Drum Winch instead of Arm Winch

[Midniteblue]

I have to decide what kind of Sail Servo to use in a new boat. In the boat that I sail now I have a Ozmun Swing Arm Winch with torque rated 180 oz.in .

What I like of the Swing Arm Winch is the simplicity, doesn’t need any programming, almost problem free. You can vary the length of the Jib Arm, offset the attachment points on the winch arm, to optimize the relationship between Jib and Main as they move from beating to running. Using a Spectrum Radio and a Jib Trim you have even more controls.

Looking for a more updated technology I discovered the Power Servo Gearboxes used for a wide variety of applications from unmanned aerial vehicles to radical robots. These Gearboxes come in a variety of options and can have tremendous power and they are built with High Quality materials.

Reading about R/C Sailing it almost looks like anything that is not a Drum Servo is obsolete, what is your opinion and why should I use the Drum instead of the Swing Arm


Specification RMD 280ES
No Load Speed 4.4 revs/sec
Stall Torque 221 oz.in
Dimensions 2.9 x 2.1 x 2.3 inch
Weight 4.7 ounce

Specification Servo City Power Gearbox HS-645MG (4:1 ratio)
Maximum Rotation 180°
6.0V Speed .80 (sec/60°)
6.0V Power 532 (ounce-inch)
Dimensions 3.8 x 1.9 x 2.8 inch
Weight 8.4 oz.


Val

[greerdr]

Some very good sailors use swing-arms.In all my other classes I too use an arm but I suggest it is hard to argue with success-over 90% of the boats I sail against use the RM<b>G</b>sailwinch.It does take a bit of getting used too but then it is like a dear friend.A little tough and rough-but dependable.

R.C.Greer

[john richmond]

I think the Servo City Power Gearbox HS-645MG (4:1 ratio) is to light, I use the 645 with 3:1 gears in my Soling 1 Meter with good results, I put a HS-805BB (3:1 ratio) Robot Zone in a Santa Barbara 2 years ago and it works great, 3:1 = 1029 oz/in, 4:1 = 1372 oz/in I think the S/B and EC12 are about the same weight and sail area.
John #316

john

[W Wagner]

I am currently using the Servo City Power Gearbox as a replacement for the failing Ozmun that was in my fixerpuuer. It uses the HS-805BB and travels through 180deg. I originally ordered it with the 5:1 ratio, which was just too slow. I just switched it to the 3:1 ratio, which works great. I sailed the last race of the season wit an A rig in solid B rig conditions and it was fast and plenty strong. The only thing is that it is a heavy unit. I did a significant amount of machine work on the aluminum housing before I assembled it trying to reduce its weight and it is still a porker. In my setup I used a swing arm with 4.25inch offsets to the turning blocks to keep it as short as I could while maintaining enough travel. I was trying to keep the winch as low as possible and the arms from hitting the hull. You could use an offset arm to get the turning blocks higher and longer but to do that would have jut added more weight to the setup.

Will

EC12 fixer-upper OZM0110 sail number 826