Hacker A20-34S performance

Dr Kiwi · Apr 28, 2005, 09:29 PM

To complete the series available to me, (22L, 26M, 34S) here are some figures for the 34S.

You can draw your own conclusions, but it certainly seems from the low temperature figures that, at least on small props, this motor can cope with far higher amps than the specs would suggest [2A-6A continuous, 8A max].

One comment I would make is that it seems bizarre that the Hacker Spec Sheet only mentions one prop (8x3.8 APC SF) for this motor. They imply that this is the ideal prop on 2s, yet at anything above 6v it is in their "red zone" [DO NOT USE] because the amp draw (9.6A @ 7v) is well outside their 8A maximum recommended draw!!!!! Worse is that I measured 10.70A @ 6.9v with this prop - so it is even further outside their recommended comfort zone.

Now Gary Wright will probably say - "I would prop for 12A and it would be fine" - and after running this little beast, I might be forced to agree with him!

I wonder how/why Hacker arrived at the modest 6A continuous/8A max limit????

I imagine the "small combat wing" boys might show an interest in 81mph pitch speed with a 5.25x6.25 APC E, and if we allow that >9A on 3s is still okay, how about almost >18oz with a 7x3.5 GWS HD!

Enough of my rambling - here are the numbers [which, dare I say it, are statistically not significantly different (students t) from those I measured using the ExtremeFlight Torque 34T]. I could post the graph, but it seems hardly worthwhile.

Cheers, Phil

Aio_1 · Apr 29, 2005, 06:25 AM

Good data Phil.

This motor looks like being a good direct speed 400 replacement on 3s. Similar prop sizes and I would think similar or better power output for 40% of the weight.
Hacker could perhaps do with a lower KV motor in the A20-XXS size.

Aidan

Dr Kiwi · Apr 29, 2005, 06:58 AM

Quote:

Originally Posted by Aio_1

Good data Phil.

This motor looks like being a good direct speed 400 replacement on 3s. Similar prop sizes and I would think similar or better power output for 40% of the weight.
Hacker could perhaps do with a lower KV motor in the A20-XXS size.

Aidan

You are right - that 1500Kv is too damned high to make it useful with a decent size prop. An addition to the range at ~1200Kv might allow you to use an 8x4, perhaps even a 9x5 on 3s.

Cheers, Phil

LJH · Apr 29, 2005, 11:59 AM

Phil,
Thanks so much for the info, I recently bought a 34S to but on a Blitz bipe and I was not all that happy with the performance and I thought it might have been the motor but as it turns out I am seeing some substaintial sag in my 2S E-tech 700HP pack. At a little over 6A I am down to 6V. With the numbers you are showing my 6.7oz blitz should be an animal with this set up, guess I have to get myself a TP730 GII pack to check that out.

Cheers,
Jim

Dr Kiwi · Apr 29, 2005, 01:29 PM

TP 730 and TP 900 seem to hold their voltage pretty well - especially once the packs heat up to ~35C - they are lousy when cold!

cmacclel · Apr 29, 2005, 11:09 PM

Thanks Dr Kiwi looks like my new blitz may be getting one of these baby's with a 2 cell and 8 x 4 HD.......thanks!

Mac

dick hanson · Apr 30, 2005, 07:58 AM

seven ounce 3D model - 9x3.8 APC prop or 8x4 GWS- 3 cells 480 TP yellow stripe
absolutly great outdoor setup .
For someone who is trying to fly a heavy model or run it flat out - NOT a good setup.
This setup is a 14 amp burst amp draw setup!
Our flying is typically pulling 4-6 amps unless we poke it .
That's when this setup really takes effect.

cmacclel · Apr 30, 2005, 08:29 AM

Quote:

Originally Posted by dick hanson

seven ounce 3D model - 9x3.8 APC prop or 8x4 GWS- 3 cells 480 TP yellow stripe
absolutly great outdoor setup .
For someone who is trying to fly a heavy model or run it flat out - NOT a good setup.
This setup is a 14 amp burst amp draw setup!
Our flying is typically pulling 4-6 amps unless we poke it .
That's when this setup really takes effect.

14amps out of a 8amp burst battery?

Mac

Dr Kiwi · Apr 30, 2005, 10:27 AM

Quote:

Originally Posted by cmacclel

14amps out of a 8amp burst battery?

Mac

Rest assured he is not GETTING that - Dick likes the big props (for good reason) but obviously has a well trained left thumb to make sure he runs at far less a load (4A-6A) with his very light planes.

Cheers, Phil

cmacclel · Apr 30, 2005, 10:47 AM

So dr. Kiwi is there a better choice in your opinion other than this motor for a EPP Blitz?? Also what battery would you recommend?

Mac

cmacclel · May 16, 2005, 10:33 AM

I just maidened my Blitz today with an AUW of just a tad over 7oz with this 34s motor swinging a 8 x 3.8 SF prop, in Dr. Kiwi tests yielded over 14oz of thrust. This should give me a 2:1 ratio which is what I was hoping for. I need to use 3/4 stick to hover and pullout is barely OK. I'm using a 2s 900mah pack which I know should deliver over 10amps. I'm using these same cells in a 3s pack that I have measured 12 amps coming out of them. I guess a need to throw a meter on my setup later tonight to see whats going on. Also I'm barely getting 8-10 minutes of flying with the 900mah pack.

Mac

Dr Kiwi · May 16, 2005, 02:43 PM

Quote:

Originally Posted by cmacclel

I just maidened my Blitz today with an AUW of just a tad over 7oz with this 34s motor swinging a 8 x 3.8 SF prop, in Dr. Kiwi tests yielded over 14oz of thrust. This should give me a 2:1 ratio which is what I was hoping for. I need to use 3/4 stick to hover and pullout is barely OK. I'm using a 2s 900mah pack which I know should deliver over 10amps. I'm using these same cells in a 3s pack that I have measured 12 amps coming out of them. I guess a need to throw a meter on my setup later tonight to see whats going on. Also I'm barely getting 8-10 minutes of flying with the 900mah pack.

Mac

I wonder what your voltage is dropping too? - that prop will be trying to pull 10-11A, but if you at barely over 6v your pack might only be able to deliver 7-8A. If you really are pulling 9A or more, mathematically you'll get less than 6 minutes flying time. I'd try an 8x4 GWS HD and see if the lower draw but higher voltage under load makes a difference.

Remember that the Hacker web site says 6A continuous/8A burst max for that motor.

cmacclel · May 16, 2005, 03:05 PM

Know of any good dealers that carry the GWS props on the east coast?

Mac

Dr Kiwi · May 16, 2005, 04:49 PM

Quote:

Originally Posted by cmacclel

Know of any good dealers that carry the GWS props on the east coast?

Mac

Balsa Products is in New Jersey - any good to you?

cmacclel · May 16, 2005, 05:24 PM

Quote:

Originally Posted by Dr Kiwi

Balsa Products is in New Jersey - any good to you?

Perfect.....I hate wating 5-7 days for shipping from the west coast!

Mac

Apr 28, 2005, 09:29 PM	#1
Dr Kiwi Registered User Join Date: May 2003 Location: Chattanooga, Tennessee, United States Posts: 19,922	Hacker A20-34S performance To complete the series available to me, (22L, 26M, 34S) here are some figures for the 34S. You can draw your own conclusions, but it certainly seems from the low temperature figures that, at least on small props, this motor can cope with far higher amps than the specs would suggest [2A-6A continuous, 8A max]. One comment I would make is that it seems bizarre that the Hacker Spec Sheet only mentions one prop (8x3.8 APC SF) for this motor. They imply that this is the ideal prop on 2s, yet at anything above 6v it is in their "red zone" [DO NOT USE] because the amp draw (9.6A @ 7v) is well outside their 8A maximum recommended draw!!!!! Worse is that I measured 10.70A @ 6.9v with this prop - so it is even further outside their recommended comfort zone. Now Gary Wright will probably say - "I would prop for 12A and it would be fine" - and after running this little beast, I might be forced to agree with him! I wonder how/why Hacker arrived at the modest 6A continuous/8A max limit???? I imagine the "small combat wing" boys might show an interest in 81mph pitch speed with a 5.25x6.25 APC E, and if we allow that >9A on 3s is still okay, how about almost >18oz with a 7x3.5 GWS HD! Enough of my rambling - here are the numbers [which, dare I say it, are statistically not significantly different (students t) from those I measured using the ExtremeFlight Torque 34T]. I could post the graph, but it seems hardly worthwhile. Cheers, Phil Attached Thumbnails 95.4 KB · Views: 1553 64.2 KB · Views: 1620 Last edited by Dr Kiwi; Dec 18, 2008 at 01:28 PM.

May 16, 2005, 10:33 AM	#11
cmacclel Registered User Join Date: Jan 2005 Posts: 247	I just maidened my Blitz today with an AUW of just a tad over 7oz with this 34s motor swinging a 8 x 3.8 SF prop, in Dr. Kiwi tests yielded over 14oz of thrust. This should give me a 2:1 ratio which is what I was hoping for. I need to use 3/4 stick to hover and pullout is barely OK. I'm using a 2s 900mah pack which I know should deliver over 10amps. I'm using these same cells in a 3s pack that I have measured 12 amps coming out of them. I guess a need to throw a meter on my setup later tonight to see whats going on. Also I'm barely getting 8-10 minutes of flying with the 900mah pack. Mac Last edited by cmacclel; May 16, 2005 at 11:00 AM.

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Apr 29, 2005, 06:25 AM	#2
Aio_1 Do it for fun Join Date: May 2002 Location: Kilkenny, Ireland Posts: 5,878	Good data Phil. This motor looks like being a good direct speed 400 replacement on 3s. Similar prop sizes and I would think similar or better power output for 40% of the weight. Hacker could perhaps do with a lower KV motor in the A20-XXS size. Aidan

Apr 29, 2005, 11:59 AM	#4
LJH Moths do not fly inverted Join Date: Sep 2000 Location: Greenwich CT. Posts: 3,974	Phil, Thanks so much for the info, I recently bought a 34S to but on a Blitz bipe and I was not all that happy with the performance and I thought it might have been the motor but as it turns out I am seeing some substaintial sag in my 2S E-tech 700HP pack. At a little over 6A I am down to 6V. With the numbers you are showing my 6.7oz blitz should be an animal with this set up, guess I have to get myself a TP730 GII pack to check that out. Cheers, Jim

Apr 29, 2005, 01:29 PM	#5
Dr Kiwi Registered User Join Date: May 2003 Location: Chattanooga, Tennessee, United States Posts: 19,922	TP 730 and TP 900 seem to hold their voltage pretty well - especially once the packs heat up to ~35C - they are lousy when cold!

Apr 29, 2005, 11:09 PM	#6
cmacclel Registered User Join Date: Jan 2005 Posts: 247	Thanks Dr Kiwi looks like my new blitz may be getting one of these baby's with a 2 cell and 8 x 4 HD.......thanks! Mac

Apr 30, 2005, 07:58 AM	#7
dick hanson Registered User Join Date: Nov 2003 Location: slc ut Posts: 867	seven ounce 3D model - 9x3.8 APC prop or 8x4 GWS- 3 cells 480 TP yellow stripe absolutly great outdoor setup . For someone who is trying to fly a heavy model or run it flat out - NOT a good setup. This setup is a 14 amp burst amp draw setup! Our flying is typically pulling 4-6 amps unless we poke it . That's when this setup really takes effect.

Apr 30, 2005, 10:47 AM	#10
cmacclel Registered User Join Date: Jan 2005 Posts: 247	So dr. Kiwi is there a better choice in your opinion other than this motor for a EPP Blitz?? Also what battery would you recommend? Mac

May 16, 2005, 03:05 PM	#13
cmacclel Registered User Join Date: Jan 2005 Posts: 247	Know of any good dealers that carry the GWS props on the east coast? Mac