garage door opener

[fredhargis]

John, no doubt in my mind that the guy in that video is a hack, but it was the first time i had seen the problem I thought they would have. If the overhead track does have some slope in it I can see how the jack shaft opener would work. Thanks for that observation. It does seem that if you loose power, opening that door manually may take a Herculean effort.

[JosephP]

How do you open a garage door with a regular opener when you lose power? There is a release on jackshaft openers as well.

[fredhargis]

What I'm suggesting is that because of a sloped rail and (maybe) a little less spring assist for the Jackshaft, it takes more lift to get it up versus a regular door opener. All that is to make the gravity fall of the door with a jackshaft opener work more smoothly.

[Roly]

What I'm suggesting is that because of a sloped rail and (maybe) a little less spring assist for the Jackshaft, it takes more lift to get it up versus a regular door opener. All that is to make the gravity fall of the door with a jackshaft opener work more smoothly.

The other thing with the horizontal. rail sloped down is what happens when you operate the manual release ? Same issue with pusher springs.    Roly

[JosephP]

What I'm suggesting is that because of a sloped rail and (maybe) a little less spring assist for the Jackshaft, it takes more lift to get it up versus a regular door opener. All that is to make the gravity fall of the door with a jackshaft opener work more smoothly.

The gear box is entirely disengaged.  It's no different lifting the door than if there was no opener installed...just like with a regular opener.

I don't know... maybe some doors are installed differently if they know a jackshaft opener will be used???  But I doubt it.

Of the 5 in my barn:
1) on a 9x7 door that goes straight up (not straight...maybe 10 degree slant - it's on the gabled end of the barn, so plenty of room for that)
2) on 12x12 doors.  The top of the opening is about 2' below where the track goes to horizontal, so about 2' of the door is vertical 
2) on 14x14 doors.  They are completely horizontal when all the way up.

All were installed without openers to save money at construction time.  A year or so later I started putting openers on one at a time.  All were equally easy to lift manually with the spring assist before openers were installed (which hasn't changed).

I'm probably gonna stop trying here.  It is a simple thing and I don't understand the over complications.  I have just  tried to offer feedback because I don't want someone to think they are not an option because of ?????? I'm not even sure what the concern is, honestly.

I've only installed 5 (on the 3 different setups described above), but I cannot imagine too many circumstances where there is a torsion spring that a jackshaft opener would not work.  Not saying they are always the best answer - cost would the main reason to do a traditional opener, IMHO.  I had to use a jackshaft opener on the end door.  The others would have taken a fair bit of construction to mount a traditional opener so it made sense on those as well.

[JosephP]

OK...one more thing I thought of:
There is a cable tension sensor on the opener (it's a physical switch ) If the cable breaks, it will recognize that the cable has lost tension.  Pretty sure it locks the gears in the unit to prevent rapid descent if that happens.  Also prevents using the opening to open the door (which that, or any opener wouldn't have the HP to do anyhow without the spring assist)

IIRC, I did have to mount that just a little lower on the vertical door because it has a bigger diameter pulley that exceeded the reach of that switch.

[Stwood_]

I watched that from your earlier link, and it really doesn't how much on the down operation. Then I looked at the manual and it's not all that clear either. It really looks to me like gravity is what shuts the door, but gravity can't get it started going down like a pull on a cord, or the push that a standard opener provides. That video did explain that the door must be in a well maintained smooth operating condition..which is kind of what I tried to imply earlier. But thanks fro trying to get me over the hump.

Edit in: I just found the video on Utube which points out what I've been saying, that opener can't push the door down. It's alittle long, so if interested go to somewhere around the 14:30 mark and you'll see the problem he had.

https://youtu.be/wIIt-GMECwE?si=_LCuhYGBYSEMZ_oz

In reading this entire thread again, and watching the videos I and you posted.........

Well, hack or not, his push tube is pretty ingenious, which fixed his problem. And it looks professional made.
As already stated, the door uses gravity to start the downward travel.
In all torsion spring doors, with the *normal* out-of-level angled tracks, if you push the door up and remove the cables, the door tends to want to come down, especially if you give it a slight nudge. The springs are holding it up.
The out of level tracks are there for a reason. In the video you posted, I believe his problem is/was that he has low clearance tracks, which set level to the low ceiling he has. You can see that in about 22.00+

Now, I've only worked/helped install one of these jack shaft openers, which worked fine afterwards. And I don't remember the brand, but it did *not* have the loose cable sensor system. Maybe that's a later engineered item. Dunno.

[fixtureman]

I have installed hundreds of doors and a properly adjusted door will stay up with no help raise the door and it should not come back down.

[fredhargis]

This has been very interesting to me. I can see the advantages of a jack shaft opener with having no hardware overhead but it's unlikely I would ever want one. When going through the manual for the jackshaft, i saw that cable tension monitor. I can only imagine if the thing kept running and the door didn't come down it would be an unholy mess so it was probably a welcome addition when ever they added it. But my only experience with a door being up and no spring tension was when my spring broke. Once i got the door open (which wasn't easy at all) it stayed up with no tendency to come down...part of what got me going on this extended diatribe. So again, i thank everyone for this discussion which has been enlightening for me.