There has to be some combination of friction and/or leverage that is messing you up. I can’t make anything too odd out in those pictures you posted but I can’t seem to get them to detach so I can try blowing them up. Can you send me a copy directly via email so that I can get a better look? maybe at a bit higher resolution too. I think you have my email address??
-Barry
Barry,
I cannot remember if I have your email address, could you PM it to me and I will forward pictures tonight. I think I am going to try the bungie cord booster idea on Lester’s site?
Also if you saw my post about Batteries, now i am thinking I will pick up a 5aa sldered pack and charger rather than the four pack (that came with radio) with an added single from radio shack, maybe I am loosing to much power?
Andrew
Is it possible that you have a duff servo? I’ve never heard of one losing power but if one of the bearings seized this servo might have the power to still work a bit. That would explain the noise and high battery consumption. These things have a lot of grunt and I don’t care how stiff your pulleys are it should not strain when just pulling in the jib. I know I don’t want my fingers in the hatch when someone moves the stick. You could test it with a little math and some weight.
Don
Don,
Could you explain the simple math for me. This servo is working fairly well and fast. How much weight sould it lift up? The main question is “Should this servo pull in your sails when on a run sails powered up, boat moving very well?”
Andrew
Don, the battery consumpsion I think was answered on my other post about Batteries.
Thank you all again.
If it’s an 815BB - my answer would be “YES” - and without a doubt. As I noted before - my 815BB on my 1 Meter multihull was chosen to handle 1100 sq. inches of sail and to do it quickly so I didn’t lose the boat to pitch-pole or capsize.
As Don notes - it can hurt your fingers at 6 volts (if everything is working)
Dick
OK the 805/815 has 343 in oz of torque. That means that it will lift 343 oz if the weight is attached 1" from the center of the hub. You have a 3.5 in arm so divide 343 by 3.5 eqials about 100. If you hang a 100 oz (6.25 lbs!!!) weight the end of your arm this servo should lift it. I would try 5 lbs, no sense hurting your back. Stand the boat on it’s stern and tie the weight on the end of the arm, don’t run the line through the block. The winch should do the 60 or 90 or whatever degrees no sweat. I don’t have a 3.5 in arm handy or I’d compare. I’ll look around.
Oh, I thought I’d posted this. Oh well. Mine will lift 3.25lbs but not 4.5. I’m surprised, only about half the advertised torque unless there’s something wrong with my thinking(I am getting on). This is with brand new batteries, a Y harness and 3.5" arm. I’ve modified my 805 to be a drum winch but that shouldn’t affect this test unless my mod introduced some friction. So yours should do at least this well.
Don
Don,
Can you discribe the set up with your 805 as a drum?
I just got home from sailing after a small modification to my 815, I added a version of the constant torque device discribed in Lester’s web site. It worked great, top end of A rig 80% of the time and even while going up wind I was able to let out and pull in the sails, even do the flick down wind for a gybe. I did not hear two much noise from the servo, but there was some. The only bad thing was the 4’ of 1/2 ice I had to brake through with my boots before sailing. I truly think that was it for sailing until next March or April.
Andrew
from the great white north
I changed out the stock potentiometer for a 10 turn 5000 ohm one. It;s not an easy mod, you pretty much need a lathe.
Don
Hi Guys,
A quick question? How do you set winch travel on these cheap servos?
If you have a programmable transmitter, then you can use the end point adjustments to set full in and full out. If not, then set up the winch servo to be correctly trimmed at full in (that way you cannot over tighten the sheets and break something). Let the extra travel occur at full out where it can do no harm. Then use your eyes to set the sail trim at full out. (or tape across the Tx slot to help stop the stick at the correct point).
John
Quick answer. End point adjustments or winch arm length. You can also do smaller adjustments by moving the anchor points or the fairleads. This is the reason I won’t buy a radio without end point adjustment.
Don
To the original poster:
I don’t know what you ended up using, but to answer the thread’s question, I think these are some tuff servos:
http://www.trossenrobotics.com/dynamixel-ex-106-robot-actuator.aspx