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Old Jun 17, 2009, 10:50 PM
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33% Cap232 & Hacker A80-10 / Spin Box max current readings?

I'm new to this size electric and sort of scratching my head in confusion.

I'm flying my Hanger 9 33% Cap232 with a Hacker A80-10, Spin 170, 12s1p 5000ma 30C Zippy packs, and an Xoar 26 x 12e.

Spin box says 83A max and the voltage is pulling down to 41.5v. I'm doing a full throttle climb from takeoff for 4 seconds to assure an accurate current reading.

Seems strange that I would only be pulling 3400 watts with this prop/motor combination, and the batteries are coming down pleanty warm, in fact one set slightly puffed tonight after some aggressive pattern flying. I previously had been running a Xoar 25 x 12e and only getting 70A max with voltage around 44v.

I suppose I need to get an inline current meter and get to the bottom of this situation. I've read someplace that the spin box does not read anything over 100 amps, but rather starts over at the 100A point. No way I can be pulling 185 amps and 8000 watts with these batteries, correct?

Anyone have any real world current meter readings using these props and motor combination? Any insight greatly appreciated.

Kevin
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Old Jun 18, 2009, 04:12 AM
edible_engine's Avatar
Just south of Cambridge, UK
Joined Oct 2003
982 Posts
add a 1 onto the front, it never adds the leading digit for some reason

my A200 only drew about 20 amps.....
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Old Jun 18, 2009, 09:30 AM
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Quote:
Originally Posted by edible_engine
add a 1 onto the front, it never adds the leading digit for some reason

my A200 only drew about 20 amps.....
I had considered that. I'm simply having trouble believing that the 12s1p Zippys are capable of that much power.

I guess a clamp-on dc amp meter is next in order. I really do not enjoy running these big motors up on the ground though.

To bad Hacker/Jeti can not get the current reading thing staightened out. At least mentioning it in the instruction manual would be of some help. The guys at Hacker Aero don't seem to have a clue about it either.

Kevin
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Old Jun 18, 2009, 10:10 AM
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Fishers, Indiana
Joined Oct 2004
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Quote:
Originally Posted by Tipover
I had considered that. I'm simply having trouble believing that the 12s1p Zippys are capable of that much power.

I guess a clamp-on dc amp meter is next in order. I really do not enjoy running these big motors up on the ground though.

To bad Hacker/Jeti can not get the current reading thing staightened out. At least mentioning it in the instruction manual would be of some help. The guys at Hacker Aero don't seem to have a clue about it either.

Kevin
Not sure if any of this will help, but... my hacker/Jeti spin set-up gives me good reading, but at first it did not as I had the ESC set for the wrong poles and wrong motor, once I set it right, the ESC gave me spot on right info.
Give Mike Donovan at Hacker a call, he seems to be the go to guy, and has always gotten me the correct info, and fast.

Good luck,
DAG
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Old Jun 18, 2009, 11:43 AM
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Thanks, Dag

I put a call into Mike, waiting for a callback.

I have pole count set to 20, 22 degree's timing, 8khz as per A80-10 specs. Should be correct.

Readings look correct except for Max current. If I really pulled 183A, that would explain everything. Still Skeptical of that much power though. Plane has pleanty power for sure, I just wanted to get it up in the 5000 watt range. That is why I swithced from the 25 x12 to 26 x12

BTW, your B-36 project is really great. I've been watching, just not worthy of getting in the discusion.

Kevin
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Old Jun 18, 2009, 12:58 PM
It only takes one good idea
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Fishers, Indiana
Joined Oct 2004
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Quote:
Originally Posted by Tipover
Thanks, Dag

I put a call into Mike, waiting for a callback.

I have pole count set to 20, 22 degree's timing, 8khz as per A80-10 specs. Should be correct.

Readings look correct except for Max current. If I really pulled 183A, that would explain everything. Still Skeptical of that much power though. Plane has pleanty power for sure, I just wanted to get it up in the 5000 watt range. That is why I swithced from the 25 x12 to 26 x12

BTW, your B-36 project is really great. I've been watching, just not worthy of getting in the discusion.

Kevin
Kevin,
I know this sounds crazy, but I jumped into electrics with both feet with park fliers, then moved to my B-36 project, what a jump. I know very little to nothing about electrics. All I do know is that when I think it is the equipments fault, it is mine. Mike at Hacker is great, tell him DAG said that he will make everything perfect for you. And anyone is worthy of saying anything on my B-36 thread, as long as it is not about stuff that has nothing to do with cool aviation stuff.

Thanks, DAG
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Old Jun 18, 2009, 02:06 PM
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Just south of Cambridge, UK
Joined Oct 2003
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also, an important thing, the Jeti is very inaccurate with current draw unless it reads 4 seconds of maximum power. Even then its only 10% accurate. if you just give it a blip on the ground you will get some really weird numbers
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Old Jun 18, 2009, 03:30 PM
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I talked to Mike.

He said the spin box likes to see 15 seconds of full power for an accurate max current reading. I don't quite understand the measurement process, but the FET's temps are data logged and the current is calculated based on average temps I guess. So a fast current spike won't heat the FET's up for an accurate enough reading.

Even so, Mike was suspect of my current readings. Based on my max voltage readings he suspects my Zippy 4mm bullet connectors are dropping to much voltage, thus giving lower than normal max current readings. The 4mm bullets that come on the 30C Zippy packs have the little spring contacts that do not fit real tight. Nice to plug and disconnect, but not so good with high current applications. He suggested Deans Ultra or machined 6mm bullets for anything up around 100 amps.

Bottom line is that a 1p setup needs very good low resistance connections to efficiently pull the high current needed by these bigger motors. Also likly is that the spin box is not picking up on actual high current spikes, only long averages.

Not looking forward to changing all those bullet connectors.

Kevin
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Last edited by Tipover; Jun 18, 2009 at 03:36 PM.
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Old Jun 18, 2009, 04:07 PM
edible_engine's Avatar
Just south of Cambridge, UK
Joined Oct 2003
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deans on 100A, you must be having a laugh!!!!


get some 5.5mm gold connectors minimum, CC6.5 are a little better and for the best, plettenberg 6mm golds!!

Deans are a no no for me above 60 or 70 A



(start the war )
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Old Jun 18, 2009, 09:21 PM
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Deans are very handy connectors. I personally don't see them as having a very large surface contact area. I do understand a lot of guys are using them on 12s setups. I wonder how their contact resistance compares to 6mm machined bullets?

Are these what you guys are using for 6mm bullets? I'm assuming these are what are referred to as machined connectors?
http://www.rctoys.com/rc-toys-and-pa...RS-WIRING.html

Kevin
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Old Jun 18, 2009, 09:54 PM
And You're Not
Timbuktu, Mali (Happy?)
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I use the 6mm bullets from Neu, like $24 for 10 pairs shipped. They look like this
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Old Jun 18, 2009, 10:11 PM
blucor basher's Avatar
United States, PA, Lancaster
Joined Jun 2003
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(start the war )

No one cares about a war. I'll just keep using Dean's on my 100A setups. If they ever get hot, I'll let you know.
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Old Jun 19, 2009, 04:14 AM
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Joined Dec 2001
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Change the deans to some god 5 och 6mm golds, you will have loses in the Deans! they are "ok" up to about 50Amps, 4mm gold 80Amp, 6mm pletti 150Amp+ and they last very very long.... good qualety.

As already said, the SPIN messures avg max Amp based on the IR in the fets, and if the motor/ esch have any kind of problem, like wrong settings so it will lose sync the readings will be wrong, try and do a static test with full power for 5sec and see the data, then use a clamp amp to confirm.
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Old Jun 19, 2009, 04:37 AM
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Moss, Norway
Joined Jul 2003
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Kevin.
On Hackers website they have an example showing the A80-10 with 12s (42V) spinning a 24x12 Mejzlik at 6150 rpm and pulling 4620W.
Assuming you get about 6000 rpm with the 26x12, the power would be approx. 5600-6000W. (Estimate!)
At 41,5V this is equivalent to 135-145A.

What sort of flight times are you getting with your set-up?

Magne
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Old Jun 19, 2009, 11:03 AM
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Quote:
Originally Posted by Magne
Kevin.
On Hackers website they have an example showing the A80-10 with 12s (42V) spinning a 24x12 Mejzlik at 6150 rpm and pulling 4620W.
Assuming you get about 6000 rpm with the 26x12, the power would be approx. 5600-6000W. (Estimate!)
At 41,5V this is equivalent to 135-145A.

What sort of flight times are you getting with your set-up?

Magne
Magne, Interesting point you bring up.

My spin box max rpm readings are generaly 6300-6500 rpm's except for that one high spirited flight. Not sure why Mike was alarmed with my 41.5V reading, not that far down from 42V.

I have my flight timer set to 7 minutes, I try to be landed by that time. On the average been putting back in 3500-4000ma. On the meltdown flight I had a max rpm of 6740. Turns out I over discharged my batteries on that flight...could not even taxi back. I put back something over 4900 in the packs Those two packs balance charged fine, I flew them last night with no issues. The slight puffing seems to have gone back down.

The larger plane covers a lot of ground and it’s easy to stay on the throttle to long. Slight learning curve

Here are my spin box readings from that one harsh flight.

Max Temp 38C
Min Temp 18C
Max Current 83.0A 41.55V 5:18
Min Currrent 52.1A 37.47V 6:25
Max Volt 50.78V
Min Volt 28.05V
Off Volt 28.56V
Motor Run 6:37
Power On 7:31
Motor Pole 20
Max RPM 6,740

Kevin
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Last edited by Tipover; Jun 19, 2009 at 11:14 AM.
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