Arborist Rigging Pistol

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jomoco

Tree Freak
Joined
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Location
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So this idea's been knockin about in my head for many years now, an attachable handle for unwieldy hard to grip n hold branches you wanna cut n chuck, rather than lower with a separate line.

At first just usin cinched to the branch speedline loops as branch handles, worked fine to swing the load over the DZ n let go of the whole mess, collect the loops later, or have them tied to the tail of my climb line.

Over my career the number of easy droppable or cut n chuck removals I've done probably exceeds the strategic removals that had to be rigged or craned out by a fair margin.

Seems like there's always that one branch/leader/top that needs special attention in an otherwise straight forward n easy removal.

I'm not talkin big hairball targets everywhere removals here, I'm talkin little Harvey homeowner removals, apartment n condo complex removals.

My first ARP prototype was simply a handsaw handle with a set of grip pliers attached to it, and a 3 foot length of wire cable. It worked well enough, wrap the cable, lock off the end in the jaws of the grip pliers, hold in my left hand, then cut it free with my right hand, swing branch over the DZ, then release usin my left thumb to activate the plier jaws release mech. The biggest drawback as cable backlash releasing fair size loads, long sleeves n gloves a must!

Now these are relatively light loads, never much over 20-30 lbs, small stuff, cut n chuck stuff.

So late in 2016 I built a far more advanced ARP prototype built into a pistol configuration, with a spool of cord that ratchets at the back, and a means of cutting the cord at the front. Kinduva glorified cord dispensing n cutting pistol.

It wasn't until a few months into 2017 that a design for the ARP popped into my head that I knew would work dependably. That was prototype 7, made of steel, heavy at just under 5 lbs, capable of holding 50 feet of paracord, and cutting loads free by simply pulling a trigger once over the DZ. Hook up of the cord to the branch could be accomplished easily with one handed use of the pistol in either hand, thanks to magnetic cord terminations weights, and slots in the pistol, also surrounded by magnets, so once the cords cut, the cord weight magnet stays attached to the pistol magnetically.

Each branch caught n cut free uses about 3 inches of cord, so 50 feet of cords good for about 200 branches caught n released before more cord's needed.

Once I was certain of the pistol's performance n reliability aloft after many weeks of rigorous testing n abuse requiring many embarrassing design modifications, I decided to send it off to an online friend of mine for further testing.

Now the ARP 7 prototype was designed n built for the specific purpose of easily attaching to hard to hold branches as a custom handle, for the catch hand to swing over the DZ n cut free, catch n release. It did just that, very well.

But my design parameters grew larger, I wanted more than an easily attached n detached branch handle for cut n chuck removals, a much more multifunctional ARP, with a saltwater fishing reel, capable of holding over 100 feet of paracord, with an integrated braking mechanism over and above the reel's stock drag washers, a brake capable of supporting my entire 200 plus pound climbing weight.

So I built the ARP 9 prototype, more than a branch handle, more than a big shot line setter, more than a small branch lowering tool, more than a passive lowering line retrieval spool, you can also fish with it.

Jomoco
 

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Just balled n slicked a nasty old date palm with about 20 feet of crud on the trunk, with my 365Special, and it dang near got the best of me!

Stinking nasty rat n bat infested thangs!

Jomoco
 
It is a mess, that a respirator or dust mask only partially solves.

Breathin in even minuscule amounts of bird n rat n mice **** can't be any good.

Gettin fresh piped in air to a full face mask'd be nice!

All these irritating career shortening industry hazards can be solved by money spent on R&D, instead of week long extravagant industry retreats on fantasy island.

Houston! We have a problem....

Jomoco
 
image.jpeg Now that the ARP 9's complete n ready for testing aloft, it still weighs in at just under 5 lbs with a full spool, just like the all steel ARP 7.

The extra added functionality for line setting n retrieval make it worth draggin around I hope.
 
image.jpeg The ARP 7's considerably smaller, more streamline n compact than the ARP 9, but only functional as an easily attached n detached ergonomic branch handle, a fairly heavy duty one.

Jomoco
 
The technical aspects building an integrated braking mechanism into the ARP 9 seemed simple enough, and indeed a simple 1/2 inch steel tube, with 5 slots cut through half its lower diameter 5/32nds wide, allowed eyelets screwed into a wood block to fit into the tube, and with spring pressure, hold the tube and eyelets in perfect alignment, with cord threaded through it.

The trigger closest to the handle pulls the eyelets out of the tube, effectively braking the cord, with very little pressure, two fingers enough to suspend 50 lbs in a static hold.

So what's the problem?

Heat, frictionally generated heat, dyneema lashing cord's kryptonite!

Lowering 15 lbs nice n easy only 20 feet's no problem, 5 points of friction seems to be enough to dissipate the heat through the tube n eyelets enough to not damage the line in a static extended stop.

But doubling that distance heats the steel components up enough to melt nylon cord.

Bummer. But hope springs eternal, as carbon fiber tubes and porcelain eyelets are readily available these days.

Ideally I'd like to have up to 200 feet of 2mm dyneema lashing line on my reel, and be able to lower a 25lb branch/saw/log from over 100 feet up.

Should be interesting to see if carbon fiber tube sleeves n porcelain eyelets solve my overheating problems.

What's next, an ARP with a water cooled barrel?

Jomoco
 

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image.jpeg So the ARP 9 got its first field test this morning, in a SOD kill oak, bouta year dead, 50 footer with a 70 foot spread.

Set my line with the pistol, using the brake to pull the heavy trueblue over the crotch n down.

There were no true targets beneath, so I brushed my central TIP leader into little chippable branches with my 200, followed suit in the next leader over the driveway, then redirected from there to a leader I pretended needed to be cut n chucked.

First thing I noticed was my pistol leash being a tad too short at my wrist, since I let it hang to start my 200, the pistol gets slapped about a bit. But it performed well, cutting 25-30 lb loads away clean n precisely. Hookup was one handed, quick n easy, though tying back onto the magnetic ring weights takes longer, about 30 seconds tying an anchor knot in the cord.

Ironically one of the best features the ARP 9 has over the ARP 7, the super strong magnet ring weight, that can't be flung off the pistol centrifically, got brushed off releasing the fifth branch!

And I was so convinced I'd never lose a magnetic line weight, that I had no spares attached to the pistol, unlike the ARP 7, which had 3 spare line weights, just in case.

So the testing was over, and hard lessons learned, keep the pistol otta the brush n twigs as much as possible when pulling the cutting trigger ring, and have spare line weights on the pistol, on your saddle, in your pocket within easy reach.

Next field test'll include lowering branches, using the ARP 9's braking tube mechanism, using a polyester jacketed 2mm dyneema cord. I'd like to test it to failure to determine how much load it takes to melt a polyester jacket? And further whether carbon fiber tubes and ceramic friction points solve the heat build up problem.

These carbon fiber tubes are truly amazing in how light n strong they are! I'm sorely tempted to build an entire pistol outta this feather weight titanium strong stuff. No wonder all the fancy new little drones are made out of it.

Jomoco
 
image.jpeg image.jpeg More testing today, this time lowering 20-30 lb log sections from 30 feet up, very slow n gentle.

The braking tube's not as sensitive n grippy as I'd like, but it did perform well, and did not overheat.

A few more friction slots n eyes in the tube are called for, before lowering anything heavier over a real target though.

Jomoco
 
image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg Well I'm loaded for bear tomorrow!

This lime green 1.8mm dyneema cord's rated at an astonishing 880 lbs.

This'll be the first ARP 9 lowering test over a real target, a roof center beam, far away from the block's COG.

Light loads, less than 50 lbs, straight down to a groundie on the roof, fortunately a very thick tile roof.

Should be cake, less than a 15 foot run.

Jomoco
 
We'll never let it be said I don't post my failures!

Three broken tiles!

The pistol performed so brilliantly on the brush, four 25-30 lb loads in a row, lowered nice n easy.

So feeling confident I went for a 50 lb log, a tad too much for the tube brake to handle, pulling the braking lever hard as I could only slowed it enough to settle gently on the roof tiles, cracking 3 of them.

Fortunately it's an old friends house, who was in on the building of it, and saved plenty of extra tiles.

So I worked for free today!

Back to the drawing board with my tail between me legs!

Pics later!

No more real target tests till that brake can stop my entire climbing weight, with two fingers.

Jomoco
 
image.jpeg image.jpeg So the husky 536T electric 36 volt cordless trimsaw's the perfect match for my ARP pistols, in that they'll push a 14 inch bar n chain.

But to replace my 200's removal capability is very costly up front!

Sure the saw's under five bills, weighing 5.2 lbs sans battery, but the backpack battery needed to buzz all day's another fifteen fuggin bills!

But as a Californy punk, I will go with the flow n pony up!

Two grand for a commercial grade trimsaw!

Hopefully the weight saving aspects of a carbon fiber ARP'll help off set the 17 lb backpack battery weight gain!

Jomoco
 
image.jpeg image.jpeg So now I'm shootin for 8 points of braking friction, along six inches of cord, being sufficient to brake my bodyweight whilst climbin, a bit over two hundred pounds, with two finger's worth of highly leveraged pull.

Don't have the heart to cannibalize the ARP 9 for failing me, so I'll start from scratch again using carbon fiber plating
the new n improved braking mech.

Jomoco
 
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