After nearly a couple of years of flying now having returned to the hobby after an absence of some forty years later. Boy, did I find the whole game had changed. I needed to get into a serious learning curve!

So what did I struggle with? New fangled 2.4 radio gear and electric power plants. I found myself totally out of my comfort zone. OK, the radio gear was fairly easily overcome but electric motors, UBECS and LiPo batteries were completely outside my knowledge library. To begin to bridge that gap, I resorted to taking advice from George Worley at 4-Max. I`m glad I did.

George bent over backwards to sort out my initial needs. Telling him I intended to work my way back into the hobby with a Hanger 9 60" Ultra Stick, he immediately worked out that I needed a PO5056-420Kv motor, a 60a ESC, 5a UBEC and a minimum 6S LiPo of 3700mAh capacity running a 15x6 prop. That is the combination that many people saw me practice for and gain my A-test with in May 2019. 

George later further specified a similar 5065- 360Kv motor, 70a ESC and 6S 4500mAh Lipo for my Dancing Wings Fokker Tri-Plane. As it transpired, that 360Kv motor soon transferred to the Ultra Stick to provide faster acceleration and the ability to make use of the greater torque which offered the increased ability to swing a larger propeller. The 420Kv motor taken from the Ultra Stick then transferred to a Seagull Fly Baby monoplane where fast flying really wasn`t anything like so important. Gradually then, I began to learn something about correct power unit selection.

So how does the often viewed specification seen on some out-runner cases apply to what you might see on a 4-Max motor case? As an example, if we examine the 4-Max PO5056 series motors discussed above, we can learn that the 50 refers to the metric diameter of the motor case, which in this instance equates to 50mm. The 65 refers to the motors` 65mm case length. The 360Kv or 420Kv refers to the motor performance. All this is far better explained in the link to the 4-Max site below. I certainly find the explanation found in the link to be most useful as indeed I hope it may also be to fellow club members who like me, might be struggling to understand the technicalities of electric power applications. Please take look.Microsoft Word - Working out the power train for electric aeroplanes - Version 1.2.doc - Working out the power train for electric aeroplanes - Version 1.0.pdf

Mike

This from UK supplier/brands, Chinese supplier direct and from (different) Chinese supplier with UK warehouse, so it seems not to matter where the final supply comes from.

Purely as an example, yesterday I received four 1300mAh 3S. As usual I immediately tested with three differing testers for positive confirmation, but as one is an ISDT unit that has been proven to be reliably accurate, I will only quote its data here.

Pack 1 - 3.75v average per cell with a range of 8mV
Pack 2 - 3.76v average per cell with a range of 11mV
Pack 3 - 3.02v cell one, cells two and three below ability of tester to measure so 0v shown.
Pack 4 - 1.82v cell one with tester resistance causing it to slowly drop further, cells two and three 3.6*v

Pack 3 on a high quality multimeter gave 5.44v across the pack, with cells at 3.02v, 1.24v and 1.15v

I have charged packs 1 and 2 and they completed charge (on a verified good charger) as follows:-

Pack 1 - 4.191v average per cell dropping after an hour to 4.183v, at that time a 2mV range
Pack 2 - 4.18v average per cell with a range of 12mV, voltage has held overnight.

The previous new supply from a different source and brand were three 2200mAh 3S, and briefly one had a shorted cell 2 so pack indicated as 2S, and another was so unbalanced that there was no way I was about to use it. (These were not budget priced items)  When claimed within an hour of tracked delivery they were replaced under warranty, then one of the two sent was badly out of balance but did balance after a couple of cycles.

SO.............checking packs VERY carefully on supply is essential!

1. I hope you are carefully check new packs before charging for use?
2. In the light of above, you may like to review HOW accurately you check new packs?
3. What level of failures are you seeing?
4. Have you had issues getting warranty replacement?  (I have not, which suggests that the suppliers KNOW they are on dodgy ground!)

What does worry me is that in theory the possibility of a failure to thermal runaway (and poss fire) must also be increasing with such erratic supply quality.

Whatever, be careful, supply quality is definitely dropping!!!

This could occur in the pits area with lots of people in close proximity and these planes can potentially cause a lot of damage to people and property so please make sure you use them safely.

Shane and I have come across a tutor 40 converted to electric by Rod that we will be using for training. It is a trad’ 46 sized trainer and has a motor and esc. It doesn’t, however, have any batteries with it, and Shane and I have no clue what capacity or even cell count. I’m thinking a 4S 4500/5000mah. Does this sound about right?

Cheers guys,

B  

I'm looking at the https://www.overlander.co.uk/tornado-thumper-v3-3542-05-1250kv-brushless-outrunner-rc-motor.html  for the plane. I plan to use a https://www.overlander.co.uk/speed-controllers-ubec/speed-controllers/overlander-xp2-speed-controllers/overlander-xp2-60a-sbec-brushless-speed-controller-esc.html for the ESC and a 4s 1300mah LiPo.

Now for the maths.

1lb is 450g give or take and with my uprated bits and bobs I'm thinking 500g flying weight so for simplicity's sake that's a plane that weighs 1lb

The rule I've always employed is;

Watts/lb

30 to 50 for ROG

40 to 60 for sport aerobatics

70 to 100 for 'good' aerobatics and EDF jets

180 to 300 for some serious speed

350+ for the RAF to be called about a ground to air missile heading to heathrow coming from a field in Croydon.

The motor I have picked out will run on a 4s with a 9x5 prop and should deliver 710 watts. 

Now I want something the will reach triple figures and keep on going. 

To put this in perspective my wot 4 foam e delivers 303 watts and it weighs 2.4lb. That motor punches it skyward at a fairly decent rate. The radjet weighs under half that and the motor gives me over twice the power.

The question I have is; will 710 watts rip the plane apart? 

Needless to say I have modded the plane greatly with many carbon rods, carbon strips, glass tape and double tape on the hinges! And I have seen radjets on youtube do this kind of speed so I know its possible!

Any input would be greatly appreciated guys!

B

P.S. Can anyone recommend and servos? They should be 9g size. Will these be up to it? https://wheelspinmodels.co.uk/i/109052/

But what if you don't have a telemetry radio? Here's one way!

There are cheap small battery monitor alarms, self contained little units which plug onto the balance port. Some of these have adjustable voltage trip level (per cell) and are extremely loud.

Set correctly they provide early warning of pack depletion under in use throttle surges plenty early enough to position and land with no urgency, and can be heard over a great distance.

One very suitable unit is:-

https://www.banggood.com/G_T_Power-Voltage-Tester-Low-Voltage-Buzzer-Alarm-For-1-8S-LiPoLi-ionLi-MnLi-Fe-Battery-p-1136769.html

Most Chargers have a LiPo Balance feature. Many "hide" this so when you choose LiPo it shows "Charge" and only if you go on down the menu tree does it then show "Balance". This catches a few people out, and a good few have thought that "Charge" does balancing (not on this firmware!) or that "Balance" means only balance, not do a balanced charge as it does..

Even with that out the way, it has to be said that Chargers generally SUCK at balancing well while charging a pack!

I have for some years been using a "Two Meter" to occasionally better balance packs, and this does a much better job than the Charger.

However, recently I have obtained a device from ISDT called the "BattGO" (Code BG-8S). This is both faster and more accurate. It also has a super clear display, AND it can be used to show the signal PPM/PWM/S BUS with receivers to trouble shoot those areas too.

http://www.isdt.co/bg-8s.html

Well worth considering.  Beginning to be widely sold, but mine came from Banggood.

B

I'm currently designing a VTOL aircraft, (I know, very ambitious for someone with not that much experience!), and there will be a few magnets in it to hold battery hatches in place etc. 

I was wondering if having wires carrying either power or signals (i.e. battery leads/BEC wires and servo wires) would be affected in any way by being very close to the magnets? They are 1.6kg 1.5x6mm neodymium magnets, and the wires will be about 20mm away from the magnets, or perhaps closer, with thin foam (5mm) in between.

Also, would mounting a receiver antenna next to a magnet have bad effects?

Finally, would mounting a flight controller (I'll be using the KK2.1 hard case) near the magnets mess with the accelerometer?

Essentially, can magnets damage components or disrupt wiring?

Thanks very much,

Sevan.

These look interesting and a European development to boot.

Might wait for version 2 though.

http://www.cnn.com/2016/05/13/aviation/ ... index.html

I've been asked to help convert an IC Acro Wot to electric and as I have very little interest or knowledge in electric, I was wondering if anyone had any ideas on motors, speed controllers, batteries etc?

Any help appreciated.

James.

http://www.gibbsguides.com/article51_Ho ... _campaign=[successful_Electrics_Issue_20]:_How_to_Choose_an_Electric_Power_System_

I managed to replace my shaft which broke on landing. It took some hammering to extract the old one, after I had undone the grub screw at one end and pulled off the main body of the motor. A press of some sort would have been better but I dont have one. The new one went in with a bit of persuasion (hammer again), first making sure the ground flat in the shaft lined up with the grub screw. The new shaft is about 2mm longer than the old one but this doesnt make much difference.

My test setup worked perfectly with a different Jeti opto ESC.

[attachment=0]photo.jpg[/attachment]

Leon showed me some info this morning that lets you vary the voltage by putting a resistance across two of the pin outs. I have added chassis wires for this but don't have a resistor until the postman arrives. Anyway it easily goes to 13.8V although over-voltage protection cuts in at 13.82V so better to keep it a little lower I guess.

Hope this helps...

Came with all metal 68mm EDF 5 blade power unit with 1.7 gms of thrust.

Looks pretty quick on the manufacturers video, http://www.rclander.com

Going to need a 4 cell lipo/9 mini servos/ receiver 2.4/ and an ESC, and probably a new charger! Any idea's?

NEED TO START SAVING AGAIN!

TTfn Oily

Whilst cutting it apart, it did become apparent that I could change the battery and the brush, but its too late now isnt it

[attachment=0]IMG_0719.JPG[/attachment]

So, my idea is to try and make this into a little free-flight model for the indoor sessions.

Runs of 1.5v (it was a AAA cell in the handle) so I'm thinking one of the e-Flite LiPos at 3.7 might just work without smoking the motor too early. I could always put a resistor in but thats be a waste of volts!

So, what design? I want it small and light and stable - anyone got any suitable plans?

The motor case is 15mm long and 6mm dia.

I put it on the battery meter, and nothing, no power at all, battery meter doesnt even come on.. Tested the meter with other Lipo's and its fine.

I will say too, I did this testing a custom made switch setup for my FPV groundstation, and accidentally plugged in cables into the switch the wrong way round as they are all blue crimp connectors, but I did it in the garden just to play it safe, and sure enough, the fraction of a second it was switched on and sparked, the lipo and its cables, and the EC5 on the end of it got VERY warm indeed, so I unplugged it and left it outside..

It happened in the blink of an eye, the time it takes to flick a switch on and immediately off again..

No puffing at all, it just got instantly hot...

Am I right in assuming it simply discharged EVERYTHING it had, all at once in that shorting out, hence it being dead, and the heat?

Whats the best way to dispose of it, as I wouldnt even consider trying to recover it for the sake of £10..?

So, I've veered a bit off the Multiplex road, crappy sat nav, and wound up with a Flyingwings Slipstream wing..

Dont ask me how it happened, probably too much caffine and lack of sleep...

Anywho...

I've seen Colins one and a few others up the field and thats pretty impressive, but never get the chance to see what power trains are running them.

I know Colins has a 2212 motor in, which goes like "I'm Richard Branson", but couldnt see the ESC in it or prop size.

Colin & the gang... if you see this, what ESC is in yours?

I have a 30A JP one doing nothing, should this cover it, and any future motor swap-outs/upgrades?

6x4 APC?

Flyingwings are hopeless at answering the phone, or emails, took me 25 calls to get an answer to my "Have you posted it yet" as my first order months ago took almost 4 weeks to arrive, and was postmarked a few days before it arrived... I've asked them what their power kits consist of, as they have zero info on what they use, but alas, no reply for weeks..

[attachment=0]sukhoi_small.jpg[/attachment]

Fancy a bit of variety on my electric flying days so would like to get a second airframe.

In an ideal world, I would like an ARTF mid-winger - something like an Extra 260, but in my limited experience these need larger packs.

Anyone got any suggestions for a model that would complement the Wot4 well?

Cheers

Arun