ikarus_dm

Hi,

I'm used to fly models and for career reasons, stopped about 7 years back. I have just moved house and now have fields right out front and have more time on my hands now too

So i've been and dusted down my old electric stuff. I have a brushless zoom electric heli which i used to fly a lot, which is still flying just fine (can you still get parts for these?).. but my main question is related to the Katana Mini, i was just building one of these when i stopped flying so i now have one unflown with the following specs:

AXI 2808/24
Graupner Slowfly Pro 11x5
Jeti 30 advance
Flightpower 3s 2250mah (12C Cont, 20C Burst)
Electron 6
HS65's

I'm trying to read through years worth of posts on the KM and finding a lot of mixed thoughts on the Axi 2808/24.

I am looking for hovers and verticals if possible. Just starting to dial in my flying again on RealFlight..

I still have a lot to remember and even more to learn about electric flight so would appreciate any input. Did anyone run with this set up before or can somebody advise whether this is ok to fly? I'd rather swap out parts now if there are better matched components

Thanks..

Dave.

Buck Rogers

Hi,

I can't comment on the motor but I do have a few other tips. I find the landing gear arrangement on my katana to be extremely fragile. When landing on grass the gear rips itself out every time. I have now strengthened the fuselage and installed a 1 piece aluminum landing gear - this has a bit more flex than the carbon fibre one. I have also removed the wheel covers to stop them getting snagged on the grass.

The other thing is that a lighter battery pack may be better for 3d - 1800s might be better and a higher c rating wouldn't hurt either.

ikarus_dm

Thanks for the feedback, I'm not sure how good these old Li-Po's would be now anyway so i think I'll take your advice and get some new ones. I see overlander are still trading

It seems when I built the Katana I already beefed up the airframe where the undercarriage mounts. I've read a lot today about people changing out the carbon units for an alum piece as you suggest. Any idea where I'd get one from?

Thanks again

Dave

Buck Rogers

Indeed, Overlander are still going but I've never tried their lipos. There are a few other shops around worth a look too.

Giant Cod are quite good for things like ESCs and Lipos - In particular I've had a lot of success with the Loongmax batteries they sell:

http://www.giantcod.co.uk/loong-lipos-c-1_287.html

I've also used places like Robotbirds and BRC Hobbies.

Regarding the undercarriage - I had the beefed up airframe too and that still wasn't enough to keep the undercarriage attached - its not like I'm prone to hard landings either.

I'm not sure where is the best place to get an aluminium undercarriage but given the size of the CF one they supply you'll need something to fit a 25 size plane since so much clearance is needed for the prop. I used a spare one I had from a Hyperion Helios 25 that I crashed - seems to fit quite nicely.

ikarus_dm

Thanks for this, i have spent the morning today researching various upgrades. I've posted a separate thread regarding motor choice. I'm just struggling a little on battery choice. I definitely want to go for something in the 1800 - 2000mAh range but I'm not sure on what brands are out performing others, and which to avoid. The Loongmax batteries that you recommended don't seem to have an option in the right capacity. I saw some high C batteries from e-flight and from thunderpower (pricy though), yet overlanders batteries seem very low priced. I guess i just don't know what's what anymore, i'll keep on reading. I assume its a case of 'you get what you pay for' but i'm not sure i need too much for this model and don't want to over spec.

Confused

idealhobbies

If the option exists for where you live...www.hobbyking.com for your batteries. I'm not sure if you'll have to pay taxes or not.

http://www.hobbyking.com/hobbyking/s...idProduct=6293

The also have a warehouse in Germany. (DE Warehouse)

I've been using the Zippy and Flightmax batteries for 3 years without complaints. I have everything from 3 cell 500mah to 6 cell 3000mah's and am happy as a lark.

ikarus_dm

Thanks for the recommendation, I'll take a look at the site..

Buck Rogers

I hear Overlander batteries are pretty good - there are quite a few guys at my club using them and they seem to perform well.


I use 2200's in my katana and it handles the weight OK - I don't do much 3D though.


Re Hobby king - as long as the order value is under £18 as stated on the package you should avoid tax charges. Just be aware if the package does incur a tax charge you'll have to pay Royal Mail a £7 processing fee.


Alternatively, how about something like this:

http://robotbirds.com/catalog/produc...oducts_id=4835

or same ones here (but out of stock at the moment):

http://www.giantcod.co.uk/loong-tipp...-p-404431.html

ikarus_dm

Thanks, to be honest i am steering now toward the Overlander li-po's, their Sport 2200mAh lists as genuine 25C constant (more than enough, i'm only looking at 25A load max), 40C burst and 2C charge (which is as much as my current charger will provide). The interesting thing though is that it's listed as weighing only 165g, which i think is quite light for a 2200, i've seen 1800's weight in at a similar weight. At £20 a go that does seem like a great deal, I think I'll try one and see how it goes before buying a few more if it performs well.

This leads me onto my next question. I have a pro-peak mercury-ex li-po charger which provides upto a 5A charge and is fully programmable, but doesn't do any cell balancing. It seems overlander do a cell balancer designed to go between the charger and the battery:

http://www.overlander.co.uk/tornado-...-balancer.html

Not sure whether this would be sufficient or whether i should bite the bullet and replace my charger too. Back in my day we didn't worry about balancing cells ?!? Seems things have moved on

Any advice on balancing / charger greatly welcomed. Be nice to actually fly again one day once I've caught up

Thanks again guys, appreciate the feedback.

Buck Rogers

Yeah, a separate balancer should work ok. I'm thinking about getting one myself because the built in balancer on my charger seems to be playing up a bit.

I balance my packs on every charge - it takes slightly longer but should stop any of the cells geting over charged or discharged. Some people say you only need to balance every few charges. Either way it seems to be worth doing.

ikarus_dm

Great, thanks, any recommendations on a balancer?

Buck Rogers

Not really - it might be worth searching the batteries and Chargers forum.