AT sawyer
ArboristSite Operative
I see this topic over and over, so I thought I'd put it to the test, since I have the gear. I put three come-a-longs (standard ratchet and bail come-a-long, Maasdam Rope puller, and a TU-17 Griphoist) on a Dillon dynamometer and tensioned them to the max.
The standard wire come-a-long was the cheapest at about 20.00 and the weakest of the bunch. It would still pull 1000lbs tension on the wire, though at that point the 16.5" long wishbone arm, mic'd at .115", was about to fail. It's undersized hooks wouldn't fit the usual 7/8" screw pin shackles I use.
The Maasdam rope puller, about 60.00, tensioned its rope to 1150lbs and still had some room to go. I tried to get a pic of the dyno on full Maasdam tension, but the rope's stretch backed down the dial by the time I got the camera ready. The 18.5" wishbone arm mic'd at .125", a bit stouter than the standard come-a-long and an overall better-made product. It's hooks fit the 7/8" shackles.
The TU-17 Griphoist, 300.00 used on Ebay, passed 1000lbs easily and ran the dyno to 2000lbs tension without full effort. Though rated at 2000lbs, its 30" lever put 2500lbs tension on the dyno without hitting the shear load of it's safety pins. It's hooks also fit the 7/8" shackles.
For my dollar, the TU-17 Griphoist took this somewhat unfair contest without a second thought, as I expected it would. The Maasdam rope puller was impressive with its quality and unlimited rope length, though rope stretch is a factor when using it for controlled felling. The standard come-a-long was (maybe) worth what I paid for it, and is a light-duty tool of dodgy quality.
Three come-a-longs
Mic on the Maasdam
Standard come-a-long struggling with 1000lbs
Maasdam pulling beyond 1000lbs
http://www.arboristsite.com/attachment.php?attachmentid=153650&stc=1&d=1286748758
TU-17 Griphoist pulling past 2000lbs tension
http://www.arboristsite.com/attachment.php?attachmentid=153649&d=1286748232
The standard wire come-a-long was the cheapest at about 20.00 and the weakest of the bunch. It would still pull 1000lbs tension on the wire, though at that point the 16.5" long wishbone arm, mic'd at .115", was about to fail. It's undersized hooks wouldn't fit the usual 7/8" screw pin shackles I use.
The Maasdam rope puller, about 60.00, tensioned its rope to 1150lbs and still had some room to go. I tried to get a pic of the dyno on full Maasdam tension, but the rope's stretch backed down the dial by the time I got the camera ready. The 18.5" wishbone arm mic'd at .125", a bit stouter than the standard come-a-long and an overall better-made product. It's hooks fit the 7/8" shackles.
The TU-17 Griphoist, 300.00 used on Ebay, passed 1000lbs easily and ran the dyno to 2000lbs tension without full effort. Though rated at 2000lbs, its 30" lever put 2500lbs tension on the dyno without hitting the shear load of it's safety pins. It's hooks also fit the 7/8" shackles.
For my dollar, the TU-17 Griphoist took this somewhat unfair contest without a second thought, as I expected it would. The Maasdam rope puller was impressive with its quality and unlimited rope length, though rope stretch is a factor when using it for controlled felling. The standard come-a-long was (maybe) worth what I paid for it, and is a light-duty tool of dodgy quality.
Three come-a-longs
Mic on the Maasdam
Standard come-a-long struggling with 1000lbs
Maasdam pulling beyond 1000lbs
http://www.arboristsite.com/attachment.php?attachmentid=153650&stc=1&d=1286748758
TU-17 Griphoist pulling past 2000lbs tension
http://www.arboristsite.com/attachment.php?attachmentid=153649&d=1286748232