Chris Bott - Moderator Posted December 23, 2008 Share Posted December 23, 2008 I'm very very pleased with my Dx6i system and the various Rx's I've bought to go with it. I just have one niggle, on Rx switch on, all servos except throttle usually go to one end of travel and then back to center. Does anyone else's do this? On one model this pushes the servo beyond the max throw of the surface. more worryingly, I just completed a Conversion of a YT 3Demon to a twin (maybe another thread??) I used a mix of throttle to Aux to give me a second throttle output. Trouble is, I'm using a UBEC so motor power is available as soon as the power is applied. A quik blip of Aux to one end arms the ESC then dropping back to centre the motor starts at half throttle. As soon as the Tx and Rx "connect" throttle stops again but thats not the point. My fix has been to use a Y lead instead of the mix. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted December 23, 2008 Share Posted December 23, 2008 Hi Chris...have you done the correct failsafe settings as per the spekky manual? Also, ensure that you switch the TX on first, and LEAVE IT ALONE for at least 15 seconds BEFORE arming the receiver with power. If the Rx is powered up before the Tx has acquired the necessary 2 x signals then the rx acts as if its in failsafe. Sometimes the Tx ( especially the DX6i ) takes a while to find a clean channel. Also, certain receivers are notoriously slow to lock in to the Tx ( ar500 being one example ) Try that and let us know how it goes. Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted December 23, 2008 Share Posted December 23, 2008 I find it does it with some servo's and not others. What I think happens is that when you put power to the Rx power is applied to the servos but no signal, some servo's won't move until they get the position signal other go to the end of their travel. As it takes the RX 0.5s or so to boot up they move to end of travel and then back to correct position when signal is sent.Doesn't happen with throttle because this is the only channel on failsafe on the DX6i Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted December 23, 2008 Author Share Posted December 23, 2008 Thanks Timbo, I'll give those a good try tomorrow. Many thanks.I don't think it will be the failsafe positions, they certainly need setting up if they are!I'll let you know what happens.Frank you are probably right too. Different servos etc... I thought the throttle channel gave out no pulses at all untill the correct Tx was received. I thought I'd seen servos sit at dead centre before, and then move to their correct trim position once the signal is established.This twitch to one end must have been the Rx output however. It was enough to arm the speed controller, which requires a "low" throttle before it will "arm" Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 24, 2008 Share Posted December 24, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted December 24, 2008 Author Share Posted December 24, 2008 OK, just did a test or two on the twin.Currently: Throttle OP from the Rx goes via Y lead to the two ESC's1. Switch Tx on for 20 seconds, then Rx (UBEC Powered). Servos twitch, 1 aileron goes to full travel. A second or so later they all go to fully trimmed centre. ESC's Beep "Armed"2. With Rx on and working from Tx., Switch Tx off. Nothing moves, motors stay stopped.3. Switch Tx back on, Rx lights come back on quite quick. Absolutely no movement from anything until a stick is moved.Both Aileron servos are the same, they are in different chanels, so why does one go to full travel in test 1?Thanks for your interestSeasons GreetingsChris Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted December 24, 2008 Share Posted December 24, 2008 Chris, I think it's as I thought earlier, apart from throttle (which has a signal because it's the only channel with failsafe) the others have no position signal (it's a voltage I think) until the Rx has booted up, but the power rail is energised immediately, some servo's see 0v as a signal and move to that end of the travel, wjereas others wait until they see a position signal.If somebody had an oscilloscope that would be a good way to check it. Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted December 24, 2008 Author Share Posted December 24, 2008 Thanks Frank.I have a 'scope (but no time this side of the new year now)I'll have a good look when I have a minute.Danny has suggested a difference between a UBEC coming up and using a Rx battery with its steady voltage. So I'll test that too.I'll report back, but it won't be for a week or two. (Family stuff from now 'till Sat, then off to Scotland for a week over new year Happy Christmas everyoneChris Quote Link to comment Share on other sites More sharing options...
Brian Lambert Posted December 24, 2008 Share Posted December 24, 2008 Chris, now you have the new setup try re binding the rx and see if anything changes.Brian Quote Link to comment Share on other sites More sharing options...
Doug Ireland Posted December 26, 2008 Share Posted December 26, 2008 Hi Chris,I had the same problem with my DSX9 but it affected both aileron servos. The bad bit about mine was the servos would go past the end points. The two aileron servos were a different make to the others and you could clearly hear them "binding" until the tx/rx link was established.See here(the link thingy took a bit of sussing out but I got there in the end!) Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted December 26, 2008 Author Share Posted December 26, 2008 Thanks DougWell done with the link Yes very useful, I'll let you know what the Rx does in the new year when I have time to check with a 'scope.If the Rx puts supply volts out and no pulses until the Signal is locked, that could explain why some servos react differently to others.Still not sure it answers why my 2 ailerons act differently? They are identical servos but plugged into Ail and Aux channels. Could the 2 channels do different things? Quote Link to comment Share on other sites More sharing options...
Doug Ireland Posted December 26, 2008 Share Posted December 26, 2008 I was that concerned with the possibility of damaging something that I've gone back to 35meg for this model. But another model has the new 2.4G gear and all JR servos and they only twitch on power-up, hardly noticeable. I'm waiting for the postie to deliver a new 2.4G nini rx (AR500) and I'll try that in the twitchy model. Quote Link to comment Share on other sites More sharing options...
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