Spektrum fix???

[Olscuzbut]

Purchased the Spektrum DX5e for my boat. Bound the receiver to the transmitter. All OK. Installed in the boat and bound it again with the throttle and rudder controls, setting the throttle stick in the mid position as my neutral stick. Worked fine with forward and reverse throttle. But when I turned off my transmitter, my throttle control went to full reverse. When I contacted Horizon Hobbies, they said that the receiver fail safe for the throttle is full back. Has anyone come up with a fix for this? I just have to make sure I turn off my receiver or ESC first before turning off my transmitter. Could see a problem if I get too far away and loose control.
Any help would be appreciated.

[Ron Olson]

You turn off the receiver first, then the transmitter. Turning on is just the opposite, TX on, RX on. That's why your radio is going into the failsafe mode as it wasn't getting a signal.
Next, Spektrum radios really aren't designed for boat use. I saw 2 boaters lose contact with their boats within a very short amount of distance. The problem lies with the radio signal bouncing off the water in the 2.4 Gig frequencies. So far, only Futaba has really taken care of that issue.

[AndyKunz]

The reason is that your radio is an aircraft system. Aircraft ESCs go to 0% to shut down. You have to use a surface radio to get a 50% shutoff.

However, the BR6000 is for robots. It binds to aircraft radios, and the failsafes are programmable.

http://www.horizonhobby.com/Products/Default.aspx?ProdID=SPM6000BR

Also, according to the Spektrum website, there is a marine product in the works. http://spektrumrc.com/Articles/Article.aspx?ArticleID=1888

Andy

[Brooks]

I've used Spektrum for sailboat, steam boat, and electric-powered tugboat over 200yd distances, never had any problems with signal bounce loss of control. At those distances, it is hard to see exactly what the smaller tugboat is doing, so I don't generally send my tug that far away, but it can be done. I sail my barque from one end of the pond to the other regularly, though, as it is big enough that I can tell what's happening @ 200yds.

Spektrum is, however, very sensitive to power loss at the rx end. If your onboard batteries get low, you can lose control. I'd suspect that was the problem with the 2 boats cited by Mr. Olson. This can happen with BEC-ESC's when the main (only) battery runs down. I've also experienced temporary loss of control when the drain on the barque batteries gets too big in strong winds (where the sheeting servos are working very hard and drawing down the voltage). I had to scrap my 4, AA Duracell battery arrangement and go to higher capacity lipo's to run the barque in strong winds. After switching to the lipo's I never had another signal glitch due to voltage drop.

Of course, any brand radio will crap out if the tx batteries get low. Early Spektrum tx's had a poor battery-voltage-step-down design, and drained tx batteries quite quickly relative to other brands ( 2 hr tx working life vs 4+ hrs with other brands). There is a fix, involving soldering. Newer Spektrum tx's have a more power-efficient design.

The Spektrum system will re-establish a link tx-2-rx if you flip off the tx for a few seconds, then turn tx back on. In those circumstances, it is wise to head for shore. My vac u tug can continue scooting around for 5-10 minutes more after such a signal failure/re-establishment, but it's a needless risk, I think. I just carry a spare boat battery and swap out.

I did have signal bounce problems on water with a Futaba FM system (float plane, 72mhz), but I've never had that problem, as far as I know, with my Spektrum in float planes or boats.

[Olscuzbut]

Hi Brooks,

Thanks for the info on the Spektrum. I swapped the throttle control to the elevator stick, which has the neutral position in the middle. (also the fail safe position) Just means I have my rudder and throttle on the one stick. Havn't got it on the water yet to check it out, but works fine on the bench. Almost like a video game joystick!!! Don't know if I will like that, but will know when I run it. Thanks again.
Norm

[Brooks]

I need to be able to run my barque and tug at the same time off the one tx; the tug is my rescue vessel :-). My radio set up: left stick = tug throttle and rudders (both barque and tug rudders) and right stick = sail sheets (foremast+ jibs and mainmast+mizzen+jigger). It is challenging to run both vessels at once, hoho, but perfectly doable to have rudder and throttle on same stick.

You can remove the centering spring(s) from the right stick if you want. I did that since the sails are set with stick over in one corner (or the opposite corner) for windward work and holding against the springs was a needless complication. To keep the springless sticks from flopping around, I tied U's of fuel hose around the joystick axes (inside the tx box); a string through the U allows me to compress or release tension to get just the feel I want. Ratchets would be even nicer, but more complicated to install since, on my radio, the sticks don't have ratchet notches on both axes.

I believe the robot rx has adjustable fail safe positions. I have not bought a new radio system or rx for a while, so specs may have changed.

As Mr Olson said, never leave the rx turned on w/o a signal from the tx; you are just asking for trouble if the rx picks up airwave crap and has no overriding tx signal to protect it. This is something I drum into my helicopter students - with faces and hands near the rotor blades when the chopper is plugged in, the potential for injury is present. "Tx on 1st, off last" is the rule. Almost got me one day when the teacher (uh, that would be me) handed the wrong tx to the student before the teach bent down to plug in the chopper battery.....red face, but no red blood, whew.

[builderboy]

I bought a Spektrum radio on the advice of the hobby shop guru, after reading your advice I think I'm going to stick with my Ace Nautical Commander. I built a Robbe Atlantis schooner a few years ago, but have never sailed it due to job pressures, the Spektrum was supposed to be the thing to get me back into this, after reading of the mods and adjustments needed, I'm doubtful. Do you think the Ace would be ok even though its about 12 years old?

[Brooks]

I must have inadvertently mislead you, if you are referring to *my* advice in your decision to abandon the Spektrum. The Spektrum is a *Superior* radio for boating, in my experience. It is much more glitch resistant than any FM or AM radio I have used. I've even used the Spektrum to control live steam locos, which are an absolute nightmare of glitch producing radio interferance (every metal-2-metal rubbing surface produces radio wave spikes, and a steam loco is All About metal-2-metal *grin*).

The Ace should be fine, though. I used one of them on a glowplug outboard motor speed boat years ago and was satisfied. Mine was an FM model. Most Aces, at that time anyway, were AM. Generally speaking, AM is more sensitive to radio interferance, either over the airways, or from brush-commutator sparking of the boat's electric motor. You can solve the sparking potential problem by soldering capacitors to the motor case. Others have more experience doing this than me, so if you are confused, you should ask or search the forum. It's not hard, from what I've read.

After sitting 12 years, your Ace will need new tx batteries. Unless topped up periodically, nicads go dead, or at least lose most of their mah capacity. You will need to remove the old nicd batteries (should not be a problem) and then measure the pack to see what currently available tx battery packs will fit. If you can't find a suitable already made-up pack, Radical RC will make up a specialty pack for you. Other vendors may do the same.

http://www.radicalrc.com/shop/

If you have questions regarding your Ace, you could pose them over on the radio forum. Even though Ace is out of the radio manufacture business, there are still enough of the units around to get repair or advice.

[Ron Olson]

Don't tell Ace that they're out of business as it may be a surprize to them, especially considering that they just came out with a very nice pistol-grip radio system.
http://www.acehobby.com/ace/ACE8306.htm

[34Ford]

I guess this is a stupid question since I see people using them but is a DX7 Air legal to use for surface?

If so then all I need is more receivers for mine.



______
Dennis

[patmat2350]

2.4 GHz is legal for surface and air. Since the technology avoids conflicts, there's no reason to separate the two anymore.

Throttle shutdown: I forget, but isn't there an option to use (or not) the throttle safety? Set it in the menu somewhere...

[AndyKunz]

Throttle shutdown: I forget, but isn't there an option to use (or not) the throttle safety? Set it in the menu somewhere...

When using a Spektrum aircraft system:

1) When you bind (bind button and plug) the throttle will failsafe to the position of the stick. If you bind, find your throttle is backwards and do a reverse, then your throttle will failsafe (on loss of signal) to full-on!

2) The other channels will hold their last-commanded positions.

I always re-bind whenever I make a major change like that, just in case.

Andy

[Olscuzbut]

When I queried Spektrum, they told me that on the DX5e if the rx loses signal, it will fail safe to the full back throttle position, which on my boat is full reverse. So I use the elevator control for throttle, as its fail safe is the mid stick position.

[Brooks]

Hi Ron, thanks for the tip about ACE. The original Ace tx's that I am familiar with were specialized for boats (and subs). For instance, my 7 channel Ace tx has one 2 axis stick, 2 slider sticks, 2 dials, and 1 flip switch. All but the flip are proportional. I converted 2 original flips to the 2 dials. Using variometers, I could get 270 deg throws out of modified servos (open the servo case, remove the swing stop from the gear, a simple mod). The dials could also get 3-4 turns out of sheeting servos, more turns than normal for those servos. The dial mod was a little tricky - turn it too far, and the servo would reverse, hoho.

The new Ace website does not have the same boat friendly, multi-channel tx's that they were once famous for; it would be nice if they brought them back.
-------
OlSB, glad you figured out a way to get a usable failsafe. You might post this on the radio forum. I bet there are other guys that could use your method.

[no stick]

When I queried Spektrum, they told me that on the DX5e if the rx loses signal, it will fail safe to the full back throttle position, which on my boat is full reverse. So I use the elevator control for throttle, as its fail safe is the mid stick position.

Throttle stick at loss of signal is where the stick was at the time of binding the Rx. All other sticks retain their lost positions when signal returns.

There are differences between receivers though.

[AndyKunz]

Failsafe is a function of the receiver, not of the transmitter. Think about it - how is the transmitter going to tell the receiver to go into failsafe when the communications link fails?

If you really want to be able to use a different failsafe arrangement, I suggest you use the BR6000 since ALL channels are programmable failsafe (at bind time).

http://www.horizonhobby.com/Products/Default.aspx?ProdID=SPM6000BR

Andy

[dcwebaccount]

or d.i.y. make sure the 2.4ghz is water-friendly !

someone has modified futaba 2pl with corona 2.4ghz system, as per his information, corona is water-friendly compared to some brand like spektrum cant be run on water surface !

see his blog : http://blog.quantifly.com/?p=12

[Brooks]

My friend and I have 5 boats that run just fine on the water surface with Spektrum equipment.

Perhaps dcweb meant *underwater*. I've read, though I've not tested this, that 2.4ghz signals won't penetrate water deep enough for RC submarines. This is supposedly a function of the wavelength, not the brand of radio. On the other hand, longwave red light quickly attunates with depth, whereas shorter wave blue light goes deeper. That would imply that 2.4 should work Better underwater than 75mhz :-/

[iDENTITi]

My friend and I have 5 boats that run just fine on the water surface with Spektrum equipment.

Perhaps dcweb meant *underwater*. I've read, though I've not tested this, that 2.4ghz signals won't penetrate water deep enough for RC submarines. This is supposedly a function of the wavelength, not the brand of radio. On the other hand, longwave red light quickly attunates with depth, whereas shorter wave blue light goes deeper. That would imply that 2.4 should work Better underwater than 75mhz :-/

Think of it this way. 2.4ghz is around the same frequency as a microwave oven. Meaning it disapates quickly into heat in the water. It's good for transmission quality and range though, as seen with commercial wi-fi systems and cordless phones. What you'll really be interested in is all those frequencies opened up when analouge tv goes in favour of digital. ;)