Archive for the ‘ Electrics ’ Category

Turnigy Update

Went flying this Saturday and I have to admit the Protos just wasn’t flying as well as it used to be. It seemed down on power and as I had begun to suspect the batteries are beginning to get tired.

In fact so bad was the the situation with one of them (2450Mah)  that one of the cells was showing 2.76v and wouldn’t charge and I have had to dispose of it.  The other one I had the (2650mAh) charged but one of the cells was left at 4.14v.

This made me think, have they been good value should I buy again?  I have checked Hobbyking for when I brought them and it goes like this:

10th Jan 2010 Turnigy 6S 30C 2450mAh $50.72/£32.46 GBP (inc del)
24th Jan 2010 Turnigy 6S 30C 2650mAh $61.79/£39.55 GBP (inc del)

I fly mostly Saturday and Sundays so based on that assumption since the beginning of Feb there has been 33 weekends (Its now 19th September).  Each Saturday I normally charge and discharge it twice.  Therefore I have had 132 flights per battery.  This works out at:

Turnigy 6S 30C 2450mAh $0.38/£0.24 GBP per flight.
Turnigy 6S 30C 2650mAh $0.46/£0.29 GBP per flight.

I think this is pretty good, especially when you consider I have actually had more flights than this as I have been on holiday an used them 3/4 times a day for 3 or more days.

It is also worth noting that except for the one that the cell died the other battery is fine for learning etc.. I am trying to learn 3D so I give my batteries a pretty tough time. I always discharge to 80% of capacity and then charge at 1C.

If your not as hard as me on the batteries and fly in a sport style then they will probably last a lot longer. Overall though a great value battery that is good value for money and performance.

Align FL760 3G Settings

I have just brought the 3G link cable so I can update the T-Rex 250’s 3G unit and tweak the settings to make it fly better.

As part of the software you can tweak each of the 22 settings and each one can have an impact on the 3G unit’s behaviour. Therefore so I can sit on the sofa read about it better I have screen shotted the lot.

Here it is for your reading and educational pleasure: Align_3G_Settings_Manual

Mini Titan starts Car

Went up to the new club that I joined for a fly yesterday and the weather was pretty good, a bit windy but nothing to harsh to stop me flying. (Unlike today maybe) Anyway wanted to share an amusing story – having not taken my leisure battery up for battery charging I decided to use my car battery to charge up a couple of the Protos packs as I wanted to fly some more.

Brilliant idea until the charger warned me of “input volt err”, so hoping and behaving in true British fashion I thought the car would still start. It didn’t. Fortunately I carry jump leads in the car so I had a backup plan but not wanting to look like a idiot came up with an idea. My charger can charge lead-acid batteries so by connecting the charger up “backwards” and using my Mini-Titan (11.1v 2200mAh) batteries I charged my car battery up 🙂

So two top rules:

1) Don’t use your car battery to charge your heli batteries.
2) If you ignore 1 then make sure your charger can charge lead acid batteries.

Give me power!

Got home today after an evening fly to find the postman had delivered the batteries I had ordered from HobbyKing (click here).

Turnigy Nano-Tech 6S 5000mAh

Turnigy Nano-Tech 6S 5000mAh

When I brought the T-Rex 550E I also got 2x Align 4600mAh packs. Ideally I think you need 4 packs (4 flights) or it is a pain when at the field. You can normally charge a pack then and keep flying. Therefore I thought I should try the 6S 5000mAh Turnigy Nano-Tech’s. They seem to work well on the Protos so why not.

They come with 10 gauge wire so I should be able to get them into the EC3 connectors that I use.  I should have them working by this weekend so I will update the blog with my first impressions then.

spare parts!

I want to get the Protos flying but it would appear the country is out of stock of Align 510 servo gears and servo horns.  Darn.

Brown times solution?

Okay, well what a weekend.  Lets start with the Mini-Titan and it’s electrical gremlins. I took the plunge on Friday night and brought a new ESC and Rx – £113.  As I use a Spectrum Dx7SE transmitter I brought the AR7600 High- Speed receiver. That way it would run at the high frame rate of 11ms. The logic being I could test to find out where my problems were.

So to work.. I changed the ESC for the new one and then started setting it up. After a while it did it’s reset thing again. This clearly means that it wasn’t the ESC and that means I now have a spare speed controller. Therefore the problem was with the receiver so I changed that for the new one and switched it on. Immediately the servos started twitching, which confused me further. I have a spare DX6i transmitter so I binded this with the new receiver and the servos stopped twitching. At this point I was ready to bin everything – so I went to bed.

Onto Saturday morning where I decided to take the transmitters and receiver back to the shop. Once I was there I showed them my problem  – on the Mini-Titan I had Hi-Tec analogue servos.

Spectrum AR-7600 on Mini-Titan

The new AR7600 fitted. Align 410M mounted alongside.

Due to the high frame rate when using a DX7SE and AR7600 receiver the analogue servos can’t keep up (news to me).    Therefore I either had to get a different receiver or upgrade the servos. I don’t need two receivers so instead I had to buy 3 Align 410M digital servos (£70). I went for the metal geared as there was a discount and they should stand up to more crashing.

In conclusion, I think I have solved the problems but until I have a test fly the jury remains out. On the positive side though I have a superb set-up for the Mini-Titan, all running at 11ms. I suppose after 2 years it was wearing out..

Brown times indeed :-(

Nightmare.  Total and utter.  Followers of the previous post will note that the Mini-Titan crashed recently whilst I was trying to learn inverted circuits.  I thought it would be a simple repair job and then I could get back into the skies for more fun and learning.  Far from it…

After putting it back together I went for a trim flight, 20 seconds after being airborne it lurched to the left and would not respond to stick input.  It therefore crashed into a wall fairly hard shattering the carbon blades and left me sweating.  Even though I had hit throttle hold it didn’t respond and thus did the “chicken dance” on the floor.   Worried me as it could of hit anyone.

Despite this I put it back together and tried again.  Didn’t do much just trimmed the heli and then left it for the night.  This evening I thought I should get to the bottom of it so I went up to the field and spooled her up.  After taking off I noticed lots of vibration on the tail so I was just monitoring it when it flipped inverted and hit the deck hard.  However when I got to the heli I noticed the receiver was flashing indicating a brown out.

Hmm.. this got me thinking so I put re-plugged the battery in an started wiggling the wires. Nothing happened and then suddenly it resets itself!  So I try again at the same point and nothing! I keep trying for a bit and then I touch around the front again and it resets itself.  For those that know the Mini-Titan then speed controller is at front and this all indicates a loose wire in the ESC (speed controller).

I have just spent the an hour or so in the cellar trying to create it again, by waggling everything but I can’t make it do it again.

Conclusion: We have to assume something in the electrics is causing a brown out and re-setting the on board electrics. It has to be said that this has been the heli I have had from the start and has so many crashes it’s hard to remember.  Maybe the ESC, Receiver, servos need replacing?  I had to replace the gyro and tail servo 3 months ago because they had started playing up. Either way the Mini-Titan is grounded until I can find the exact component.   My gut feeling in that I should get a new ESC (£40) and a new Rx (£65 for the 11ms frame rate) to be safe.  I mean after all the crashes I guess things wear out?  Problem is I want to practice my inverted stuff and the 450 size heli’s are the best for this.