Mechanical gin pole

[Kneejerk Bombas]

Lowering device.

Let's talk a little about the loads.

Just for example, I envision using this this on logs 6' long maybe 30" diameter, so we are talking around 1800 lb.s, right?

Say those straps are similar to the straps on a Hobbs or GRCS. Each of those is rated at over 20,000 lbs., so in fact they could be a lighter duty version, maybe 2000 lb.s SWL(5 to 1) each.

A couple folks recommend a titaninum alloy, I was thinking steel. It would be raised and attached in two seperate pieces so that makes the weight less of a factor.

If the movement is slow, from top to bottom, the loads don't appear to get much greater than the log weight. What method to use to slow the movement as the log swings down, that's the question.

One thought I had, was using a disc brake on the axle of the device. You could even have a little remote control with a hand lever.

You could set the brake, make the cut, put away your saw, and the piece would be held in place until the brake is realesed. Then as the piece is tipped over, variable brake pressure could control the decent.

 

[Kneejerk Bombas]

Had to draw it.

 

[Tom Dunlap]

Second try, Netscape crashed and I lost the first one...

I'm with Roger on this one. In order to have a high enough safety factor the unit would have to be very heavy duty which translates into big money. Guying of any gin pole is also mandatory. Calculate the leverage that is being generated.

Take a look at this site:

http://www.osha-slc.gov/SLTC/logging_advisor/manual/yarding/cableyardingsystem.html

That should be enough to get your creative juices going.

Other ideas:

Antennae sections, but they would have to be guyed out
Extension ladders, again guying is mandatory
Look on pages 206-7 of On Rope

many years ago a fellow invented a device exactly like what is being proposed here. The unit was pretty heavy and could only be used to tip over five inch leads. With that limitation it seemed to me that the hassle of hauling the rig into the tree and setting it up was negated. I have no clue how much it sold for. I do remember that there was an add and an article in AA for one month and then it disappeared.


Tom

 

[John Paul Sanborn]

I never guyed gin poses in antena rigging, but I never did huge construction.

If your goingg several feet and half a ton, then I could see the leverage being very great.

My concept is maybe 200# pieces for areas where you cannot drop anything. I've has it where I had to chunk out pieces I could hand down to a guy on a ladder.

Dropping on plywood covered tires would not have worked. 20 x 20 backyards in old parts of the city where you would have to cut down trees by the driveway to get a bucket in, much less a crane.

Maybe I would be better phrasing it ans no shock loading vise very little dynamic loading.

Anyways, just a thought.

 

[rbtree]

Tom, you da man!!!

with the links!!!

Many thanks. Oxman has sent me that one, I think, for ideas for high lining our big maple. Don't think I saved it tho. We were thinking of fixing the speed line high in the opposite anchor tree, and attaching the branches via a fiddle block or prussic with pulley, then pulling a trigger line to let the branch down. The concept seemed too risky. besides we needed to lift most of the branches, so we rigged the line above them in the maple, thus creating a bite in the rope, which we pulled out, lifting the branch. Pretty basic. Just a lot of slacking required at the end to get the branch to ground.

Back in '72, pre tree work, I landed a job in the islands off Ketchican, with a gypo logger. They had two high lead operations going, one to yard the side to a landing, the other to yard them down a fixed skid road to the water. One day, while chasing (unhooking chokers) at the landing, I carelessly ran underneath while the lower donkey was operating. The haulback broke and went snaking down the hill, no more than 1 second after I was out of its path.

I reckon the operation was close to what that site calls the North Bend system- real spar trees, stumps for tail holds, etc. When it was time to move to another side, the new one was so steep, with such soft ground, that, in the process of the donkey yarding itself up the hill ( on big log skids), and then rigging the spar, almost all available stumps pulled out of the ground. They almost had to let the logs lay!!!!

I really liked the balloon logging rigging!!!

Rog

 

[DDM]

Mike, you might want to think in terms of a Self contained Hydraulic cylinder on a slide as a braking device. If you are familiar with a self lowering vertical bandsaw thats the kind of cylinder im speeking of.If not it has a thumb screw
to adjust the speed of the cylinder .you could add a slide so that it would slide down as the cyl contracts. What size Steel are you thinking of? C-chanel?

 

[Kneejerk Bombas]

Shock absorbers, excellent idea! They could engage just past the balancing point and supply friction right to the bottom.
C-channel seems logical to start. The gauge and size will depend on loads we are going to feed the tool.
I'm also encouraged by Tom's comment that a similar device may have already been tested and put into production, if even for a limited time. Failure of a production run is in no way indicative of product functionality.
I can see why, with such limited uses, it may never be a big money maker, it may still be worth investigating. Last time I spoke to Greg Good, he was still not to his break even point on his GRCS as I recall, and that tool is fantastic with all kinds of uses.
Anyway thanks Dave, keep the ideas comming, at least you're not a naysayer on this topic. John's goal of 200 pound capacity could be reached, I think, quite simply.

 

[DDM]

200#? If you built it out of 4 X 1/4" C-Chanel and machined out a hinge out of O 1" barstock for the thru pin and 1-1/4 for the hinge and added 4 of those
Straps the ones used to tie down loads on a flat bed because they are basically
self contained structually the unit could handle 1000 + lbs without a shock factor.
Using a absorber of some sort cylinder ect. Now if you were to add a electric winch to the unit and a drop cord to a nearby vehicle you could lower it effortlesly.

 

[DDM]

Actually This might envoke some interesting ideas Hmmmm with a few modifications
http://www.northerntool.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=7179&prmenbr=6970

No shock

 

[Tom Dunlap]

Yesterday when I got "errored out" I had written about a hydraulic slave system.

By adding a porta power unit to the hinge mechanism you could scissor the chunk off the side. Think of the elbow of a grapple loader or some bucket trucks.

I wouldn't be too encouraged by this other device years ago. Remember, the pieces that it was rated for were only a little larger than a climber could handle with bare hands and a snap cut at the base.

After all of this cyber engineering gets done, it would probably be easier to cut a bunch of cookies and lower them individually than to setup any contraption.

Go ahead and prove me wrong. Start the engineering and welding!

Tom

 

[Kneejerk Bombas]

Great ideas Dave, but I don't like the use of electricity so much because there shouldn't be to much lifting involved.

Our disscusion may be getting a little diluted because there are two types of devices being discussed back and forth, the folding device and the gin pole.

The pick up truck hoist looks like what I had envisioned for the gin pole, no guys, just strap the tool to the tree, attach a rope, and cut.

One modification I would make to the hoist is to remove the winch and pulley, and put a friction device here, say a port-a-wrap. This could reduce the load to the tool by 40%.

I do like the little hydralic jack, it could be used to take the slack out and actually lift.

Another feature is the ability to rotate. You could cut, lift, rotate, and lower.

 

[John Paul Sanborn]

With a rope running to the gorund the rotation may get in the way of the rope. maybe a limit of 45 degrees or something?

Instead of a component lift system, (though the bottle jack sounds great!) allowing it to be used with an exisiting winch device would suffice.

Myabe Greg would allow you the use of his machine shop?

 

[DDM]

Mike, When you get ready to assemble something and need a few parts machined send me drawings i'll machine them for you.Hinge pins bushings ect.

 

[Kneejerk Bombas]

Thanks dave, I may take you up on that.

Here's my latest drawing. I added a redirect(green), I though it might split the loads a little.

I also added a port-a-wrap type thing to replace the pulley.

What do you think of those changes?

The problems of making the device lighter, raising the device easily into place, and moving it down and reattaching quickly after each cut, need to be addressed.

 

[Kevin]

Another consideration would be cutting through the tree with the chainsaw without running the chain into the base of the boom and if you`re cutting from only one side there`s a very good chance your bar will get pinched.

 

[Kneejerk Bombas]

There is a bottle jack on the side for lifting the piece, off your saw if nescessary.

 

[Kevin]

A couple of < shaped brackets against the tree might help.

 

[TheTreeSpyder]

Am trying to stay with you all here; and the situation of use that you propose.

What about setting up a normal block that catches hinged load like we are used to. But, having oil dampened delivery; for folding into block system; adjustable from ground and releaseable from air. Perhaps, the crew would pull from line on top to fold into arraingment as you cut, like super hinge.

Just a stray thought!

 

[DDM]

Mike, you could always put the 12 volt winch back on it then it could pull itself up in the tree. I'm thinking of adding a winch to my Frontend loader any thoughts on that?

 

[DDM]

That picture of the hoist i posted i was also considering putting one of those on the back of my dumptruck to hoist up bigger wood on jobs too small to haul the loader to.