4 post lifts that require being bolted down. Why?

[ybnormal70]

Why do some 4 post lifts have to be bolted down and some don't? Yes I know, ask the manufacturer, I did. I asked Worth about the 12000EWT that I just received and the answer was "Yes the lift has to be bolted down this is a Heavy Duty Commercial 4 Post, Not a parking / Hobby 4 Post". My question still remains, why???

My particular lift in question:

http://www.worthequipment.com/4postlifts.htm

Is it just because of the weight rating, the design itself or what? It seems to me that all the forces applied during a lift would still be straight down on the 4 posts and the top beam where the cylinder is would stop any movement of those 2 columns.

I know in the end I will be bolting it down, I just want to know why....

Kevin

P.S. Here are more examples of this type of lift and ALL say they have to be bolted down:

https://www.bestbuyautoequipment.co...dustries-wfp12r-e-12k-lbs-p/whip-wfp12r-e.htm

https://www.bestbuyautoequipment.com/4-post-car-lift-al4-14k-chain-driven-14000-lb-p/al4-14k.htm

https://www.bestbuyautoequipment.com/challenger-44018-medium-duty-4-post-vehicle-lift-p/44018.htm

 

[ezover]

only a guess, but if you max out the weight there mite be concern about side to side racking.

 

[ybnormal70]

That's really the only thing I can think but wouldn't that be the same concern even when maxing out a 9000lb lift?

Kevin

 

[59 wagon man]

probably a insurance thing

 

[JRC3]

These are pretty good examples of why.

 

[ybnormal70]

Yet those look like lifts that don't require being bolted down.

Kevin

 

[wssix99]

Bolting down any lift (whether the manufacturer requires it, or not) will make it stronger.

When a load on the lift at height, there will be rotational forces around the legs and they will have a tendency to splay outward. A newborn horse deals with this same issue:

Bolting to the floor constrains the legs and helps resist these forces.

 

[Firebrick43]

As weights go up being lifted the equipment not only is heavier but is more apt to be less balanced, taller center of gravity, and greater racking forces generated while servicing. Never would consider a 42" 3/4 drive ratchet on a corvette but on a one ton truck with rusty spring bolt or a forklift, sure.

All these things together put great strain at the joints and legs. This could be taken care of by making the legs much larger in outside dimensions but then people find it inconvenient and objectionable. While thicker walls helps shear and bending strength some what, it's no where near as effective as increasing the outside dimensions of a beam or tube. . The other option is to solidly bolt it down which minimizes bending in the legs and makes a box structure as the floor is now acting as a beam and intergral member of the lift. One little principal to show it. A 2x6 is twice as strong in bending as a 2x4 even though you didn't double the amount of wood. A 2x8 is nearly twice as strong as a 2x6 or 4 times that of a 2x4 even though you only doubled the wood and is twice as sting as a 4 x4 even though it's has the same amount of wood in it.

Engineers have lots of masters wanting different things and every element is a compromise.

They are tailoring the design to the average customer. The average customer of a 12k+ lift is a commercial shop and would bolt down any lift

I am sure the engineers would love to make it a requirement to bolt down 8k lifts but a larger portion of the customers see portability as a feature.

 

[WhiffySpark]

I would bolt it down for the simple fact I would think it would slide forward when loading a car. Sometimes we would drive a car back and forth on the lift to find a noise. Etc.

I'm not comfortable with it not being bolted down. Just my opinion

 

[polizei1]

Bolt it down. The difference between the two are pretty drastic IMO, there was a noticeable wobble/rotational force when it wasn't bolted down. It's much more sturdy after being bolted.

 

[rburke65]

The 4 post lift legs, that the red GTO is....was....on, look pretty small. Would live to know who mfg. that.

 

[ybnormal70]

I believe that black lift with the red GTO is a Direct Lift Pro Park something or other.

I do plan to bolt it down, although I would love to not have to and be able to move it around if needed without drilling holes again.

Kevin

 

[Stuart in MN]

I think it has to do with how the lift itself is constructed, and how the crossmembers are connected to the uprights. Some designs are going to be naturally more stabile when lifted than others.

 

[Bobf]

The pix with the GTO appears the left column latch is down at least one if not two positions on the ladder. Looks like the secondary didn't catch either. I wonder if tipping allowed the latch to pop out of the ladder?
I have the same basic 8K china lift, and neither garage has a high ceiling so I use it outside, not bolted down. It is currently on the apron of the detached garage, and the apron has a strong 2 degree-ish slope for run off. I haven't experienced any tilting or wobbling with a couple trans swaps. oil changes etc.
Definitely something to be aware of of course.

 

[PoorOwner]

It has happened to me for the platform to catch at different slots.
this was during testing and no car on it. But it was a valuable lesson on how to use a 4 post lift.

I was lead to believe during descending you can just let go on the lock release handle at anytime and let it catch onto the next one down. The further end pair of posts happened have a fraction of a second of delay due to all the rods, or may just be slightly higher to catch the higher slot, then the other end that missed the same slots cannot will not descend too much further but are hung up. I got really lucky for that few milliseconds window to make it happen.

After this, I let go of the hydraulic so it is holding everything up, go around to make sure all 4 locks will be down on the same slots, then drop it down. Chances are it almost 100% will be, but a few more seconds to do this check is much safer.

4 posts are fairly fool proof when going up, but you need to be extra careful when having it come back down. (and that goes with any lifting equipment)

 

[lakeroadster]

Once the legs are bolted to the floor the rigidity of that connection adds to the rigidity of the structure.

If the lift was engineered assuming this rigidity, then the lift must be bolted down.

Just that simple.

 

[ybnormal70]

Guess the kicking mechanism on the Worth may be better on that there is only 1 single point locking mechanism. Each post has slack chain emergency stops that lock in any position also. Seems that would stop any problems with lock engagements.

Kevin

 

[JRC3]

I would think a potential latch/catch/balaning malfunction or whatever is just another reason to bolt it down. In that case I'd assume having it bolted down would keep a bad situation from getting far worse.

 

[Oldbear]

I believe that black lift with the red GTO is a Direct Lift Pro Park something or other.

I do plan to bolt it down, although I would love to not have to and be able to move it around if needed without drilling holes again.

Kevin

I plan on using internal (flush mount) with the bolt going into (down) the anchor. I can then undo the bolts and move the lift if need be. Even an extra set of anchors in the other bay. More flexibility without any hardware sticking out of the ground.

 

[lakeroadster]

The 4 post lift legs, that the red GTO is....was....on, look pretty small. Would live to know who mfg. that.

Looks just like the Direct Lift I used to have...

 

[Lotek]

I've worked under some sketchy equipment over the years...but a hoist that isn't bolted to the floor? Not on your life! I don't care if some pointy headed engineer/marketing type says it's safe, he isn't the one working under it.

 

[denis4x4]

Bought a Backyard Buddy almost 20 years ago and have never bolted it down. The BYB cross pieces slip over the solid 4"x4" tube posts and the safety catch slots are actually cut into the posts. I did buy a retro fit safety catch kit that replaced one that did not always release and caused the ramps to twist.

 

[ybnormal70]

It seems there are a lot of lifts that are not bolted down that have had no problems. I know I am going to bolt it down as it says, I just hate making things permanent in the shop. Love being able to move things around when/if the need arises.

Kevin

 

[sidd_V]

I have the same problem with placing a lift in my workshop. The workshop has a very uneven slab and not enough thickness for chemical anchors.
My idea was to make a sheetmetal framework (5mm thick) connecting the post to keep them sliding outward and adding 4 adjustable feet to stabilise everything.
With a little engineering you could adjust the idea and add some (temporary) adjustable castors to move it when needed.




Verstuurd vanaf mijn SM-G920F met Tapatalk

 

[jinman]

The C Channel post design just worries me in general. I know there's a million of them out there operating safely, both bolted and unbolted, I just couldn't bring myself to going with one. I think the lifts that utilize the solid square post with holes cut out for locks and slider design seem to do better with being left unbolted.

 

[jinman]

Looking at those pictures of lift failures, it appears to me that the force of movement on the posts is a sliding "side to side" force, not an upward lift force. Why couldn't you drill a nice clean hole in the concrete slab at each corner and drop a steel pin of similar size through the the hole in the post footing plate and into the hole in floor. Then, when you want to move the lift around, simply pull the pins and move it. Seems like that would eliminate the possibility of the posts from sliding one way or the other under load and be easier than unbolting and rebolting everytime you want to move the lift around.

 

[ybnormal70]

For me at least, I want a lift I can just nice to another location if plans in the shop change. I'm not wanting to just move it and put it back in the same location.

I like the idea of the metal framework to keep things in place.

Kevin

 

[86turbodsl]

Good question. I've got the exact same type of lift as you're asking about and am an engineer, i've looked at the design a bit. What i think makes these lifts different than some of the ones that don't require bolting is that the connection for the cross bars includes a pivot for the secondary/emergency lock mechanism. That would allow side forces to allow rotation of the cross bars around the pivot and it could fall over. Granted, it's probably unlikely, but i think it would be possible. My opinion. I didn't design it so take it with a grain of salt.

 

[c39er]

The horses legs look to be as big as the Direct Lifts legs!
Slim and winky.
That's a problem on the lift.

 

[ybnormal70]

Going to say I think I might have found the reason for bolting this style of lift down. Kind of seems obvious after starting to assemble it. The 2 posts with the large top cross rail and hydraulic cylinder are very tippy. I would think that could be the very reason. I know most 4 posts the posts are easily moved when nothing on them, but this one has some serious weight on the very top of it and would bet that if it wasn't bolted down and you had the runways off the ground that the whole thing could just tip over very easily.

Kevin

 

[Krylon32]

Just installed a new 4 post lift and even though it seemed stable unbolted I elected to bolt it down as I don't figure I'll move it in my lifetime.I feel a lot more secure with it bolted down.