Navy_Flyer

I am putting an onboard glow on my plane to keep the fires burning in an inverted FS-91 Surpass at low throttle. The onboard glow works as advertised, and is programmed to come on when throttle is less than 25%. What I would like to do, for safety and for saving the glow battery, is to plug the glow system into an unused channel, say, channel 5 landing gear switch, and somehow 'Mix" the throttle channel with that channel so as to use the channel 5 switch as a master on-off for the onboard glow system. I have a Futaba 7UAFS. Anyone know how to do this?

Thanks in advance

daveopam

My Feedback: (9)

What system do you have. The one I have is only on when the radio is on. Are you sure it's glowing with the radio off?

David

Navy_Flyer

It's not supposed to glow when the radio is off. But, would like to have a way to switch it off while flying after takeoff, and switch it on for final approach when the glow system is critical.

daveopam

My Feedback: (9)

I understand now. I wish I could tell you how to do it. I will tinker with my 9C and see if I can figure it out. You could also adjust it to where the glow was only on at idle and not 25%. This would not cure your problem but it would help.

Another thought. What about a micro servo pushing a micro switch to turn the glow on/off? I have seen this done as a safety on mechanical retracts. It works very well if you can't get the radio to do it.

David

EdwardB

My Feedback: (6)

The MPI Super Glow modules might do what you're looking for. They have the usual low throttle threshold setting, but they also have a manual mode that you can control with an aux channel. I'm using this module in two planes with 4-cycle twins, and the manual mode has saved me a couple of times when I lost a cylinder. Here's the link to their instructions:

http://www.maxxprod.com/pdf/mx-9900instructionsheet.pdf

khodges

My Feedback: (1)

I've set an on-board glow both ways, but it really doesn't save the battery all that much. I use a 2200mAh NiMH battery ("A" size) and I can fly all day without recharging it, and that's using it with the glow system in its "automatic" setup where it comes on at 1/4 throttle. I have to recharge the Rx battery more often than the glow battery, although I put a full charge on them both the night before flying.

I had a manual setup that was set up on the 3-position switch on my 9C. Forward position was glow off, middle position was glow on, throttle cut off, and back position was glow off and throttle cut on, to kill the engine. Just plug the glow controller into a spare channel and set that channel to that switch. Mix the throttle cut to the same switch and choose the switch positions to control them the way you want.
The thing about having it manual, you really never know when you'll need it at lower rpms, just put it on auto and set the throttle to the point you think is critical for the glow to operate. I was using one on a floatplane, who wants to deadstick way the heck out over the lake. As the engine got more time on it, I found I rarely if ever needed it at all.

BillyGoat

I'm with khodges on this, when ever I used an onboard glow, the glow battery had more left in it than the flight packs after a day of flying. If both are charged before going to the field there really isn't much to worry about. Keep it simple.

42etus

My Feedback: (2)

Not sure about your 7U, but on my 9C I use one of the 3 position switches.
Up is glow off
Center is glow on at throttle 15% and lower
Down is glow on
Shouldn't be too hard to figure out similar programing for your transmitter. After having this setup for a while, I find that the only time I really use it is for starting the engine. I really don't need to light the plug at idle. It's kind of a pain in the butt actually, having to charge my normal glow ignitor and also make sure to charge the on board system when I want to fly that plane. If I was to do it again, I wouldn't use an on board system unless my engine really needed it. Just my 2ΒΆ.
Paul

DelRay

As long as you have the set point for the glo unit to come on at a very low throttle setting, once you get into the flight the throttle is above this point and the unit is switched off and only comes back on when the throttle is moved back to the set point. That's how I set all my M.P.I. units up, I don't use the channel five option at all, it's really not needed. I do make a switch that I mount on the plane to disarm the glo unit when the radio and plane are on and the throttle is at idle. A d.p.s.t. switch installed in the servo lead going to the glo unit does this very nicely. You can switch the battery side of the glo unit also per the instructions with the units. It sounds like you're using the M.P.I. units. I also use the Futaba 7UA transmitter. If you want to use the channel five option like mentioned, you will have to run another servo lead to the glo unit from the channel five output of the receiver. I think the automatic mode is much nicer and a lot simpler, just to have the option to shut the unit off completely without having to turn the transmitter off is nice though, whether from the transmitter or a switch on the plane.