stepheva

Okay guys, I need some help here. I'm scratching my head. I have done all necessary mods to the PZ super decathlon, changed the motor to the venom 370, and am running a 9 4 7 prop. I have switched the radio out to a JR with micro reciever and sub micro servos, so it is lighter than ever before. I am still using the standard 8.4v 600mah pack, i have some 1100's on the way. The issue is this. I never flew it stock, so i have nothing to compare it too. I have read in some posts people boasting huge power, ability to climb 400 fps and do consecutive loops. Even with the mods, I still have to drop the nose to gain enough speed to do a loop. Anyone have any ideas?

Glacier Girl

My Feedback: (4)

Did you change the battery connectors? Switching to a Deans will help get the power to the motor. The stock connectors have the ability to loosen up, which doesn't allow full power to get through.
Also, what are you using to charge the batteries? If it's the included charger, try another charger. The included one has a bit of a history.

You are running a 9X4.7 prop?
Switch to a 9x7 Gws or 8.5x8 Megatech, 4.7 pitch is too low, not letting the motor spin up the prop.

1100 pack may be too much weight for this., Plus it may not fit.

stepheva

Yeah, I switched to deans for the battery and motor. I'll try the 9x7. Right now there is hardly any ground clearance though. Also, isn't the stock prop a 8.5? I'll try anything to get this thing going. Glacier girl, did you previously post that you tried a brushless in this and that the venom is still the best way to go? As for the 1100 pack, I believe it is the same size as the stock one. Made for firebirds, 7 cell. Got them off ebay.

Glacier Girl

My Feedback: (4)

The Firebird packs, if I remember correctly are what we used in the Strykers, as an upgrade.
They are a much larger pack size.
Stock prop was an 8.5 but pitch was around a 5. Higher pitch will give higher prop speed.
Ground clearance, Install a set of Dave Brown lite treaded foam wheels.
Will make take offs and landings a lot easier.

The Venom is THE brushed motor to use
For a brushless, I love the Hacker E3-49, You'll end up with a Cub that will run with stock Strykers.

What about my question on chargers/packs fully charged?

stepheva

Well, the charger is stock. What history do they have, and what should I be using? I'm getting about a 8 minute flight with the 600mah battery. I will switch the prop too. also, the 600 mah pack has 'for use in firebird (5)(e29)' stamped on the side. it is a 7 cell, so when i saw the ones on ebay that were 7 cell 1100mah 'for use in firebirds' i assume they are the same pack, with just different capabilities.

Glacier Girl

My Feedback: (4)

Many different versions of the firebird, packs vary,depending on the model.

I promised David from PZ I would be nice and not bad mouth the products.

stepheva

okay, what charger do you recommend. also, the batteries i got are 2/3a, 8.4v 1100mah. will these fit into the same cage?

Glacier Girl

My Feedback: (4)

I believe what you were looking at were these.
http://www.batteryspace.com/index.as...ROD&ProdID=850
This is a firebird pack, and what we used in the Strykers. DEFINETLY won't fit the Cub.

Do you have someone else in your area that flies? Try their charger first.
I only recommend what I use.
http://www2.towerhobbies.com/cgi-bin...?&I=LXUF46&P=7
Has served me well. Comes with a power pack for home use, plus can work off cig liter.

stepheva

Yep, those are the batteries I ordered. But, it is for a decathlon, not a cub. Will they fit the decathlon? And sadly no, no one else flies electric around me. I did take my charger to my LHS and they said it worked fine.

Glacier Girl

My Feedback: (4)

Sorry about calling the "D" a Cub.
But it's the same package with different wrappings.
If those are the big Firebird cells, they won't fit.
The standard cells are like midgit AA cells
The 2/3 ones are bigger in heigth and diameter. And weight.

Ok let's work with what you have availible to you.
It sounds like you have a good hobby shop to deal with. At least they checked your charger.
Off the track a little, but how did they check it?
Do you have or have access to an Astro or Watt meter? If not, you need to get one, this is a must for flying elec powered planes. It will tell you everything you need to know about the system. Volts,amps,watts,capacity. All the vitals of electricity.
Ok if you don't have one now. Take your charged battery pack to the LHS (local hobby shop)
Have them plug it into a meter. It will give you a volt reading. Fresh off the charger, your pack should read 10 to 10.5 volts. If it isn't you've got a problem. Yes I know it's an 8.4 pack, that's working voltage, packs start to degrade the instant you take them off a charger, and when you put a load on them. We'll not get into why.
Anyhow if the pack isn't fully charged, see if you can weasel the LHS into charging the pack on a regular charger, for you. Or at least check the pack to be sure it's a good one.
Don't give up. I've been there, where you are now, and it get's very frustrating.
But when you get it to work, you'll forget all about the trials you went through to get there.
Keep me posted.
GG

stepheva

Well, the voltage seems fine. It is warm off my charger when it's done, but not overly. They did charge it in the store, with my charger and it seemed okay. But alas, I think the li-po's are calling my name. I'm looking at Thunder Power pro lite 1320 2c paks. 2 of those, with a charger(and power supply) with a balancer for $170 US. Seems like a good deal. Oh, the prop is changed, but i haven't flown it yet. Maybe today. I got to put some ailerons on this thing!

stepheva

Well, I took it out today, even in the 10+ mph gusty wind and this thing hauled! Climb rate was awesom. Battery life is still 8mins, so I ordered the lipo's today from Draganfly. I didn't get the balancer at this time. In one forum, the guy said he had 300 flights on his pro-lite he was testing and it wasn't out of balance. Plus, i'm not going to abuse the pack. I'll get a balancer eventually. As a side note, I was reading the review thread on the SD and someone mentioned the tail always dragging in the air. I filed my firewall mount flat, as the gearbox already had down and right thrust built in. Now, it flies good and straight! I thought it had been tail heavy, but it always balanced perfect. Pretty quick little nugget, ain't she! Even at 1/2 throttle with the venom, she will climb nice and easy.

Glacier Girl

My Feedback: (4)

Glad it worked out for you.
When you get bored with the Venom, holler. I'll tell you about the next step, BRUSHLESS.
My latest, "Super Cub"

stepheva

Quick question, since I'm new to the electric scene. The 1320mah battery specs are 13c (17 amps) with 20c (27amp) bursts. I have a 20 amp fma direct super 20 speed control in this. I am guessing this will be fine since the motor only draws 7.7amps as per Greg Covey's review, with the venom motor? Do I have anything to worry about here? By the way, nice ailerons on the cub. I'm wanting to add them to the SD as well to get better control. Do you think that cutting the hole in the wing to mount the servo takes away from the structural integrity of the foam? I was going to mount it on it's side with some bellcranks on each wing, thus avoiding cutting the hole. What material do you recommend for making the ailerons, and do you just use packing tape to fix them on?

Glacier Girl

My Feedback: (4)

Pack should work fine.
Not familure with the FMA esc, does it have setable cut off for voltage?
If not you have to be careful you don't run the pack below 6 volts resting.
If you run the pack too low it's trash.
How you can get around it if it doesn't have the cutoff. Time your flights.
Fly for 5 minutes, land and check the pack voltage, repeat untill you get close to 6 volts on your pack. Add up the time and deduct a couple of minutes. This will give you an average length of flying time and a small buffer, for those times you over run your limit.

Or you can buy a seperate cut off, it hooks between the RX and ESC.

Ailerons are from a second Cub wing, but can be made from foam or balsa.
I have a piece of lite ply under the cut out area, for the servo, to make up for the loss of foam.
If you go this route, use epoxy for gluing, it holds well and doesn't eat the foam.
I've used tape and hinges for them. Tape gives a smoother finish, but has to be replaced every so often.