gordon rigg 1

i had something similar with the control surfaces revesing on my wot4.After I while yesterday I figured it out. DX8 as master, DX7 as slave. Both txs set up bound to the wotty rx so they worked correctly. There are two ways to buddy - P-link and program master on the DX8 master tx. I set the Dx7 to slave/plink. When P link is used on the DX8 all controls are transferred to the DX7, but the Dx8 retains thew programming and trims. All the controls work the same way. When programmable master was used on the Dx8 all the controlls were reversed on the DX7, but I could switch the various channels so only the chosen ones transferred. DX8 however retained the trim srttings with trims not working on the dx7. Eventually I found there are three training settings on the DX7 (the DX8 only has 2) slave/plink, p-link, and normal. When set to normal the DX7 appears to be looking for a slave tranny, but in fact works correctly as slave with the DX8 in programmabler master (the chosen controls transfer and work the right way and the trim setting transfer too). Using programmable master allows a trainer friendly mellow setup on the slave tx, but the normal expert control throws on the master tx. I anticipate the full range of control might be needed to save the model on occasion! So now I'm all set for some warmer weather, dont want him put off by the cold. The thing with the zagi is a minor annoyance - I'm sure he'll cope with aileron and elevator and in the end its almost indistructable anyway! I agree about the deplorably poor documtation of the buddy box facilities. The std answer seems to be but two identical txs, but we know JR amd spektrum (and some other cheaper ones) do actually work together. Incidentaly the buddy lead for spektrum is a mono 3.5 jack but it also works with a stereo lead. A large online supplier where I bought my DX8 supplied a stereo 3.5 jack lead as the buddy lead but it diodn't work, when I belled it out what would havebeen left and right audio were crossed in the lead! Thatone had me scratching my head for a while! (They swapped the lead of course).

I've been trying to get my buddy box setup sorted on my DX8, working with a DX7. One reason got the DX8 rather than a DX6i was the DX8 allows you to send just chosen channels to the slave transmitter. I will teach my son to fly, he's only 8 - so starting with just the roll control and then adding the others appealed to me. I have a zagi type foam glider and found something interesting. If i send all the channels its fine. The programmable master on the Dx8 offers me a choice of RX outputs to send to the slave, not a choice of channels. I cannot transfer airleron, or elevator individually on this elevon mixed glider. I can send the left or the right control surface! So I can send elevator and aileron mixed to my trainer tx for one side of the glider, and retain control of the other isde of the glider. I think the chances of coordingating this with my pupil are slim! Looks like a serious screw up in spektrums programming... My searches on the internet reveal buddy boxig is little used, and hardly anyone understands how it works - and the tx manuals are extremely unhelpful and brief on the subject.

I was a little disappointed when the Rochdale Garden centre pushed me of the google Gordon Rigg top places I'm the other bloke with the same name who flies various things, sometimes with me actually on them  Thanks for that specific info on the Wot 4 electreic conversaion. 50004s should work out similar to 4000 5s, after all its the same actuall joules in there. With 5S it'd probably just need a diffferent prop on it, and perhaps an 80A ESC - I'm guessing a cheap 60A shouldn't go near its current limit. I usually use my 5S4000 in a heli with an Align 60A ESC and that has been fine.  However in this case I decided to stick a .50 heli engine in this Wot4 for now. If my lad get rally interested maybe the next one will be electric.  Gordon

I pretty much agree with the above post, what we see with electrics is bigger and bigger C rating packs rather than larger capacity packs. It would be more efficient to go up in voltage with lower c rating and you would have more energy for the same weight.however things seem to be focussed in sucking the power out of the packs faster, by pulling more current out of a higher C rated pack - running at higher C rating means running out of capacity in less time. On a helicopter IC power is limited by the available torque, as eventually you pull the rotor revs down and then you get a dreadfull drop off in power. So the pressure is to up the capacity of the engine - 30s became 45, 50 became 55, 60 became 70 then 90 and now 120. What you get with a nitro is a limit to how quickly you can get the power out of the fuel as adding motor capacity adds a lot of weight, but duration is as long as you want as the weight of the fuel is not significant. Looks like the case is the same for fixed wing, though an underpowered plane is probably more fun to fly - an underpowered helicopter isn't much fun.  Meanwhle electrics deliver more torque as the revs get less so in fact you can do things with an electric heli that are impossible with a nitro heli as long as the lipo doesn't burst, or the ESC fry (which does happen quite often). So you get 12S 4000 packs being flown and emptied in 5 mins. Incidentally 45V is the max DC current considered safe in a user envoronment (but don't stick the + and - across your nipples with that or you may well die). C rating has inflated to 40+ so you can pull the power out of the pack as fast as you like but adding duration has a very heavy weight cost.  So in short its just like cars. You can make a very impressive electric drag racer, and practical car to go round town or to sainsburys, but you can use an electric car to drive to the south of France with the family for a fortnight, or go for a long weekend 150 miles away.      

The 50 sx is supposed to have max power at 17000 an I run it a little above that on my Heli so it pills down onto the max power under load. Remembering the ancient past my hp 40 with ed tumef pipe turned a 10x6 at 16000 on the ground static so must have been something close to 17000. Did noise concerns mean rpms dropped a bit over the years? Power isn't critical to begin with so I'll start with a 12x6. Are those ?1 props from giant cod good for 17000revs? Seems odd to pay a fraction of what I used to pay in 1979 for a prop! But it's the same story with servos! Electric seems to be trapped in a short duration high power to weight ratio setup which is where it beats nitro. Ther seems to be little knowledge about pootling about for 20 mins or more with electric and nitro will do that and have good power to weight too. This is the story with helis... 4mins is the norm 6mins the max with electric ...seems to be similar with fixed wing. To get the costs down on rtf models there is a fixation with 3s2000-2500 packs meaning anything of decent size must be very lightweight to work. maybe a wot should use a couple of these 3s packs as 6s2500 which is the more popular for a 500size Heli rather Han my 5s4200 which I chose to charge two packs with my 10s charger. More cells is more efficient and less c rate demanding but you do need to upgrade the bec to handle it.

All interesting stuff this.... I think I've decided to go nitro and to get a wot4.. It'll be more interesting for me anyway. He's showing a bit of interest in the sim anyway... I realised I can fit my spare os50sx-h in a wot 4. The prop driver bids are heading my way... Just need a suitable silencer as all mine fit 90 degrees out for helis. Looking at one from just engines the quiet or super quiet. So that is the engine sorted for 20 quid or so. What prop to use on a 50 sx? Quite a bit more power than an Irvine 46 or 53 for that matter. I assume I can use some of my perfectly good but very old Sanwa srm102 servos... The wot4 uses 5 so I guess that is one each aileron?

Not too worried about the packs as they are old though a good brand and lasting well (revolectrx, same cell make now in the optipower) Some are over 3years old and will still tick tock my 500 Heli! I might save the electric idea for a second aerobatic model and just go with the nitro. Thanks for the info. Beginner electrics tend to be built light to use 3s electrickery to keep costs down and use cheaper lipos. Flying a fixed wing over 50" span on 3s2500 can't possibly be like a .40nitro unless it only flies for 3mins. That's the norm with electrics... fly for half the time and then pretend they have more power than nitro!

I'm not so much a beginner, but I'm looking to teach my son to fly buddy box using a .40 size trainer. So this post is about a beginner model setup. I want a reasonably large and heavy model because our club field is high and exposed and usually windy. I already have enough std servos and a spare AR7000 - so I'm looking at a dx6i to buddy with my dx7 and seagull boomerang with an irvine 40 (about £200 quid cost) Questions are:Is an irvine 46 worth the extra compared to the 40? What size prop wold this need? 11x5 or something like that? I'm a bit fixed wing rusty since I flew my gangster 52" in 1982! All my current models are helicopters.  I was also wondering if I could make an electric conversion - to use some of my 5s4000 packs as I have 8 of those for my 500 size helicopter. Opionion seems to be that 5S is too much for a tainer but I don't understand as these packs are from a heli much smaller than a .30 size heli, so how can they be too much for a .40 size fixed wing? suggestions for ESC/motor/prop invited.