Bridge Crane build

[rabler]

That thing looks awesome!

It's the Sherwin-Williams safety yellow

Thanks!

 

[rwm]

Wow! Looking great. I hope to duplicate this someday.

 

[Jim V.]

I have a ~40 ft span 5 ton bridge crane. sitting in my yard that I am likely never going to get around to installing in the years I have left. I will let it go reasonably to a god home. Jim

 

[Dabbler]

I have a ~40 ft span 5 ton bridge crane. sitting in my yard that I am likely never going to get around to installing in the years I have left. I will let it go reasonably to a god home. Jim

I will let it go reasonably to a god home. Jim

Gosh, Jim, I almost bought a property where that crane could have been installed first thing In Quesnel, British Columbia! Besides not buying it, the 27 hour one-way drive seems a little.... extreme.

I do hope you find a great home for it!

 

[rabler]

I have a ~40 ft span 5 ton bridge crane. sitting in my yard that I am likely never going to get around to installing in the years I have left. I will let it go reasonably to a god home. Jim

I did look at some existing cranes. Mostly via auction, some others via used machinery dealers. Hard to find the right dimensions.

I suppose an existing crane could be cut down if it doesn’t fit, or you could build to fit the crane. Personally I’d be somewhat concerned about cutting if it required structural welding.

 

[rabler]

Spent yesterday working in CAD to draw up the designs for the driveshaft supports for the crane. Need two of these.

Back (gray) piece is a 1/4" plate support bracket that attaches to the side of the bridge.
Middle (black) piece is an acetal (Delrin) bushing for the driveshaft to ride on.
Front (purple) piece is a cap block to hold the bushing in place. Two #8 screws to hold it all together, not shown above.

Turned out the cap and acetal bushings so far today. Turning the acetal worked fine using aluminum inserts.


Here's a picture of the drive motor assembly on the crane. Cable management/routing pending. The driveshaft attaches to the stub shaft coming out of the worm gear (metallic box). The supports (above) will go at roughly the 1/3 and 2/3's locations along the bridge beam length.

 

[rabler]

Victory​

Well, it's almost exactly one year since my first post starting this thread. The crane is functional! This is going to be a really nice addition to my shop, whether for swapping chucks, or rearranging machinery. Well, Ok, rearranging some of the machinery, the really big stuff, the K&T 3K mill, the Monarch 612-2516 lathe, and the Tree 750 VMC are too big. The crane is certainly useful for working on those, just not picking the whole thing up.

Here's a few seconds of video hoisting the cheap press. Yeah, I'm not a youtube cinematographer.

I load tested it, deflection limit hit at 4500 lbs. Design goal was 4000 lbs so that was good. I loaded all the way to 1.25x (5,000 lbs load). The granite table weighs ~7000 lbs, so it never left the ground. Dial indicator over the hoist point and over the bridge ends (3 all together). Orange thing above the chain hoist is a 6600 lbs rated scale. No load in this picture, so if you want to claim it didn't happen I'm not going to argue, lol. Of course you're not the one working under it!
The motorized hoist in the video, and on the right in this pic, is only rated for 2000 lbs so it wasn't used for this test.



The last detail was getting this coupling assembled and driveshaft aligned. Just a thick piece of rubber stall mat cut round and put between the two flanges. The driveshaft runs almost the full length of the bridge beam, about 21 feet, in two segements. This is right in the middle to give it a hint of flex. The beam deflects around 3/8" under full load, and the shafts are not precision straightened, so they're not going to run perfectly true. This gives a bit of flex while coupling the drive motor end (see above) to the opposite side truck.


I still have a some programming work. As you can see in the video, there is a cable running from the motor control cabinet to the remote. Hardware is there for a bluetooth or wifi connection between the two, I just need to code that up. (Simple matter of programming, famous last words). And I could still do a bit of clean up, some zip ties that need to be trimmed for example. But it is now usable for around the shop chores, projects, etc.

Time to pour a cold one.

 

[woodchucker]

congratulations. how much did it deflect at 4500lbs? I had to go back and reread that you said 3/8. You going to get a load cell to make sure you under going forward?

 

[rabler]

congratulations. how much did it deflect at 4500lbs? I had to go back and reread that you said 3/8. You going to get a load cell to make sure you under going forward?

You need to go back and reread again!

Orange thing above the chain hoist is a 6600 lbs rated scale.

I have one which I used in the load test. Doubt I'll use it often as it needs to be removed to recharge, just eats usable Z height, and I won't frequently be anywhere near capacity.

 

[Dabbler]

I load tested it, deflection limit hit at 4500 lbs. Design goal was 4000 lbs so that was good.

Fantastic! That was a successful deflection test for sure!

I also have a crane scale (2200lbs) which we have tested at 100 500 and 1000 lbs. For an offshore cheapie (1/8 the price for a calibrated, made-in-the-G7 scale) it is within 3% of the 'actual weights' as we know them.

I use mine several times every year, 3 times already in 2024.

I like how you managed to get the great coverage you did. Mine will be short of the sides of my shop by about 7 feet on one side, and 6 feet on the other.

Nice job!