450 Woe's (Pl's help)!

[3ndurance]

This is new to me and I'm interested to know how to go about measuring my flight packs under load!
When I programmed the ESC LVC was set to low' ! what ever that is I don't know?
I don't think me or my bank balance can take much more of this! lol.

[cjcj1949]

The cheapest way is to use a voltage monitor alarm. You can get these from China/Ebay for about £2 including postage. You can set the alarm voltage for each cell and a very load alarm goes off when the volts drop to the level you have set. Escs usually use the total battery voltage and this can be a problem as usually when lipos get old, one cell goes before the others and so you can hit a LVC with two good cells and one very low one. If it's set to 9V you could have two good cells at 3.5V and one bad cell at 2V. This will give very unpredictable results as the low cell will not be capable of supplying enough current.

The amount a cell drops under load gets more as the cell ages and also as temperature drops. Many people warm their batteries up before use. It makes a big difference, something like a factor of two in flight times.

You can check how good your lipos are by measuring the internal resistance. Many better chargers do this approximately or you can get an accurate meter like the Wayne Giles from electriflyer. The icharger 106B also measures internal resistance and costs about the same as the Wane Giles meter, but is not so accurate.

You can also measure internal resistance by looking the the individual cell volts when charging. If you charge at 1 amp and then at 2 amps you will notice a difference in cell voltage (for the same state of charge) and this voltage difference is the internal resistance. For a 2200 mah cell the difference should be less than 10mv which corresponds to a resistance of 10 milliohms.

The battery alarm can also be bought from Giant Shark GT Power 2-8S Battery Tester

That one is out of stock, but other model shops have them. I have a spare you can borrow until you get one if you want. Quite a few people have found them very useful. I set the volts to 3.7 for good batteries and 3.6 for old batteries and they tend to end up at 3.8 off load which is a good level for making lipos last.

[AlastairC]

450 Woe's (Pl's help)!

I had a similar falling out of air moment with my 450 and as said above it was the bec in my esc. It would get warm and then fail. Cool down and work again.

Where in Edinburgh are you (I work near Stuarts Melville)?

[3ndurance]

Hi Ali,

I,m down in the grove (Granton) just off boswall!..

[AlastairC]

450 Woe's (Pl's help)!

Hi Ali,

I,m down in the grove (Granton) just off boswall!..

If you want to meet up nearby sometime let me know. I have a spare 3gx that did me very well on my 450 if you want to try it.

[3ndurance]

"Spot on buddy" !

Once l've sorted this mess out and decided on a plan of action !
With the weather improving it would be good to meet up !

I have a AR7200BX that I want to try out from an old wreck of a mini titan !
The 3GX sounds interesting and I might take you up on that offer in time thanks.
Also gonna spring for a new ESC just to be safe rather than sorry, sods law would have it being the only
component I don't replace that is the culprit!
where about do you fly your models?
I was a member of the penicuik model flying association but everyone flew planks!
So I packed that one in' now I shoot down to the waterfront to do my flying.
Can get gusty down their tho!

[AlastairC]

450 Woe's (Pl's help)!

"Spot on buddy" !

Once l've sorted this mess out and decided on a plan of action !
With the weather improving it would be good to meet up !

I have a AR7200BX that I want to try out from an old wreck of a mini titan !
The 3GX sounds interesting and I might take you up on that offer in time thanks.
Also gonna spring for a new ESC just to be safe rather than sorry, sods law would have it being the only
component I don't replace that is the culprit!
where about do you fly your models?
I was a member of the penicuik model flying association but everyone flew planks!
So I packed that one in' now I shoot down to the waterfront to do my flying.
Can get gusty down their tho!

I travel with work quite a bit at the moment and family takes priority at home so not been out much recently. Looking at clubs right now but most are fixed wing or too far for me.

Yea get a new esc and put the beastx in and enjoy.

Cheers,
Alastair

[cjcj1949]

It may well be the esc cutting out. If it's a linear BEC rather than an SBEC it could be close to the limit at the best of times. I had the problem with the Twister Storm ESC. Fitting a separate SBEC solved the problem.

[3ndurance]

UPDATE!

Ok I'm nearly their!

I have just finished soldering new connectors to my new ESC which is a Turnigy dlux 40a 3a sbec , I bought the programming box to! and can't tell if I am supposed to set it at 8Khz or 16Khz???
does anyone know what is best for this setup:

AR7200BX
3x Savox SH-0263MG
1x Savox SH-1257MG

I have no idea what this setting means and cant find any aswers on the web!

[3ndurance]

I've only just realized that this setting has something to do with the motor !
This is what I have :Specs:
Model: NTM Rotor Drive Series 2938 3400kv
Kv: 3400rpm/v
Poles: 3
Max Cont. Current: 30A
Burst Current (5 sec): 46A
Max Power: 500W @ 11.1V

[cjcj1949]

The 8 or 16khz doesn't matter that much. It's the switching frequency of the esc. 8kHz is usual.

[3ndurance]

Thx C.J

If I used 16khz would I see any improvement in performance or flight time?

[cjcj1949]

That depends. It's complicated. Some factors will improve and others will get worse. In the end it's the feel that's important and not what the engineering says.

[3ndurance]

Remake01.jpgremake02.jpgremake03.jpg Almost done ! just need a good day to test!

[cjcj1949]

Some good days coming up.