Home brew boom pole

[patrick_g]

Citifarma, What you loose in max load capability out at the end of the pole will be more than made up in the greater utility of the extra height of reach and enhanced dexterity with curl and lift.

Pat

 

[cityfarma]

I have finally got my pole adapted for the FEL as well as the 3PH. The actual pole is changed from one adapter to the other.

On the FEL, the bracket sits on the bucket edge and the top hooks into the top lip of the bucket. The picture shows a length of all thread. This is only a temporary fitting to test out the length of the top section. The top hook is to be a separate section to the main bracket to allow the hook to be put behind the lip then a pin will be inserted to join them. The hook consists of a length of square tube with a piece of angle welded on.

It certainly made it a lot easier to build the frame of my garage.

Cityfarma

 

[patrick_g]

I have finally got my pole adapted for the FEL as well as the 3PH. The actual pole is changed from one adapter to the other.

On the FEL, the bracket sits on the bucket edge and the top hooks into the top lip of the bucket. The picture shows a length of all thread. This is only a temporary fitting to test out the length of the top section. The top hook is to be a separate section to the main bracket to allow the hook to be put behind the lip then a pin will be inserted to join them. The hook consists of a length of square tube with a piece of angle welded on.

It certainly made it a lot easier to build the frame of my garage.

Cityfarma

Neat. I tried to describe something like what you did over the phone to a friend who wanted to put a pipe over his hay spike and use it to lift trusses (BAD IDEA) but with your pix I can easily make what I was talking about more clear. I suspect he tried anyway and probably bent his hay spike.

Just curious but I would have thought the "spreader" holding the upper guy rod out from the boom would have been better co-located with the attachment point of the lower braces (or vice versa.)

Pat

 

[cityfarma]

"Just curious but I would have thought the "spreader" holding the upper guy rod out from the boom would have been better co-located with the attachment point of the lower braces (or vice versa.)
"

Not sure what you mean. The orange part is my original pole made to attach to the bracket made for the 3PH. The new brackets were then made to adapt the pole to the bucket. As the pole and adapters where made from pre loved metal, I was constrained to the existing lengths. The pole was already welded rightangle. If designed for new steel, then it would have been done slightly different as I could then cut and weld as required.

Cityfarma

 

[patrick_g]

citifarma, It might not matter if the strength of your assy is high compared to the max load you will lift.

Anyway what I mean is the piece of steel at right angles to the pole which separates the pole from the guy wire (rod) which in sailor talk is a "spreader" because it spreads out the guy wire/rod from the mast/pole.

The two braces that support the pole from the bottom would have made for a stronger assy if they connected to the pole right below where the spreader is connected.

It isn't a big deal if the assy isn't overstressed. If it is overstressed the pole will bend at the location where the lower braces attach.

Pat.

 

[RonMar]

I think in this application the vertical is refered to as a kingpost. That on the main beam and the top wire/support forms a kingpost truss common in many bridge designs.

I agree that the lower angled supports should meet the beam below the kingpost. This way the upward forces go up thru the beam and along the post and spread out along the upper diagonals which are in tension. like this attached .BMP. Basically you are trying to bend the beam below the post and the the post and wires prevent this.

 

[cityfarma]

Pat & Ron thanks for your comments. As they say "A picture saves a thousand words."

The reason for this arrangement is that the original pole did not have a spreader on top and I detected a slight bend when tested. I added the spreader later. I will consider replacing the lower braces as you suggest when I get some spare time. I was thinking that they probably should be heavier to strengthen the pole anyway. At this time it is only being used for fairly light work.

Cityfarma

 

[patrick_g]

I think in this application the vertical is refered to as a kingpost. That on the main beam and the top wire/support forms a kingpost truss common in many bridge designs.

Thanks for the lesson Ron. I'm not a mechanical engineer type nor am I conversant with a lot of the terminology. My applicable background is physics (and related vector analysis) and sailboats, both of which of course calls the same things by different names than proper engineers.

Your drawing illustrates the concept very well. It is easy to see what happens when the lower supports are not co-located with the kingpost. A torque is generated that is unopposed except for the resistance to bending of the boom pole and if it is sufficient will start to bend the pole there.

Of course there are alternatives such as stiffening gussets or whatever in the plane formed by the wire/rod and the pole to beef up the region otherwise subject to being bent.

Pat