4 post lift design question

[mikedodge]

Nieusence = several more steps?


Correct, if your floor is level, the adjustable lock ladders don't offer much benefit for you. In that case, I'd focus more on other upgrades, like hidden/protected lock linkages, cables tucked into the columns, etc. BTW, I skipped over it before, but your statement in post #19 is not correct. The runways should not be supported by the cables when all the way down.

It is a nieusence it causes upto 3 more points that need to be adjusted vs nothing to get adjusted at all once the columns are leveled. Like I said it's not an upgrade at all its a different way of doing things.

On some the cables act the same way as 2 post lifts that they push and pull to keep the lift rising evenly. Looking at instructions for Bendpak with the adjustable safety it looks like there's only the one ram and it moves them all at once so you're right they wouldn't support anything all the way down unless something was not level and way out of whack.

 

[racecougar]

It is a nieusence it causes upto 3 more points that need to be adjusted vs nothing to get adjusted at all once the columns are leveled.

I just picked up that you mean nuisance. It would be a pretty minor inconvenience to set the lock ladder heights while setting the cable lengths if you have a flat floor. On the other hand, if you have a sloped floor, it's one heck of a benefit. Take the example of a floor sloped toward the overhead door. With the square tube / box column type, you're stuck shimming the posts to get the runways level while you're on the locks. Now the ramp side of the runways sits an inch or more higher than the floor level, making the ramps even steeper, which is a real issue for low cars. With adjustable lock ladders, the runways sit on the floor when down, but level when on the locks.

Like I said it's not an upgrade at all its a different way of doing things.

It is an upgrade in the fact that it is an additional feature above and beyond the square tube / box column type.

On some the cables act the same way as 2 post lifts that they push and pull to keep the lift rising evenly.

What lift is pushing cables?

Looking at instructions for Bendpak with the adjustable safety it looks like there's only the one ram and it moves them all at once so you're right they wouldn't support anything all the way down unless something was not level and way out of whack.

Yep. The runways should not be supported by the cables when all the way down.

 

[mikedodge]

I just picked up that you mean nuisance. It would be a pretty minor inconvenience to set the lock ladder heights while setting the cable lengths if you have a flat floor. On the other hand, if you have a sloped floor, it's one heck of a benefit. Take the example of a floor sloped toward the overhead door. With the square tube / box column type, you're stuck shimming the posts to get the runways level while you're on the locks. Now the ramp side of the runways sits an inch or more higher than the floor level, making the ramps even steeper, which is a real issue for low cars. With adjustable lock ladders, the runways sit on the floor when down, but level when on the locks.


It is an upgrade in the fact that it is an additional feature above and beyond the square tube / box column type.


What lift is pushing cables?


Yep. The runways should not be supported by the cables when all the way down.

It's not really an additional feature either, again it's only a different way of doing it.
Even with the adjustable lock ladder the installation instructions still say the 4 posts should be installed as level as possible and to shim them as required so you're not supposed to be depending on the adjustable lock ladder to be doing much of the leveling.

 

[whateg01]

On some the cables act the same way as 2 post lifts that they push and pull to keep the lift rising evenly.

What lift is pushing cables?

It would be like pushing a wet noodle!

 

[kngelv]

It's not really an additional feature either, again it's only a different way of doing it.
Even with the adjustable lock ladder the installation instructions still say the 4 posts should be installed as level as possible and to shim them as required so you're not supposed to be depending on the adjustable lock ladder to be doing much of the leveling.

Exactly! He also conveniently ignores the ladder type wobble and having to anchor the posts as Bendpak for example advises. What good are casters if your lift is bolted to the floor. That looks like a useless feature.

James

 

[firebirdparts]

So I guess if its a little off +- 1/4" everything has enough slop or flex to compensate.

They will certainly flex, but it's not a good idea in my opinion. The 4 post lift relies on sliding moment connections at all the legs to avoid just falling over. That's all that stops it from collapsing. If I had one, I'd abuse that as little as possible and I'd certain prefer bolting it to the floor.

 

[finn]

They will certainly flex, but it's not a good idea in my opinion. The 4 post lift relies on sliding moment connections at all the legs to avoid just falling over. That's all that stops it from collapsing. If I had one, I'd abuse that as little as possible and I'd certain prefer bolting it to the floor.

I’ve never encountered a condition where I felt either of my advantage lifts moved around or would be more stable if bolted to the floor.

The carrier has nylon or poly sliding guide blocks and I don’t see any binding. The forces are pretty much normal to the floor and I haven’t observed any walking.

An alignment lift in heavy commercial use daily, with multiple operators should be bolted down, but one of the main draws of a four post lift for a hobbyist is portability.

 

[racecougar]

It's not really an additional feature either, again it's only a different way of doing it.

The square tube/box column lifts have adjustable lock heights? It is an additional feature.

It would be like pushing a wet noodle!

My thoughts exactly. I'd love to know what lift is relying on pushing cables to hoist a vehicle in the air.

He also conveniently ignores the ladder type wobble and having to anchor the posts as Bendpak for example advises.

Yes, I was skipping over the Backyard Buddy ad reference out of decency. Same goes for the additional design issues posed by the square tube / box column path. I can provide some insight that in real life, where Backyard Buddy doesn't assemble the adjustable lock ladder type lift, it sure doesn't shake like that.

What good are casters if your lift is bolted to the floor.

I'll take that sentence as a question and provide a real-world answer. If you want to bolt a 4-post lift to the floor, but retain the ability to easily relocate it using a caster kit, utilize drop-in anchors. These sit flush, or just below flush, with the floor surface so as not to impede moving the lift or causing a trip hazard. That said, many folks don't bolt down their 4-post lifts.

 

[mikedodge]

The square tube/box column lifts have adjustable lock heights? It is an additional feature.

It's not an additional feature when it's not needed with a different design. An additional feature is like being able to get the wheels to move it around.

 

[racecougar]

An additional feature is like being able to get the wheels to move it around.

Or to be able to adjust for uneven floors?

A second take on this, in regards to your first sentence: wheels aren't needed. If those are an additional feature, adjustable lock ladders are as well.

 

[mikedodge]

Or to be able to adjust for uneven floors?

A second take on this, in regards to your first sentence: wheels aren't needed. If those are an additional feature, adjustable lock ladders are as well.

Shim it. Different way of doing things for different designs.

Without Wheels you can't move it.

Being able to get a rolling bridge jack for it is another additional feature.

 

[racecougar]

See post #42 regarding shimming. That would be a downgrade vs adjustable lock ladders.

 

[mikedodge]

See post #42 regarding shimming. That would be a downgrade vs adjustable lock ladders.

See post #43. Even with adjustable lock ladders as per the manufacturers instructions the lift is supposed to be shimmed to be as level as possible so it shouldn't be sitting an inch or more off to begin with.

 

[racecougar]

See post #43. Even with adjustable lock ladders as per the manufacturers instructions the lift is supposed to be shimmed to be as level as possible so it shouldn't be sitting an inch or more off to begin with.

Installation instructions vary here. For example, Direct Lift & Forward mention that if the installer chooses to add shims to plumb the columns (only if the installer is choosing to bolt the lift to the floor), that the shim thickness is not to exceed 1/2". The runway level is to be adjusted by the lock ladder heights.

At the end of the day, I believe we've answered the OP's question satisfactorily. The adjustable lock ladders are capable of supporting FAR more weight than the lift is rated for.

 

[mikedodge]

Installation instructions vary here. For example, Direct Lift & Forward mention that if the installer chooses to add shims to plumb the columns (only if the installer is choosing to bolt the lift to the floor), that the shim thickness is not to exceed 1/2". The runway level is to be adjusted by the lock ladder heights.

At the end of the day, I believe we've answered the OP's question satisfactorily. The adjustable lock ladders are capable of supporting FAR more weight than the lift is rated for.

Direct lift also mentions that if one colum needs to be raised to match the plane of others that full size base shim plates should be used, but no mention of thickness.
BendPak notes it's to be installed as level as possible and to shim as required. Without adjustable lock ladders there's no more work it's done.

You're right there shouldn't be any worry about weight issues one way or another. It comes down to preference and getting the right lift that suits your needs. These have been around long enough with sold from multiple vendors that if something was failing we'd be hearing about it.

 

[racecougar]

You're right there shouldn't be any worry about weight issues one way or another.

Yep.

 

[kngelv]

Yes, I was skipping over the Backyard Buddy ad reference out of decency. Same goes for the additional design issues posed by the square tube / box column path. I can provide some insight that in real life, where Backyard Buddy doesn't assemble the adjustable lock ladder type lift, it sure doesn't shake like that.

No ad. There are plenty of decent square tube style lifts by other companies. I just happen to own that brand which is why I posted a pic of mine. You are just pontificating and posting a bunch of half truths about them.

 

[racecougar]

No ad. There are plenty of decent square tube style lifts by other companies. I just happen to own that brand which is why I posted a pic of mine. You are just pontificating and posting a bunch of half truths about them.

Was there not just a conversation on this forum about gaslighting? I am not disparaging the square tube lifts other than to point out the lack of adjustability for uneven floor surfaces. The same cannot be said in the other direction. The fact that all of this animosity spurred simply from pointing out the upgrade/downgrade of adjustability between designs is pretty amazing to me. Again, the OP was worried about the strength of the lock ladder stems, which as pointed out, is a non-concern. If the OP remains concerned, he/she could certainly buy a square tube type lift.

 

[mikedodge]

Was there not just a conversation on this forum about gaslighting? I am not disparaging the square tube lifts other than to point out the lack of adjustability for uneven floor surfaces. The same cannot be said in the other direction. The fact that all of this animosity spurred simply from pointing out the upgrade/downgrade of adjustability between designs is pretty amazing to me. Again, the OP was worried about the strength of the lock ladder stems, which as pointed out, is a non-concern. If the OP remains concerned, he/she could certainly buy a square tube type lift.

If they're both leveled like they're supposed to be theres no reason to have any extra adjustability. There is no reason at all to choose one over the other. People should get whatever make/model suits them best. At the end they all serve the same purpose.