Shop Potential modification of Shop Crane for parallel feet

[StevSmar]

Now that the stand for my Mill is completed, my next issue is how the splayed feet on the typical shop crane often makes it difficult to lift things. This was a pain when I was moving my lathe, now it's become more of a pain. I haven't decided if I'll actually modify my shop crane as my next project, as I'd prefer to be setting up my Mill. But I can see that eventually it's something that will make it a lot easier to move things around my shop.

I'm interested in opinions on the design I've come up with. What I don't like about my scheme below is that it's much more complicated than I'd like.

My shop is fairly small, so this is the list of requirements:
- The feet can be moved in and out, with a range of 600mm to 1320mm (24" to 52"). 600mm so I can get behind my lathe. 52" so I can straddle a 48" pallet.
- The feet can be moved backwards, so the crane can get closer to loads that are up against a wall.
- It can be pulled apart into pieces which are somewhat flat, so that when it's not in use I can pull it apart and store it under my desk or shelf.

Parts which are a modification of my Princess Auto shop crane are shown in Red or Green.




To allow the parts to be stored somewhat flat, I put casters on both ends of the feet. This is a bit of a pain since the feet extensions will need to be removed when storing the crane:


The minimum width is set by the width of the frame, however because this is relatively small it means that multiple sets of extension pieces will be needed to widen the stance to what I think will be my typical width (say 900mm) and then another set to to take it out to 52"- so that's 8(!) extension pieces. At least they'll be easy to make:

The actual extension piece:


The four wheels on the new base are just for moving the base around when the feet are not fitted. This does mean that to fit the feet, each side will need to be lifted up. Probably also to move the feet backward or forward. In the current design my guess is that about 1/2" of height difference would be about right:


The main casters shown above are a little high, but I didn't model them- just downloaded a model from GrabCAD. I think the casters currently on the shop crane are about the right height(?).

I'd love to have a mobile gantry, but it's another piece of shop equipment that won't be used that often and will need to be pulled apart and stored. So that hope is that a more useful shop crane will largely negate the need for this.

Opinions?

 

[djberta]

Interesting ideas. On the crane hoist idea. If you search online there are some designs out there for a 4 wheeled A frame crane that is sized to fit over a lathe or other equipment when not in use. Another idea is a small gib Crane. I have a similar PA engine hoist. I have assembled it for a lift then disassemble which is a pita. Interested in this project for sure.

 

[Dabbler]

John N and I modified a Princess auto crane for parallel legs...We cut the legs and rewelded them at an angle that would make them parallel, or if put in the other way, extra wide. I'll try to get a photo in the next couple of days.

 

[Bandit]

I have the storage problem also, the engine hoist, a pallet jack, and a fairly large cart. ( only 1 of my many storage problems, reduce, reduce. But, but, I might need that!) While 2 of them will go 1 over the other, the 3 don't well.
My engine hoist has legs which will telescope out about 24 inchs or more, which helps a bit, though they are angled also ( length wise), also the cross legs telescope a smaller amount. .
Will be watching. Do the legs fold up on yours?

 

[StevSmar]

We cut the legs and rewelded them at an angle that would make them parallel, or if put in the other way, extra wide. I'll try to get a photo in the next couple of days.

That sounds interesting, it will be great to see a photo.

 

[StevSmar]

Do the legs fold up on yours?

Not on the design above, which is another issue I have with my first design.

 

[StevSmar]

…If you search online there are some designs out there for a 4 wheeled A frame crane that is sized to fit over a lathe or other equipment when not in use…

I’d then have to find a place to store this, which I’d rather not do. Dreaming in technicolor I think if I put in a crane it would be permanently mounted to run along the walls (very unlikely I’d ever do this…)

Another idea is a small gib Crane.

I want it to lift the Mill stand (maybe 200kg/440lb?) and the Mill (approx 320kg/700lbs). Ideally both together.

… I have a similar PA engine hoist. I have assembled it for a lift then disassemble which is a pita.…

It definitely is a PITA…

 

[StevSmar]

I think I might go back to the drawing board and make the feet parallel with 1000mm clearance, and lower it closer to the ground. Maybe by cutting up the existing frame to use for parts?

Still thinking…

 

[Dabbler]

John and I spent all dday dealing with auction winnings, and didn't pull out "the legs"... I'll try again tomorrow.

 

[Bandit]

I have thought about making the legs so they could pivot a bit, so could be angled or parallel as needed. The problem being the more complex things get, the stronger material needs to be and/or pivot points
Mine will lift about 8ft. at full extension while lifting a 1000lb. Boom pulled back, lift 5000lb., but not as high, (of course).

 

[StevSmar]

... and didn't pull out "the legs"... I'll try again tomorrow...

No hurry, I think I understand what you did- cut the feet and made them parallel when installed. Spayed even further apart when swapped from one side to the other.

I have thought about making the legs so they could pivot a bit, so could be angled or parallel as needed. The problem being the more complex things get, the stronger material needs to be and/or pivot points.

For sure, the more "adjustability" you've got- the more complicated.

Mine will lift about 8ft. at full extension while lifting a 1000lb. Boom pulled back, lift 5000lb., but not as high, (of course).

It's frustrating that the manual for my Princess Auto crane says 2 ton capacity, but it doesn't say anywhere whether that's an imperial ton or a metric ton or a short ton... Their website says it has a capacity of 4400lbs. Which implies 2 metric tons, but did someone accidentally transcribe this...? I sure don't want to be the person to find out it was lbs, not kg...

I drew up the parts for the existing base, to see what I'll reuse if I modify it to have 1000mm clearance between the feet:

 

[wmetfab]

Years ago I built a copy of this unit. The legs were 3x3x.188 with a 2.5x2.5x .188 slip fit. It clamps onto any S beam
When i sold it 6 yrs ago got such a low price for what it was

 

[wmetfab]

I was using one of these engine hoist to load a small lathe into a pick up truck the load passed too far beyond the centre of gravity and it tipped over. A man was standing inside the famework guiding the machine when it tipped.
Thankfully he did not get hurt coulda been a broken leg easy and the lathe was already over the tailgate when the thing tipped.
Personally i dont like these things, never have

 

[StevSmar]

Personally i dont like these things, never have

I nearly dropped my lathe using the engine hoist. It had been a long day getting the lathe down into the basement and I tried to move the lathe out from under the dropped ceiling at the bottom of the basement stairs. The slings slipped and slid towards the tailstock. Luckily, very luckily, we righted the shop crane. I still have to straighten the lead screw that was bent when the slings slid up the bed.

A permanently installed gantry crane is what I’d love… But it’s very unlikely it will happen.

 

[Dabbler]

Years ago I built a copy of this unit. The legs were 3x3x.188 with a 2.5x2.5x .188 slip fit. It clamps onto any S beam

The one I made is 4X4 legs and risers. Risers .188 wall, the legs are about .150 (bad memory) All bolts and pins are 3/4 inch. It is designed to be set up quickly from the pile of parts and fasteners. It has been checked by a crane engineer, and rated at 5 tonnes at 11'4" span.

Some day, sooner than later, I'll have to sell it, and make/buy a 3X3X.140 version - the big one is getting too heavy for an old man to lift!

I've stayed away from the PA 2 tonne gantry, as it isn't designed to got from job to shop and back.

 

[StevSmar]

John N and I modified a Princess auto crane for parallel legs...

It's a great idea, here's the legs parallel:


And when they're flipped around, splayed out:


Unfortunately it's not going to work for me. I added my stand at it's approximate center of gravity and it fouls the legs:

(Above is with the stand sideways, the best case scenario for clearance. It's even worse when I rotate the Mill by 90 degrees- like I'd want to do so I could move the stand against the wall)

I'll work on a design to make the legs parallel 1000mm apart.

 

[wmetfab]

Nice work on the cad

 

[Greywynd]

If you use your original design, but add two more crosswise receiver tubes (going left to right so to speak) beside the first set, you could have your width adjustment vary a lot more, with much longer tubes to start with.

 

[DavidR8]

My Wanna-Be CAD designer bows down... Wow...

 

[Susquatch]

It's even worse when I rotate the Mill by 90 degrees- like I'd want to do so I could move the stand against the wall)

My engine hoist doesn't have adjustable legs. They only fold.

Generally speaking, I am alone when I move things. I find it easier to lift things up onto blocks that are higher than the legs, then put the hoist into position, move the machine, lower back onto the blocks, and then from there back to the floor.

Once in a while you need to install lift bolts to facilitate getting it up onto blocks, but usually there is already enough room under it to do that.