Mustang7302's Polakium SSHQuad v3 Build Log

[jhitesma]

Just curious...how long did the order from RTFQ take? I've been seriously considering some motors from him but with his warning that they won't ship for at least a week and my experience with my last order taking a week from when he shipped to get to me it has me leaning towards just ordering from RCtimer instead since it will probably take about the same time to ship from overseas. But if he's actually getting motor orders out quicker.....

 

[Mustang7302]

Just curious...how long did the order from RTFQ take? I've been seriously considering some motors from him but with his warning that they won't ship for at least a week and my experience with my last order taking a week from when he shipped to get to me it has me leaning towards just ordering from RCtimer instead since it will probably take about the same time to ship from overseas. But if he's actually getting motor orders out quicker.....

The RTFQ order was placed the evening of 4/17, shipping label was created the morning of 4/21, the package was moving through the mail on 4/23, and the package was delivered on 4/25. Not good service, but I did get an order from him this time.

What motors are you looking at getting?

 

[FinalGlideAus]

Cool looking Quad Mustang!

 

[jhitesma]

I've been looking at his Red Specials and his flip standard Just not sure how well they'd do with 8" props being lower KV than what I've been running. I've been experimenting with ecalc but have too many guesses on some numbers to trust what I'm getting out of it.

The RCTimer motors still seem like the best bang for the buck I've just never ordered from them and while I haven't heard anything bad they're still in HK so I'm sure the order will take a long time.

Seems like most of the suitable motors I'm finding are lower KV and I can't really go up in prop on my current setup. So I may hold off and just step up to some SunnySky's and a new frame that will handle 10" props since I do want something bigger and more stable for better video. Still I'd like to find something affordable in the 1400kv 150watt range for my knuckle so I can use it as an acro and FPV fun flyer....Being on a budget sucks - if I didn't have to deal with that I'd have a lot more options

 

[Mustang7302]

I put the Polak on the bench, weighted it down, and watched the telemetry as I ran up the throttle. At full throttle the total combined current was 16.5 amps, so we're looking at maximum of 4A per motor spinning these 5030 props. I think 6030 props might be in the future at some point...

Cool looking Quad Mustang!

Thank you .

I've been looking at his Red Specials and his flip standard Just not sure how well they'd do with 8" props being lower KV than what I've been running. I've been experimenting with ecalc but have too many guesses on some numbers to trust what I'm getting out of it.

The RCTimer motors still seem like the best bang for the buck I've just never ordered from them and while I haven't heard anything bad they're still in HK so I'm sure the order will take a long time.

Seems like most of the suitable motors I'm finding are lower KV and I can't really go up in prop on my current setup. So I may hold off and just step up to some SunnySky's and a new frame that will handle 10" props since I do want something bigger and more stable for better video. Still I'd like to find something affordable in the 1400kv 150watt range for my knuckle so I can use it as an acro and FPV fun flyer....Being on a budget sucks - if I didn't have to deal with that I'd have a lot more options

Take a gander at the Suppo 2212/40 1400KV 180W Motors or the Suppo 2208/14 1450KV 130W Motors from Altitude Hobbies. Perfect for a 8" prop on 3S for the size/weight of your quad. Cranial runs the second option on his Knuckle Quad, Bat Bone, and Any Copter Quad. AH also has a good assortment of props to choose from. Above all you'll have the order to your door in two to three business days.

 

[jhitesma]

Take a gander at the Suppo 2212/40 1400KV 180W Motors or the Suppo 2208/14 1450KV 130W Motors from Altitude Hobbies. Perfect for a 8" prop on 3S for the size/weight of your quad. Cranial runs the second option on his Knuckle Quad, Bat Bone, and Any Copter Quad. AH also has a good assortment of props to choose from. Above all you'll have the order to your door in two to three business days.

Yeah, I've seen those...but the RCTimer motors still look like more bang for the buck. Fast shipping isn't as important to me as good price and AH's prices are just a bit higher than I can really pay right now. RTFQ has slower than overseas shipping but at least their prices are more in line with overseas shopping as well. If I get into the $15+ range for motors I'm looking at just going $20 each and getting some lower KV SunnySky's and a bigger quad...unless I find something in the $15 range that can exceed the RCTimers for $10 each. (I'd also rather see a bolt on prop adapter than short shaft if I go to $15 or above. At $10 I can live with it but if I'm paying more than that per motor I'd rather have something a bit more robust.)

 

[cranialrectosis]

My only order from RCTimer took 4 weeks. True I ordered using the cheapest shipping method, but I still didn't expect canoe...

If you go RCTimer, pay for better shipping or have another project on the bench.

I am eager to hear that RTFQ is catching up on orders. His selection is choice. If you go that route, please let us know how it goes.

 

[Mustang7302]

Yeah, I've seen those...but the RCTimer motors still look like more bang for the buck. Fast shipping isn't as important to me as good price and AH's prices are just a bit higher than I can really pay right now. RTFQ has slower than overseas shipping but at least their prices are more in line with overseas shopping as well. If I get into the $15+ range for motors I'm looking at just going $20 each and getting some lower KV SunnySky's and a bigger quad...unless I find something in the $15 range that can exceed the RCTimers for $10 each. (I'd also rather see a bolt on prop adapter than short shaft if I go to $15 or above. At $10 I can live with it but if I'm paying more than that per motor I'd rather have something a bit more robust.)

Here is the 1450KV 130W option for $3 less and still from a US supplier: http://www.buddyrc.com/golden-a2208-14-1450kv-brushless-motor.html

 

[Mustang7302]

So I have had the weekend to do a bit of flying; and crashing. There have been three major crashes so far.

1.) While the Yaw P gain was too high, the copter would shoot upwards coming out of a spin. The more aggressive the spin, the higher it would shoot up. Battling 15 to 25 MPH winds all weekend, one of the balloning up motions was caught by the wind like a kite and was being carried down wind faster than I could reorient myself. I chopped the throttle and it fell from 25 to 30 feet up. Thud. No damage, not even a bent prop.

2.) Working on coordinating throttle cuts with flips and rolls, I miss timed my inputs and it dove face first into the ground under power from 15 feet up. Splat. Bent a couple of props and sheered a blade off of another.

3.) Even though I had sorted out the Yaw P Gain issue and it no longer ballooned, the craft was still being carried down wind faster than I could reorient my self. Chop the throttle again from 15 feet up. Pow! A motor popped off the frame and bent a prop. Motor went right back on with new hardware, no idea how locktite'd screws disappeared. This motor might have a damaged bearing now as it make a humming noise at low RPM.

This build by far has met all of the things I had hoped for in a small, acrobatic, bashing around quad. The frame is exceptionally durable and rigid. The frame has a lot of nice little features to help keep things tidy. The motors make ample power, even on small 5030 props. The ESCs are quick, smooth, and respond very well to the Naze's commands. The Naze makes the craft so locked in and exhibits no drama in bumpiness or oscillations; even when flying in 25 MPH winds. The Naze on this Polak build handled the wind way better than the DJI Naza M-Lite in my F330 this weekend, which I found to be quite a surprise.

For giggles I put one of my Zippy Compact 2200mAh 3S 20C batteries on the Mini Panda. I found that it took about 7A to hover (versus 5A), which put the throttle at 50% throw to hover. It consumed 1100mAh of capacity in 9 minutes (versus 12), but it did have a total run time of 16 minutes. The extra 60 grams makes a bit of a difference after all in comsumption, especially when it is 15% more than the normal AUFW of 390 grams.

 

[cranialrectosis]

The demon wind...

 

[Mustang7302]

Here is the current Naze32 settings I run for general cruising, swooping about, and flips/rolls in Horizon mode:

 

[FinalGlideAus]

One thing that might be worth trying is to remove the expo on the Naze and put it on the elevator and aileron in the TX. The expo in the Naze puts expo over the rudder as well. Doing it in the TX will allow a snappier rudder and you can dial down the YAW rate. If more twitchiness is needed you can always plug in negative expo on the TX for the rudder. I've done that with about -30% and it's much better.

Also, what's your looptime set at?

 

[Mustang7302]

Looptime is set to default, which is 3500. What is looptime and is there a value more beneficial?

I have considered moving the expo to the transmitter, but I am still learning the Taranis. I've already learned so much trying to not to overwhelm myself and forget little things.

 

[FinalGlideAus]

Lol yeah, baby steps. Change one thing and go fly. Change one thing and go fly. Doing more than that can confuse what is helping and what is not. Basically looptime it is the frequency that the FC calculates things. Lower looptime= higher frequency. Instead of putting it in my own words I will cut and paste an explanation of it from a local guru here in Brisbane. Be right back. For reference, I have set my looptime to 2500 and has allowed my P gain to be increased .7 and. D gain to be increased by 12.

 

[FinalGlideAus]

Sorry I took so long. This is from Scotti who is a bit of genius. He also knows Timecop who makes the Naze 32. He also designed the mini H racing quad before the Blackout was around but that is before my time. His designs are free to download here on this website so if you have acess to a CNC much fun can be had. A lot of guys here fly these using cheaper fibreglass and call them "whiteout quads".
http://untestedprototype.com



Looptime for the Naze32/Multiwii platforms is the delta between each call of the main control loop. If your hardware is capable of having a low loop time (high refresh rate), then you have a whole lot more controller bandwidth. The more controller bandwidth (faster refresh rate), the better the estimation of the current state and the more frequently it adjusts itself. The reason we flash our ESCs with SimonK is so that we can get more bandwidth for our actuators. Stock ESCs usually have lower bandwidth because that is all they would need for the original expected application. They only needed to change as fast as you were moving the sticks.

So, this implies that a lower loop time is better (it is), however, increasing the loop time is like adding a low pass filter. It will increase the rejection of higher frequency components, caused by motor vibrations that you typically want to filter out. Alternatively, you could sample at a very high rate and then apply filtering in software. The Multiwii software (which the Naze32 forks from) implements very rudimentary filtering because the original hardware just didn't have the processing power. The CC3D for example, has a very high refresh rate of the control task, and sensor sampling tasks, then software filters are used on this data to try and reject noise from vibrations.

Now, the smaller forces on a smaller quad mean that the mechanical system has a higher bandwidth than that of a larger quad. You want to be able to measure the quad at a much faster rate than it can move. This means that you will benefit in stability by reducing the loop time (increasing refresh rate) to capture the dynamics of the smaller mechanical system. As long as you deal with the vibrations that the larger loop time is filtering out!

 

[Mustang7302]

Interesting. The more I learn about the Naze32, the more I am amazed by its versatility.

This build flies so well I am reluctant to update firmware (there is a April 2014 build from what I understand, no idea what it changes) or tinker with things like refresh rate. I have to stress just how smooth the Mini Panda handled even 25 MPH winds; no oscillation, no warbling, plenty of power to go up wind, and execute flips and rolls like it was in a controlled environment. The "stick scaling" is turned up a little warm, which isn't for a novice (or casual Naza pilot), but it makes for great LOS swooping around and flips/rolls.

Watching the Naza struggle a lot with the wind this past weekend has started to make me reconsider my FPV craft of choice...

 

[cranialrectosis]

jeeeeeez I have a lot to learn....

 

[FinalGlideAus]

Naza pilots only love Naza because they've not tried anything else . Go fly and enjoy the quad but when you get comfortable get back to tuning because if you think it's solid now, you'll be amazed at how much further it will go. It's a fantastic little FC.

You and me both Cranial lol.

 

[Mustang7302]

If anyone had an interest in scratch building a mini quad, it looks like GetFPV looks like they just got a batch of the RCX 1804 2400KV motors in stock: http://www.getfpv.com/rcx-1804-2400kv-micro-brushless-motor-cw-thread.html.

 

[Mustang7302]

Took the Mini Panda out for a couple of batteries after I got home, even got some video from the hat cam. Enjoy.