B400 Motor Replacement - Scorpion 2221-6

[skigolfmike]

My Blade 400 has been begging for a little more power since I put on the Thunder Power CF blades. I've played around with gearing, different ESCs and the E-Flite CF blades and nothing has been satisfactory. Well, I finally got my hands on a Scorpion 2221-6 4400kV motor, so here we go.

The plan is to use my CC35 ESC in governor mode, mostly to prevent over-speeding the head. The headspeed calculators show 3000 for this motor with a 10T pinion at 90% efficiency, so, based on past experience, I figure I can run 2800-2900 in gov mode and have enough head room for punch-out and 3D. I expect flight times to shorten from 5:30-6:00 to about 4:30. I may also need better batteries for this to work too.

So, it looks like I have a little work to do on the B400. I need to change the motor and speed control, which will require a little soldering since I have to tie the ccBec into the Deans. Plus, the Scorpion needs a 3.17/3.2mm pinion, plus there is no flat on the output shaft. I can probably drill out a B400 pinion and grind a flat on the shaft with a Dremel.

I will post pics and follow-up as I go along.

[skigolfmike]

It took a little figuring out. The shaft on the motor is a 3.17mm, or .127" , so I opened up a Blade 400 10T pinion w/ a 1/8" (.125") drill. I also had to dremel a flat on the shaft for the set screw.

There are 2 sets of holes on the bottom of the motor with 2 different spacings. One fits the B400 motor mount, the other is wider. I used the holes that lined up with the B400 motor mount; however that put the wires exiting the motor on the wrong side of the heli. I ended up mounting the motor that way and routing the wires through the normal hole in the frame.

As you can see, this motor is much bigger than a stock B400 motor. Some of it's the fan on the top of the motor, excluding the fan the motor is still a little bigger. Also, the magnets in this motor are something else compared to the stock motor.

I did get the CC35 setup again and I spooled the heli up. It has a completely different sound with this motor. Tomorrow, I'll put it back in gov mode and finish setting it up.

[sokal]

My Blade 400 has been begging for a little more power since I put on the Thunder Power CF blades. I've played around with gearing, different ESCs and the E-Flite CF blades and nothing has been satisfactory. Well, I finally got my hands on a Scorpion 2221-6 4400kV motor, so here we go.

The plan is to use my CC35 ESC in governor mode, mostly to prevent over-speeding the head. The headspeed calculators show 3000 for this motor with a 10T pinion at 90% efficiency, so, based on past experience, I figure I can run 2800-2900 in gov mode and have enough head room for punch-out and 3D. I expect flight times to shorten from 5:30-6:00 to about 4:30. I may also need better batteries for this to work too.

So, it looks like I have a little work to do on the B400. I need to change the motor and speed control, which will require a little soldering since I have to tie the ccBec into the Deans. Plus, the Scorpion needs a 3.17/3.2mm pinion, plus there is no flat on the output shaft. I can probably drill out a B400 pinion and grind a flat on the shaft with a Dremel.

I will post pics and follow-up as I go along.
not fair ski i wanted to mod the 400 with the -8 v2 and the 45A esc and some 25c batts
(sigh) i bet she will scream with power:Bang

[skigolfmike]

The -8 motor will probably work fine too. I think you'll need an 11T pinion to make it work though. Better batts is probably going to be a necessity. I set up gov mode and did a short test hop before going to work this morning with the stock battery. It's still a little short on power. I'm guessing it's the batteries.

For the test hop this morning I first set the headspeed at 2850 in gov mode. I had it pushing 3000 easily, but decided to back off a little. I was pretty pleased with the way the cc35 and the -6 played together. No tail kicks or oscillations, and I didn't need to mess with the gyro. The stock motor didn't work as well with the cc35 and I never found a combo that I really liked. With the -6 it was real steady in hover and slow flight maneuvers. I did one punch out and it bogged, but I'm thinking the stock battery doesn't have enough punch for this combo.

I'm going to try it later today with the TP 2100 ProLites. The 2100s are only 15C though, but they always had more punch than the stock E-Flite batts. If that doesn't work I will try a TP extreme V2 25C 2200. That should give it some punch. Since I have a lot of flights on my batts it might also be they have lost their punch, so I might need new batts anyway.

With a 3.17mm shaft (1/8th") running a 9T on these motors is out of the question. There wouldn't be enough of the pinion left with a hole that big in it. 10T and 11T will be OK. Bigger than 11T won't work since there isn't enough adjustment of the motor mount in the frame.

According to the headspeed calculator, with 4400kV and 90% efficiency I should see just over 3000 rpm. Typically the headspeeds I see are in the 95% efficiency range, which works out to 3200. The -8 is a 3595kV motor, so it needs an 11T to turn 3000.

I'll post a video if and when I get it sorted out.

[sokal]

The -8 motor will probably work fine too. I think you'll need an 11T pinion to make it work though. Better batts is probably going to be a necessity. I set up gov mode and did a short test hop before going to work this morning with the stock battery. It's still a little short on power. I'm guessing it's the batteries.

For the test hop this morning I first set the headspeed at 2850 in gov mode. I had it pushing 3000 easily, but decided to back off a little. I was pretty pleased with the way the cc35 and the -6 played together. No tail kicks or oscillations, and I didn't need to mess with the gyro. The stock motor didn't work as well with the cc35 and I never found a combo that I really liked. With the -6 it was real steady in hover and slow flight maneuvers. I did one punch out and it bogged, but I'm thinking the stock battery doesn't have enough punch for this combo.

I'm going to try it later today with the TP 2100 ProLites. The 2100s are only 15C though, but they always had more punch than the stock E-Flite batts. If that doesn't work I will try a TP extreme V2 25C 2200. That should give it some punch. Since I have a lot of flights on my batts it might also be they have lost their punch, so I might need new batts anyway.

With a 3.17mm shaft (1/8th") running a 9T on these motors is out of the question. There wouldn't be enough of the pinion left with a hole that big in it. 10T and 11T will be OK. Bigger than 11T won't work since there isn't enough adjustment of the motor mount in the frame.

According to the headspeed calculator, with 4400kV and 90% efficiency I should see just over 3000 rpm. Typically the headspeeds I see are in the 95% efficiency range, which works out to 3200. The -8 is a 3595kV motor, so it needs an 11T to turn 3000.

I'll post a video if and when I get it sorted out.
the -8 has a much better torque and virtualy no bogging

[skigolfmike]

My initial testing has proved to me, beyond a shadow of a doubt, the stock batteries are not adequate for this motor. After 4 minutes they are smokin hot and that was 4 minutes of hover. I only put back in 1300mAh, so I didn't over discharge the batts. I think the motor is pulling too much current for the stock batts.

My testing got delayed due to a crash caused by a servo failure. Got it back together and should have more results soon.

[JustPlaneChris]

My initial testing has proved to me, beyond a shadow of a doubt, the stock batteries are not adequate for this motor.Not much of a surprise there! Kinda makes one wonder if the batteries might have been your limiting factor all along, and you didn't really need that big honkin Scorpion. :)

[skigolfmike]

That very well could be. There are a lot of flights on those batteries, so it might have something to do with it.

The TP ProLite 2100s are better. They don't get as hot and they have better punch. I have a FP 2170 EVO 25 I'm going to try. That should have all kinds of punch.

[Ti RX-8]

Perhaps a CC35 isn't quite enough ESC as well. How many Watts is that 2221-6 rated at?

[skigolfmike]

Specifications Scorpion 2221-6

Stator Diameter ............................ 22.0 mm (0.866 in)
Stator Thickness ........................... 21.0 mm (0.827 in)
No. of Stator Arms ................................................. 9
No. of Magnet Poles ................................................ 6
Motor Wind ............................................ 6 Turn Delta
Motor Wire ...................... 20-Strand 0.21mm (31 AWG)
Motor Kv ........................................... 4400 RPM / Volt
No-Load Current (Io) ................. 2.89 Amps @ 10 volts
Motor Resistance (Rm) ............................. 0.016 Ohms
Max Continuous Current ............................... 52 Amps
Max Continuous Power ................................ 525 Watts
Weight .......................................... 79 Grams (2.79oz)
Outside Diameter .......................... 27.9 mm (1.097 in)
Shaft Diameter ............................. 3.17 mm (0.125 in)
Body Length ................................. 33.6 mm (1.323 in)
Overall Shaft Length ...................... 57.0 mm (2.244 in)


Specs for CC35
Part # PHX-35
Retail Price $99.95
Volts w/BEC12.6 max
Volts NO BEC19.2 max
Lipo Cells w/BEC3S max
Lipo Cells NO BEC4S max
NiCad or NiMh Cells w/BEC12 max
NiCad or NiMh Cells NO BEC16 max
Continuous35 amps
Switching Rate Programmable(11, 22, or 41 khz)
Resistance 0.0045 ohms
Brake Yes
Reversible Yes - change any two wires
Low VoltageCut-off Programmable
Size 0.95 x 1.72 x 0.4"
Weight (w/wires) 0.9 oz (24.5g)
Connector Type Universal

IMHO, I'd say the CC35 is OK for the following reasons:

The stock motor pulls about 12-14A in hover. The Scorpion is certainly going to pull more amperage, but I bet it's probably about 16-18A.

The ESC can handle 35A continuous. I'm guessing it can handle 45A bursts. As light as the B400 is I doubt it pulls much more than that. There also is programmable current limiting in the ESC, I think I have it set on normal right now. I've run it on insensitive and disabled in the past.

The CC35 works on a TRex 450 with this motor and it's a heavier bird, with more amp draw. The CC45 is definitely enough.

I've done a series of 4 minute hover flights so far. The E-Flite 1800 stock batteries are at 150*F at 4 minutes. Takes 1300mAh to charge. The ThunderPower 2100 ProLites are at 120* at 4 minutes and took 1400mAh to charge. Punchouts with both batts saw a drop in head speed. The TP 2100 PLs recovered the headspeed faster. I have not tried the Flight Power 2170 35C battery yet.

The fact that the TP 2100s used more capacity to me means they have the ability to handle higher amp draw. That's not a big surprise because the stock ESC and Motor has more power with these batts than stock. I also think there is more performance to be gained by tweaking the CC35 settings too.

I should have more info after this weekend, assuming I get to fly.

[JustPlaneChris]

I hate to be "Mr Gloom and Doom", but I see much magic smoke escaping in your future. ;)

First, some math: 1400 mah in 4 minutes is an average current draw of 21 amps. You are on the ragged edge of what those Prolites will handle. When you put the 25C packs in, your current draw will likely increase again (as will your headspeed) and something's going to give. I remain convinced that the lack of power you were experiencing was poor batteries, and not due to a lack of power output ability from the stock motor. The fact that you didn't see a monstrous leap in performance with a motor that is capable of nearly twice the power output of the stock motor backs up that theory. If it were mine, I'd put the stock motor back on and try flying it with a known good battery, and save that monster Scorpion for a heli that really needs that kind of power. But hey, that's me. :)

[hamslice]

you definitely need very good batteries to keep up with that motor. i had to throw on a cc45 amp speedy also. the -6 is a power hungry beast. i would recommend getting 2500mah 25c rated batteries and that little blade will scream.

[skigolfmike]

I hate to be "Mr Gloom and Doom", but I see much magic smoke escaping in your future. ;)

First, some math: 1400 mAh in 4 minutes is an average current draw of 21 amps.

I got in a flight tonight with the Flight Power 2170 25C batts and only used 1150mAh in 4 minutes. Plus the batteries, motor and ESC were cool. That's 17.25A average. The 25C batts can easily take that. Looks like I can fly these safely for at least 5 minutes.

Basically, the stock E-Flites aren't going to work with this combo and the TP 2100 ProLites could be marginal. I still don't have the governor set right. I think the gain is too low which is causing a problem in the tail, especially on punchouts. I'll try to get out tomorrow morning with my lap top and play with the ESC settings a little.

[hamslice]

i wouldnt even bother with gov mode. just set a flat throttle curve and be done with it. you could even run a small v curve but i have had the better results with just running a smaller pinion and flat 100% throttle.

[skigolfmike]

I might have to do that. Unfortunately, I cannot go to a smaller pinion on that motor. The reason for using the governor was to control the head speed; however, I could do it with a flat or V shaped throttle curve. I'll have to keep playing to see what works the best.

[skigolfmike]

It took a little more playing with the ESC settings, but I got it working a lot better. First of all I had to switch to the 1.56 Beta version of the software. Then I ended up running high gain (80%). With this setup RPM chasing by the governor was minimized and there is just an occasional hint of a tail kick. There is a little RPM loss when I hammer it, but it recovers quickly without over-speeding.

Power with this motor is outstanding. It's good even with the TP 2100 ProLites. It's even better with the FP 2170 EVO 25. On a 4 min flight w/ mild 3D I'm putting in 1200-1300mAh, so that's not too bad.

I do need to get the new gears to speed up the tail. It doesn't have enough power to overcome the torque of the motor on punchouts. Not a big deal for most maneuvers though because there is so much power that I'm not moving the collective much.

As far as letting the magic smoke out, I'll be fine with FP 2170 EVO 30s. The TPs will be fine for 4:00 flights. The stock batts - no way. The FPs barely fit under the canopy and it takes some wiggling to get the canopy on.

Speaking of letting the smoke out. I did smoke the motor in my Gaui 550 this weekend. It happened in flight, so I got to do my first auto. Fortunately, I've been practicing those on the sim, so I got it down OK.

I'll try to post some video when I get a chance. Got to find a camera person.