Bob Moore

Not being one to give up easily I did a few more tests on the Corona rx. Soldered the GWS crystal on and tried it with the Wot. Same thing, sometimes working next minute not. So I tried it with a different tx. No joy at all. So I tried plugging in a battery rx battery pack and 3 servos, and lo and behold it worked , for a couple of minutes or more and seemed ok. So I plugged it back in the Wot with the external servos plugged in and powered by the BEC. Nada. It just has a bad joint somewhere, at one point it was working and when I was handling it, it stopped working. I give up. What can you expect for a few quid?

- @Tom. TX works well with all other models so I think it's OK.   Report on my Corona experience. Not a good one! Tested the Corona Single Conversion RS610II Receiver 35mhz on my sometimes glitchy leccy Wot4. First plugged in the Micro RX GWS crystal from Micron. Then all other connections, being careful not to get polarity wrong as it can blow the thing up apparently. Nada. Zilch . No response whatsoever. The esc just bleeped to say I'm not getting any info. ie the motor will not respond and elevator, etc won't work. The crystal is a very loose fit in it slot so I bent the pins slightly inwards to make sure it was making good contact. Remade all connections and it worked. Rudder, elevator and motor. Turned it off and on again and zilch again. (I'd already decided I wasn't going to fit this rx?) But maybe it didn't like the crystal I thought. (GWS micro is reported to be OK with this rx.) So I tested a Hitec one by holding it carefully against the crystal socket. It worked so I soldered a couple of small copper wires to the Hitec Xstal and soldered it to the VERY small contacts in the RX. Very fiddly job. Plugged it all up again. Nada. Pulled all servos off and tried and there was life? It connected, the bleeps said it was OK and the throttle ran the prop up on the leccy. So this Crystal does work ok anyway and my soldering was good. SO I reconnected the servos and zilch again. Just to be sure it had an intermittent fault I plugged it all up in another model and powered it by a normal RX battery. Still working intermittently. So that was a waste of £15 or £20 for the RX and Crystal (with P and P). I think the thing has a processor problem or poor solder joint somewhere. Incidentally, the pins are very close together on these RX and I had to file down the servo plugs a bit to slim them down as if not they are very very tight. Put the old Hitec Dual conversion RX back in my leccy Wot4 and it ran straight away, so I feel the problems weren't with the model. I think I'll go with the Hitec, and the Corona is going into the bin. I've had a good look at the circuit board and can't see any obvious poor solder joints. Maybe I was just unlucky? Edited By Bob Moore on 13/09/2012 14:10:07 Edited By Bob Moore on 13/09/2012 14:14:33

Blow by blow account of progress! I don't recommend adding 20% unleaded petrol to the mix. (Adding petrol was suggested above. And successful.) Mine won't run at all on that. Maybe 20% was too much. It was worth a try. Time to buy some new fuel. Edited By Bob Moore on 12/09/2012 12:41:15

Thanks for those valuable comments John. Oh well, I've just come in from an unproductive 20 mins trying to get the sc40 to run properly on my regular GX 10. (Which as said has been in the shed for a good couple of years. It starts easily, runs but won't pick up well and the exhaust has a slight burbling at all revs (apart from screaming.) It also feels unreliable and liable to stop on throttle opening. I tried a couple of clicks out. Won't run, and couple of clicks in no improvement? I'm reluctant to mess with the slow speed needle on an engine now that I know it CAN run well. So definitely a fuel problem of some sort. It ran so sweetly on the tank of pro synth I scrounged. Maybe I should start thinking about using a different fuel? I bought a brand new Irving 40 a while back and couldn't get that to run very well on my fuel. (And it wasn't as old then.) I've always used idle bar plugs, but I just tried 3 or 4 idle bar and non idle bar plugs in this test (though only no 3.) With the non idle bar it wouldn't run at all?   I don't fly IC very often, partly cos of the unreliability I've suffered. It's a catch 22 situation. The trouble with trying different fuels is, at £15 a time for a can of something that might not be any improvement, it gets to be an expensive method of testing.     Edited By Bob Moore on 12/09/2012 11:51:41

@Martin. It's a 2 stroke. I have read that 4 strokes need a different mix. @David. Nice idea. I'm a bit of a skinflint too and apart from that don't like chucking out something that can be revived. How much petrol in the mix? Try a little and see how it goes?

As it happens I went to my model shop to buy some new fuel today and he was closed! So I may just try it one more time as I do have a good third of 5 litres left. I forget to mention that the tank of fuel I scrounged was (he said) one of best and very expensive. It was Weston UK Pro Synth 2000? New to me, but the SC did run beautifully on it. Had my local man been open I was just going to buy some more of my usual regular Model Technics Expert GX10 which is 20% castor oil, 10% equivalent Nitro, and 70% Methanol.   PS re TX servicing etc. I fly a few other models and don't get any glitches whatsoever with them, which I think rules out any probs with my tx? Edited By Bob Moore on 11/09/2012 23:40:58

Sorry my mistake, I was having a grey moment! There's a thread on it here on RC Groups. Bob

I thought it was the other way around (ie lengthen battery leads) because of back emf's from the motor affecting it's performance? Edited By Bob Moore on 10/09/2012 22:32:00

Good service from Micron RC who posted 1st class today. They appear to have most channels in stock in type GWS, etc. if anyone else is looking for a crystal suitable for a Corona rx.

Interesting. The reviews on it are excellent I must say and it does read as though they have improved signal processing. I've already bitten the bullet and bought a crystal reported to work on the basis of why risk a couple hundred quids worth of model for the sake of a tenner! ( I was half tempted to try a standard Hitec one though.)  Last flight it involuntarily did a roll while climbing, (big aileron glitch) don't want any low level glitches that pile it in   I'll find some way of securing the crystal as reviewers did mention it was a bit vulnerable. Thanks Bob. Edited By Bob Moore on 10/09/2012 13:50:03

Interesting responses about 35 mhz being banned! I agree, I think there would be some uproar if it was tried at my club. ah, it's your fault John. No problem really as it seems the GWS ones are ok to use and Micron RC appear to have mine in stock. RE ESC's , when I modified my Wot 4 to leccy there was little choice about where to place stuff. The esc is quite big and chunky and the wiring heavy so it had to sit behind the motor and above the battery which is as far forward as it could go to achieve CoG. My only option is to move the rx back and maybe sit it above the servos? Or even in the rear of the fusi behind the servos (which will require some surgery. I'll explore the idea of changing servos if necessary. But I plan to fit ferrite rings in those leads too. Edited By Bob Moore on 10/09/2012 12:13:41

Oh well, after faffing about trying to get the rather large old dual conversion rx in, I've given up and ordered a single conversion Corona 6 channel rx from GC and a GWS micro half size crystal from Micron RC. (Hope it's the right Xstal as it's cost me a tenner with P and P!)   At least the Corona is small enough to fit a bit further away from the esc and gives me a chance to put a couple more ferrite rings in. As I said before I've two small leccies and get no glitches with them, so I wonder if its the biogger esc in the Wot that radiates more interference. Watch this space! Edited By Bob Moore on 10/09/2012 10:59:39

I am very tempted by the corona , and would order one now but for the fact they don't have the mini crystals in ch 70 in stock. Can anyone tell me please if a normal crystal would be ok?

Thanks. I'm just this minute fiddling about fitting an old Hitec Dual conversion receiver in the Wot to try that out. A little bit futher away from the esc and slightly better aerial run. If that doesn't work I think I'll try a Corona. The spec and reviews on them are very good.

No probs Tom. My glitches have only occured when the model is in air and some distance away I'm pleased to say. I can see that a rogue model on the ground could be a problem. One of our guys (on 2.4ghz) had his model run into his leg causing several stitches when I think he accidentally switched off the tx prematurely and hadn't set up his failsafe properly. The motor went full speed and ran into him. I don't have the whole story though. The first thing I do when I retrieve my Wot is pull out my battery link that I've fitted in the side of the fusi. Interesting Pat. I had wondered if servos might cause interference. Edited By Bob Moore on 09/09/2012 22:06:01

@John, I found keeping the tx antenna very vertical improved things too. The Corona does sound interesting, I'll look into that too.  Out of stock at GC at the moment. Correction, they are in stock. Any idea what crystal will work with them. Just a usual Hitec single conversion one? edit again! I see they take mini crystals but they don't have 70 in stock. Is there any reason why a normal crystal (with legs bent if necessary) wouldn't work, or do these have fatter pins. It looks a bit like that on the GC illustrations? @Tom. Banning 35 mhz, and about time too? And why's that then? Most people at my club use 35 Mhz without any problems (as have I for ten years) and many can't afford to bin their gear and shell out for a new tx and a pile of rx's.     Edited By Bob Moore on 09/09/2012 21:25:29 Edited By Bob Moore on 09/09/2012 21:30:01 Edited By Bob Moore on 09/09/2012 21:57:31

Thanks for that, certainly worth a thought. I'll try my dual conversion rx and other solutions first though.

Useful advice thanks. I've actually got a spare dual conversion rx kicking about but couldn't fit it when I tried because of space, with an extension lead to the power input it should go in. (It has the appropriate crystal in. ) With luck that will improve things.The Wot is on 4s but I can't see that making a difference really.

I'm almost 100% sure that it's not possible with the Sport model. (Or not that easy.) I enquired from my dealer when I bought it. And this was confirmed when I Googled it. There is a hack module available from HK but I don't think I want to go down that road really.

Thanks for that. I have one ring in the feed to the rx, but the space is too tight for another. What I have in mind is to use a small extension lead to put the rx further away and it will also allow me to fit another ferrite ring or two.

Thanks for the replies guys. @Ultymate, I have a Hitec Optic 6 Sport which unfortunately won't take a module. @Chris , Think I will have a go and moving the rx further away and the foil idea too. The glitches with the previous rx weren't that bad, but testing the other one yesterday I had a couple of serious glitches. Fortunately they don't happen when close to landing, as I assume the tx signal is strong enough to overcome any interference. I'm assuming that a rx being closer to servos shouldn't cause glitches? Edited By Bob Moore on 09/09/2012 12:40:09

Hi all, A while back I converted my Wot 4 to electric and I'm still using 35Mhz. reluctant to change to 2.4 because I have a few models and the cost involved. When flying I get occasional rudder and aileron twitches. Last week I tried a diferent rx in the model and it was even worse. What I'm wondering is are glitches due to interference through the 5v rx supply from the ESC (I do have one little ferrite ring in that line) or is it the proximity of the motor or esc to the rx? I'm just wondering if it's worth relocating the rx further to the rear in the fusi? And adding another ferrite ring thingy. I've got two other leccy models, an Orion Westwings glider, and a lttle Depron Edge and don't get glitches with those, but they are much smaller motor esc set ups compared to the Wot 4. Any suggestions welcome please. .I don't really want to buy another tx and rx just for this model. Too much hassle and expense.

Don't ever listen to people when they say fuel doesn't go off! Went to the field today and after a couple of flights with the leccy Wot 4, scrounged a tank of fuel from the only other guy there, for the SC40. It ran like a dream. Didn't even have to change any carb settings apart from bringing the tick over right down. All my wasted time, effort and frustrations with this engine and I was on a loser from the beginning because of the fuel. The stuff I scrounged was expensive stuff, Pro Synth 2000 (10%) from Weston UK., but I'm fairly convinced it would run ok if I got some new of my usual stuff. Back to the leccy thing though. I now have 3 LiPOs and made the mistake of putting one I 'd used back in for a second flight. Took off ok but my Wot will usually climb vertically pretty much with a fresh battery, however when I tried it, it fell out of the sky. (Not literally.) I Climbed and stalled and fell. I landed quickly and checked the voltages. Dooh! I'll be more careful next time. Thanks again guys for the advice on my troublesome SC .

I must admit I've never got into changing plugs, though it's a good idea. I'm inclined to try fuel first because I can almost hear it faltering at some speeds when running and there was an inordinate amount of oil on the ground when I ran it up for a while, even though it wasn't running rich. My sc25 was as good as gold. Never let me down and started with a flick of the finger, so I know they can be good (sometimes.)

Petrol certainly goes off if left in a can, even a sealed can. It even smells different. It certainly is frustrating though. I go to my strip and see people flying IC without problems mostly (though there is the odd dead stick) . Havings said that, a lot of them fly more often than I do so engines get used more and I suspect fuel is more fresh. I do other stuff, paraglide, mountain bike, kayak etc., so get to the strip less often. I will report back if it solves the issue.