DualdudE

Would this combo work? And could i do basic aerobatics with it, like a loop and some rolls? Or would that be seriously underpowered.

I used the search and google, but couldn't find much useful information.

edit:
Changed the topic title since i've got a motor now.
Changed it again cause i got a diffrent plane too

Greg Covey

Alex,

I would not recommend that combination. Use an AXI 4120/14 on a 4 Star 40 model.

DualdudE

Did some research on that motor, and it looks like a great alterternative for almost every 40 sized plane.. I'm seriously considering getting that one.
I think i'll discuss it at the flying field tomorrow.

Matt Kirsch

My Feedback: (21)

Which one, the 4120/14 or the 2820/12?

If you are building the 4 Star 40 from a kit, you could make some serious efforts to save weight, and the 2820/12 could be used quite effectively. However, such a motor would normally be used on a typical .25-sized conversion with 10-12 cells.

The 4120/14 on 14 to 16 cells makes a great conversion motor for your typical .40-size.

DualdudE

The 4120/14 i meant Cause if i get the 2820/12 i'd have to get al light '3D' like plane for sportsflying. Like the Diablo Mini from JR. I have more faith in flying a Fourstar. It's a much more decent construction as a 3D like plane.

DualdudE

I got the 4120/14 today

Greg Covey

Alex,

When you set up the power system, I usually program the controller for hard timing and brake off.

Hard timing works best for the outrunner motors and the brake feature is annoying on a sport aerobatic model.

DualdudE

I think i'll get a Jeti/Hacker Master 70A without bec, since you can't use the bec when you hook it up to 12-cells. And i think i'm going to use 12-14 cells. But recommandations are welcome. Also for prop sizes I want the master cause it's got the 30 degrees timing mode that the Advance doesn't have.

stuey

I would say go for 14 cells and either a 13x6.5 or 13x8 APC-E on the 4120/14. I have the same Hacker Master 70 controller and have seen as much as 10A difference between the lowest and highest timing settings with my motor. It does give a bit more power and rpm but i would venture the overall efficiency drops with the timing high. I have the frequency set at 8khz as that is what the Model Motors controllers run at, haven't experimented with it though. Should give plenty of power in a Fourstar 40.

Greg Covey

Although I am still confiming it, I doubt there is any difference between the Hacker Master controllers and the newer Jeti Advance controllers.

For larger, more powerful setups, you are best off using the Opto versions for better noise isolation.

DualdudE

The only drifference between the Jeti Advance and the Jeti/Hacker Master is the software inside the controller. The Advance supports timing mode 1 and 3, the Master supports mode 1, 2, 3 and 4. Same counts for the frequency. The Advance only supports mode 1, where the Master supports mode 1, 2 and 3.

Greg Covey

Alex,

That sounds right.

The new Jeti "Advance" controllers have some, but not all, of the features of the Hacker Master controllers. In keeping with Jeti's overall approach to keeping the consumer products powerful, yet simple in operation, the "Advance" controllers have two user set timing choices and two prop brake choices. SOFT timing is good with low pole motors and the HARD timing is best for the outrunner type motors. With the brake option ON, the low voltage cut-off is abrupt (good with powered gliders and hotliners). With the brake set to OFF, the low voltage cut-off is gradual (good for power planes and aerobats).The controllers are Lithium friendly, meaning that the controller automatically senses the battery type and sets the appropriate low voltage cut-off. All settings are done with the transmitter throttle stick and once set they do not change till you change them.

Most modelers have no use for all of the features of the Hacker Master, therefore the Jeti "Advance" has its place.

gyronuts

Hi,
I tried a 2820/12 and 14 cells with 10 x 7 apc but have now fitted a 4120/14 on 14 x 2400 nicad or 3000nimh cells with a 13 x 6.5 APCE. The prop is critical. I tried other props but was amazed by the 13 x 6.5. Very impressive and lots of power.
My controller is a jeti advance and I used the AXI radial mount. Bill

N1EDM

My Feedback: (2)

I'm working on a similar type of conversion, but I'm a newbee...

Where do I find 14-16 cell NiCad or NiMH packs?

Also, what's the significance of the /14 or the /18 for the 4120? Do those numbers actually mean anything (i.e., max recommended number of cells, etc?)

Thanks..

Bob

Greg Covey

Bill,

Great information! Thanks for sharing. I've used the APC 13x6.5 prop on a .30-size Extra 300S befoe and it is a good combination of thrust with reasonable pitch speed. Great for electrics!

Bob,

The /14 and /18 numbers are the motor winds. The less # of winds, the higher the Kv or RPMs/volt. Higher winds favor more power when used with a higher cell count to keep the current within limits. Power = I x V so when V increases with additional cells, the current can remain constant but your power output level go up. The down side here is the additional weight of the added cells. This can be made more effective through the use of Lithium cells.

DualdudE

I got hold of a Simprop F4U Corsair (Seagull Model, .40 size) for a very reasonable price. So it's not going to be a Fourstar but i will put the AXI in the F4U Corsair.

DualdudE

Tuesday i received the speed controller

The plane:


The gear:


It's the new master that is programmable with the interface, which i will get soon too. Now i just keep praying Lipo's become very cheap in the next couple of months

DualdudE

For a more 'scale-like' look i would need a black three blade prop. I could use a master airscrew threeblade prop and paint the tips yellow, but my guess is this isn't the best for power. Due to all the things i've read i conclude the APC-Electric props do best on these motors. Still not sure what number of cells i should use and what prop would be best.


Plane roughly put together:


Those wheels are horrible. I need to find bigger ones that look a little more 'scale'.

DualdudE

Could anyone predict flight times based on experience...when i use a 12x8 prop and 16-cells? (GP/Sanyo NiMh 3300's)

Matt Kirsch

My Feedback: (21)

I was getting 5 minutes from taxi out to taxi back with my Global .40-size Corsair, using HR4/5FAUP 2000mAh cells. The heavier Sub Cs will require the use of higher power levels, so I'd expect about the same.

Muah

hi matt...........


I am in the midst of converting a 40 Size Global Corsair....the setup is going to be........

AXI 2826/10
14 cell GP3300
Prop ?????

could you care to share your setup????

thanks!!!

DualdudE

ì decided to go for a glow engine, calculations made me come also to about 5 minutes of flying time...just too short for me

Matt Kirsch

My Feedback: (21)

Gotta pay more attention I guess.

The AXi 2826 wasn't out when I converted my Corsair, and the 2820/12 just didn't have the capacity to handle the power I wanted to put through it, so I ended up with the bigger 4120/14. In the end this turned out to be a good thing since the plane needed the weight to balance. I suspect that with a 2826 on the nose, you'll need to figure out a way to get the battery partially ahead of the firewall.

Originally, I started with a 16-cell pack of 1950mAh HR4/5FAUP NiMH cells, for a 5 minute flight. Since then I picked up some of the new Kokam 2000 15C packs in a 4S2P configuration, doubling the battery capacity and reducing weight by roughly 6 ounces. Voltage is down slightly, but you wouldn't know it, because the Kokams can run the motor at 40 Amps vs the 37 I was getting from the Sanyos, and the plane is 6oz lighter.

Prop is 12x8.

Muah

hi matt....
thanks.....another question.....how do you charge your batteries? i can't bare to cut a hatch on the fuse...and was thinking of undoing the wing everytime i need to charge her......i probably stick with teh 2826 for a trial....is the 41 giving a lot of power????

later