Impromptu gantry crane build

[justin1]

Figured I should get a move on building one of these things so I can work on skid steer rebuild easier and unload new to me milling machine Wednesday feel like it will make it much easier!

Anyways journey starts with digging around in snow to find were I stored all my free range metals.
Now with that found now we can get cracking the gantry crane. (Got excited on height forgot my garage door is only 10' I would of been some mad once after I built and and figured that out.) is gonna look something like this.
And is gonna be made out of this lovely reclaimed sawmill steel for the nice low cost of little bit of cleaning. Thank God I had the for thought to hoard some of this stuff.
and so far that is were I am at. It'll add more pictures as I go feel free to add some input or say something if you feel like I'm doing something stupid

Gonna build in mind with using these casters not exactly what I would like but 1100lb rating Soo four of them should do 4400lbs if I don't point load em

https://www.princessauto.com/en/poly-steel-swivel-with-brake-casters/product/PA1000001598?skuId=8717415

 

[crittermutt]

I always take pictures of my outside steel supplie in fall so can found under the snow with as little digging as possible.

 

[justin1]

Ye I was looking threw all my photos trying to see if I had pic of what I had but lucky enough my memory is ok.

Any update before dinner so after 2 zip cuts and one 1/4 disc later aswell as a cold chisel later. Got everything prepped and ready to weld

 

[justin1]

when I know something is gonna live out side I drill 1/8 drain holes just in case water finds it's way inside help prevent bulging. I also use 1/8 too keep wasps from getting in too far.

 

[curmudgeon]

It's a sad day when you chip a cold chisel.

One of our high school shop projects was to forge, temper, harden and sharpen a cold chisel. One of the teacher's tests was to throw the chisels at the floor as hard as he could. A surprisingly large number didn't survive.

 

[justin1]

Meh doesn't take much to fix my fault anyways shouldn't of been lazy and dug out my spring steel wedges. Spring steel loves the abuse

It's not hard to over temper tool steel or file steel so I'm not surprised a large number broke.

Any last update for today got them all welded now just got to pick up casters tomorrow and finish this puppy up. I figured it would be easier to weld casters on table before install columns to beam

 

[6.5 Fan]

I would put braces on the top of your crane from the top beam to the legs.

 

[justin1]

I would put braces on the top of your crane from the top beam to the legs.

Ye I thought about adding some and still may add some using pieces of the cut offs but wasn't sure if adding 6" brace would make much of a difference besides shear strength.

I was gonna try picking up whole skid steer it weights 4000lbs and see what kinda of defection I get.

Some how this thing got a 4000lbs load rating and the connection design up is so they could save 2' of beam cost it looks like.

https://www.princessauto.com/en/2-ton-gantry-crane/product/PA0008430092

Found better listing for same PA crane with material sizes listed

https://www.palletforks.com/workshop/cranes/2-ton-adjustable-gantry-crane/840043.html

 

[phaxtris]

I agree with the corner braces, it will add significant lateral strength, if your 4k loads the frame sideways your going to have a lot of stress on the relatively small connection between the hoist beam and the column

 

[Dabbler]

There's no lift in the wild that is perfectly straight or ideally loaded. Corner braces are a good thing.

The 2 ton PA crane is surprisingly strong for its build, but I'd still not trust it with a 4000 lb lift.

Really nice start! looking forward to seeing it lift!

Surprise to me how different our processes are. I spent months in design and nearly a year scrounging parts. 3 months to build, and then hated how heavy it was, and another month to revise it and keep the strength. Total time from "yes" to lifting was almost 3 years.

 

[justin1]

Fair I'll probly end up side loading the crane at some point and I don't think I'll notice losing a bit of track length shouldn't have any issues getting the extra width if I really need it.

So I'm gonna cut some braces up for it add them in and I figure if I leave a air gap I can use them as rigging points to rig on a 45 easier so a win win.

I try and design around what I have and what I can get easiest (and cheap) When I do the occasional demo job I try and grab as much useable steel as possible never know when it comes in handy. As far as any real design I just try to reference what I've seen or used in past.

I'm not a big fan of redoing things if I can avoid it but sometimes it's inevitable we all make mistakes or maybe something doesn't function same as what was in head lol.

 

[justin1]

Anyways got it all build, made up some gussets and mounting plates for casters and searched my collection of collection of random bolts and found everything I needed in every colour. after that got it all the bits welded on and had to level everything and square up the legs with the help of math. 3/4/5 method

then bam some swearing and cursing later had it all welded together. Now just to stand it up :/

 

[justin1]

Got it stood up with tractor wasn't too bad little bit sketchy but worked out and quickly got to load testing

A half inch off the ground counts right? Also don't look too hard at rigging it's not the OSHA approved method definitely better ways to rig it....

I set up a Lazer level off corner of mezzanine and a speed square to do a rough measurement of deflection at just under 4000lbs it only moved about an 1/8 but not sure if that was 100% the weight or when I let off the weight the gantry moved around but all in all I'm pretty happy.

Going to have to build some jacking feet or something for this thing if moves around like a bastard. I wanted to buy locking wheels but they didn't have any in 1200lbs but o well easy fix.

 

[phaxtris]

Good stuff!

Be careful lifting heavy stuff like that off the top flange though, especially with an s beam Wich often has a thinner web than a wide flange, buckling the web or having the beam twist and fail is definitely a possibility, getting a small trolley would be wise

 

[Darren]

In my old shop, I had a 9' long beam on the ceiling for pulling engines. It was 2 pieces of 4" C channel welded back to back to form an I beam. At each end i had a strap of 3/8"x2" flat bar, about 8" long welded perpendicular to the beams length, and one in the middle span. These were drilled with 5/8" holes set wide enough to let the trolley pass by. On top of the trusses, I had a 12' long wood 4x4 with matching drilled straps, running across 6 trusses. To sandwich the 3.5" wood beam, 3.5" truss, 0.5" OSB ceiling, 3/'8" beam strap, I used 1/2" ready rod with nyloc nuts.

Anyway, I picked up my 4000 lb Bobcat off of that, and to my surprise the roof didn't collapse. Numerous other shenanigans occurred over my 15 years there, and that beam is still there.

I think you have more than enough strength. Nice work.

 

[Dabbler]

just under 4000lbs it only moved about an 1/8

Allowable deflection rule-of-thumb for a structural I beam is 1/300... For a 10 foot span, your maximum allowable deflection is around ,4 inches.

 

[justin1]

Good stuff!

Be careful lifting heavy stuff like that off the top flange though, especially with an s beam Wich often has a thinner web than a wide flange, buckling the web or having the beam twist and fail is definitely a possibility, getting a small trolley would be wise

Ye I got a trolly in seacan somewhere just have dig it out I got excited and wanted to test prove of concept Not gonna be my everyday rigging that's for sure.

It's amazing what stuff will hold and not break I've done some heavy lifts of 2 inch tubing sitting on bar grate just because there isn't anything better to rig off. Then again anything that's properly csa'd has minimum 5 to 1 safety rigging wise so hard not push the boundaries some times :/

 

[justin1]

Allowable deflection rule-of-thumb for a structural I beam is 1/300... For a 10 foot span, your maximum allowable deflection is around ,4 inches.

Ye which is probly fine depends on code it's being built too and structural is way more loose then crane code if I remember right for a overhead crane they want a L/700 or something it changes with type of service and risk to life.

But as far as private use with no insurance company to please you can pretty much do anything

 

[phaxtris]

It's amazing what stuff will hold and not break I've done some heavy lifts of 2 inch tubing sitting on bar grate just because there isn't anything better to rig off. Then again anything that's properly csa'd has minimum 5 to 1 safety rigging wise so hard not push the boundaries some times :/

Ha yea, the stuff I have lifted off a couple pieces of 4x4 dunnage spanned over an 3ft opening would surprise/scare people, I did a couple sets of stairs off 3 pieces of 2x2 spanned ~4ft a month or so ago, a solid 1/2" of deflection there, but that's all I had atm...red tape and away we go !

I know everyone here thinks beams are the be all end all of strength, but they like to roll with weight and span, especially point load on the top flange mid span, and when they roll with weight they fail, it's the only reason I brought that up, you seem to have a pretty good handle on it !

Gantry looks good though! Splash of primer and it'll look like a million bucks !

 

[justin1]

Beams work great when used correctly that is for sure (not sideloaded but in my defense I loaded both sides of flange)

Dunnage is great to rig off just add more if needed and doesn't mess up nylons as much and is pretty much everywhere on industrial sites in Alberta 4x6 and 6x6 poplar

Ye painting it's probly a summer project lol I would love to sand blast it and get galvanized buttttt I'm not made of money Soo probly just hvlp it with primer like phaxtris suggested with some nice Rust-Oleum beam red