3 ms·

At my home country we used counter-weights, pulleys and cables. Took more space, it is arguably uglier (but who cares how it looks on the inside?) but the cable

At my home country we used counter-weights, pulleys and cables. Took more space, it is arguably uglier (but who cares how it looks on the inside?) but the cable usually lasts for ages and fixing it is not a life-threatening procedure.

elzbardico 3y ago
Torsion springs are BMWs, the expensive, over-engineered, beautiful, high performance style of doing this. Most of use would be just fine with a Toyota instead.
LeifCarrotson 3y ago
How does a counterweight work? A torsion spring is great because as it unwinds, the tension decreases. As the garage door transitions from 200 lbs of vertical load in the closed position to almost 0 lbs when it's mostly parallel to the ceiling, a properly sized and wound spring reduces the force in synchrony with the door position. Wouldn't a counterweight provide insufficient force at the bottom and/or excess force at the top?
- Horffupolde 3y ago
  It’s like for an elevator. The motor is there for the friction but the potential energy of the system is approximately constant.
  - sokoloff 3y ago
    An elevator on the ground floor and an elevator at the top floor have the "same" weight. Not so for a 100%, 50%, and 0% open garage door. The 0% open door is the full weight; the 100% open door has very little weight (as most of the door is on the horizontal track).
- cyberax 3y ago
  You use multiple weights that telescope into each other ( https://www.hermco.ca/products/2000-series/ https://www.hermco.ca/products/2000-series/ ), or a segmented counterweight (Kelley E-Systems one company that does this). But they require space and a sturdy housing. Springs are as compact as you can get. There are also some safety concerns, a cable connecting the door to the counterweight can break, and/or slip. This can result in pieces of metal flying everywhere. A broken spring typically stays contained. Personally, I would do one of the counterweight systems for my new house.
alliao 3y ago
oh that is cool what country is that? I'd like to check them out. Honestly sounds really good.
- elzbardico 3y ago
  Brazil. Actually I found out that now the more popular system for this kind of door there doesn't even use counterweights or springs, but an endless screw inside a rail or a linear gear. https://ppa-rp.com.br/item/motor-de-portao-basculante-ppa-home-jetflex-14-hp-abertura-rapida https://ppa-rp.com.br/item/motor-de-portao-basculante-ppa-ho... max door weight = 250kg https://ppa-rp.com.br/item/motor-de-portao-basculante-ppa-bv-condominium-jetflex-12-hp-braco-150-mts-abertura-rapida https://ppa-rp.com.br/item/motor-de-portao-basculante-ppa-bv... max door weight = 500kg For reference: 5.0 R$ ~= 1.0 USD 250 kg ~= 550 lbs

elzbardico 3y ago

Torsion springs are BMWs, the expensive, over-engineered, beautiful, high performance style of doing this. Most of use would be just fine with a Toyota instead.

LeifCarrotson 3y ago

How does a counterweight work? A torsion spring is great because as it unwinds, the tension decreases. As the garage door transitions from 200 lbs of vertical load in the closed position to almost 0 lbs when it's mostly parallel to the ceiling, a properly sized and wound spring reduces the force in synchrony with the door position. Wouldn't a counterweight provide insufficient force at the bottom and/or excess force at the top?

Horffupolde 3y ago
It’s like for an elevator. The motor is there for the friction but the potential energy of the system is approximately constant.
- sokoloff 3y ago
  An elevator on the ground floor and an elevator at the top floor have the "same" weight. Not so for a 100%, 50%, and 0% open garage door. The 0% open door is the full weight; the 100% open door has very little weight (as most of the door is on the horizontal track).
cyberax 3y ago
You use multiple weights that telescope into each other ( https://www.hermco.ca/products/2000-series/ https://www.hermco.ca/products/2000-series/ ), or a segmented counterweight (Kelley E-Systems one company that does this). But they require space and a sturdy housing. Springs are as compact as you can get. There are also some safety concerns, a cable connecting the door to the counterweight can break, and/or slip. This can result in pieces of metal flying everywhere. A broken spring typically stays contained. Personally, I would do one of the counterweight systems for my new house.

alliao 3y ago

oh that is cool what country is that? I'd like to check them out. Honestly sounds really good.

elzbardico 3y ago
Brazil. Actually I found out that now the more popular system for this kind of door there doesn't even use counterweights or springs, but an endless screw inside a rail or a linear gear. https://ppa-rp.com.br/item/motor-de-portao-basculante-ppa-home-jetflex-14-hp-abertura-rapida https://ppa-rp.com.br/item/motor-de-portao-basculante-ppa-ho... max door weight = 250kg https://ppa-rp.com.br/item/motor-de-portao-basculante-ppa-bv-condominium-jetflex-12-hp-braco-150-mts-abertura-rapida https://ppa-rp.com.br/item/motor-de-portao-basculante-ppa-bv... max door weight = 500kg For reference: 5.0 R$ ~= 1.0 USD 250 kg ~= 550 lbs