RCXPLANES

My Feedback: (1)

Well after waiting a bit longer than most, I just finished some very non scientific tests of the Hacker A20-34S and the Little Screamers Purple Peril motors on our new Allure. All of these tests were performed on planes either in the air or with a static amp draw test and a watt meter.
After some extensive conversations with Scott at Little Screamers, I opened my mind and switched over to the GWS 8x4 HD prop for both motors. First of all I want to say that this prop design works much better on either motor and does some really great things for our new line of sub 9 oz. planes when compared to the slow fly designs we have been tied to thus far. My fears of a reduction of propwash from this HD design were unfounded. Thanks for that alone Scott. I also tried the GWS 11x7 HD on one of our 6mm planes and the results seem the same. More about that later.
The Allure was designed around the Hacker A20-34S motors and will accept the AXI and Park outrunners radial mounts with no adaptor needed. This put the Purple Peril at a disadvantage from the start by having to carry an aditional 3 grams of plywood adaptor plate and nylon hardware. I am also not a fan of the propsaver either so an additional weight penalty was added to the Purple Peril in the form of a clamp on style solid prop adaptor. This also put the prop around .25" farther forward. It still came in ready to bolt to the plane at 11 grams lighter. Wow.
I flew several TP 730 mAh 3s1p batteries back to back with both motors and the same prop. Starting with the Hacker A20-34S and X7 controler, I have to say that this felt like a pretty darn good power system with a hint of throttle lag when asking for more power from 1/2 stick hover. Next I tried the Little Screamer with a Castle PHX 10 programed as instructed by Bob at Little Screamers.
HOLY COW!! The Purple Peril was obviously turning a higher RPM and would hover at just over 1/3 stick. When asked to accelerate from hover, the power was instant and always there. The motor torque effect I normally feel on the plane at hover and in consecutive waterfalls at full throttle was nearly eliminated. When the 7 minute timer went off I landed with more power left in the battery and felt the motor/battery and speed control. All were cool. I was able to fly an additional minute and a half before feeling the battery start to slow. The Hacker will use the battery up in the 7 minutes. Right away the Little Screamer was tons better.
In order to give the A20-34S a more fair evaluation, I attached it to the Castle PHX 10 and tried again. Well this was much better but clearly no match for the Little Screamer yet. It just doesn't spool up from hover RPM nearly as fast as the Little Screamer. Period.
Now I decided to try and give the Hacker a bit of an advantage over a stock unit. I cut the shaft off at the back around 1/32" from the clip groove and left the collar off. I turned the bolt on solid prop adaptor down as far as I dared to. I also lathed A LOT of material off the magnet can end bell without getting into the area where the prop mount bolts. Total Time, 30 minutes. Total weight savings, 4 grams of rotational mass from the Hacker.
While this modification helped the A20-34S a great deal, it was still 7 grams heavier and refused to spool up from any RPM to another as fast as the Purple Peril. It would'nt pull the plane around with as much authority in any 3D situation and it has more motor torque effect on the plane when maintaining and accelerating from a hover.
I was also told by Bob of Little Screamers that the Cool Running A-12 was an even better ESC so one of these was attached to each motor. While the A-12 is heavier than the PHX 10 the performance of both motors was enhanced but the Little Screamer gained a step and a half while the A20-34S gained just a step.

Scott, I AM A BELIEVER. I am making a strong recomendation to everyone to use the Little Screamer Purple Peril on our new indoor line of planes. A mounting plate for your four leg plastic motor mount will be available for all of the Indoor RCXPLANES models coming out and if I get my act together they may even be included in every kit.

Don't think I am knocking the Hacker A20-34S. It is a great product and does a nice job flying our little planes around with good authority without any modification. It's just that the Purple Peril is the ultimate in available power, battery usage and rotational torque reduction on our planes. These qualities give the Little Screamer a big nod from me over the Hacker A20-34S.

Thanks for the Eye Opener Scott. Keep up the good windings.

Bud

rcflyer2

My Feedback: (6)

Thank you for your kind words

Scott
littlescreamers.com

RCXPLANES

My Feedback: (1)

Scott,

As you may know, there are those that require numbers so to that end I built our first motor test stand today. It is a dirrect result of looking at Dr. Kiwi's test stand pictures so I thank him for that.

The words that I originally posted were all earned. There have been some ripples in the pond lately so some more testing will be done. As always, the "In Flight Feel" will prevail.

Bud

awdtsi

My Feedback: (3)

Can you comment on the power of both motors with a 2 cell Lipo. I am getting an Allure and want to run TP2s730 packs as I just picked some up.

Thanks,
Ryan

RCXPLANES

My Feedback: (1)

Here is the raw numbers from the test stand from both the LSPP and the Hacker A20-34S on 2 and 3 cells. AS you can see the Hacker with the APC 9x4.7 makes the most thrust of the two on two cells because the LSPP won't run the Slow Fly prop without balking. With the same 9x5 HD prop the thrust numbers were identical. The main issue here then is the AUW difference.

The A20-34S on 3 cells with the 8x4 HD prop is a good package and I am sure anyone would be happy with it. The LSPP on 3 cells with the 8x4 HD prop is a rediculous amount of power for the plane.

Going to a 2 cell package with the 9x5 prop on the LSPP is probably the best two cell package due to the reduced weight and the personality the 9x5 HD prop gives the Allure. The Hacker with the APC 9x4.7 SF prop does make up for the weight difference in thrust. That package has the same thrust feel as the LSPP 2 cell and 9x5 HD prop when punching out of hover. The flying weight does have a better feel in the air with the LSPP.

These two motors are quite different in how they approach making power. The LSPP likes higher rpm while the Hacker will pull a more loaded prop like the APC 9x4.7 SF. Some people will appreciate the lower weight of the LSPP package while others will like the ability to run different props with the Hacker A20-34S.

Bud

bhole74

How do they compare $ wise? No prices on website, that I saw.

rgrensing

Bud,

What was Bob's recomended PHX 10 setup for the Little Screamer.

Thanks,
Russ

RCXPLANES

My Feedback: (1)

Hi All,
Pricewise the A20-34S lists at 59.99. I believe the LSPP was 49.99 but I am not certian if that has changed or not.

I will check the PHX 10 that I set up tomorrow but Bob's recomended PHX 10 settings as I remember them were.

Cutoff Voltage = Auto Detect or Battery Dependent
Cutoff Type= Soft
Brake Type= Disabled
Throttle Type= Auto Callibrating
Soft Start = Fast
Motor Timing = Standard Advance
Current Limiting = Normal
PWM Frequency = 11 khz.

Like I said this is how I remember but I will plug it in to the PHX Link tomorrow to be sure.

Bud

Glacier Girl

My Feedback: (4)

Bud,
Was the PP the old style with the metal end bells or the one with the lexan ones?
12 wind or 11?

RCXPLANES

My Feedback: (1)

The LSPP tested was the old style with the metal and screw prop saver at 12 turns. Scott modified them for me to accept a clamp on solid prop adaptor. Due to my smacking the ground with it in that configuration, I bent the shaft pretty badly. Scott is replacing the shaft and the endbell with the Lexan version prop saver cause I can't seem to keep it off the ground from time to time. [&:].

Bud

rgrensing

Bud and all,

You may want to check this out:

http://www.rcgroups.com/forums/showthread.php?t=388646

It recommends v1.021 for Castle Creations speed controllers when using CDROM motors.
I'm using a 16 turn CDROM motor for my shocky which likes high RPM and low load. This is probably why the GWS HD direct drive props are working out better then the APC slow fly props. But I was still getting a stutter on hard acceleration with the 8x4 HD prop and v1.14 for the PH10. After reading that thread I switched to v1.021 and it seems to be working fine although the auto lipo feature is not in that version.

I know this isn't a little screamer but the description of the problems you are having with the PH10 sounds related. The Cool Running ESC sounds like a very good solution but if you already have a PH10 then this might help.

Russ

RCXPLANES

My Feedback: (1)

Russ,
Thanks for the link. I have seen this and it is good information. The CR A-12 has no problem starting any of the motors I have tried it on. Thats good news. The bigger issue between the APC SF and GWS HD prop designs for me is the in flight feel difference. Scott at LS recomends the HD design only for his motors and due to that recomendation, they have been tested on all of the motors and planes as a mater of course. My flying style (or lack there of) really appreciates the HD design over anyones Slow Fly design. I have heard some talk of an even more efficent APC prop with the same weight and perhaps better in flight personality than the HD comming down the road sometime. That would be a real great prop to try next.

Bud

rightflyer

Just got my repaired Littlescreamer back. For $20 Scott not only rebuilt it, but included all the goodies that come with a new motor. That is excellent customer support in my book. I have a Purple Peril on the way and can't wait!

RCXPLANES

My Feedback: (1)

Hi all,
I have revised all of the real world data making sure that all motor weights were correct and that all motors were run with the same ESC and TP Prolite cells. The new data can be seen here, http://www.rcxplanes.com/images/RCXP_Sm_OR_Data.pdf for small outrunners.
Or here, http://www.rcxplanes.com/images/RCXP_Lg_OR_Data.pdf for larger outrunners.

The Phoenix ESCs were setup as follows.

Cutoff Voltage = Auto Lipo
Cutoff Type= Soft
Brake Type= Disabled
Throttle Type= Auto Callibrating
Soft Start = Fast
Motor Timing = High Advance
Current Limiting = Insensitive
PWM Frequency = 13 khz.

Bud