2.4 ghz radio system

[Dave Mains]

I forgot to mention in my previous post....when setting the rudder (aileron) to exponential mode, if I crank in enough to make it feel good for me, I don't have enough range on the trim. The obvious answer is to get lighter on the ole thumb. However.....has anyone thought of this and come up with a work-around?

I know I'm setting myself up for replies like:
If you set the boat up properly you don't need much(any) rudder trim.

And I'm gonna work on that. [;)]


Dave
Orange Park, FL
#1566

[Jim Linville]

OK, I found the special set-up procedure for my Spektrum DX6 on the RMG web site, and my Spektrum is now driving my RMG 280DL perfectly. My problem is that the rudder and jib trim servos are inconsistent and jump all over the place. It's probably my fault because I like to try new things. I installed Cirrus P-CS704MG servos for both functions. These servos claim to produce 189 oz in of torque at 6V (way high for what we need, but I though it would be nice). When I plug standard Futaba S-148s into the receiver everything works fine, so I'm thinking the problem is these new fangled (current sucking) servos.

My question is: Which servos are you other Spektrum users using for rudder and jib trim?

--Jim Linville

[s vernon]

Jim,

Of course you used the alternate wiring shown on page 5 of my 280DL book or on Rick West's site, right? I am sure you did. Everyone at this point knows you need to do that if you have high amp draw servos.

I do not know if that is what is causing the jumping. Just nice to eliminate that possibile cause for problems.

Scott

[Jim Linville]

Yeah, I used the alternate wiring method. This thing really has me baffled. I don't think it's the radio. I just put the Spektrum in a US One Meter with a Futaba 5801 drum winch, S-148 rudder, and S-3802 backstay adjuster... EVERYTHING works perfectly. Sigh... --Jim

[s vernon]

Jim,

I think Rick West has a wiring diagram for putting 2 batteries in a boat on his site. Or you ought be able to figure it out if not.

That seems like something that might shed some light on the problem - just for temporary - just for the info. Making sure that the high amp draw servos have lots of power? I hope someone else writes some ideas because obvously electrics are not my strong suit.

Now making clear mylar sails with Scotch tape. I am probably near the top of that short list.

Scott

[Jim Linville]

I know it's off the subject, and I won't do it again, but your mention of making clear mylar sails with Scotch Tape reminds me of the guy in our club who makes US One Meter sails out of left over gift wrap mylar. He has "Santa Sails" for Christmas, "Pumpkin Sails" for Halloween, "heart Sails" for Valentine Day. If you head's in the right place you can have a lot of fun making sails! [:)] --Jim Linville

[bogordoug]

I use the alternative wiring method on the rmg site.

http://www.users.bigpond.com/rmgsw/alt-cct.htm

I find the dual switches really helpful when programming the winch and at startup. I turn on the receiver/transmitter first, wait until I have a conncetion (by testing the rudder) and then can toggle the winch on and off as needed. No need to plug, unplug from the receiver.

I have also put extension servo wires on the receiver so when I plug stuff into the receiver, I am doing so to wires which I have labeled and do not fool with the pins on the receiver. The only problem I have had is battery drain in the transmitter. The 600 mhz battery provided barely lasts 2 hours of recreational sailing. I am going to raid the Radio Shack recycled battery bin for a connector and purchase a 2000mAh battery pack. (See www.batteryspace.com)

Doug Hale

[Jim Linville]

Thanks, Doug, I put pigtails on the battery connectors (Deans) and used only one switch. I'll try using the second switch.

One more thing... not only does the Spektrum work perfectly in my US One Meter with Futaba 5801, the EC12 set-up (RMG280DL with Cirrus Servos for rudder and jib trim) works perfectly with my 75 mHz radio.

Arghhh....

--Jim

[Jim Linville]

If anybody cares, I figured it out. Turns out that I had somehow misread the schematic/wiring diagram in the RMG Instruction Manual and had it wired up wrong... not wrong enough to stop it from working completely, mind you, just enough so that it worked with lots of glitching. Everything seems to be working perfectly now. Thanks to everyone for the help and advice.

To paraphrase my old shop teacher, the lesson I learned is, read the wiring diagram twice and solder once.

--Jim Linville

[jrflorida]

Ok, I have joined the Spektrum group, I got one for my Soling 1M (gasp) which I have just for practice. I have not finished building the S1M so of course I installed the receiver in my EC12. Took the boat to the pond and sailed about 10 minutes or so and it then went across the lake without any control. I walked around and even a few feet away it would not respond, so I turned off the boat, and then turned it back on again ane we were in business once again. Happened again in another short time, and same thing, walk around the pond, etc. About then the miserable 600 mA battery ran down (I was experimenting the day before without recharging), so that was it for the day.

I called Horizon and after some discussion the tech said I must have a faulty reciever so send it back. I had gotten another reciever, needed one for each boat, so I put it in the boat. I didn't have time to go to the pond, so I thought if I turned on the boat and walked around the house while I was doing things, the reciever wouldn't know I wasn't sailing. No shutdowns, but I found if I wiggled the rudder back and forth, you know, sculling, (illegal, but I wasn't racing) suddenly the RMG would pull in to half way and then let back out. I was shocked, amazed and bewildered. So, of course, I wrote to Rob ar RMG. He had some thoughts but the most unique was the following: (I will quote his email as I know he reads a lot of this stuff - Hi Rob!): Just remembered, I have heard of similar problem before. On one occasion it was cured by connecting a large capacitor into a spare rx channel. This give the rx a power supply buffer and protects against brown out. I wonder if that wasn't what happened to your other rx. Brown out is where the rx micro controller goes out of control and won't come back till the power supply is cycled. Spektrum actually has a capacitor available for this purpose.

OK, now I have talked to Horizon twice, and no mention of this capacitor, but I will be asking tomorrow. I tried my land test on the first receiver and the servos I am going to use on the S1M, including a heavy duty sail servo with a Y connector that seems to act like the SMG alternate wiring setup, which I use, and no problems.

Long note, but those of you have the Spektrum, any situations like this? I have the receiver velcroed against the deck with the alternate RMG wiring, a 6 volt battery in the boat, and have never had any problems with the JR radio that seems to be the father of this Spektrum, they look identical.

Thanks for any comments, John Rowley

[jrflorida]

Here I am answering part of my own post. Horizon Hobbies does have a Spektrum Capacitor, $6 each and the part number is SPM1600. I am going to get a couple and see if that does the job, but according to Rob, that should be the solution.
John Rowley

[Windjammin]

For anyone looking to upgrade to the <b><font color="orange">Spektrum DX6 2.4 GHz </font id="orange"> </b>

<b>Windjammin Sails </b> has them for <font color="red">$184.99 </font id="red"> w/out servos. See
<font color="blue">http://www.beanbag.com/wjsails/dx6.asp</font id="blue">

Also, one recommendation is to get the TX battery upgrade offered. The battery that comes with the DX6 was intended for park flyers, and thus your transmitter will only last 2 hours with the standard 600 Mah installed. Windjammin offer a 1500 mah pack which will triple this tx run time.
Spektrum battery packs easily plug and unplug into the back of the transmitter, so I keep my replaced 600 mah charged and ready as a back up just in case I needed more than the 6 hours the 1500 mah gives.

[Windjammin]

John,

The problem you are experiencing is with the RMG and the Spektrum. I had the same thing happen at the 2006 EC12 Region 4 regatta. I would get hit by a puff, and the boat would continue sailing for 6 seconds with all loss of control. For me, I would regain control after 6 seconds (usually about 5 boat lengths past the mark I was trying to round.)

What was happening is the RMG at times steals enough power that the connections between the Spektrum receiver and Transmitter are lost for just a millisecond. With traditional radios, one would not notice this 1/2 second loss of connection. However, with the Spektrum, once the signal is lost, the 2.4 GHz frog requires the radio to re-search what freq are available, choose 2, then reconnect... takes about 6 seconds. My test the radio would reconnect after 6 seconds. However, I have been told that others would loose signal and their boats would not re-connect.

<b>Solutions: </b> I have not tested yet, but I will be this week as I am headed to the Regionals and I will test all of the following.
<ul><li>1. I have been told going from a 4.8 volt RX battery to 6.0 volts will help eliminate the drop in voltage low enough to dis connect the receiver. </li><li>2. You can re-wire the boat in a Y so the battery goes to the RMG and the receiver. You just need to pull the red wire out of the plug from the RMG to the receiver so you are not double feeding the Receiver... direct and back feeding it from the RMG. The RMG web site has a diagram on this. </li><li>3. The simple fix... Spektrum has a voltage regulator as you mentioned, SPM1600 that you just plug into any open channel on the receiver, and it prevents any voltage spikes or drops to the receiver. See http://www.beanbag.com/wjsails/products.asp?cat=188 </li></ul>

Hope this helps....
I will know if all these work fro sure after the Regional Aug 4-5. i will let you know.

[Chuck Luscomb]

Hi Scott,

I have only one regatta under my belt with the RMG winch and the Spektrum radio. I use a 5 cell 2100mAh battery for the RX. I did not have any drop outs of any kind. Day one was very light air but day two we had a bit more breeze. Still no drop outs but no big gusts either.

I did change out the stock TX battery with a 1650mAh battery but still got a low battery alarm at the end of sailing on the first day. It was very light air and one race took nearly and hour to complete. The radio was off between races but it still sounded the alarm at the end of the day. I guess that means I got about 5-6 full hours on the bigger battery. I have since upgraded the voltage regulator but have not tested to see if it will work as advertised.


Good luck at the R4 event!

Chuck
#1684