I have been using a Whirlwind winch with a 6v battery pack. Will it increase the torque if I upgrade to 7.2 volts? And if so, can I still just plug the battery into my receiver along with the winch, or do I have to somehow directly connect the battery to the winch? I guess what I am worried about is that 7.2 volts may be too much for the receiver. Most receivers seem to be designed for 6 volts. Mine is non-BEC (not that I really understand what the difference is). Any advice will be greatly appreciated! Thanks, Colin
Colin, I use a Whirlwind Olympic winch in my 9 pound marblehead. It will literally pick up the entire boat on 6v. Most important to get rid of any friction in the sheeting system to make best use of available torque, use pulleys for all sheeting turns. Alternatively RMG winches are very strong. Nightmare #13 uses a RMG on 6v and no problems sheeting in but sometimes wish for more speed. Clyde
P.S. my whirlwind specifies 6v only, don’t know if it will take 7.2v long term
Clyde, Many thanks for your advice. I bought my Whirlwind so many years ago that I have lost the instructions (though I vaguely seem to remember that they said 7.2 volts was possible). I’ll stick with 6 volts for the time being. My the righting moment on my trimaran is more in the region of an AC boat than a Marblehead. It weights just under 7 pounds and is 1.7 meters wide and around 1.85 meters long. The sail is 2.5 meters tall. I have not yet got it on the water, though in its earlier incarnation before I lengthened it, I used the Whirlwind on 6 volts and it was only just strong enough – and at that point I was only using a 2 meter tall sail. So with the new sailk there is going to be considerably more tension on the sheets. I may reduce the beam a bit so as not to overstress the winch. I may eventually go with RMG, but they are expensive! Point taken about the use of pulleys. I guess you mean at the base of the sheet tubes. Best, Colin
Colin, I just spent an hour looking for the Whirlwind Olympic winch instructions and managed to find all sorts of interesting paper, but not the instructions. The friction situation is critical in our sheeting systems. An article by Jim Hitchens from the early 80’s has percentage losses for various systems for arm winches: hole in sheet metal arm 67%, hole in 1/8 inch ply arm 57%, hole in 1/8 inch plexiglas arm 52%, 3/32 inch plated eyelet in arm 37%, Pop-Up no snag pulley 12%, ball bearing pulley 4%. Losses in system can also be lowered with teflon sheet exits. The Whirlwind also had smaller pulleys available for greater torque, but less line movement. Clyde
Does anyone know what ever happened to Keith Skipper?
:zbeer:
Clyde, many thanks again for this info about the friction losses. I will insert a teflon tube inside the carbon fibre sheeting tube, which may help matters. It is difficult to fit pulleys at either end, due to space limitations, but I’ll try. By the way, I need not have looked for my instructions regarding the maximum voltage for the winch – I eventually noticed that the label on the winch stipulates 6v max! Colin
Although Keith Skipper is no longer supporting the whirlwind winches, is there anyone familiar with repairing and servicing the winch? Mine gave it all in last Sunday’s races. I have a 6 volt winch but would like to get this working again.
Don’t know if this is of any help, but I have a new, unused Whirlwind Low Profile winch, which I am happy to sell. Bought ten years ago, but never got around to using it.
Mike
merltd@tiscali.co.uk