ok i was only a little bit drunk:)
wondering what servo to use on my canting keel r/c yacht to cant my keel any ideas im using hitec digital servos and controler
keel length is around 800mm or 31 and a half inches
max cord is 90mm or 3 and a half inches
min cord is 75mm 0r 3 inches
leweight 1.5 kg(but i think it will be way to much so maby 1kg) after looking at sodiums boat sailing today which is out of the same mold just slightly shorter than mine but with the same weight but less lenght in keel his weight is about right for a fixed keel so it may even be less than 1 kg(well i hope it is)
arm is about 60mm
hull is bascialy a marbelhead and rig is same
i have about 45 of cant
i was thnking about going a hitec sail winch or arm because oc cost but i dont know if they will be able to handel the load and be quict enough
When the Apprentice knows more than the Mentor its time to quit!
It depends entirely on these factors:1) the length of the fin from the pivot point to the CG of the ballast,2) the amount of ballast,3) the length of the inside lever from pivot to top end, 4) the speed(zero degrees to full out) and 5)cant angle you want to shoot for.
If you’re using a long fin and much over 2-2.5lb.'s of ballast you’ll probably want to consider a Guyatt 280 or 380HD.
If you want to post the answers to the above I(and maybe others) could help you figure this out.
A big one! On my ‘CKT’ I used a hitec sail winch, after working out the loads on it and testing the winch lifting static weights. If its a bigger boat with a heavyer and/or longer keel you would want a stronger winch. I was specificaly going low-cost. How big is the boat?
If you keep that length and 1.5 kg. figure on a Guyatt 380HD on 7.2 volts; If you go to a shorter keel and one kg you MIGHT make it with the 280. Since there is not too much difference in price or weight go with the 380HD which has metal gears and is designed for this application.
You can use a “string” method or a gear method like John Beavis and Grunta to move the thing. The “string” method allows the maximum cant angle the hull beam will permit but you have to rig it right with spectra line and “slack” springs plus a way to tension the lines initially while the spectra “creeps”. Once the spectra creeps there is no longer any stretch and line tension needs no attention (except the springs).
bugger i was afraid that was what was going to come back to me was hopeing for a cheaper way because the 380 is quiet a bit of money(more than i wanted to spend) is there any other ways that any one knows of that are cheap
would a hitec ball bearing sail winch handle the loads yes it would be slow wich is not ideal but about a 3rd of the cost
When the Apprentice knows more than the Mentor its time to quit!
You mentioned in General Discussionunder blocks that the block let go; did it seem that the winch would handle the load before it let go? Which Hi tec are you trying ?
um yes and no hard to tell the winch would cant the keel from one side to the other with out a problem on dry land but not to sure about when saing with all the added extra loads a hitec hs-725 bb running of a y harness with only 4.8 volts. i decided that the Guyatt was to expensive and i could live with it being slow and the boat my be a dog i dont know if its not a dg i will look at a Guyatt if the hitec cant handle the pace but you never know
When the Apprentice knows more than the Mentor its time to quit!
I know of a tiny motor that my mate who is a engineer has made, its 10mm long, the gear ratio is 240:1 & its 3v, he said that he can only just stop it moving, they cost about AU$60