# Home built gantry cranes



## Dabbler (Apr 1, 2021)

I thought people would like to discuss gantry cranes and how they might be built, used, etc.There seems to be some interest in me describing the build of mine, so here goes:

I needed it to be versatile, from 7' tall overall, to doing an 11 foot lift.  I knew that I'd be lifting stuff up to 2 tonnes, so I built it to carry at least twice that - this is common practice for rating lifting equipment.

My first design choice was to make the tubing size all 4".  Right away I screwed up and bought steel for the legs with .250 wall.  Way too heavy, after all I wasn't building a 50 ton crane!  I re-purchased .166 wall which is still stronger than I needed...

Here's a photo in Bert's basement, with a 7' ceiling.  Note it is using the short main beam for maneuverability and lower height.  It is made from the 4" X.250 wall tubing discussed above.






The castors are 2800lb Casterland casters with rotational locks.
The legs are 6 foot long 4X4 .166 wall tubing.
The diagonal braces are 2X2X.125 angle iron
The risers the move up and down, and hold the main beam are 6 foot long 4X4X.188 wall tubing
Those trapezoidal plates are high tensile steel, waterjet cut .250 thick
This main beam is 6' long 4X4 .250 wall
The long main beam shown below is 4" X8" X.288  wall structural tubing X 10 feet 4 inches long
All fasteners are 3/4" diameter national coarse, except:
The plates connecting the main beam to the risers are 3/8 plate, with tow 5/8 fasteners per plate, 4 plates
Here's it is in use at my shop:






A few design notes:  With the large beam it will safely lift 5 tonnes, so I overbuilt by a bit.  With the small beam it will lift closer to 7 tonnes, because of the short span and thick main beam walls.

The build was mostly "drill holes", get plates from water jet, assemble.  The only welding was for the plates the casters sit on, the casters will fail before the compression welds give out.

A quick word on the weight.  It isn't light.  the main beam measured 225 lbs.  Each end assembled is over 225 lbs, but one guy can lift it up to vertical with out too much grunt.

Feel free to ask any questions,...


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## Tom Kitta (Apr 1, 2021)

I assume the top bar is also 4" steel just b/c you were buying a lot of it - have you considered using a T beam or two C beams so that you can have a trolley move side to side?


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## Dabbler (Apr 1, 2021)

The trolley will run on top of either main beam.  Custom built, of course - because, my-way.


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## Dabbler (Apr 1, 2021)

Oh, and because I was broke and had the 4X4X.250 in the back yard.


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## Hacker (Apr 1, 2021)

Nice looking gantry. I like that you can adjust the height adds some versatility to how you can use it.


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## Dabbler (Apr 1, 2021)

Part of the reason for not documenting it earlier is that the build is still ongoing.  I have some improvements in mind for next time I need it.  Little tweaks, but things that will make it nicer to use.


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## Chicken lights (Apr 1, 2021)

Dabbler said:


> Part of the reason for not documenting it earlier is that the build is still ongoing.  I have some improvements in mind for next time I need it.  Little tweaks, but things that will make it nicer to use.


That’s the part that makes it fun. I can do “this” but I need to change “that”

There’s no perfect it’s always an evolution


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## Janger (Apr 1, 2021)

As impressive as the pictures are it is way more impressive in real life.


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## Canadium (Apr 1, 2021)

Totally awesome! Something I really need to see and think about. Thank you so much Dabbler for posting this!!!


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## Hacker (Apr 1, 2021)

How do you raise and lower the gantry?


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## Dabbler (Apr 1, 2021)

Hacker said:


> How do you raise and lower the gantry?



Ahh, a great question... 

The very first time it took 7 hours of messing about with various lifting devices.  It also had the heavy legs at the time, making each A frame a 2 man lift.  --It was horrible!

The second time I built a wooden crane deck at the top of my garage roof, and it took a couple hours and a little butt-puckering....

Nowadays it is a simple 1/2 hour job.  the A frames are built and spaced at the lends of the beams, pointing outward.  I then use a Genie lift like this to raise the main beam:






Then each A frame is raised and a pin inserted.  then the diagonal member is installed.  Gantry is ready...
After seeing the process once,  @RobinHood did it on his own quite easily.


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## Dabbler (Apr 1, 2021)

And the elephant in the room: price.  All in, it cost about 1200 dollars.  The Princess Auto, fixed height '2 ton' gantry was 1100$ at the time.  So even though it is extravagant, it was about the same as the PA one.


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## Canadium (Apr 1, 2021)

How do you store it?


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## Dabbler (Apr 1, 2021)

I break it down completely and store it in the backyard.  For a while the A frames remained fully assembled, but they are pretty heavy to lug around with one guy.  Disassembled it is very easy.


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## Canadium (Apr 1, 2021)

Dabbler said:


> The trolley will run on top of either main beam.  Custom built, of course - because, my-way.



I'm wondering if a trolley is really desirable. If the crane was slightly off level wouldn't gravity pull a loaded trolley crashing to one side?


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## Hacker (Apr 2, 2021)

Dabbler said:


> And the elephant in the room: price.  All in, it cost about 1200 dollars.  The Princess Auto, fixed height '2 ton' gantry was 1100$ at the time.  So even though it is extravagant, it was about the same as the PA one.


I would say that is very good value for the money and time invested.  A gantry is something that I have been contemplating building for a while. Thanks for sharing this.


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## Hacker (Apr 2, 2021)

I would think that if would not be a very good practice to do any lifting with any equipment that is not level. Too many variables are introduced when things are not square and level when doing heavy lifts.


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## Canadium (Apr 2, 2021)

Hacker said:


> I would think that if would not be a very good practice to do any lifting with any equipment that is not level. Too many variables are introduced when things are not square and level when doing heavy lifts.



The devil is in the detail. Just exactly how level is good enough. Do we just eye ball it or do we use a machinists level? Is shimming it to level acceptable? Would shims add an element of instability? Personally my guess would be that eye balling might be good enough if a trolley is not used. But greater precision in level might be required if a trolley is used.


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## Hacker (Apr 2, 2021)

The ones that I have used with a trolley if the chain is hanging straight down it is usually good enough to use. Always put a bit of load to test if the trolley is going to walk on you. You really shouldn't use a gantry to move around heavy loads on an uneven surface.


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## Canadium (Apr 2, 2021)

Hacker said:


> The ones that I have used with a trolley if the chain is hanging straight down it is usually good enough to use. Always put a bit of load to test if the trolley is going to walk on you. You really shouldn't use a gantry to move around heavy loads on an uneven surface.



Suppose as in my case the object is merely to get a heavy object off the trailer and onto the ground. The ground just outside my shop is a gravel driveway that might not be perfectly level. I have no intention of moving the gantry any where with the load. Merely to raise the load a few inches off the trailer and then down to the ground after the trailer is driven away. My guess is I would be best off without a trolley. An approximate level might be good enough.


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## Hacker (Apr 2, 2021)

A degree or two off of slope is usually fine. If it feels a little sketchy you might want to reevaluate what you are doing. The trolley is nice to have especially if you are positioning something. If you are just doing a  straight lift off of a vehicle, use a sling on the horizontal beam. Make sure the sling is rated and protected from sharp edges.


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## historicalarms (Apr 2, 2021)

the thing is...with trolley installed, it is there to use when the gantry is level...if it isnt level, just move trolley to the side & double wrap the cross bar with chain as a non-sliding lifting point...trolley will still be there for next time.


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## Dabbler (Apr 2, 2021)

Canadium said:


> I'm wondering if a trolley is really desirable. If the crane was slightly off level wouldn't gravity pull a loaded trolley crashing to one side?



That's why I didn't use an I beam for the main.  The trolley I designed has a built in brake in it to prevent it moving due to gravity.  It will press against the sides of the tube to create friction.



Hacker said:


> I would think that if would not be a very good practice to do any lifting with any equipment that is not level.



My garage door/lane-way is anything but straight or level.  the main beam was about a 10 degree incline when I lifted my surface grinder with it.  Extra strength and extra rigidity help.  It has a lot of slop in the design, which helps it accommodate twist.  If you were using a gantry crane only on flat concrete surfaces, it could be a lot lighter build and still be safe.



Hacker said:


> You really shouldn't use a gantry to move around heavy loads on an uneven surface.



absolutely.  I have moved loads with a gantry under special circumstances. 1) the load is almost touching the floor 2) I have a very wide stance in the crane, over 6 feet, 3) I move one side of the gantry at a time, moving very slowly, say 5 or 6 inches at a time.  4) the load is stabilized by a second person


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## Tom O (Apr 2, 2021)

I just figure you know what looks safe or not and as far as moving the machine could be anchored at 4 points to the gantry or just one to stop it rolling on the track due to incline. A lot would depend on what you have for wheels that would be my main concern if moving is involved given the types of surfaces used.


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## Dabbler (Apr 10, 2021)

Here's another home built gantry crane that is designed for heavier loads.  One of my friends on another forum built it to move this lathe... I think it is around 12,000 lbs:


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## Brent H (Apr 10, 2021)

My neighbour just gave me a couple lengths of I beam —— what to do next?


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## Dabbler (Apr 10, 2021)

So begins the descent into  design, more materials acquisition, fabrication, and... madness.


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## Hacker (Apr 10, 2021)

If you are on this thread, I think you already know what you are going to do. LOL


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## Janger (Apr 11, 2021)

Clever how the legs/feet lift up out of the way so the wheels work. I suppose that is more to move the crane around and probably not with a load supported? That lathe up in the air is pretty impressive. What weight would that crane lift John?


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## Dabbler (Apr 11, 2021)

Janger said:


> What weight would that crane lift John?



With the 4 height extenders, it is probably at it's weight limit.  on the casters, a little less, because the casters are the weak spot, probably around 8000 lbs, evenly loaded.  Take the casters off, and it would easily lift 20,000lbs or 10 tons. (9 tonnes)


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## Hacker (Apr 11, 2021)

Dabbler said:


> Here's another home built gantry crane that is designed for heavier loads.  One of my friends on another forum built it to move this lathe... I think it is around 12,000 lbs:
> 
> View attachment 14124


That is impressive! The only negative and I am not sure it is a negative is the size of the pads on the legs.


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## kevin.decelles (Apr 11, 2021)

In that picture , are all three chainfall hoists in use? Tough to see what each is doing


Sent from my iPhone using Tapatalk


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## Janger (Apr 11, 2021)

kevin.decelles said:


> In that picture , are all three chainfall hoists in use? Tough to see what each is doing
> 
> 
> Sent from my iPhone using Tapatalk



The middle one looks like it's attached to a sling going through the casting. it's not quite hanging straight though? The right one though does look like it's perhaps involved too. I see a single chain is holding it all up wrapped around the i-beam? Makes me uncomfortable as big loads always do. That's probably a good thing.

hmm mcmaster has chain 1/2" thick rated for 12000 pounds. pricey.


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## Dabbler (Apr 11, 2021)

I talked with him and he thought it was 9000 lbs, but has now reconsidered it to be a little over 8000 lbs.  the two small chain falls that are holding the weight are both 2 ton hoists.


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## Brent H (Apr 11, 2021)

Here is something for you guys about lifting things - stuff you don't see everyday

Dry Dock 2016: lifting out the Props and shafts from the ship.  Weight of each prop and shaft set : 20000 lb (10 tons)

Some serious chainfalls at work - most of they are ones for this application are air driven and in the 15 to 25 ton range.  Yard workers weld on the lifting eyes to the hull in order to extract the shafts.  Typically just burned out of 1" plate, although now they need a rating stamped on them - did not used to be that way - LOL






This was the first yard to use a flat bed type arrangement to move the shafts - typically a mobile crane scoots them across the yard.  See that saw tooth pattern on the one blade?:  we sucked in a piece of mooring line some twit on another ship threw over the side - we sucked it in breaking out a harbour and caught a shackle up in the Kort nozzle.  Had to have divers in to lance it out.

I always thought this job would be easier if they had a double gantry and just popped out the shafts easy peasy.   I guess 10 tons can be a bit awkward. - Pretty beefy saw horses eh!?


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## Dabbler (Apr 11, 2021)

Brent H said:


> Pretty beefy saw horses eh!?



the whole post is cool!!!


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## YYCHM (Apr 11, 2021)

Dabbler said:


> the whole post is cool!!!



I agree... I had to look up Kort nozzle


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## Dusty (Apr 11, 2021)

YYCHM said:


> I agree... I had to look up Kort nozzle



Me too Craig, I assume they work somewhat along the lines of an modern day commercial fan jet engine although they pull and push water.
Most likely preventing much disturbance from around the rudder. Just guessing in any case a real monster of a job although when you have the knowhow and right equipment its a cake walk.


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## Brent H (Apr 11, 2021)

Sorry @YYCHM and @Dusty - guess I should clarify some of the nautical jargon - LOL  the Kort nozzle surrounds the prop and is indeed an airfoil design .  Basic principle of operation is to focus the thrust from the prop and channel the  thrust that flys off the prop in the radial directions.  Increases the efficiency about 10 to 15% over an un-nozzled prop.  Used mostly on tugs - adds protection as well.  Larger ships without the nozzle can use the radial thrust or side prop wash to “walk” the stern of the vessel.  Some times the nozzle is fitted and can be rotated to direct thrust.  Some large ships have them fitted for this reason.  

I digress....now back to your regular scheduled gantry channel......


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## YYCHM (Apr 11, 2021)

Brent H said:


> Sorry @YYCHM and @Dusty - guess I should clarify some of the nautical jargon - LOL  the Kort nozzle surrounds the prop and is indeed an airfoil design .  Basic principle of operation is to focus the thrust from the prop and channel the  thrust that flys off the prop in the radial directions.  Increases the efficiency about 10 to 15% over an un-nozzled prop.  Used mostly on tugs - adds protection as well.  Larger ships without the nozzle can use the radial thrust or side prop wash to “walk” the stern of the vessel.  Some times the nozzle is fitted and can be rotated to direct thrust.  Some large ships have them fitted for this reason.
> 
> I digress....now back to your regular scheduled gantry channel......



Please elaborate more.  Was the prop replaced or repaired?  What were the symptoms that the prop had ingested something?


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## RobinHood (Apr 11, 2021)

Is that a variable pitch prop? Are the light coloured areas that are supported by the “saw horses” the plain bearing journals?

You can also see how they have wooden dunnage to protect the shaft and increase friction to stop it from sliding if it were just steel on steel.


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## Janger (Apr 11, 2021)

Is the pitch of the screw blades adjustable? While in operation? oops Rudy already asked this. I'll ask another. Do ships like this have bow thrusters?


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## CalgaryPT (Apr 11, 2021)

Brent H said:


> Here is something for you guys about lifting things - stuff you don't see everyday
> 
> Dry Dock 2016: ...Pretty beefy saw horses eh!?


Always look forward to your updates Brent. If you ever need a stowaway who will make himself useful on board, I'm your man.


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## Brent H (Apr 11, 2021)

Thanks guys - I started a thread in the off topic zone so as not to hijack @Dabbler ’s thread on the gantry.  .


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## Brent H (Apr 13, 2021)

@Dabbler : have you or any one you know built an overhead crane verses the gantry style?  The crane type where you can basically run an I beam back and forth across your shop ceiling with an electric hoist that can slide back and forth?  I gather it would be more expensive depending on the span, but if you were going for perhaps 12 feet (say half a 24 x 24 foot garage) it might not be way out of the question.   Thinking of that of the classic beam trolley down the middle.  

I would say the beam trolley has a lot more limitations, but might be adequate in many uses.  Your design lends itself to He-man portability which would also have many benefits .....

Just thinking of plans......


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## Dabbler (Apr 13, 2021)

so...  you ask at a good time.  I'm building a 15' wide X 22' long bridge crane in my shop right now.  The  engineering is a bit tricky, but we can discuss some of the details here...

John N has built several bridge cranes and has more practical experience than I do.  My cousin has been buiding bridge cranes for 45 years, and has helped me refine some of my lifting ideas.  My Dad used to maintain the 200 and 400 ton bridge cranes at Stelco Hamilton, so I got a little info from him as well as I was growing up.

My design is using a 3X3X 3/16 wide flange aluminum I beam for all of the support members.  I got the material for a steal from another member...  The entire design stems from what capacity your trusses will hold at the rails.  The rails must be perpendicular to the trusses, or you are in for a lot of restucturing.  My trusses will hold 250 lbs on the bottom of the chord quite safely - we tested this with myself and my daughter on the same truss several times while insulating the ceiling.  You have to determine what is safe for your situation.

If your requirement is only to lift that amount (such as in my case, 250lbs) then you need to then size your I beam accordingly.  For a 250lb lift I'd make the rails out of 2X2X3/16 wide flange I beam.  You have to use wide flange I beam for all structure, as the trusses aren't good at bracing the load at unexpected angles.  A stiffer I beam will also help spread the load across I beams.

Next go to an I beam calculator  and use the load and span to find out what I beam you need to support your design load.  Here again you must use wide flange I beams.  When a load is moving or seinging in a random direction the normal flange I beams will fail a far below the calculated load.  Make sure that your bridge will support at least 2 - 2.5 times the max load.

Both rails need a novel mounting scheme, as they just cannot screw into the trusses, weakening their bottom chord, and risking pull out.  I'm using a wooden beam above the trusses to further average out the load, but my lifting requirements are much higher than a single truss will tolerate.

I'm being cagey about the details here because doing this wrong or at loads that are too high can damage your trusses.  Every truss system has weaknesses and I cannot generalize here.  In the late 1970s I designed and implemented truss design software, so I can be sure that what I'm doing on my trusses will work.  Depending on the number of chords (diagonal members) and design limits, your trusses might be stronger or weaker than mine.  Note that stiffness does not mean strength.  You can infer the strength of your trusses by measuring deflection under load, as long as that deflection is very small.

There are tests you can do to help you, but you should not deform the bottom chord of your truss by very much at all.  This is because deflecting this puts tension stresses in your top chord connector plates that were designed for compression loads.  At the place where your rails join to your trusses, you want a deflection less than .250 * IF* you are near the centre of the truss.  Depending how how far you are from the wall, you will find this to be in the range of 200-400 lbsf.   You should never exceed this value during any lift. * NOTE THIS IS A VERY BROAD DESCRIPTION THAT CAN BE COMPROMISED BY A MEASUREMENT AT THE WRONG PLACE.  iF YOU ARE WITHIN 24" OF A WALL THE .250 DEFLECTION IS NONESENSE.  READER DISCRETION IS STRONGLY ADVISED. *

This is just an overview of the 50 or so hours of design work I did for my bridge crane - but my gantry crane had as much or more design effort.  I'm not trying to scare you here, but I'm trying to say that lifting equipment can be tricky, and it has to be thought through carefully - for safety's sake.


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## Brent H (Apr 13, 2021)

Hmmmmm.....

I would be going the way of supports that would not be connected to the garage, but rather be self supporting -
 issue 1 - I would think is the footing - but that would depend on load.

Something like this:






Obviously a simple drawing but this type of set up would be more the tickle of my fancy- Like you could park in the garage and take out the engine if you wanted, or move things around a shop and maintain the work space.


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## Dabbler (Apr 13, 2021)

There are commercial versions of your above design.  The posts do not need reinforcing.  Even 3X3X .100 square tubing can support over 1000 lbsf.  What you are missing here is racking protection in both directions.  The cheaper-but-good versions use cables in an X formation on the rails to prevent racking.  The racking in the moving beam direction has to transfer the load to the concrete.  This can be done by a 10 or 12" triangle and a concrete fastener (or equivalent)  You can also gusset near the top to provide racking. 

Racking protection should be able to withstand 10% of the rated load.  Remember that if bracing for racking at the floor to keep in mind the moment arm of the crane.

I magine the heavy load moving so as to describe a cone with the lifting strap, and bracing for this.  The diameter of the cone being 1/8 of the lifting height.

youtuber bobcloc02 installed a 20 ton bridge crane into his barn-shop.  He is a structual engineer, so his  experience is applicable.


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## Brent H (Apr 29, 2021)

Hey @Dabbler this was what was dropped off for me:





One beam is 15 feet the other is 11 foot six.  The web is 1/4” and the flanges 5/16”.  They are 5-1/4 wide and 8-1/4 high. The other steel is a bonus I guess.


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## Dabbler (Apr 29, 2021)

very useful pieces -- they will make a nice crane.


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## Chicken lights (May 2, 2021)

I’m hauling part of a mobile gantry crane. Those things are cool to see zooming around


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## Brent H (May 2, 2021)

COOL!!


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## Canadium (May 2, 2021)

Brent H said:


> Hey @Dabbler this was what was dropped off for me
> One beam is 15 feet the other is 11 foot six.  The web is 1/4” and the flanges 5/16”.  They are 5-1/4 wide and 8-1/4 high. The other steel is a bonus I guess.



This is inspirational! I'm getting ideas!


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## Dabbler (May 16, 2021)

Here's a short video of the building of a jib crane.  Some very good ideas, and reasonable load expectations:


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