums. The tapered portion of the drum is set up with the proper cable length, so the cable is winding up on the tapered portion when the door is going up from 0" to 18", thus changing the "gear ratio" and providing the door with the same up force even though the torque of the spring is reduced. At 18" the door starts to transition to horizontal, and the cable transitions to the flat portion of the drum. As the drum and spring rotate, less spring torque is needed but less door weight is vertical.

hope this helps rather than confuses. I high lifted a 16wX12h insulated shop door and the springs were required to be WAY bigger.

The theory about the tapered drums makes sense. I know I will need the new drums and new cables. I am hoping to not have to replace the springs. Hopefully just tension them appropriately. My doors are Insulated 9 wide and 7 tall

 

[jstroede]

If your door is a 9x7, just do it right. To do it right will require a new spring. A new spring for that door is not that expensive.

John

 

[77Mini]

If your door is a 9x7, just do it right. To do it right will require a new spring. A new spring for that door is not that expensive.

John

The setup for my door has 2 springs on each door.

 

[jstroede]

Whether it is one spring or two does not change the price that much. The price is mainly determined by the weight of the spring wire plus the cones. The weight of the wire does not change much whether it is one spring or two.

John

 

[superskaterxes]

so all of this makes much more sense now. My door and springs are only about 2 years old so i did not want to have to replace them so soon. I am going to live with the door for now as i still need to install the lift but later this spring i am going to revisit this. Thanks for all your help guys!!!

 

[Z2V]

My door has 4 springs now in standard installation. It's 16X7 with cedar cover. I want to high lift the door to add four post lift. I received quotes to do the work just going with 2 springs instead of the 4 springs I have now. Any thoughts on this? My thoughts are I would be better with 4 than 2 because if one spring breaks I would loose 25% of my spring tension. With 2 springs, if one breaks I would loose 50%. I know a broken spring has to be fixed either way but am I wrong in my way of thinking?
I don't yet know the exact weight of door. Will buy two scales today to weigh the door.
I'm strongly considering doing the high lift conversion myself.
Any input is greatly appreciated.

Thanks guys

OP, sorry for jacking your thread.��