Making of an "A" framed adjustable height rolling gantry crane

Brucker

Hard Core 4+
Joined
Jul 10, 2013
Messages
782
Location
Broomfield, CO
The shop has been in need of a more graceful way of handling heavy objects then just our forklift. The shop is small and the scheduled is always packed, so shop space is limited, usually leading to having to move a bunch of equipment and various projects around in order to make room for forklift to maneuver. This eats up a lot of time and energy. Been also missing having an overhead hoist like the old shop had. It made loading the plasma table effortless. And with the new plasma table on the schedule to be finished up this year, as well as a couple vehicle body swaps, figured a solution should be found sooner than later.

Having looked at a lot of commercially available options and the price tags associated, nothing quite fit the bill. Decided to design and build exactly what was needed in house, rather than paying a pretty penny for something that wouldn't fit the needs perfectly without modification.

The crane needs to be capable of lifting and moving at least 1 ton (2000 pounds) of weight. But would like to build in a safety factor of at least twice the desired lifting capacity (so 2 ton overall capacity) to insure it will always be safe to use around the shop without pushing its limits. It will need at least one set powered hoists and trolleys. It needs be able to roll easily around the shop, but also stay locked into a certain position when called for. "A" framed sides would allow for the most clearance and maximum amount center leg length opposed to an upside down "T" or triangle side. So 4 high capacity swivel casters with brakes will be needed. But anyone who has tried to push around a heavy object on 4 swivel casters knows it can be a pain to keep tracking in the correct orientation. So swivel locks will be needed as well to aid in that process.

It will need to be wide enough to span the plasma table the short way (about 6' wide) while still being able to access the floor beside it for the loading and unloading of materials (up to 5' wide). It also needs to be able to lift a vehicle body off of it's chassis, move it next to the chassis, and be lowered down onto stands. Though it needs to be narrow enough to fit the long way through the shop's big overhead door (15.5' wide). And ideally as narrow as possible to save valuable space. So a 14' span between the legs and just over 14.5' overall width was chosen. The height was fairly straight forward. It needs to be able to fit out the lowest overhead shop door, and then extend to as how as the legs would allow. The lowest door is 94" tall so about 93.5" will be the shortest and there should be about 60" of total adjustment meaning the tallest would be about 153.5", or just over 12.5'. Given our highest ceiling is 12', this should work nicely.

After running the numbers for the I beam, a design was quickly sketched up and a materials and cut lists were made and parts were ordered. I beam and the other materials were then cut to length on the swivel mast bandsaw and cleaned up with a flap disc on an angle grinder. Then the small parts were drilled and tapped as needed.

attachment.php


attachment.php


attachment.php


Short video of the caster plates being tapped with the old FlexArm tapping arm:

 

Brucker

Hard Core 4+
Joined
Jul 10, 2013
Messages
782
Location
Broomfield, CO
The casters and locks arrived. Same setup we use with the majority of heavy equipment we build and use around the shop. Casters are a HD 8"x2" greaseable swivel plate caster with brakes.

attachment.php


attachment.php


And the swivel locks are a simple unit that can be engaged and disengaged by hand or foot. They are able to lock each caster into 1 of four positions or allows the caster to swivel freely.

attachment.php


attachment.php


attachment.php


attachment.php


attachment.php


attachment.php


Assembled together onto the mounting plates

attachment.php


attachment.php


attachment.php
 

Brucker

Hard Core 4+
Joined
Jul 10, 2013
Messages
782
Location
Broomfield, CO
Once the sides were almost welded together completely, it was noticed their overall width was going to end up WAY too wide.

attachment.php


So made the decision to add a bend to each leg of each side to narrow the overall profile. Taking the width from about 7.5-8' wide to about 5'. Like this:

attachment.php


Yes, this would lessen the stability some, but not enough to matter much at the heights this will see.
The legs were cut, mitered, and welded back together with only minimal scrap.

attachment.php


attachment.php


attachment.php


Added a gusset along the inside miter joint

attachment.php


attachment.php


welded and sanded smooth:

attachment.php


attachment.php


attachment.php


The scrap from the change

attachment.php
 

Brucker

Hard Core 4+
Joined
Jul 10, 2013
Messages
782
Location
Broomfield, CO
Welded together the pieces to complete the sides

attachment.php


attachment.php


attachment.php


attachment.php


Must have welded them together fairly square and balanced as they stand on their own very well.

attachment.php


attachment.php


Closer look at the pin plate

attachment.php


Closer look at the hook minders at he bottom of each side. These will be used to keep the hooks and chain/cables in place without swinging when not in use.

attachment.php
 

Brucker

Hard Core 4+
Joined
Jul 10, 2013
Messages
782
Location
Broomfield, CO
Next up are the legs for the I beam. These will slide within the sides that were just made. Instead of using regular square tubing, I opt to use 2 lengths of rectangular tubing that when welded together to form square beams. This will provide more strength and support throughout the middle of the tubing instead of just at the edges. Also added some round tubing to help relieve some pressure off the shear points and act as guides for the pins for easy alignment.

Drilled the holes in the rectangular tubing, then mated them together and added the round tubing into the thru holes. Welded everything together, then countersunk/beveled the adjustment holes.

attachment.php


attachment.php


attachment.php


attachment.php


attachment.php


attachment.php


attachment.php


Test fit the legs into the sides with the pins

attachment.php


attachment.php
 

drwest

New-ish
Joined
Jan 16, 2022
Messages
18
Wow! that is some beautiful craftsmanship.

I have always take pride in my welds, but now feeling pretty humbled.
 

Brucker

Hard Core 4+
Joined
Jul 10, 2013
Messages
782
Location
Broomfield, CO
I notice a couple of concerns - out of plane failures, tipping moment, the axial and spreading loads are really concerning since you mention moving with loads over offset casters with the compromised legs.
Gantry cranes are not meant to be moved while loaded. They are meant to be moved into postion, and the used.
 

Jenny Cruiser

Hard Core 4+
Joined
Nov 22, 2006
Messages
1,175
Location
North of Hell
I'm going to echo what has already been said and ask if you have any vid of you welding. Holy shiznit those welds are nice. You're a flipping wizard. Absolute F'ing art. And no stupid music - perfect.
I have a few buddies that work for a variety of companies that have regular "conversations" with engineers on staff (just out of school - the computer says we can do it, so it has to be possible) and the stories they tell are hilarious. When you know what you're doing - you don't need a computer to tell you what's possible.
 

Brucker

Hard Core 4+
Joined
Jul 10, 2013
Messages
782
Location
Broomfield, CO
I'm going to echo what has already been said and ask if you have any vid of you welding. Holy shiznit those welds are nice. You're a flipping wizard. Absolute F'ing art. And no stupid music - perfect.
Thank you for the kind words
 

Brucker

Hard Core 4+
Joined
Jul 10, 2013
Messages
782
Location
Broomfield, CO
Name plaques and stainless hardware looking :smokin:

attachment.php


attachment.php


attachment.php


Added the first manual trolley and chainfall:

attachment.php


Then the first powered trolley and hoist:

attachment.php


attachment.php


Still have to complete the power cord management system, but until then, an extension cord was run for testing. Figured the most dense object that could be found in the shop should be used for the first test. So let's see if it can handle lifting me. And yes, this definitely isn't OSHA approved or even safe. I should have had my safety glasses on... So graceful...

 

Brucker

Hard Core 4+
Joined
Jul 10, 2013
Messages
782
Location
Broomfield, CO
Time for the real test of the new shop built, adjustable height rolling gantry crane. Using one of the new trolleys and hoists, we lift from the center of the gantry which is it's weakest point. Lifting our main fab table which is just over 1300 pounds completely unloaded. Currently it holds about 600-700 pounds of fixturing, jigs, tooling, clamps, etc. So the table is just under the 2000 pound (1 ton) mark. Once the table is off the ground suspended from the center of the gantry, it is easy to see there is no deflection or distortion of the crane.

attachment.php


The heavy load is easily handled by the new setup. Success!

Just need to fabricate the cord management system and it will be fully complete
 

simps80

Rising Sun Member
Joined
Jan 22, 2009
Messages
2,720
Location
Arvada, CO
Damn
Amazing work as always
Love watching your builds!!
 
Top