POWER SPAR       

May 5, 2014      
Jon Bell

• A low-cost self-contained winching device for forest material recovery.
• Works like a winch-truck but without the truck. It is the mythical "Sky Hook".
• Supplies lift to logs out as far as 60 feet due to the height of the spar tower.
• Can be deployed and operated by one person.
• Battery lasts for hours and re-charges overnight.
• Handles green wood, often as whole trees with branches still on.
• Material processing takes place at the landing and at a comfortable working height.
• Bending, reaching, lifting, and walking materials is almost eliminated.

Weight: 80 pounds -not including battery
Length: 12 feet
Winch:  5,000 pound-capacity 12-volt electric

The spar is a welded truss custom-made from thin-wall electrical EMT conduit.

The winch has 100 feet of 1/8th inch cable instead of the stock 50 feet of 1/4".

The power spar shown in the video is an experimental prototype and I was trying to keep costs very low. Based on testing to date, I would not hesitate to spend a bit more money and get a larger and perhaps higher quality electric winch. I would make sure all pulley wheels are steel -not aluminum. I would use 3/16" cable.

MATERIALS PRICES [and sources]

[hardware store or lumber yard]
$33     EMT conduit
$20     miscellaneous steel and bolts

[auto-parts store]
$100    standard full-sized car battery
$10     jumper cable clamps for battery wires

[Harbor Freight list prices -substantial savings when things are on sale]
$250    winch -includes fairlead, control lanyard, 12 volt wires, switching module
$15     100 feet of 1/8" cable
$54     90 feet of 3/16" cable
$60     optional remote control
$10     top pulley
$40     tow-strap webbing to attach spar to anchor tree
$12     choker slings
$10     side pulley for deflection pulling
$25     side pulley sling and carabeener

I invite others to copy this design and make their own. I am quite happy with mine.

Also see specs for Jon Bell's Sawbuck

I am available at:
Jon Bell
303-747-2611
jonbell@indra.com