Engine hoist capacity beware

[KenC]

One of the reasons I opted for folding legs: six wheels rather than the four used on extendable legs. That really makes it less wobbly when moving while loaded.

Mine has swivel casters at all six points making it kind of hard to steer, but it works.

it is a no name unit purchased from a wholesaler years ago when I was in a resale business.

Take a look at surpluscenter.com for caster replacements. I bought replacement wheels for y HF tool box there when the urethane broke of the originals. Lots of good choices and cheaper than most. They have a good search/selector function too to pick size/weight/swivel etc.

 

[whateg01]

One of the reasons I opted for folding legs: six wheels rather than the four used on extendable legs. That really makes it less wobbly when moving while loaded.

...

Take a look at surpluscenter.com for caster replacements. I bought replacement wheels for y HF tool box there when the urethane broke of the originals. Lots of good choices and cheaper than most. They have a good search/selector function too to pick size/weight/swivel etc.

On every hoist with folding or removable legs that I've ever used or seen, only four casters ever contacted the ground once assembled. On my smaller one with removable legs the rear most casters lift as soon as a load is lifted. On the ones with folding legs, the middle casters had to be lifted off the ground to get the pins in the legs.

I've always wondered in the stuff from surplus center is of good quality. I looked at hydraulic parts there but I've never bought anything from them.

 

[MushCreek]

I'm planning to replace the front casters on mine with something bigger and stronger. They take most of the weight, and mine are very hard to steer with a load. I'm going to weld up some brackets to accommodate the taller casters so the thing stays level. Something like these:

http://www.steelcasterstore.com/5-x-2-cast-iron-wheel-swivel-caster-1-200-lbs-capacity/

 

[whateg01]

The best casters for swiveling under a load are kingpinless casters, but they tend to be $$$. I am sure those are going to be better than the OEM casters, though. Some of the larger, more expensive versions use something more like a pallet jack handle for steering, along with the large wheels there. That, along with some smaller casters slightly in the air on the rear corners to keep from tipping, would help a lot in maneuverability, I would think.

Dave

 

[u2slow]

I'm planning to replace the front casters on mine with something bigger and stronger. They take most of the weight, and mine are very hard to steer with a load. I'm going to weld up some brackets to accommodate the taller casters so the thing stays level. Something like these:

http://www.steelcasterstore.com/5-x-2-cast-iron-wheel-swivel-caster-1-200-lbs-capacity/

I think that's about the size I put on mine. Installed 4 so it stays level. Kept 2 of the small ones under the middle - they only contact the ground (and see use) when its folded up.

 

[finn]

My very first sentence in that reply said, assuming the load doesn't move fore/aft, the load on the casters will remain the same so statics says I'm right. If the load starts swinging, that's a different story. I should clarify that the same is true for left/right weight distribution. If the boom is hanging in the center of the perfectly level hoist, the left/right distribution will remain the same whether the boom is all the way up or all the way down. That is something that should be paid attention to also, as not all booms travel straight up the center of the hoist, and side ways on a hill, the boom could easily extend past the vertical plane of the casters.

Lowering the load reduces the load on the boom/mast and lowers the cg, but if the cg is 10" behind the front casters while it is in the air and 10" behind the front casters when it is sitting on the legs, the weight on each caster remains the same. Lowering the boom may make that better or worse. On small items with not much height, where the load can be kept close to the boom, as it swings downward, below horizontal, the load does come closer to the mast. However, that's not always the case. When lifting my surface grinder, the boom was above horizontal when the grinder was on the ground. So, lowering it actually moved the cg farther forward. I had the legs extended far enough forward to not be a tipping hazard, and I still lowered the load to get the cg as low as I could for an already top-heavy item.

I've stated several times that I am well aware that making the front casters fixed increased the side load. I think I stated that in the first post. These particular casters do not take that well, unlike better casters from other manufacturers that are rated for far less weight than these apparently are.

Mention of similar failures on hoists that have not been modified in this way support rating these wheels at a lower weight. Comparison of reputable caster manufactures' wheels and their weight ratings to these support the same.

Dave

If the load is hanging off a boom chain 10 inches behind the front casters, considerably more weight will be on the front casters than on the rear casters, unless the “wheelbase” of the lift is only 20 inches.

Statics

I’m not defending the cheap imported lifts or their wheel design, either.

I have a couple, and, while they serve a purpose, I cringe any time I see one in a commercial venue. They are inexpensive and likely underengineered, if they are engineered at all.

The alternative is to have some sort of certification bureaucracy and homolgation process, which would either stop the capacity overrating as currently advertised, or drive the cost and design to the level of existing commercial equipment.

No free lunch here. Buy cheap-get cheap.

 

[whateg01]

If the load is hanging off a boom chain 10 inches behind the front casters, considerably more weight will be on the front casters than on the rear casters, unless the “wheelbase” of the lift is only 20 inches.

Statics

Ah, I see where the misunderstanding is. But my original statement is still as correct now as it was then. You seem to have misunderstood my statement about the loading not changing. You also seem to think that the person I responded to, by lowering the load, is somehow more evenly distributing the weight over the casters. That's not why he did it, and I never said that doing so causes the loading of the casters to become or not become equal. I simply stated that lowering the load does not alter the distribution of that weight. So, aside from the examples given where the load moves fore or aft when lowering, the distribution of the weight of the load still remains unchanged. I hope that clears up what "Assuming the weight is at the same place fore/aft, the weight distribution doesn't change." means.

Dave

 

[finn]

Ah, I see where the misunderstanding is. But my original statement is still as correct now as it was then. You seem to have misunderstood my statement about the loading not changing. You also seem to think that the person I responded to, by lowering the load, is somehow more evenly distributing the weight over the casters. That's not why he did it, and I never said that doing so causes the loading of the casters to become or not become equal. I simply stated that lowering the load does not alter the distribution of that weight. So, aside from the examples given where the load moves fore or aft when lowering, the distribution of the weight of the load still remains unchanged. I hope that clears up what "Assuming the weight is at the same place fore/aft, the weight distribution doesn't change." means.

Dave

Lowering the load does affect the polar moment of inertia of the load / lift system, which will in turn change loading on the caster, specifically the web, as the lift is moved.

 

[whateg01]

Lowering the load does affect the polar moment of inertia of the load / lift system, which will in turn change loading on the caster, specifically the web, as the lift is moved.

You just want to pick little bits out of what I post without reading the whole thing, don't you? Last sentence of the first post about the cg says: "...unless it's swinging around."

 

[BFBOB]

On my hoist, not HF but a cheapazz clone (Or maybe not! Gift to us from FIL!) Lowering the boom CAN move the COG rearward, if it's level. If it starts above level, lowering it moves the COG forward, then rearward as it passes through level.
It all depends on how high you have to lift your load, and how low you can lower it.

but, as for swinging the load, nothing works like a gravel driveway!!

In this case, I ended up moving one "corner" of the lift an inch at a time with a pinch bar. Slow, tedious, but safe. Got the job done without dropping the $$$load$$$.

 

[Kev442]

You just want to pick little bits out of what I post without reading the whole thing, don't you? Last sentence of the first post about the cg says: "...unless it's swinging around."

And you want to assume that the load is perfectly balanced on a cheap hoist with the boom extended. Believe me when I say that the engineering of the typical cheap hoist is way off. I have had to put my foot on the back of it to keep the casters touching the ground on several occasions, meaning it is at best a 70-30 situation.

Anyway, the load on the casters changes as the boom is lowered, bringing the center of weight more to the center. As it is set onto two 4x4's, one almost to the ram, the weight is distributed almost perfectly centered.

 

[Lonnies Performance]

I unfortunately dumped a Duramax Diesel engine off of my hoist one time due to the top boom being extended too far. It was working fine until I pushed it across the garage, where it caught something on the floor that stopped 1 wheel. It swung & the back wheels came off the ground. I immediately jumped on the back to hold it down, but to no avail. The engine landed on the oil pan & cracked it. Mental note, always extend the legs further.... you can overlook it when its pushed under the vehicle & you need more reach, so you extend the boom, then it flips on you later as I did.

 

[chipjumper]

This is full of tools. Weighs and ungodly amount. Harbor Fright crane fully erect handled it like a champ.

 

[welderjosh]

If safe lifting practices were followed why was this table moved 1 foot off the ground. Safe lifting would dictate only lifting it as far as necessary to move it.

 

[whateg01]

If safe lifting practices were followed why was this table moved 1 foot off the ground. Safe lifting would dictate only lifting it as far as necessary to move it.

Well it has to be about 16" off the ground to clear the edge of the trailer.

Dave

 

[whateg01]

...

Would be very interested to know whether those solid wheels work better for you. Why do you assume a 4x safety margin?

Am also interested in more details on your mods (tractor hitch, soft wheels, etc.)!

Mike

Sorry, I keep forgetting to take pics of the mods. The front legs were telescoping on this one, so I just made stubs with axles and put 10" pneumatic tires on it. It would have been better with some wider tires, like lawnmower or golf cart tires because if you roll across the yard, the narrow tires want to sink in. Except that I used stub extensions, they look like the front tires in Slednut's pic here:

The other end uses telescoping legs, too, so to pull it behind the mower, I just remove those and stick a tongue in the square tubing shown here.

Dave