Gantry Crane

[Paul M. Kaplowitz]

I have been turning large bowls for the last two years, ever since I bought a VB36. When I say large I mean 24" in diameter was the largest, the average being 16". Using the McNaughton Center Saver, I am able to make a lot of bowls. Handling the big blanks has become a major problem. I use a hand truck to bring them into the shop, and a one ton shop crane to mount them on the lathe.

The problem is outside. I can bring the logs home and cut them up into sections equal to the diameter, and using a peavey move them around. I roll the sections onto pressure treated (PT) 4x4's. Since each section weights over 70 Lbs., I cannot stack them. The problem comes when I rip them in half and round the halves into bowls blanks. In order to do this I am bent over using a chain saw with a 20" bar. It was killing my back even with a weight belt on. What to do? I needed to get the sections up on a saw buck. Given the wieght of each, how was I going to do this?

I remembered seeing boats put into the water and taken out at a local marina using a mobil gantry crane. I googled mobil gantry crane and there were pictures, plans and dimensions of cranes used in factories to move heavey objects between work stations. I reduced the size to 4' long, 3' wide, 6' high and built one using PT lumber that I got out of dumpsters at a local town house construction site. HF had 10" pneumatic tires with fixed and swivel brackets for $14 each and a 1 ton chain hoist for $50.

It works better than I imagined. No back strain and more accurate cutting.

 

[James E Gaydos]

Crane

Hi Paul,
Would you post some photos of your crane ?
Jim

 

[Joel Nucifore]

love to see it..............PLEASE..................

 

[Bill Boehme]

Is it like an overhead traveling crane (such as found on the ceiling inside a manufacturing building) or a portal crane (such as found in a shipyard or on the pad of a launch vehicle. Both types allow horizontal travel, but the main difference is that the portal crane makes use of a vertical structure to support the horizontal track. Portal cranes may be either stationary or portable.

I have thought about an overhead traveling crane, but found a simpler solution to be a cart with a table that is raised by a pair of scissor arms attached to a hydraulic jack.

 

[Joe Greiner]

Sounds like some contraptions we used in the precast concrete industry, before building a new factory with overhead travelling cranes. They were all steel, with an I-beam topside to carry a travelling hoist. Diagonal bracing stabilized the cross beam against the legs. The end legs were A-frames, with a lower beam to maintain the shape between the wheels.

I've since used a surplus swing set, but without the wheels, and without capability to roll the hoist along the top beam. It's all tubular steel, and breaks down into five components for compact storage. When I get a round tuit, I'll add lower stabilizers, wheels, and a roller for the hoist. Come-along and chain works OK for now.

For rolling REALLY BIG logs uphill, I dig a tunnel under the log (using a soil auger), pass a stout rope under the log, with one end (lower) secured to something solid, and a come-along between the upper end and the same something solid. Provides a mechanical advantage of 2:1. "Something solid" is usually another tree.

 

[Paul M. Kaplowitz]

I will take and post some pictures this week.

 

[MichaelMouse]

Why not engine hoists indoors? http://www2.northerntool.com/auto-repair/engine-hoists-stands.htm Great, if you have the floor to support them. Usually easier than making support for the same weight up high.

I use the bucket on the Kubota outdoors, but the less fortunate might want to do some shopping here. http://store.logrite.com/

Other outdoor skidding suggestions for the woods:
Summer. http://en.wikipedia.org/wiki/Michigan_logging_wheels
Winter. http://www.forestry-suppliers.com/product_pages/View_Catalog_Page.asp?mi=1505&title=Skidding+Tongs

 

[TJ Hamilton]

Paul, it sounds like you've solved your problem. Ingeniously and economically too.

Another solution I've seen out there, points to the internet, is a home made two wheeled dolly where the sides are the final height you want the log to be. The user wheels the dolly up to the log, straps it on and tilts the dolly until the handles are on the ground and the log is up at cutting height.

Leverage is a wonderful thing.

Best regards, Tom

 

[Nate Hawkes]

Why not engine hoists indoors? http://www2.northerntool.com/auto-repair/engine-hoists-stands.htm Great, if you have the floor to support them. Usually easier than making support for the same weight up high.

I use the bucket on the Kubota outdoors, but the less fortunate might want to do some shopping here. http://store.logrite.com/

Other outdoor skidding suggestions for the woods:
Summer. http://en.wikipedia.org/wiki/Michigan_logging_wheels
Winter. http://www.forestry-suppliers.com/product_pages/View_Catalog_Page.asp?mi=1505&title=Skidding+Tongs

I wish I could fit an engine hoist in my shop!!! On the Logrite; I have their 60" model with the "log stand" attachment which allows you to get the whole end of a log off the ground--I can get a fairly large log completely off the ground on one end, and use my foot to slide something under one end to get it off the ground for bucking into lengths for bowl blanks.

 

[Paul M. Kaplowitz]

Pictures of Gantry Crane

Here is what I built. Wheels at HF $14 each, chain hoist $50, Lumber -dumpster diving(no cost), screws $5. Total with tax $120. It rolls around and turns with little effort. I'm amazed I didn't think of this sooner, because I'm so bright my Ma calls me sunny.

 

[Charlie Knighton]

thanks for sharing , Paul

 

[Bill Boehme]

Here is what I built. Wheels at HF $14 each, chain hoist $50, Lumber -dumpster diving(no cost), screws $5. Total with tax $120. It rolls around and turns with little effort. I'm amazed I didn't think of this sooner, because I'm so bright my Ma calls me sunny.

Nice work, Sunny. I have a couple suggestions to improve the stiffness of the base of the rig. It appears that there is the potential of having a considerable bending load on the horizontal 2X6 where the wheels are mounted. The braces will help to keep the 4X4 post from swaying, but won't transfer much of the vertical load to the wheels. Over time, this assembly may get a bit loose from rolling across the ground with a heavy load. My first suggestion is to screw and glue a 2X6 or 2X8 on edge to the horizontal 2X6. Use long deck screws at about 3 or 4 inch spacing. In order to add more stiffness to the vertical post, I would cut a triangular piece of scrap plywood to match the shape of the angle braces. Fasten it with glue and screws to the angle braces, vertical post, and horizontal member.

When traveling from the woodpile to your lathe, if the distance is very far and across rough ground, it also might be good to have a temporary cross brace at the bottom which can be quickly installed and removed.

 

[James E Gaydos]

Crane

Thank you for the photos Paul.
I just might need one of these, great looking crane:cool2:
Jim

 

[Joe Greiner]

Looks fairly robust to me. And a good choice to use two fixed casters as you did. If all four were swivel, sideways movement could induce cross-grain bending in the lower planks - very, very bad.

You didn't mention the fasteners you used, and I can't see enough detail in the pictures. Carriage bolts and lag screws would be my first choices, wherever possible. Easy to re-tighten if necessary. The post connections are particularly vulnerable, if end-grain fasteners are used - too weak for my tastes. The triangular gussets that Bill suggests would be good reinforcement, but they don't need to engage the brackets if the brackets are strongly connected.

If you put the 2x's vertical at the bottom, put them outboard. Then the temporary bottom brace(s) can be attached with C-clamps. It doesn't have to cabinet-grade construction.

 

[Dean Center]

That's terrific. Thanks for sharing. If I ever save up the dough for a big lathe, I'll definitely want one of these.

 

[GuyO]

One improvement might be a load leveler and maybe a couple of spikes to drive into the ends for lifting (ice tongs -- not the ones for your icebucket). That single strap could slip..

 

[DOCworks]

hoist option

Danny Hoffman has a really neat hoist that he has made for some of our club members. It attaches to the bed of the lathe swings out and can pick up and hoist a log into place without putting strain on your back. The cool thing is that it comes apart and stores very easily or hangs on a wall.

 

[Martin Osborn]

Now I know exactly what to do with the heavy duty wood jungle gym in the back yard that the kids no longer play on! : D