Futaba 2.4 Ghz SAILBOAT winch problems? Solutions? - Page 2 - RC Groups
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Aug 10, 2017, 02:59 PM
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Quote:
Originally Posted by Tillerman6
I am running dual battery systems right now.

Cost- These winch servos can run into the hundreds of dollars even if they are not HV versions. So I am hoping that this one is still OK.
I am sure you are doing the right thing and have a shared ground but two batteries in a sailboat is different. It seems like 2.4 shares a power bus so you can plug the battery into any channel. If you had the recievery battery (black/red) and the servo connected with all three (power/ground/signal) you were feeding feeding different voltage as the batteries discharged or tried to equalize.

So what is the minimum configuration that can reproduce the fault? Two standard servos? The winch in the rudder channel?
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Aug 10, 2017, 03:04 PM
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winch


I looked up your transmitter manual , that is a rx that has MANY options. Certainly more than whats required for a boat. Note that 2.4 is NOT required, And you can still use the older JR for a boat unless your in a club that requires 2.4.
You can get a winch servo from OmniModels for about $35. Servo city also has them for same price. There Hitec not futaba but work fine with Fut recievers. They have a max rotation of 3 1/2 turns and you can cut that down to about 1/2 turn with your transmitter end-point adjustment. I suspect your transmitter setup in transmitting in wrong mode, or you have something not set right. You need to provide more info, what receiver are you using, that transmitter will only work with a specific receiver. Also the transmitter comes in several configurations, does the throttle stick self center (spring loaded) or if you put the stick full up does it stay there or pop back to center. Cant use self centering throttle for a boat. You can change it by removing the springs, manual should indicate how.
Also I would use a LIFE (A123) battery for the receiver, not a NiCad, Nicads drop voltage with hjgher loading. A123 ,2 C about 1100 Ma is what I use in a boat. The winch servos I indicated are larger and more weight then a standard servo, I don't know the size of your boat.
That transmitter is more for drones, so it will take a lot of reading of the manual to get it set right. A 6x would have been a better choice and cheaper.
I have a picture of a Dumas Star 30 with the winch setup in it, might want to look it up here on rcgroups.
phil
Last edited by pphil611; Aug 10, 2017 at 03:12 PM. Reason: add picture
Aug 10, 2017, 03:29 PM
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Well the first test(battery swap) seems to have fixed the immediate problem of the winch servo taking off on it's own. I ran three tests today with the electric part of the boat and one with the head sail tack attachment point. First I ran alkaline batteries on the winch servo for 20 minutes. No glitches. Then I ran te NiCD battery that I had been using when the problems shwoed up. No problem for 20 minutes, then the receiver started sending strange commands to the winch servo and the rudder servo channel started mixing. So I shut it down and measured the RX voltage. it was 3.2 again. So then I put the alkaline batteries back in and went sailing again today. Results- After a solid hour- no glitches at all!

Incidentally the "fail safe mode" was NOT set because I didn't know where it should be set, and in a sailboat, there is not too much point in having a fail safe if the boat cannot go over the horizon. (sailing in a wide creek) And if you did set a fail safe condition to put the rudder hard over for instance, the boat would still be stuck out of reach anyway.

So I didn't take the hatches off again yet. I may have to do that to get the winch re-centered because the trim limits keep changing. Not too sure what is up with that?

Maybe when the new batteries get here I will set everything up again and see if it will hold the trim limit positions any better than squat.

The trim limits don't seem to change unless the Rx voltage drops into the 3.8? 3.2 Volt range. I don't know why this would happen, but those are the symptoms. I'm getting real tired of peeling off a tape hatch cover to re-calibrate the winch drum position!

Any ideas for that one would be much appreciated!
Aug 10, 2017, 03:42 PM
a.k.a. Bob Parks
My failsafe setup is lots of rudder & the mainsail let out. When I turn off the TX, the boat just circles where it is.

I sail in a lake, and I use it for parking the boat if I need to get something out of the car, or if I am helping another sailor. Turn on the TX & the boat is back in control.

It is not really for emergencies, or TX failures at a distance. There are paddle boats available if the sailboat fails to respond.

BP
Aug 10, 2017, 03:45 PM
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Dick L.'s Avatar
Plastic packaging tape to keep water out, electronics visible and not designed for graphic good looks.
[3M - 3 inch wide]

I used for flat decks during my original RG65builds/trials.
Aug 10, 2017, 03:56 PM
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The Futaba manual shows only two positions for plugging in the battery. These are labeled SB/6 AND SB2/8 . Right now I'm in the SB/6 port. Haven't tried the other port, and now the battery problem has shown itself to be the problem, so I probably won't switch battery ports.

I already ordered some NiMH batteries and a charger. The NIMH batteries will be 6V and 5 cell and will still fit inside the battery jar. This was one major consideration besides cost and finding something that would balance against the weight of my existing Futaba winch servo which is no light weight servo.

My reasons for getting the T6K were not just for the boat, but I wanted something that was legal (they will confiscate your whole rig if they catch you on 72MHZ with a surface model) And then it's hard to find anything on 50 Mhz, 53 Mhz or 75 Mhz AND FM or FAAST systems that are reliable enough, that are of recent manufacture and will also be ground legal. I still have my JR for Aircraft use and the 2.4 can do either one if it works properly (although I would NEVER put it in an aircraft unless it was made out of sponge rubber, because the throttle channel goes whacko when the rx voltage gets too low.

I know there are plenty of people with aircraft on 2.4, but that is a bit risky for me and my pocket book. I can't think of a "fail safe" condition for an aircraft except maybe if it's equipped with a parachute.

The other model I will end up with is probably going to be a motor glider of some sort. Probably on 72Mhz again.
Aug 10, 2017, 04:02 PM
Registered User
That sounds OK, but you are still off in the paddle boat regardless. Same here. I think the "fail Safe" mode was invented by the MFGRs as a marketing gimmick when they realized that the RX would go haywire at 3.2 volts or whatever voltage lets it drop out of operation. I will probably go ahead and set mine up for the fail safe condition and see if I like it. At any rate it is much safer in a boat than a plane or multirotor.
Aug 10, 2017, 04:04 PM
Registered User
Quote:
Originally Posted by Tillerman6
I am running dual battery systems right now.

Cost- These winch servos can run into the hundreds of dollars even if they are not HV versions. So I am hoping that this one is still OK.

Availability - I don't know if there is even any HV winch servo version available anywhere? Futaba is not making this winch ( FP-S 110) any more, and I don't think they make a HV winch servo either. There are HV servos yes, but they are not Winch servos which is a breed all of it's own as you may know.
Hitec HS785HB - costs nothing like hundreds of dollars. Full on top of the range winches can cost plenty, but merely very effective ones don't.
But a servo tester can be had for just a very few $s. Well worth having in the tool box to help eliminate radio guesswork.
Aug 10, 2017, 04:26 PM
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This Tx is a futaba T6K which is overkill I agree, but I was wanting something that could do more than one model. And it has telemetry if you can get all the goodies for it set up and running. So you could See if your model batteries were getting low before they actually failed.

Anyway that was the idea initially. And no I'm not in the wrong mode, or it would not be working as well as it is with the fresh alkaline cells that I sailed with today. The only question now is when I get the real batteries that I will be using and it's all re-calibrated and has the telemetry set up will it hold the trim limits and report back often about the model battery condition so that I don't have to go fish it out of the lake!
Aug 10, 2017, 05:02 PM
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Just the ground (black wire) was shared between battery systems, so no current flow with the different systems. The Winch servo has this separate voltage supply cable coming out of it and also the normal 3 wire connector to the RX just like any normal servo has.
Aug 10, 2017, 06:35 PM
Registered User
Quote:
Originally Posted by Tillerman6
Just the ground (black wire) was shared between battery systems, so no current flow with the different systems. The Winch servo has this separate voltage supply cable coming out of it and also the normal 3 wire connector to the RX just like any normal servo has.
Electricity, like water flows down hill. If the servo is using 3 pin you might be powering the reciever twice. Leave the winch plugged in an remove the receiver battery and see if the reciever is still powered. There is a profound difference in the way power is passed in recent hardware.
Aug 10, 2017, 08:24 PM
Registered User
pwallace,

your test is negative. With the rcvr battery disconnected, the system is dead. no pwr coming from the winch servo connections. I suppose that could have happened if the winch servo circuitry was damaged in some way, so the test was worth doing. Anyway electricity flows from negative to positive and that is regardless of up hill or down hill. Maybe you mean from a physics standpoint in a relative way. I was an electronics technician for 35 years. I do know my trons.

And by the way, the first problem was the old Nicad battery going low in 28 minutes to the point that the rcvr was sending erroneous commands to the throttle channel.

New batteries made everything work normally again. But thanks for your input it was a great one!
Aug 10, 2017, 08:31 PM
Registered User
Hitek HS 785HB

Sounds good I will have to try and find the specs for the Futaba I have now and see if the Hitek is in the same ballpark. It would be good to get something in the boat that was a little lighter because this particular Futaba servo is pretty heavy and big. (but it never stops working if the rest of the system is OK. )

The boat is a One Meter. The sails are a main and a jib and I think the area is a little less than one meter as well.

I went to the bigger Futaba because I kept
Aug 10, 2017, 08:32 PM
Registered User
burning out servo boards on the smaller units.
Aug 10, 2017, 08:37 PM
Registered User
So I tok your advice and set the fail safe on this TX with the rudder hard over and the sails out.

Hopefully I will not have to use that feature!

And by the way I also engaged the telemetry for the RX battery voltage to be transferred to the screen on the TX. And it works fine at least at short range, so that would probably solve this problem pretty well near 100%!

If I had completed the set up sooner, this all would never have happened! My bad!
But the manual is 159 pages, so it took some time to go thru it all.


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