Cheap overhead crane
- Thread starter bobadame
- Start date
Very nice setup.
pirana
Well-known member
Now if you just had a little more headroom.
Very nice. That thing looks handy. It would lift the arms off of my Bobcat nicely when I need to replace the pins.
The cross beam looks like overkill. If your winch capacity is 2000 lbs, could you have gone with a lighter beam?
I'm just curious as I know virtually nothing about steel beam properties.
The cross beam looks like overkill. If your winch capacity is 2000 lbs, could you have gone with a lighter beam?
I'm just curious as I know virtually nothing about steel beam properties.
The capacity of each trolley is 2 tons. I used it to unload the machine in the background. It weighs 6800 lbs. The I beam was available close by for $150. That's why I chose that particular one. I doubt that I will ever lift anything heavier that CNC mill but I could just by replacing the bottom trolley with a heavier one. I'm thinking about using 2 HF trolleys on each end as well. This would allow me to raise the lower beam about 5" and double the capacity.
Spareparts
Well-known member
Using 2 dollies will let it track down the rails smoother, and not cause binding under a heavy load, don't grease the flange of the rails it will collect dust and grime over time. Nice looking setup .
babzog
Well-known member
Forgive a potentially clueless question, but, are those bolts holding the carriages to the I beam strong enough to hold a full load? That beam looks mighty heavy on its own without anything slung underneath.
There's a piece of 1/2" allthread through the web near the ends to keep the lower trolley from rolling off.
Those little 7/16 bolts do look a bit spooky but worst case with the hoist over a load at the end, the strain on the bolts would be the load, the entire lower I beam, the lower trolley, the hoist and my froggy body pulling down on the chain to make the load go up. That strain, not counting the actual load is just under 1000 lbs. There are 8, 7/16 grade 8 bolts supporting each end of the beam. The cross sectional area of each bolt at it's minor diameter is just a bit over 1/10 square inch. The ultimate tensile strength of the bolts I used is 150,000 psi so it would take about 60 tons of force at each end to make it come down. The bolts are not the weak link. That would probably be the Harbor freight hoist I suppose. It's rated at 3 tons, the trolleys are each rated at 2 tons. I've had 6800 lbs on one. It handled that without a problem. I think the 2 ton rating is pretty conservative.
Those little 7/16 bolts do look a bit spooky but worst case with the hoist over a load at the end, the strain on the bolts would be the load, the entire lower I beam, the lower trolley, the hoist and my froggy body pulling down on the chain to make the load go up. That strain, not counting the actual load is just under 1000 lbs. There are 8, 7/16 grade 8 bolts supporting each end of the beam. The cross sectional area of each bolt at it's minor diameter is just a bit over 1/10 square inch. The ultimate tensile strength of the bolts I used is 150,000 psi so it would take about 60 tons of force at each end to make it come down. The bolts are not the weak link. That would probably be the Harbor freight hoist I suppose. It's rated at 3 tons, the trolleys are each rated at 2 tons. I've had 6800 lbs on one. It handled that without a problem. I think the 2 ton rating is pretty conservative.
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trbomax
Well-known member
With the verticals where they are,how do you use the travel at the ends of the rails?
I don't. The travel is 21' north and south and 24'east and west. (cheap crane)
That's a Leadwell MCVOP VMC that I found on craigslist.
bimmer1980
Well-known member
nice work!! and it sounds like you have actually calculated some loads and set up a realistic lifting capacity.
I was thinking the bolts "looked" undersized, but after seeing your post on the calulated forces.....
I was thinking the bolts "looked" undersized, but after seeing your post on the calulated forces.....
Nealcrenshaw
Well-known member
Are you planning on coating it? Great engineering!
I've been thinking about building me an outdoor gantry crane.
I've been thinking about building me an outdoor gantry crane.
I spent part of the week end finishing up a shelf and last night I started to paint the steel. I'm afraid it's starting to look a bit over the top. It's not my usual style of doing things. Since this is likely the last building I will build, I figured I would try to leave nothing half done.
Nealcrenshaw
Well-known member
POst some pics after you paint it up!!
Nice job on the crane and the engineering. I have an overhead at work and don't know how I would get my job done without it.
For less than 1k you can get a harbor freight rolling gantry that does 2tons(?). I would love to have one but my tiny shop is not big enough.
Stew
For less than 1k you can get a harbor freight rolling gantry that does 2tons(?). I would love to have one but my tiny shop is not big enough.
Stew
bimmer1980
Well-known member
what is the first machine? Some type of a punch?
Yes, it's a home made copy of a Strippitt 30-30. I started with a tool holder that I dug out of a metal scrap hopper. It's the green yoke in the picture. It uses Strippit quick change tooling and has adjustable x axis stops, about 10 of them and an adjustable y axis stop.
This one tracks very well. When I put up the main I beams I was very careful to set them exactly parallel, within about about 1/8" over 21'. The last barn I built used home made roller trucks that had a longer spread between the rollers (per side). It doesn't work as well as this one because the main I beams aren't set as accurately as this one. I was a little worried that this one wouldn't track very well using the HF trolleys because the bearing wheels are only about 10" apart. I was surprised, it rolls nice and smooth.