Extending a car lift arm

[Lucid Moments]

So I do most of my work by myself and find myself occasionally needing to get stuff out of my truck that weighs more, or is bigger than, I can conveniently lift by myself. As an example I picked up a tanker desk from u/Pathfinders today. As a desk it is fairly heavy. Certainly more than I can lift by myself. But at the end of the day it is still just a desk. It might be 200 lbs. Four people put it into my truck very easily.

I was trying to unload it after I got home. By myself. I couldn't get it done. One way I tried was to extend the arm on my Atlas PV10P lift as far as it would go to see if I could use that to suspend the desk. Unfortunately it would not reach far enough to lift the desk.

The arm is a piece of square tubing roughly 3.25" X 3.125". It is retained by a set bolt and would be easy to replace.

The question is could I replace that with a longer piece of steel and use that to lift things out of the bed of my truck. Clearly I am not talking about truly heavy items. Off the top of my head I am thinking 500lbs tops. Clearly the issue here isn't the strength of the arm or hydraulics, but the balance of the load and the strength of the anchors in the concrete at the base of the lift column. How much is safe? If I add a counter weight does that increase the limit or just further unbalance the load?

As usual all thoughts are welcome.

 

[ItsNemo]

Do it bridge style...a fairly hefty steel beam running between arms from each post and some sort of cross piece so you can use both arms too. That way the lift would be properly loaded.

 

[matt_i]

Along the lines of ItsNemo, I would remove 2 pads, create a cross-beam with same dia & length pads that you put in place as a bridge between two arms.

Use as close to the centerline between the two posts as possible.

 

[Scud67]

Put the lift up, drive truck under lift, move the lift arms so they are above the load, use strap/ cables to lift load off of truck, drive truck out and lower the load.

 

[firebirdparts]

It’s a lot easier to just bridge over for something that light. A 2 by 4 is good enough for that. I pick up my lawn tractor with a 2 by 4 bridge.

An alternative that might be good for more weight, but not involve a lot of work, would be to take out the inner arms and put in a long square tubing that went all the way across the bay. Connect two arms straight.

 

[Lucid Moments]

Problem with the bridge mode is that it requires the lift to go high enough to get over the load. Modern pickups are so damned tall that it doesn't take much to make that a little difficult sometimes.

 

[pmiranda]

I don't think a bridge would be much higher than just putting a strap around the item and the lift arm... or are you trying to get the lift arm under the object? That seems pretty likely to get out of control...

Just had another thought: I've seen many 2-post lifts with a cross brace on top. Some already have a hook-eye with a rated loading. I'd think if yours doesn't already have one you might be able to add one that just sits on top of the posts when the lift is down. I'd weld some tabs on the ends to "cup" the tops of the columns so it can't slip off. Can't put side load on it, and don't forget to take it off or the lift cylinders wouldn't be happy.

Of course, never modify a lift without the blessing of the manufacturer, your mileage may vary, you'll probably die and burn your house down.

 

[Lucid Moments]

I am trying to figure out a way to get the lift under the load. My lift has a foot, maybe 18 inches over the bed rails. I would have to measure to be sure. That isn't a lot of room to allow for any slack, and that is also assuming whatever I am trying to lift is not taller than the bed rails. My truck is at factory height too BTW.

It may not be worth doing for cost and safety reasons, but I just want to explore my options.

 

[firebirdparts]

Okay, I am with you. I hang stuff by running chains and straps from arm to arm, but of course I am aware of the forces on the arms and I act accordingly (I got straight A's in engineering science and mechanics).

Anything that requires you to "act accordingly" is usually fodder for a couple pages of posts. Just know that I know that there is some force involved in 3 dimensions.

To answer your original question, the answer is "yes" but you may not want to add all the features that your current arms have, and so they could slip out. Also, you will have to derate the lift yourself in your head.

 

[Lucid Moments]

Also, you will have to derate the lift yourself in your head.

Oh absolutely. The lift is rated at 10K lbs. So for the sake of discussion each arm could be argued to be rated at 2500 lbs. Using one arm unbalanced the way it would be and with a longer arm on it at that I wouldn't consider lifting anything above about 500 lbs. I might consider higher load than that with a counter balance on it. The weak point is not the arms, and certainly not the hydraulics, but where the post anchors into the concrete.

 

[vision8]

Support a plywood sheet from the arms of the hoist . Back truck up to elevated plywood . Roll , push, slide desk onto plywood. Drive truck away . Lower desk onto dolleys or floor . Done !