Originally Posted by stgdz

Anyone here able to 3/4 to full speed horizontal line into ke spin

You can see it done here at 2:10: It's really a KE Wall into a KE spin.

Daniel Holman PCFC freestyle round 3 (7 min 41 sec)

For those flying the 70" Extra on 7s and 8s, what size ESC are you all using?

How many amps are you all pulling?

I am using the AXI 5325-18 with 6s and an 85amp ICE. I am going to be trying some new ESC's, and was not sure if I should step up to a 120-amp if I am flying a 7s or 8s setup. Can an 80amp handle the needs of an 8s setup?

Bauman,
That question is all Kv and prop related.

I'm building my 70" extra now coming from the 70" slick and transferring my 8s system across.
I'm running the motrolfy dm5320-300 on 19x8 or 19x10 Xoar props.
Using the ztw120hv I can get peaks of around 100A. But never over this number.

Depends all on your Kv and prop size.

Yep... the AXI 5325/18 is a 308Kv. Using the PropEngine, we can estimate that that a 19x10 on a 308Kv will do about 87 to 88 Amps peak at 3.75 volts per cell, which is cutting it close. A 19x8, on the other hand, will peak at about 70A and 2100 Watts. So as long as you don't over-prop the motor, it should manage a 19x8 with the 85A ESC, IMO.

If you can tell us the prop you were using, and either the Amps or the volts reading, we can match up a prop to the new cell count to keep the Amps down so you won't need a new ESC.

Kv is something I just never really grasped well.

Motor specs say 308 rpm/v
http://www.modelmotors.cz/index.php?...e=18&line=GOLD

I know I can use a variety of props, I just was hoping someone else had already figured out the best prop combination with that motor on 7s and 8s...

It is really just an exercise really; I do not need a new ESC. But a friend has asked me to try a new line for him before they take it to market. They are offering an 80 and a 120amp. I was concerned the 80amp might not be up to the task, but I need to get down with the motor calc and play with some figures.

Originally Posted by Aeroplayin

Yep... the AXI 5325/18 is a 308Kv. Using the PropEngine...

is that the same as "ecalc"?

Are you kidding? It's better... ... because I programmed it...

http://rcwebclub.com/PropEngine.aspx

Bottom line is a 19x8 electric prop on 8S with the 85A should be fine, but you should always check with a Watts meter, like the Watts-Up to make sure you're not putting your plane at risk.

Thanks Aero! I am embarrassed to admit I did not know that
I look forward to playing with it tonight, and learning more about my setups! It appears to be more user friendly and straight forward than others that I have seen; nice work!!

I keep the Watts-Up in my tx case; I will be sure to check the amp draw in real time. Thanks for putting this out there for all us to use!

My pleasure... it was actually fun, and we had plenty of data to test it with from the guys on the Power thread.

Originally Posted by Aeroplayin

Are you kidding? It's better... ... because I programmed it...

http://rcwebclub.com/PropEngine.aspx

Bottom line is a 19x8 electric prop on 8S with the 85A should be fine, but you should always check with a Watts meter, like the Watts-Up to make sure you're not putting your plane at risk.

And a darn fine job of programming it is too. It's the tool I use most lately.

Originally Posted by bsbauman

Thanks Aero! I am embarrassed to admit I did not know that
I look forward to playing with it tonight, and learning more about my setups! It appears to be more user friendly and straight forward than others that I have seen; nice work!!

I keep the Watts-Up in my tx case; I will be sure to check the amp draw in real time. Thanks for putting this out there for all us to use!

Nah, just fly it and see if it smokes??

Just joking, always, always use the watts meter on new setups to make sure and even then they might still smoke.

IMHO, the DM5320-300 rocks on 19x8 and 19x10 props and maybe my 120A esc is a bit of overkill but the ztw's are lighter then the equivalent Castle esc and I had that before I fell in love with castle speedies which is now my go-to esc for most of my old and new setups as they comes along.

I have 2 x 100A green castle esc Ice that are rock solid in 60" planes and it was a real performance boost when I went to them over the 85A ztw I had which was always hitting thermal shutdown on hot days if I didn't let the system cool.
I have the castle 160A HV in my 5600W 12s 50cc scale Sbach and its great, no heat issues and performs very well even on hot days.

Just got a 100A castle Ice light to try in my 57" extra on 4s, hopefully it will be great as well, and its significantly lighter then the same green ice version from castle thats in my 6s 60" ef planes.

What kind of flight times do you get on a "50cc" electric plane?

Originally Posted by bigroger

I have 2 x 100A green castle esc Ice that are rock solid in 60" planes and it was a real performance boost when I went to them over the 85A ztw...

CC Ices have also found a home in every one of my planes but one, ranging from the 50Lite to the big ones. CC raised the standard.
That said, I am eager to try something new and see how they compare.



ROTF~ I plugged in my numbers and was surprised at the results (low low watts). I went in and peaked through the cowl... The motor is actually the AXI 5325-16, and not the XXXX-18 that I previously posted

at 350kv your program is spot on

Originally Posted by bsbauman

Kv is something I just never really grasped well.

Motor specs say 308 rpm/v
http://www.modelmotors.cz/index.php?...e=18&line=GOLD

I know I can use a variety of props, I just was hoping someone else had already figured out the best prop combination with that motor on 7s and 8s...

It is really just an exercise really; I do not need a new ESC. But a friend has asked me to try a new line for him before they take it to market. They are offering an 80 and a 120amp. I was concerned the 80amp might not be up to the task, but I need to get down with the motor calc and play with some figures.

kv is easy. Simply it is how many RPM the motor will attempt to turn with 1 volt of electricity. So a 308kv motor is powered by 10 volts will attempt to turn 308 * 10 = 3080 rpm. Or on an 8s setup the voltage is 3.7v * 8 cells = 29.6 volts, so 308kv on 8s will attempt to turn 9117 RPM. Now in reality it won't quite achieve that, but it will try. So a 300kv motor on the same battery will turn fewer rpm, and thus pull fewer watts/amps on the same prop. A higher kv motor will try to turn more RPM and pull even more watts/amps. Efficiency comes into play here too, but you can mostly not worry much about that for understanding kv.

Originally Posted by DonEmmel

What kind of flight times do you get on a "50cc" electric plane?

6-7 minutes on a 12s5000 setup.

Originally Posted by danielph

You can see it done here at 2:10: It's really a KE Wall into a KE spin.
http://www.youtube.com/watch?v=9wL2P...A-TcDg&index=6

Done that, but I'm talking a level horizontal line into a KE spin. Not a horizontal KE spin either but a standard KE spin.


I can do it by jaming down and rolling into(left aileron only) it then KE spin it but if I try KE spin inputs from a full throttle horiontal line it tumbles forward. I'm really close but its hard to figure out how to bleed off that speed but its pretty awesome when I can get less than one roll rotation and then KE spin it.




Also anyone got some 4mm c-clips?