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Snarls 250 Summer Quad - Performance ZMR Build

Snarls

Gravity Tester
Mentor
#1
Hi everyone, for this summer I am planning to add a mini quad to my small arsenal of RC gear. I am hoping to get pretty serious with this new quad as well as with my 550mm spider quad with gimbal. Due to it currently being my first year in college I have only been able to log a handful of flight hours since last summer. To supplement the addiction I have spent countless hours on the simulator and browsing the forums. You may have seen me commenting and asking various questions on other mini quad threads recently.

After drooling over other people's builds I have finally composed a list of components for my own 250 size build. Initially I was trying to build with $150 budget in mind, but this quickly became unlikely. My 550mm quad is built with budget parts so I thought I would go big this time and treat myself with top grade components for a performance machine. I will likely not be competing in races any time soon, but I am looking to do high speed aerobatics through natural and man made structures like Charpu, as well as start making videos. I won't be able to do anything until later in May, but I want to get some initial feedback so I can order parts as soon as they come back in stock.

Once summer hits I will transform this thread into a build log rather than starting something new.

Detailed Parts List:
Main:
Frame: ZMR 250 Composite - $24.95 - Full carbon better?
PDB: HK PDB - $1.99 Too Large
Motors: 4 X Cobra 2204 2300kv - $83.96
ESC: 4 X RotorGeeks 12A V4 - $56.00
FC: Naze 32 (vert. pin) - $29.99
Receiver: Turnigy 9X Receiver - $8.99 - Unreliable/Dangerous
Batteries: 3 X Nanotech 45-90C - $40.65
Props: 4 X Gemfan 6X3 4pc - $10.36
HQ Props: 2 X HQ 6X4.5 2pc - $6.98

Hardware:
Nylon Spacer: 5.6X13mm M3 - $0.76
Heat Shrink: 3mm/30mm - $1.60
Right Angle Coax: Right Angle Pigtail - $4.49
ESC Programmer: For RG BLHeli ESC - $15.50 - Any cheaper HK version?
Wires/Plugs: XT60s + 12AWG wire - $6.19
Lipo Bag: HK Jumbo Size - $2.94 - Trustworthy?

Added:
Module: OrangeRX DSMX/DSM2 Module - $29.99
Receiver: Lemon Satellite DSM2 - $7.50

Low Voltage Alarm? - Or TX timer?
FPV Filters?

Total Price:
$325 or 1 Textbook


Right now everything on this list will require purchasing from Hobbyking, BuddyRC, and RotorGeeks. Although I'm looking for high performance, I am trying to save money where I can - I could easily switch to Sunnyskys with Velotech ESCs from BuddyRC and save $50. If you know of any way to save money without having to purchase from a dozen vendors it is much appreciated. I am also worried about having to re-tune my PIDs when I switch from Gemfan 6X3s to HQ 6X4.5. Should I just invest in a load of HQs? Most of my concern is getting enough of the right props and whether these items will ever be in stock :p

Also huge thanks to SnowRocker88 for his ZMR250 build thread which really inspired me to get a ZMR and join the mini quad world.

Thank you everyone, I can't wait to get started!
 
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Snarls

Gravity Tester
Mentor
#2
Quick Build Summary:

MiniPartsSmall.jpg
The parts of this mini quad build, all laid out.

OpenTX.jpg
Installed a white backlight kit and built a wiring harness to flash the Turnigy 9x with OpenTX. A lot more user friendly and intuitive than the stock firmware and the beeping only occurs as an alarm. My dog is happy about that.

CutToSize.jpg
Removed the heat shrink from the ESCs and cut the motor wires to size. It is pretty scary to do this, but I think it is necessary for a lighter, cleaner build.

AllShrunk.jpg
All four ESCs and motors soldered up before one of them got smoked by accident.

PowerHarness.jpg
Soldered up power harness. This will be hidden between the two bottom plates of the ZMR frame and the main battery wires will be covered in black mesh.

Chasis.jpg
Installed the wiring harness in between the bottom plates. Main battery connection soldered up.

NazeSoldered.jpg
Pins soldered to the Naze32. Right angle pins on the bottom and facing inward to save space. Buzzer,vbat, and possibly telemetry to be added.

Almost.jpg
Naze32 installed onto the frame. JST added to the wire harness for the FPV gear. VTX and antenna added to the top plate.

NazeSoldered2.jpg
Buzzer, vbat, and satellite connection added to the Naze32.

Finished Build Pictures:
done3S.jpg

done1S.jpg

Done2S.jpg

WeightS.jpg

 
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#3
Initial Comments:

You can use the http://www.hobbyking.com/hobbyking/store/__12901__Hobby_King_2_4Ghz_Receiver_6Ch_V2.html if you are interested in a smaller RX. Or consider a module swap to DSMX and use CPPM with a LemonRx (I'm assuming you are using a turnigy 9x).

I would also consider replacing the PDB with a custom harness. If you have access to a soldering iron and heat shrink, it gives you more flexibility.

I am using the SS2204 with the Velotech ESCs and have nothing bad to say about them. They work for my LOS flying and haven't had any problems running GF 5x3 props on 3s. Save the ESC programmer for a later purchase when you upgrade ESCs. Having a spare motor and esc isn't a bad idea either.

Buy lots of props from Banggood or any other cheap supplier!

Set a timer on your TX. Or use the cheap lipo alarm and strap it fast with your Velcro straps.

Here is my build in case your interested:
http://forum.flitetest.com/showthread.php?15067-ZMR250-Quad-Build-Log-My-first-quad-build
 

SnowRocker88

Amateur pilot and builder
#4
Frame: ZMR 250 Composite - $24.95 - Full carbon better?
This may spawn an argument but I think the composite is much better. After reading threads and watching YouTube videos it seems the full carbon versions have a much greater tendency to break where the composite or full G10 frames will actually flex on impact.

I can say, regarding my own experiences, that I expected my frame to be TRASH 5 times over by now the way I've crashed it (mostly just falling from the sky from incredible heights) and haven't broken ANYTHING. It's taken enough impact to actually slot the mounting holes in the arms...but besides that it's still perfect!

The only advantage to full carbon is weight. Which equals something around 10-15 grams...not a ton of weight to be concerned about.

Also huge thanks to SnowRocker88 for his ZMR250 build thread which really inspired me to get a ZMR and join the mini quad world.
Very happy to have helped. But, really, I'm no good at anything RC yet. I'm just doing my best to compile information in an organized manner. My attempt to repay this community for all the help everyone has offered!
 
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jipp

Senior Member
#5
i spend a few bucks and just ordered a Voltage LED/Pezio buzzer to plug into the balance port on the battery. once i get a idea of flight time.

i can then setup a timer based on that. that is the direction i would go. i also am going with a lemon RX. like 5.00 on line, it is small and very light. no plastic case or anything to remove.. comes with double sided foam to stick it where you want too.

good luck on your build.. i hope to finish mine when i feel well enough.. maybe today ill feel up to working on it.

as for carbon/mix. id say go for carbon.. then you have at least a 50/50 percent getting 100 percent carbon? or maybe they have just started to use real carbon these days..

chris.
 
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SnowRocker88

Amateur pilot and builder
#6
You can use the http://www.hobbyking.com/hobbyking/store/__12901__Hobby_King_2_4Ghz_Receiver_6Ch_V2.html if you are interested in a smaller RX. Or consider a module swap to DSMX and use CPPM with a LemonRx (I'm assuming you are using a turnigy 9x).
This is the Rx I'm using. It's CPPM and VERY small. Can't really vouch for it though as I've had some receiver problems. My first one died on me. The second one seems much better. I may have just gotten a bad one initially.

http://www.hobbyking.com/hobbyking/...MX_Compatible_6Ch_2_4GHz_Receiver_w_CPPM.html

Set a timer on your TX. Or use the cheap lipo alarm and strap it fast with your Velcro straps.
Cleanflight has a feature to let the Naze32 act as a voltage alarm. Attach a buzzer and it'll beep when total voltage drops to a certain level.

Also, I recommend adding the buzzer anyways so you can make it beep if it ever flies off or crashes somewhere beyond line of sight, it's a good feature to help find it.
 

jipp

Senior Member
#7
also make sure you run your battery cable down the middle.. my kit came i with a picture of it assembled etc and showed the battery cable coming on the left side.. unfortunately this is not the best place.. but im probably the only idiot who has done this.

i would of been better off if my kit had no picture, after all it had no dang instructions..

thats cool naz suports the voltage buzz.. but i would use the small voltage led/buzz too.. and then save the buzzer on the naz for the finder thing you mention.. i just like to see numbers to make things more legit over a buzzer. heh. you can get 4 of them voltage LED/buzzer thigs for 10.00 i just paid 8.00 and got one that came in a protective casing so i could velcro it to something.. and give it some protection from rocks my biggest fear living in the desert.

chris.
 

SnowRocker88

Amateur pilot and builder
#8
i spend a few bucks and just ordered a Voltage LED/Pezio buzzer to plug into the balance port on the battery. once i get a idea of flight time.
I really like these too. Especially if you get a LiPo that's pretty worn out, it'll check individual cell voltage and let you know if one of them dips. I have a LiPo now with a cell going out and one will hit 3.3v when the other two are 3.6v.

thats cool naz suports the voltage buzz.. but i would use the small voltage led/buzz too.. and then save the buzzer on the naz for the finder thing you mention.
You can run both the voltage warning and the switched beeping. It's two different tones as well. Really a cool feature.

I'm all for running the battery checkers tho. Nothing will ever be as good as the individual cell checking that the battery checkers give you.
 
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Snarls

Gravity Tester
Mentor
#9
Thanks for the responses guys. I am definitely going to upgrade my 9X with a DSMX/DSM2 module later, but for now I think I'll stick with the proprietary receiver so I can use it on my planes later. offaxis, there was discussion whether a harness or PDB was more prone to interference issues. I'm leaning towards making a harness, but I'm picking up a cheap PDB if I change my mind. As for the voltage alarm, i like the capability of the Naze to have its own buzzer so I'll likely get one of those. I do have a hard case alarm that gives cell voltages, but I'm afraid its going to hog the balance port and most of all it makes an ear piercing noise every time you plug it in.
 

SnowRocker88

Amateur pilot and builder
#10

jhitesma

Some guy in the desert
Mentor
#11
I would STRONGLY advise against using the stock 9x RX's on a multi. Why? Because they don't have a usable failsafe. If they loose signal then they stick on the last settings received.

If you really don't want to upgrade your TX module to use something else then I would suggest a DIY RX as they're the only option for the FlySky protocol that supports failsafe. As an added bonus you get PPM (and RSSI is in testing as well.)

They're not hard to make, all you need is an arduino pro mini and an A7105 RF module both available on ebay. The arudino's will run about $2-$3 from China and the A7105's start at that same price but can go up to $10-$15 if you want the ones with an external antenna. I've been using the RF modules with built in antenna and for park flying they've had plenty of range so far. I suggest going with a 16mhz 3.3v arduino - they're a bit harder to find but work best for this application because you need 3.3v to run the A7105 but you also need 16mhz to do PPM output.

If you're not up for making one your self shoot me a PM and we'll see if we can work something out as I'd hate to see you loose your quad to a flyaway due to lack of failsafe and I have the bits to whip another one or two up on hand. Flysky isn't the most bulletproof protocol so signal loss is always a possiblity and failsafe really is all but required on a multi.
 

SnowRocker88

Amateur pilot and builder
#12
I would STRONGLY advise against using the stock 9x RX's on a multi. Why? Because they don't have a usable failsafe. If they loose signal then they stick on the last settings received.
Wow. The sinking feeling of your quad just flying away because your Tx's batteries died...ugh. That would SUCK!
 

jhitesma

Some guy in the desert
Mentor
#13
Wow. The sinking feeling of your quad just flying away because your Tx's batteries died...ugh. That would SUCK!
Or because someone turned on a high power WIFI and jammed your signal. Or because FlySky protocol glitched. Or as what happened to me a wire broke....

Which reminds me. Don't forget to put your name and contact info on the frame in a way that can't wash off in the rain. I had only done it on mine because I was flying openLRS and legally you need to have your callsign on the craft when operating in the ham bands like that...but it was what brought my quad back to me 2 days after it flew away when someone found it and gave me a call saying they had found it!

A Dremel engraving tool can be had for <$20 and works well for etching your contact info into CF permanently.

Harbor Freight has one for <$10: http://www.harborfreight.com/electric-engraver-46099.html

But I've had my Dremel engraver for over 25 years and it was my dads for a few years before he gave it to me...it still works great. (He gave it to me before I went to college so I could mark all my electronics and computer gear in case something happened to it. Ever since I've pretty much engraved my callsign or name or SSN into almost everything I'd like to have a chance of getting back if it was ever stolen.) Once you have an engraver it's amazing how many uses you find for it :D
 
#14
nice im building an emax might hawk with fpv this summer right after i get back from visiting family in India i would build it there but my cousins will fight over it and if the quad breaks that's 415 bucks down the drain also its illegal to fly in India
 

jipp

Senior Member
#15
I would STRONGLY advise against using the stock 9x RX's on a multi. Why? Because they don't have a usable failsafe. If they loose signal then they stick on the last settings received.
i have experiece this los single fly away thing with the blade nano.. and it sucks not being able to do anything.

you speak of fail safes.. is it the TX/RX He is going to use that is the problem/

i will be using a DX6i.. ( found one for less than a dx5e.) and i was gonna use a lemon 6ch DSMX.. RX.

do i have to have a special RX? im confused now.. i thought fail safe was something you did in the software..
im glad i have not felt well enough to work on it even tho i have the parts here.. this could of been bad for me.. i cant afford a flyaway.. heh. but it would be a good excuse to start over from what i have learn.. i know i would do a lot of things different and just source my parts now i know what is consider the standard for high quality/god price. rotogeek ESC for example over the emax simon series. but hey that shows im learning, so BONUS.. now i just have to get to feeling better, sucks having p oor health.. you mentally just don't care some times..

i did look at some that said sat light capable was not sure what the meant.. if you think i would be better off using a different RX, i will buy one.. no point trying to save money on a item like the RX.
chris.
 

jhitesma

Some guy in the desert
Mentor
#16
Failsafe is a function of the RX and the flight controller.

Failsafe in the RX will let you either set it to go to whatever settings you program it for when it looses signal - or drop the channels to 0. The flight controller then gets setup to watch for that and does it's failsafe routine when RX signal is lost. Usually it will drop the throttle to a level just below idle for a short period of time and then cut power completely. Depending on the build and how you're using that can be setup to try and give a semi-controlled landing. Or on something like a 230 acro build cut power immediately and let it fall from the sky since it can disappear so quickly :)

I don't really know spektrum RX's that well. I have a lemon 6ch here and I'm pretty sure it has failsafe...but to be honest I've only ever used it to bind the sat receiver :) The lemon sats will drop all channels to 0 on loss of signal.
 

Snarls

Gravity Tester
Mentor
#17
Thanks for the concern jhitesma, it really got me searching last night. I don't want to burden you with making a custom RX and I think a better long term solution would be making some room in my budget to upgrade my 9X now. Right now I'm looking at this Orange module along with a Lemon receiver. Does this 6ch Lemon have a failsafe, or should I go with this one which appears to come with a satellite. Also I'm concerned that the antenna sticking out the back of the module will cause some problems when setting the TX down so I'm thinking of getting an extension pigtail to route the antenna closer up top (ignore the SMA male/female).

Also fell better jipp! You will have a good time with your build don't worry about it.
 

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
#18
Snarls,

Go with the lemon sat only.

You'll have to be careful wiring it up (it doesn't like 5v, but there is 3.3v on the board it will like), and you'll have to play with cleanflight to get it to bind (but it can without a full RX), but it's a small package that you can mount nearly anywhere and you'll only need the three thin wires for power/ground/signal -- not the whole harness.

As for failsafe, satellites are perfect -- a satellite only reports what it heard. If it stops hearing reports (somehow lost the link), it stops talking to the Naze, and it won't take but a split second for the Naze to realize it and start deciding how long it wants to fly without a master (failsafe).

the Failsafe.md doc covers the settings, and I'd recommend giving failsafe_delay at least one second (10), failsafe_off_delay no more than 5 seconds (50, but I'd recommend 0 -- I prefer to play it safe and repair opposed to risk loss/injury). failsafe_throttle you'll have to set for yourself, but you'll have to take care it's well below hover . . . or your failsafe will make it worse.

These should all be in the configuration tab of Cleanflight, but for the life of me I can't get a pic up to verify these are how they're labeled :p
 

SnowRocker88

Amateur pilot and builder
#19
Snarls,

Go with the lemon sat only.

You'll have to be careful wiring it up (it doesn't like 5v, but there is 3.3v on the board it will like), and you'll have to play with cleanflight to get it to bind (but it can without a full RX), but it's a small package that you can mount nearly anywhere and you'll only need the three thin wires for power/ground/signal -- not the whole harness.

As for failsafe, satellites are perfect -- a satellite only reports what it heard. If it stops hearing reports (somehow lost the link), it stops talking to the Naze, and it won't take but a split second for the Naze to realize it and start deciding how long it wants to fly without a master (failsafe).
This is new. So Cleanflight can handle running just a satelite and that's it? So effectively it'll run without a 'receiver' and just with a satelite plugged into the FC?!? If that's correct, that's wild!

the Failsafe.md doc covers the settings, and I'd recommend giving failsafe_delay at least one second (10), failsafe_off_delay no more than 5 seconds (50, but I'd recommend 0 -- I prefer to play it safe and repair opposed to risk loss/injury). failsafe_throttle you'll have to set for yourself, but you'll have to take care it's well below hover . . . or your failsafe will make it worse.

These should all be in the configuration tab of Cleanflight, but for the life of me I can't get a pic up to verify these are how they're labeled :p
It seems the alternate opinion is that zero throttle for failsafe is preferred. It's ultimately the route I chose to go with. Instead of risking it drifting into something or someone, I'd prefer it just fall out of the sky. Then again, I'm not flying that high yet either.

Is the theory that it will have a controlled decent long enough to, hopefully, regain control/signal and recover?
 
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Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
#20
This is new. So Cleanflight can handle running just a satelite and that's it? So effectively it'll run without a 'receiver' and just with a satelite plugged into the FC?!? If that's correct, that's wild!
It's actually an old feature of the Naze, but it's only recently picked up the ability to throw the RX into bind mode. Neat add-on to it: with the standard parallel input you're limited to 6 channels in, and less if you use servos. With the sat, you get as many channels as your radio can support -- have a DX9, you can get all 9 in :)

It seems the alternate opinion is that zero throttle for failsafe is preferred. It's ultimately the route I chose to go with. Instead of risking it drifting into something or someone, I'd prefer it just fall out of the sky. Then again, I'm not flying that high yet either.

Is the theory that it will have a controlled decent long enough to, hopefully, regain control/signal and recover?
Effectively it's the same thing -- either set the timer to 0 and it switches tot eh dead mode immediately, or set the throttle to 0 and that phase kills the motors. No harm in setting both to 0 though.