Not your normal ZMR 250 build

by bluefishnz | November 25, 2014 | (9) Posted in Projects


This all started with me wanting to try out a mini quadcopter, well it is the crazy at the moment right.  I first started with a FPV250 from Hobbyking and and some RCX1806 motors with Turnigy 12amp plush ESC's running a Naze32. After an untidy build, there is no room on that frame, I got flying. It took me a while to adjust and tune for a mini quad. So after some pretty hard crashes and broken parts I got an ok flying quad.

Of course I then proceeded to push and had a very hard smack into the tarmac.... I failed to pull out of a triple flip ... It was not pretty.

So this lead me to searching for a new frame, ESCs, Motors .... on a budget still. This lead me to the ZMR250. For $30US I didnt think you could go wrong.

So I embarked on a ZMR250 build, after some trial and tribulations I got a nice little quad build. But I also wanted an acro frame seperate from my learner FPV mini quad. I didnt want to have all my FPV gear on a frame that I was doing line of sight acro learning.

So I ended up with 2 ZMR250 mini quads, both following the same objectives. One is a carbon fiber frame and the other a silver glass fiber frame. 

Below I have documented the main differneces to my build of the ZMR over the standard build, which is mostly the inclusion of alloy stand offs and the 3D designed and printed parts. There are plenty of good documented builds the normal way. A few linked below. No need to reinvent the wheel

Builds and reviews for reference


With all my builds I try and do them as tidy as possiable so I had a few objectives.

  • Clear arms, ESC's inboard (required spacers)
  • Lights for night flying (3D designed & printed light bars)
  • Arm protection, as I fly mostly over tarmac (3D designed and printed parts)
  • Slim profile, I dont like the look of tall quad

Main parts List

ZMR250 Carbon
ZMR250 Silver 

RCX 12amp (would not purchase again)
HobbyKing afro 12amp (great ESCs)

DYS 1806 2400kv 


Flight Controller
NAZE32 .. anywhere you can get them or a Flip32

FrSky DR4-II

2mm connectors

On the FPV Quad
Fatshark Camera
Fatshark Transmitter  

Other parts were your general bolts and heat shrink

The build differences

Ok lets get down to the differences in the builds. The main one is the use of standoff to provide space between the lower plates to allow room for the ESCs to sit inside of the frame. I also thought this would make it easier to replace arms if one broke or bent. As there have been reports that this happens easily due ot the ZMR250 arm design. 

I used the same 10mm standoffs for both the carbon frame and the silver fiber glass frames, This gives a total of 13mm between the plates to fit the ESC and wiring into.

The next tricky part is getting the ESC and the 35mm power distribution boards in that space. Using the RCX ESC's this was a real push as the ESC are large for a 12amp rated ESC. I would not use these again as the first time I powered them on one burnt out and took a motor with it .... I was displeased. Luckily I had ordered spare ESC's and motors.

Without the 35mm PDB I would not have been able to do it.



 Doing the same thing with the Afro ESCs was much easier, they are a great little ESC.




For the top plates I use differnet heigth standoffs, On the carbon I used 22mm this was enough for the Fatshark FPV camera to be sandwiched nicely between the plates. On the Sliver I used 16mm which was enough to allow the NAZE32 to be mounted.


3d Printed Parts

The joy of having a 3D printer is that you can make alot of things that are not available. It has been great for my quad builds, I have made gimbals, anti vibration systems, flight controller cases... pretty much anything. It was well worth the $500 investment.

Arm protector

So for the ZMR250 I wanted some arm protection, Since I fly alot of time over tarmac and gravity is alway trying to make me hit it I designed some arm protectors that fit on the end of the ZMR250 arms. Its a tight fit on the carbon arms, and is a little loss on the silver ones, but once zip tided on they are very secure.

The hole lines up to the ones in the ZMR250 arms


Light bars

Since I do alot of evening flying, only chance I get most of my quads and LEDs on them. The minis are no different. I wanted something that would allow a decent set of LEDs and was also out of the way so that they wouldnt get damged in a crash. After a little bit of trial and error this is a completed Lightbar with the LEDs on it. 

The larger verson is printed in two halfs due ot the limitaitons of the printable size of my printer and then just super glued together. The thickness is 13mm which fits the space between the two bottom plates with the spacers. They use the holes already in the frame for mounting. Longer screws/bolts are used and they go into the top plate standoffs.


 A complete large light bar. it has enough space fro 6 LEDs from the common 12 LED strips. I run 3 red, 3 Green same as on a plane to help with orientation at night.

On the Carbon frame FPV I also put a large bar on the back with a multi LED colour controller so I can have alsorts of fun with colors.


I also made a smaller 3 LED sized bar for the silver quad. (Below fresh off the printer)


Landing Skids

Since I fly low over tarmac alot of the time that are touch downs and slides so I wanted an easily replaceable skid plate for the bottom of the quads. These are mounted using the same bolts & fame holes that the light bars use.


Over all I think I have ended up with nice tidy quads


The weight differnce between the frames is 4 grams. This is only including the arms and the three frame plates which is all I used.



I hope this perks your interest in what other options you have with this great little frame.

Also of note, yes you can break the arms, a failed double flip onto concrete did it for me ... plus 2 motors ...


3D files

You can download the .stl files for the 3D printed parts. Please feel free to use them for you own personal use.   


More info and videos are over on my personal blog


I think I have an addiction



Another ZMR buuild this time using 2204 motors and 6045 props. 

Here is the build log

Here is a video of its first flight out ... and me dumb thumbing it into tarmac.



Noobi1951 on November 26, 2014
Beautiful work! I'm not into quads, or anything else that doesn't have a glide ratio that I can handle, but if I were I would surely follow your ideas, and could only hope to reach your level of construction.
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AndyPants on November 26, 2014
Wow, your ZMR 250s look amazing, thank you so much for sharing! I definitely got some great ideas for changes to mine! Very well done!
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rcflyer729 on November 30, 2014
nice build man good job
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bluefishnz on December 1, 2014
Thanks for all positive feedback. The next step is to replace the RCX ESCs on the carbon frame with a newly purchased 4 in 1 12amp BLHeli ESC. It should make for a very clean build.
I will put up another article about this change.

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Nat992nbd on December 29, 2014
can you please provide a link for the power distribution board you used, i can't seem to find it

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bluefishnz on January 5, 2015
I got it when I purchased the Naze32 board from, it was part of the purchae options for the Naze32 boards.
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tmm777 on February 18, 2015
I am a not a 250 pilot yet but I have been amassing parts for my first one. Ive had bigger quads but I've got the FPV racing bug. has exactly the product you want. is the page with esc on it. Their esc are super small and can take reflashing. Many are putting Blheli firmware on their 250 class esc because of the high KV motors and sync issues with simonk firmware.
I just know that that is where I will get my esc's for any build from now on. I have no stake in that website or company. Many friends and I have bought from this site. He is reliable and has state of the art parts that are super small and light. Making room for bigger batteries and better/clean builds.
Excellent review. Quite succinct.
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Dronin on March 3, 2015
Hi, thanks for the great article!! I am wondering what type of 3d printer you used? I understand that the prices and models of the printers change with time, and so am just wondering, what type of printer would you look for when purchasing one to 3d print quad copter parts?

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bluefishnz on March 3, 2015
Thank you. I did some research and decided on a UP! Mini. I went to a MakerSpace and talked to folk who ran that and they said that it was the most consistent and trouble free. I needed the 3D printer to be a tool and not a hobby where i had to tinker with it all the time. So far its worked out great. And if I need a part bigger than the print dimensions I just cut it in half for printing then superglue it together as I only use ABS.
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etegration on April 15, 2015
I've ordered more than 20 of those 12A ESCs from MyRCMart, all were good and non burn upon powering up but you're right about the size, it's a tad bigger compared to others like the Hobbyking Afro 12A and there's a slim version but with the shipping (im in asia), it adds up really quickly getting the Afro 12A(s)....with the based price already at USD$1 cheaper with a minimum of 4 if you're building a quad. More if building a hex. On my 3 quads and an upcoming tricopter, it could turn expensive.
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aeroalcky on May 11, 2015
Great write up! Super excited to use your 3D models! Thanks for posting on thingiverse!

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Web_Master on May 30, 2015
Hey Bluefishnz
This is such an awesome build that you did.
One question, do you ever have problems with the motor arms moving or sliding up and down the 10mm standoffs because of the space between the frame boards for your ESCs. If you do how have you fixed them down?
Thanks Grant
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bluefishnz on May 30, 2015
Not 100% sure what you mean, but I hope this covers it. The stand offs I use are treaded. So the bottom bolt passes through the bottom plate and the arm and into the treaded stand off. I got bolts that were long enough that it screws into the stand off about 4mm. Once tightened it holds the arm very securely in-place, as the stand off tightens down onto the arm. Then then its the same process for the top plate, bolt goes down through the top plate into the stand-off, Once all tightened up it makes for a very rigid base. The only issue I have has is after a hard smack into the ground the arm some times moves front to back (about 3-4mm), due to the play in the bolt holes. But this is easily fixed by puling on the arms out. And it only happens after a very hard hit. (Check the updated video I added to the article, thats what I mean but a hard hit!!)
I hope this answers your question.
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Muzz105 on June 13, 2015
What size props did you use on the 1806's?
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bluefishnz on June 13, 2015
On the silver one, which is my rough and ready hack quad, I run 5030s, as I have a stack to get through. On the black ZMR I run 5040s. I have not tried anything more than that.
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festaman on June 13, 2015
How did you mount the PDB to the frame? I am having some issues with the mouting screws pushing up the ESC even cut flush to the nut. SHoul di just stick it on?
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bluefishnz on June 13, 2015
I will come down to the height of the ESCs, and the standoffs you have. I did a few test fits and on one of my builds and I had to use 12mm standoffs not 10mm to give enough clearance for the ESCs. I also mounted one of the PCB under the center plate not on the bottom which also gave extra room. I have even used zipties in really tight spaces. Just make sure if the frame is carbon or carbon glass that the PDB does not touch the frame otherwise it will short. I have had this happen.
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Boydrone on January 15, 2016
Have you thought of printing simple L brackets that you can mount under the arms to reinforce those flimsy arms?

They could double as your skid plates as well
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Not your normal ZMR 250 build