Light Durty Overhead Track Crane

[starlight_tools]

Mike

So far the design seems pretty good. One of the guys that used to be active on PM is a crane designer and he is reviewing my plans for me.

I am hoping to get it to a rating of about 4000 lbs (2 Tons) but I am waiting to hear what are my weak points and what he recommends.

I am seriously considering slotting the subfloor and making the hangers as U shapped straps that hang over the floor joists, this will prevent any weakening of the joists and will spread the load more evenly. This will however excite SWMBO'd as that will mean ripping up the carpet and routering out the subfloor for the hangers to drop through. Will have to wait for her to go on holidays I suppose, then go at it. LOL

Walter

[Hawkeye]

Are the joists solid or TJIs? If they're solid, bolting through at 2/3 of the way up shouldn't weaken them at all. It would mean double hangers, but it would be pretty strong.

[starlight_tools]

Joists are solid 39 year old SPF.

I have been given a rating of approx. 1250 lbs per joist, so I have proposed lengthening the Bridge Trolley by 16" which will safely distribute the weight over at least 3 joists, so should get a lot closer to the 4000 lbs I am aiming for. I loose 8" of travel in each direction, but that is OK.

Hangers, planned to use two hangers per joist, per track, so joist would be sandwiched between two 1/4" plates and have lengthened them from the original diagram so that the bolt holes are now 6-1/2" up on a 9-1/2" joist.

Walter

[Hawkeye]

Sounds solid. I like the chain lift I added to mine after you saw it. Slower than a B&T, but lifts easily.

[rleete]

I'm curious as to why you think you need that much capacity. Are you lifting cars?

I work in a place that moves stuff around by crane, and the largest one we have is 2000 pounds. I can't imagine needing any more than a few hundred pounds at home. I certainly wouldn't want to be moving around nearly 2 tons by myself.

[starlight_tools]

The heaviest machine in my shop is a B&S #13 T&C Grinder which weighs in at 2900 Lbs, or so the manual says (2 T Cherry Picker begged to differ), the lathe is just under 2000 lbs and the mill is 2200 lbs. Right now, in order to lift any of them, I have to move a lot of stuff in order to get the cherry picker into the shop and then I have a hard time manouvering as there is no room left. There is no way that I could ever get a forklift into the building as the headroom is too low and the room is just too narrow.

If I can get the bridge crane to have a SWL of at least 4000 lbs, and use a 2 Ton Chainfall, I know that I will never overload it.

If on the other hand, I use barn door track and have a SWL of maybe 400 lbs, I will be overloading it all the time.

So if I overbuild it today, then I will be safe for whatever I throw at it tomorrow, knowing full well that most of my lifting will be so light that the crane will not even realize it is being used but yes I agree with you that very seldom would we ever need a home shop crane with that capacity.

Walter.

[rleete]

Ha! You're like my former boss. Way over-designed everything. If a 2x4 would do, he's use a 6x6, just because. We used to joke that it was "farmer engineering". We have a saying around here now: never settle for a 1/4-20 bolt when a 1-12 will fit.

I do see your point, though. Do it once, never worry about it ever again.

[starlight_tools]

Well, I take after my dad in many ways, we build Brick Poop-Houses!

Another point is that I am only a marginal Hobby Shop. This is also where I work full time and make my pitance of an income. Never figured I would get rich doing this, but at least I can go to work each day and enjoy what I do.

Did you see my 3 phase power set -up? I had posted it on that other forum. Not a set up for the faint of heart. When the inspector came to l;ook it over he commented that it was better than most commercial electricians would do. Neat, tidy and well done.

Walter

[starlight_tools]

OK so the numbers have been crunched.

With the 3 x 4 x 0.250 HSS tubing, the maximum SWL is 2300 lbs. The limiting factor is the 1/4" flange thickness of the Cross Beams.

By using 3 x 5 x 0.375 HSS tubing, the maximum SWL is 3600 lbs. The limiting factor being the joists which the system will be supported from. This is also based on the bridge trolley being lengthened to 43 inches long and having 11 wheels per track so that the weight is distributed by at least 3 joists at any time.

So now to finish redrawing the prints, then to start amalgamating the materials.

I would like to thank everybody for their input, especially AAB who I met through the PM forum.

Walter

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