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CranialRectosis' Polakium Engineering Super Simple H Quad (v3)

cranialrectosis

Well-Known Member
Mentor
#1
I find myself still in the grips of building frenzy and wanting to put to use all the things I have learned in recent builds. Both my Warp Quad String Theory frame and my Polakium SuperSimple Mini-Spider Hex have been rebuilt since the original flights. Still, I found myself wanting to build and its hailing on us this weekend.

Adam Polak offers a light little H-Quad copter frame that is almost as light as the WarpQuad String theory 230mm frame and has a little extra space for a camera or FPV gear if that is your thing.

This build is not for a first build and flying a copter this small is not for the novice. This frame is light plastic from a 3D printer. It will not tolerate abuse like carbon fiber and is harder to fix than wood. If you are looking for a light, acrobatic copter with a little trunk space for some FPV gear for < $70, and you are not a novice, this copter is worth looking into.

The Parts
Frame, landing struts and rollbar:
http://polakiumengineering.org/?product=super-simple-mini-h-quad-v3-sshquad-fpv
http://polakiumengineering.org/?product=sshquad-fpv-v3-landing-gear
http://polakiumengineering.org/?product=roll-bar-sshquad

Motors and ESCs:
http://shop.multirotorminis.com/EMAX-MT-1806-2280KV-EMT18062280KV.htm
http://shop.multirotorminis.com/EMAX-SimonK-Series-12A-ESC-ESimonK12AESC.htm

Flight Controller:
http://rotorgeeks.com/index.php?route=product/product&path=34_44&product_id=70

Receiver/Transmitter module:
http://www.alofthobbies.com/jr-transmiter-telemetry-module.html
http://www.alofthobbies.com/frsky-d4r-ii.html

Wire and sundries:
http://www.altitudehobbies.com/parts-and-accessories/silicon-wire


Service and delivery:
For this build, I tried shopping at three new (to me) online hobby stores, RotorGeeks , Aloft Hobbies and MultirotorMinis. All three delivered in under 5 days. Beat that Hobby King!

Final Build Weight and Photo:
Final build as of 6/8/14 is 280 grams.

037_FinalAssembly.JPG
 
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cranialrectosis

Well-Known Member
Mentor
#2
Frame, flight controller and receiver

This frame really is super simple. The main body of the frame is one piece. The landing struts and roll bar are optional and are attached by zip ties to the main body. Simple does not mean unintelligent. Adam thought this frame through. It includes counter sunk M3 sized hex shaped mounting holes for a variety of sized flight controllers. Adam included slots for zip ties in strategic places and mounting holes for a variety of motors. It will (barely) accommodate 6" rotors with the roll bar attached.

I have used the foam mounting pad and zip tie method for every build I have until the WarpQuad. Soma uses small rubber O rings on the screws above and below the FCB to mitigate vibration. I have borrowed that method here today to allow me to mount my receiver under my FCB. Note that to use the roll bar and have clearance for the voltage connector and USB ports, I have rotated my Naze 32 by 90 degrees. Naze has a command line command that makes accommodating this shift simple.
020_AssembleFCB.JPG

Recently I took jhitesma's advice and took the plunge into FrSky by buying a module and some 4 channel receivers from Aloft Hobbies. I have since ditched my Turnigy 9X receivers and FlySky module in favor of PPM and these itty bitty receivers. I can use these 4 channel receivers because in PPM, the signals for 8 channels are transmitted in channel 1. I am running 5 channels on a 4 channel receiver with 1 signal wire!

Thank you for that jhitesma.

I spent some real time looking at these new little receivers and the Naze 32 Acro. I love how the Naze 32 fits so well with the Lemon Sat receivers and am jealous and wanting a similar solution. After looking at it for an hour, I called my friend Mustang who is good at pushing me out of a box.

The result is amazing. Mustang was looking at my receiver with the little jumper on signal pins 3 and 4 for PPM mode and thinking about the three pin bind plugs you get with the Turnigy receivers and thought we might be able to line up the receiver pins with the Naze 32 receiver pins and jump them with a plug.
011_ReceiverAttached.JPG

So I built the triple jumper by clipping a 3 wire servo cable 1/4" from the connector. I pulled out the center wire, and soldered the two end wires together. I did this for three, 3 pin connectors then stacked them together with a bit of electrical tape covering the exposed wire on the center connector and heat shrinked them together.
004_ReceiverJumper.JPG

006_ReceiverJumper.JPG

005_ReceiverJumper.JPG

Then I used a bit of two sided tape to stick the receiver to the bottom of the Naze 32 so that the pins for channel 1, power and ground line up perfectly with the Naze 32 pins for power, ground, channels 1, 4, 5 and 6. Once everything was lined up, I plugged the triple jumper in. Because I removed the center wires from the jumper, channels 4, 5 and 6 on the Naze are simply covered by the plug and not used or engaged.
016_ReceiverAttached.JPG 018_ReceiverAttached.JPG

I also decided to re-work how the pins are attached to the Naze 32. I used solder wick to suck all the solder off all the vertical pins and pulled them all out. I then replaced the three pin set next to the USB with a 90 degree pin set I had. This gives me more clearance from the roll bar and a cleaner copter overall IMO.

The FCB/Receiver combo may now be mounted to the copter on nylon standoffs as one unit:
021_AssembleFCB.JPG 022_AssembleFCB.JPG

I have nylon screws in transit to replace the metal screws currently holding the Naze to the standoffs. The standoffs themselves were 20mm cut by a hacksaw, reamed out with an M3 machine screw and filed to the same length by hand. I have 10mm and 15mm standoffs also in transit. :)

Lifting the FCB and receiver up by 12mm or so gave me more space under the board and above the battery strap for cabling. I built a 1 into 6 X 2 power harness, giving me extra rails for voltage monitoring on the Naze 32 and for LED lights (also still in transit).
003_PowerHarnessAssembly.JPG
 
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cranialrectosis

Well-Known Member
Mentor
#3
ESCs and final assembly

With the main power harness built it was time to clean up the ESCs and get them ready to build. I am pretty retentive with my solder joints after having an Anycopter fall out of the sky due to a cold solder on a power distro board. I suck almost all the solder off ESCs when I get them, leaving only the capacitors stuck to the power leads before tinning them with my own solder. Here are 4 emax ESCs (red) next to a Turnigy Blue series. You can see how the emax ESCs are narrower. This keeps them from overhanging the booms making for a nicer copter and less crud in the thrust column. These also have red LEDs that shine on my booms and red boards that match my red booms. NICE!.
025_CleaningESCs.JPG

These ESCs are a bit harder to work because the pads are between the FETs. I am lucky to use a good Weller soldering station with adjustable heat and a tiny tip. As you can see, I strip the solder off the servo wire leads and then polish the whole thing with rubbing alcohol and a Q-Tip (earbud for you Aussies). The key here is to remember where to connect the positive and negative wires once all your examples are 'cleaned'. :)
026_CleaningESCs.JPG

With the ESCs cleaned and prepped, I can solder them to the power harness and then solder the motors to the ESCs. With these ESCs you need to be careful to tin the pads in the center and the motor leads. The motor leads must be trimmed and soldered in place so that when you smoosh the wires the leads don't short out. Use a hot iron with a well tinned tip and be quick about your work when in between the FETs. :)
027_AttachingMotors.JPG

With a build this tight, you end up doing a few things at once. Here I am sliding the clear heat shrink over the motor and boom and ESC while adding the double sided tape to the ESC and sliding everything into position so I may mount the motor.
028_AttachingMotors.JPG

With the motors mounted and direction tested, I am free to shrink the heat shrink and seal this up until my LED lights arrive. My name, phone number and address as well as the two antennae from the FrSky receiver all get sealed up under the clear heat shrink.

I also added the landing struts and the roll bar and zip tied the power harness and buzzer to the frame.

And here it is, the newest edition to the CranialRectosis hangar the 'LadyBug'.
030_FinalAssembly.JPG 031_FinalAssembly.JPG 032_FinalAssembly.JPG 035_FinalAssembly.JPG 029_FinalAssembly.JPG

I filmed the maiden. I can hear something rubbing and will be pulling apart the motors today. I usually do this with all new motors when I glue the leads in place, but I was in a rush and didn't get it done last night. You can also here the default PID tuning for a Naze 32 Acro warbling.

But it was a fun build and I am sure, this copter is gonna scream with a little tuning.

Thank you for reading. I couldn't have done this without the help of all the folks here at FliteTest. I would also like to send a special thanks to Mustang. The idea to make the jumper for the FrSky receiver was epic. Way to go Mustang!
 
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FinalGlideAus

terrorizing squirrels
#5
Nice work Cranial. Those ESC's look to be the same kind as the Plush 12a and use BLHeli. There a number of places using that same PCB for their own esc. The rotor geeks 12a is another version. I've heard good things about them c
 

cranialrectosis

Well-Known Member
Mentor
#7
Nice work Cranial. Those ESC's look to be the same kind as the Plush 12a and use BLHeli. There a number of places using that same PCB for their own esc. The rotor geeks 12a is another version. I've heard good things about them c
They have Simon K all over them but I have heard from two people now that these are BLHeli ESCs. The instructions show these come with plenty of options although I have not had need to alter the timing settings. I love the narrower width.
 

cranialrectosis

Well-Known Member
Mentor
#8
My pleasure, Scratch. I should have some LEDs in a few days and then I can finish and go for some flips. At my age, it is getting hard to see these little copters at 50 yards.
 
#9
Nice work Cranial. Those ESC's look to be the same kind as the Plush 12a and use BLHeli. There a number of places using that same PCB for their own esc. The rotor geeks 12a is another version. I've heard good things about them c
I've been following that line of development. They're similar, but not exactly the same. And I am coming to believe they're BLHeli indeed, just using "simon series" as a form of marketing like "kleenex" is to tissue paper here in the states.

My pleasure, Scratch. I should have some LEDs in a few days and then I can finish and go for some flips. At my age, it is getting hard to see these little copters at 50 yards.
This from the man that could see a 22 caliber hole on paper at 50 yards with his naked eye... Sense the irony, I do.
 

FinalGlideAus

terrorizing squirrels
#10
They have Simon K all over them but I have heard from two people now that these are BLHeli ESCs. The instructions show these come with plenty of options although I have not had need to alter the timing settings. I love the narrower width.
Those pcb's have Silabs chips on them (from what I can see on my phone) and those chips can't run SimonK, only BLHeli. I would think they don't know what's on it.
 

FinalGlideAus

terrorizing squirrels
#12
I've been following that line of development. They're similar, but not exactly the same. And I am coming to believe they're BLHeli indeed, just using "simon series" as a form of marketing like "kleenex" is to tissue paper here in the states.



This from the man that could see a 22 caliber hole on paper at 50 yards with his naked eye... Sense the irony, I do.
Yes they're not the same as the plush ESC's but they do seem to use the same PCB. Just they have a slightly different layout. The rotor geeks ESC's have both opto and normal layouts.
 

cranialrectosis

Well-Known Member
Mentor
#13
On a slightly unrelated yet related note, how does the 3d printed frame compare to a G10 or CF one?
I own the WarpQuad String Theory and the Polakium hex and now the quad.

The WQ can take a hit like nothing else. If you break your WarpQuad you really, really whacked it one.

My 230mm String Theory weighs 80 grams with the CF cap and all 8 nylon standoffs. My Polakium Quad weighs 92 and that includes the landing struts and rollbar. I can run 5030s on 4S or 6045s on 3S on either copter and the motor placement dimetions are almost identical so pound for pound the copters are VERY similar as far as flight characteristics. CF is RF opaque. Your fancy FPV radio transmitter and RF receiver will be subject to blackouts in flight if you are not careful with CF. Plastic has no such considerations but melts if you get the motors too hot.

The Polakium is easier to build because you have no CF finishing to deal with.

The big differences are cost, strength and real estate. The Polakium has LOTS more places to put stuff like a Mobius. It costs Vastly less to the point where you can buy two or three for one WarpQuad. For many breaks the fix is a few drops of good CA and an hour with a clamp. That's good. Because you will break the 3D printed frame FAR more often than a WarpQuad.
 

jhitesma

Some guy in the desert
Mentor
#14
Great build! I like 3D printing but I'm not a huge fan of buying a 3D printed frame unless there's a reason for it to be 3D printed other than so it can be easily produced in someones spare room. Yet I love the idea of people manufacturing things in their spare room, I'm complex :) ANd they do look like nice little copters though for those who don't share my hangup over buying 3D printed kits :D


Recently I took jhitesma's advice and took the plunge into FrSky by buying a module and some 4 channel receivers from Aloft Hobbies. I have since ditched my Turnigy 9X receivers and FlySky module in favor of PPM and these itty bitty receivers. I can use these 4 channel receivers because in PPM, the signals for 8 channels are transmitted in channel 1. I am running 5 channels on a 4 channel receiver with 1 signal wire!

Thank you for that jhitesma.
Funny thing is with the issues I'm having with my openLRS unit I'm back to using a non ppm RX again...and I miss it! PPM is so much nicer to deal with!
 

cranialrectosis

Well-Known Member
Mentor
#16
Great build! I like 3D printing but I'm not a huge fan of buying a 3D printed frame unless there's a reason for it to be 3D printed other than so it can be easily produced in someones spare room. Yet I love the idea of people manufacturing things in their spare room, I'm complex :) ANd they do look like nice little copters though for those who don't share my hangup over buying 3D printed kits :D




Funny thing is with the issues I'm having with my openLRS unit I'm back to using a non ppm RX again...and I miss it! PPM is so much nicer to deal with!
I read that. Bummer, man. I say build spares. :)
 

Balu

Moderator
Staff member
Admin
Moderator
#18
Yeah, don't leave your 3d printed parts in a car in the sun. I will make a picture of the feet of my multirotor as soon as I can.

But as you can imagine, a plastic that is heated and pressed through an extruder nozzle doesn't like it to get hot again.
 

cranialrectosis

Well-Known Member
Mentor
#19
Yeah, don't leave your 3d printed parts in a car in the sun. I will make a picture of the feet of my multirotor as soon as I can.

But as you can imagine, a plastic that is heated and pressed through an extruder nozzle doesn't like it to get hot again.
Ahh bummer, man. Check any lipos that may have been with it. Lipos don't like hot cars either. :)