Manual Telescoping BoomDesign

I am hoping you fabricators out there will review my design. I am planning on building this manual telescoping boom for use with loader on my Ford 860.
I plan on using:
5" square tubing, 3/16" wall
4" square tubing, 3/16"wall
3.5" square tubing, 1/4" wall
4" x 1/4" plate for the hook mount
5" x 1/2" plate for the loader mounts

My tractor only has a single aux valve to lift the loader (trip bucket), so I am thinking about using a winch with a snatch block to control the lift (angle) of the boom. I think a winch with a load capacity of 2000 lbs. or higher would work fine. I plan to mount the winch to the loader frame.

My sketches are attached and hopefully the dimensions are readable.

I estimate that it will weigh ~420 lbs. and be able to lift ~300 lbs. when extended.

Please let me know your thoughts. Your collective knowledge is better than building it twice.

Thanks,
Thad

Your choice of material and boom design
look good to me and should hold 300 lbs
extended, and much more close in. I
question if your tractor or loader will
tho. For a 2k winch to hold 300lbs at 22'
you will need to hook about 4-5' up from
your pivot, i dont see thst in your design.

When you put the tubes together make sure
you put the welds on the side rather than
top or bottom or they will slide hard.

Is there a reason why you can't make the
boom fixed and use the electric winch to
lift?

I would add a band around each end where the next tube slides out so it could not split out ,look at a wrecker boom

I think you are heading for big trouble mounting that much boom on that small of a tractor and loader. The weak spot in your design is not the
boom, it is the loader. I have no idea what you intend to lift, but imho, by the time you figure your material and fabrication time, you would
likely be getting close to the cost of hiring it done safely. Add in the cost of injury, damage or death. You are designing a trap! ( just my
opinion).

My only advice is look at the engine hoists available ( 2-5 ton) and adapt that engineering to your project. Your tractor will need HEAVY ballast on the rear. It may be to much for the FEL hydraulics. HTH

Never like to rain on a guys parade, but too much work for the end results. The tractor front end will just not stand 300 lb out that far in front of it. You are just going to get hurt or tear up something.

Little different design than you had in mind,

http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=ttalk&th=1098707

could you mount it on the rear of the tractor it would take the weight better maybe use one larger ram not sure what you are trying to do maybe some info on what you are trying to accomplish for the brain trust they can help

thads I have to agree with the other posters here on the length of your boom design. looking at the tractor you plan to mount that on I would cut the extended length in 1/2, don't forget thad the further out you extend the boom you must cut your weight lifting capacity accordingly. if a 6' boom will SAFELY lift 2000. lbs, at 12' that capacity will be around 500 lbs. your drawing shows a folded length of 106" or 8' 8", and fully extended at 268" or 22' 4" at full extension your safe working load will be around 150 lbs to 200 lbs max with out damaging your loader, or worse doing a face plant with your tractor. if you google up lifting boom safe work load limits it will shock you how much you have to derate a boom capacity when you double the length.

I have a homemade contraption that does not telescope - but it resembles your drawing. I made the "tee" portion to fit inside my loader bucket. I use a double chain to support the boom out in front of the loader, tied back to the loader arms behind the bucket. I think the boom is about 25 feet long. I used 6" I-beam. I've set trusses all over the neighborhood with it. The largest trusses that I've set were 40 feet long on a ten foot wall. The tractor and loader is a narrow front JD 630 with a JD 45 loader. It has 1200 pounds of wheel weights on the rear, but no other ballast. I've never had an exciting moment, but it's level ground only, and slooow and easy. I always have a ground man with a tag line. I have no photos of it, but I could get measurements and pics if wanted.

One thing I don't think you addressed in your post - you need a way to positively tie it down. If you raised the boom too high, it could flip backwards and get you like a big fly swatter. I use a load binder and chain to secure mine down to the loader bucket.

This is a serious issue - someone could get hurt or killed. Always think of the widow. Your friend won't sue you but his widow will.

I made up a tripod unit out of three pieces of ten foot long pipe. I hooked two pipes with a bar between them to the bucket pivot point and the third pipe up or back on the loader frame. I used it for lifting 28 foot rafters in place when I built a garage and it worked real good.

1. Square tubing is probably not the best material to use. Most HSS tubing (ASTM 500B) is rolled and then seam welded down the length. This weld could be a weak point. Also square tubing has local buckling problems that are worse than say round pipe.
2. The sliding connection when extended could cause a local buckling failure if the tubes are too loose/not provided enough support.
3. Most items in a lifting scenario (except for very heavy special lifts) are designed for a 4x Factor of Safety. This means if you want to safely lift 300 pounds, you have to design it for 1200 pounds. If a 2000# winch is
good to lift 300# then you should be using a 8000# winch. This safety factor is to account for dynamic loading, out of plane loading, and other considerations when lifting overhead.
4. The weak point may not be the boom. The loader pins/hydralics/ attachments might also be a weak point.
5. Ballast will be an absolute must.
6. Even if it is "strong" enough, deflection, especially at the length you are proposing, might be an issue (think of a fishing pole), which would cause more bounce and higher loads if you want to move the item while on
the "hook"
Find a local structural engineer and see what they think...

bjb PE in Tx

Just for comparison purposes, my Hiab knuckleboom which will lift 4tons next to the truck, will only lift about 800lbs at that distance from the pivot point of the main boom. Any slewing movement of
the boom at that distance from the column is very exaggerated.

Thank you for all of the comments.

The objective for the boom is to set 18' trusses at 20' up. They should weigh about 57lbs.

I have modeled this after a skid steer boom.

Trust me, safety is a top concern. I intended a back stop as part of the loader frame to prevent the boom from flopping backwards, since a winch cannot apply back force like hydraulics would. Good feedback to also chain in place before moving.

I have loaded rear tires, wheel weights and a weighted box blade that I put on the rear, but I am concerned that I may still be light after reading the comments. Fortunately, I am good at physics so I will re-run my numbers to better understand the limits.

Thank you again for the feedback.

I say just rent a Broderson IC-80. For the time and money you will throw at your project, you can have the rental paid for and possibly
have a tax deduction. I, myself, enjoy taking on projects such as yours, however the older I get the less excited I am about working on one
project just to complete another!

If only setting 57 lb trusses get a
couple buddies one on each end and a
ground man. There are fall protection
harnesses sold at home Depot for
cheaper than you will have into that
lifting rig. Tie a rope on each end
and pull them up. Another thought is
you will want the fall protection when
installing vthe roof after the trusses
are up.