The remarkable mechanical winch

Comparison chart

How the Grasshopper winch compares to the two main methods of launching.

Feature Grasshopper winch Hi-start Electric winch Notes
Launch altitude High Moderate Highest 6
Ease of setup Easy Easiest Hardest  
Ease of use Easy Easiest Hardest  
Ease of catching thermals High Moderate Highest 4
Required field size (for same altitude) Small Medium Small 1
Immune to UV Yes No Yes  
Adjustable tension Yes No With skill 7
All energy goes into launch Yes No Yes 2
Price Medium Low High  
Steady linear pull Yes No With skill  
One device for varying plane sizes Yes No With skill  
Minimizes stress on plane Yes No With skill 5
Minimizes walking dist per launch height Yes No Yes 3
Eliminates cumbersome turn-around pulley Yes Yes No  
Carrying weight 13 lbs ~3 lbs ~75 lbs (w/car bat.)  
Eliminates need to charge battery Yes Yes No  
Eliminates interruption of discharged battery Yes Yes No  
Useable in cold weather Yes Degrades ~45F Yes  
Complete system Yes Sometimes Sometimes  

Notes:
(1) Hi-starts take more field space due to the high non-linearity and the sagging of the rubber.
(2) In a hi-start significant energy is wasted lifting the tubing and dragging the tubing along the ground. The weight of the rubber imparts some extra energy at the end of the tow but most of the energy in lifting the rubber is lost.
(3) There is less walking because of the linearity. In a hi-start your initial steps don't add much energy to the system.
(4) It's easier to catch thermals if you launch higher.
(5) With a hi-start one tends to pull up to the limit that the plane can take since most of the energy is applied in the first part of the launch. With a linear pull winch you can setup for slightly less stress and still launch higher since full pull continues throughout the launch.
(6) Launches higher than most hi-starts because hi-starts have a "point of no return" on length. At a certain length, making them longer has no benefit. The reason is that the ground friction energy loss increases with length.
(7) Allows use as a standard tow or bungee style launch and to fine tune to your plane.

Close-up of spring and internal connector.

The Grasshopper winch gives highest launches for lighter planes - HLG and 2M. Very high launches are possible with planes weighing around 1 lb and moderate height around 2 lbs. At 3 lbs or more the advantage over a hi-start depends on the hi-start. The winch is supplied with 250 yards of tow line - you can use any amount of line.

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