Opinions on the ZMR 250 quadcopter frame

[IceFyre13th]

I am looking to build a 250 class racer and a local shop has these

http://flitefactory.com/product/zmr250-frame/

Any opinions on this as a racer?

 

[Andy]

I've got the Eachine 250 RTF for a little over $300 with everything. I'm wanting out of it because of the radio. You can't change any perimeters on the radio. Also if you try to upgrade anything on the quad you have to buy a new radio plus a new flight controller. Just my buck fifty worth. I know your not looking at this but other people maybe considering this drone. Also if you fly FPV you have to have a HAM radio operators license. Hopefully this helps someone

 

[joesrevolution]

Hi IceFyre. Ive had a ZMR250 for nearly two years now. And for the price its a great little quad! Its light and cheap with a lot of after market accessories like the red plate separator in my display picture, which I use to keep my radio receiver and ubec in .Its nice that you have a lot of choice in things like that because it is such a popular frame. Obviously with it being really cheap it does have downsides. I have broken two arms so far which is a pain but these can be swapped out in 10 mins at the field if you want. There's also enough space in the frame for a fc, pdb, vtx, rx, osd and ubec which makes it versatile. In my opinion its a great place to start with fpv racing maybe graduate onto a more expensive tougher frame after a while if you really get into the hobby.

Also see this post I put on phantom pilots in regards to building up a mini Quad. If you want I can also forward you the email conversation that me and the OP

Custom 220mm bird?

Here is the first email I sent him. Gives a good outline IMO, If anyone thinks that I have missed anything let me know!

First you will need a frame

Zmr 250 (cheaper alternative)
H250 ZMR250 250mm Carbon Fiber Mini Quadcopter Multicopter Frame Kit

Lumenier QAV250 tougher and better quality (more expensive)
QAV250

Power distribution board (doesnt really matter what one provided you have one some offer more features than others)
Emaxmodel.com-R/C Store - QAV250 CC3D Flight Controller Mini Power Distribution Board PCB 10100012012

Then an flight controler I have used both of these I found the CC3D easier to set up but the naze32 arco is a more powerful board just make sure you ask for the pins to be soldered if you haven't done much soldering before also the programming is harder.

OpenPilot CC3D Board - OpenPilot.org - The Next Generation Open Source UAV Autopilot

AfroFlight Naze32 Acro FunFly Controller

Next comes your motors. You want a motor with a KV of about 2000+ for a mini quad 3000+ if you want to go for a 220mm frame but since these are generally more expensive and harder to build I would stick with a 250mm frame. Do a bit of research into what KV is.

Emax motors (great! I wouldn't fault them) make sure you get 2x clockwise threads and 2x counter clockwise threads so that your props self tighten
http://www.emaxmodel.com/brushless-motor/emax-mt2205-ii-racing-edition-kv2300.html

T-motors are better quality if you want the best of the best but I would stick with emax or similar for your first build in case you kill a motor early on.
F40 - FPV Series Motors - T-MOTOR

You will also need 4x escs Think about how many cells you will want to have in your battery 3s if fine for most of the time and to learn on 4s gives more 'punch' but will require compatible escs and motors.

Emax 12a what i use on my mini quad (will do 4s provided you run a less aggressive prop more on that later...)
Emaxmodel.com-R/C Store - BLHeli Series 12A ESC (ONESHOT available)

Emax 20A allows the use of more aggressive props with a 4s battery
Emaxmodel.com-R/C Store - BLHeli Series 20A ESC(ONESHOT available) - BLHeli Series ESC - ESC

See where is says bec on the tables down the page? A bec is what powers your FC and receiver. If you go for an opto esc they do not have a bec. you will need a separate bec to power your fc/rx.
http://www.helipal.com/product_info...cts_id=10459&gclid=CKnCp7LRx8oCFcluGwodNUcJmQ
I use escs with a bec though... so much simpler...

Props. You will most likely be running a 5 or 6 inch prop on the frames I have sent. you will ushally see this in the for 6045 or 5030. The 60 or 50 is the diameter in inches and the 45 or 30 is the degree of the blade. A blade with a higher angle will provide more lift but needs more power to turn it. So if you want a high angle wide prop on 4s you will need more power from your escs so make sure they are rated for it. Check your motors too but provided they are 4s compatible you're good to go.

I use HQ props.
http://flyduino.net/HQProp-6x45-1524cm-Propeller-Set-Black-4-pcs-Carbon-reinforced

There you have it. Add a 6ch or greater radio and an fpv system of your choice and you're done!

Imo get a cheap radio set like the flysky i6
http://www.radioc.co.uk/Flysky-FS-i6-2-4Ghz-6CH-Transmitter-Receiver-p/3510.htm
Instead of your dji radio which is a pretty basic set and then get used to flying your 250mm without fpv at all as this adds weight and value to your quad. Not ideal if you're learning with a much faster more nimble frame compared to what you are used to. If you want me to run through fpv stuff though just let me know

Hope that is not too much to digest. Best bet is to read up on the products I have sent, watch a bunch of videos on building these and trawl the forums too for discussions about this.

If you have any more questions feel free to message me again.

 

[IceFyre13th]

Actually I understood everything you said, I have been flying larger UAV's for years now and have even developed a few of my own. Mostly 500 class and above.

I just saw some people racing locally and though it would be fun to try. The shop I posted with the ZMR250 is within a few streets of my house and the owner was one of the racers I met.....even let my fly his for a few minutes, guess what....hook line and sinker gotta have one..lol

Th QAV250 looks like a much stronger frame, but I would be concerned with the arms being part of the chassis....at least the ZMR has separate 4mm thick arms and by using aluminum or plastic screws it gives you a "break away" feature for hard hits.

The flight controller information is one area I appreciate your input on, I don't think my go to's (3D Robotics APM / Pixhawk) would be a good fit.....one cost to much to crash with....two way too heavy for a small bird.

Motors, I have been a fan of and use almost exclusively Hacker motors, but they do not have any of the correct Kv / RPM range or for the 3S / 4S batterys for 250 class UAV's, so my second choice motors have been Scorpion Power Systems ( Motors - Scorpion Power System ). I have never ever had a failure with either brand......yes they would need a larger ESC, but those I have plenty of and some really light weight 20 - 30 amp ones too.

Tx / Rx radios, I have everything from 2 channels all the way up to 14 channels.......been into R/C for a very long time......my DX6i would be used here, I am used to it and it can be programed for just about anything I fly......

But I will ask for help with FPV gear because I think my big bird stuff is way to complicated for a small racer.....just don't think 4K resolution is going to be needed or the "many" watt transmitter. I am not a goggle fan either, so I will fly by / with a 8-10 inch monitor attached to the Dx6i via its holder I have.

The small FPV Rx / Tx gear I have no clue on.......I would guess less than 500 mW output would be needed but what about OSD, antennas, transmitter, camera, etc........

thanks for your help already too!!!

 

[IceFyre13th]

And now I found the RMRC Mudskipper 250

RMRC Mudskipper 250 - Kit [RMRC-MS-KIT] - $69.99 : Ready Made RC LLC, The Leader in All Things FPV, RC, and Beyond

I really like the camera mounting on this one.......opinions?

 

[joesrevolution]

Good good. Well with the uni body they are generally much stronger and there are less failure points. But if you're looking at the zmr250 v2 with the 4mm arms then you should be in a better place than me. I've got the v1 with 3mm arms.

For fcs there's loads out there. Depends what you want to spend. You will be looking for something along the lines of a cc3d or a naze 32. The cc3d is cheaper and easier to set up but the naze32 is the more powerful board. There is loads out there though. So do a bit of looking round. The 'seriously pro fc' is getting more and more popular as it is pnp. But the naze is still considered the best out at the moment.

For motors and escs you want a 2000+ kv motor. Ideally 2300ish for a 250 quad. Escs you will want 20-30 amps yes. I take it you know about becs in escs? You will need an external bec if you go for the lighter weight opto escs.

For your fpv system with mini fob quads less is often more... you have so much rf interference in a small area you don't want to add to it. So a 200mw vtx is what I suggest. Some clubs will even have a restriction on vtx power to this level as the 600mw ones can mess with other people's feeds. You would probably even be okay with 25mw if you wanted to be careful.

An osd is a preference thing really... There's a lot out there. All you 'need' is voltage. But you can get away without an osd entirely by using radio telemetry if yours supports it. There are more full featured odds out there like the dal osd which is what I use but without the gps. Without the gps it gives time voltage height and an artificial horizon. If you want a cheap voltage one though which is all you really need hobbyking do on for about £10.

For antennas just use a cloverleaf circular polarised antenna. Don't worry about the other types for the air end. For your receiver another cloverleaf will work great and will give good all round reception. If you want great reception but in a restricted angle a patch antenna is better for flying right in front of it. You will loose feed if you fly behind yourself though.

As for cameras it's very personal. I have a tbs chip chip and a cheap eachine camera. Both work fine but the chip chip has better resolution and is programmable by a small remote that come with it. With cameras it depends on what you want to spend on it really. A cheap camera will work fine but the more expensive ones will give slightly better resolution and you will be able to tune them better.

For your vtx they are all similar really... the immersion rc ones are good but are are limited to 8 channels. There are lots of 32ch ones out there too. Just take the time to check the voltage output for your camera to make sure it will either power or not blow it up Haha. Some vtxs will output 12v and some 5v. Might also be worth looking into 'raceband transmitters and receivers. These have 8 channels which are spaced out a lot to remove the risk of interference on your video stream. Just keep the power below 250mw.

That mudskipper looks really cool actually! I like the fact that it would be low profile when you are tilted forwards. The arms are 5mm carbon so super strong. It's also an actually x quad not a huge quad (even though it looks like one) which means the motors are evenly spaced. So it's easier to tune.

I hope that's answered a few questions. Let me know how you get on and if you need any help with anything else.

 

[Chris G]

Hey Ice, what frame did you pick?
Joes gave you some great info, thumbs up JoesR..
The ZMR 3mm frame is cheap, and will eventually break.
I have a quad similar to the H250 Joes linked above, But as I also broke an arm the other day, see pic, so I'm building a new Q250 frame with 4.75mm replaceable arms, 1.75mm thicker.
This Q250 weighs 190g, where the ZMR250 weighs in around 145g.
The best feature of the ZMR is the many accessories that are available, and its cheap, but if you want to race in the trees, and your quad likes to act like a thrown hatchet, the thicker arms will definitely come in handy.
Keep in mind that having thicker arms just means that your quad with break in another place, or potentially throw it's junk on impact. So the smaller arms with reduced weight and slightly more flexibility might be just as durable, in the long run, for all the gear your quad is carrying.

I also like frames where the Arm ends are large enough to save the motors from impact, as they provide some clearance between the edge of the CF and the motor.

 

[IceFyre13th]

Currently I am gathering parts to build a " Student Driver Quad"......lol

So far I have:

FPV
Quanum Cyclops FPV Goggle w/ integrated Monitor and Receiver
Quanum Elite X50-2 200mw, 40 Channel Raceband, FPV Transmitter

Camera
http://www.hobbyking.com/hobbyking/..._HD_Video_Camera_Set_With_Live_Video_Out.html
http://www.hobbyking.com/hobbyking/store/__61655__Mobius_USB_to_AV_Out_FPV_cable_with_Charging.html

I am going to build up an FPV quad using a modified Predator 650 frame ( http://www.hobbyking.com/hobbyking/...ng_Quad_Copter_Carbon_Fiber_Version_Kit_.html ), I have never flown under "full FPV" with goggles without having "line of sight" to reference my location before so I figure building a slow flying quad first to learn how to fly this way would be wise.

This frame has a 3DR APM flight controller with full GPS ( safety setting programed with return to home if signal loss and or "panic button" ) and OSD telemetry ( almost like heads up aircraft display ) with aircraft "health" and location / altitude / artificial horizon displays. It was one of my "camera birds" before I got a 3DR Solo.

Right now though its over 110 F / 45 C outside temperature in AZ, so standing outside and flying is not very fun.........but building Multi-rotors inside is OK.

 

[Chris G]

I like the combo of value priced items, Very good choices.
I might add a pair of something like this Clover Antenna set. but not critical
And I'd be curious as to how much latency(Delay) you might get from the Mobius Live out to the googles, but you're not racing this thing, its for practice. You could use a TVL600/700/800 instead, for the FPV, But I think the Mobius should work too, with possibly better quality.
Can't wait to hear your first impressions

 

[joesrevolution]

Good looking frame ice! Great thing to learn with.

Very much worth getting a clover lead antenna set like chris mentioned. A linear will loose reception when you bank and roll as the antennas will not line up as well. As you progress too a proper fpv board came it will help a lot as they have better latency and adjust from light to dark areas better.

Last things is try to use the gps modes as more like a failsafe than what you fly in. If you move to a fpv racer style quad you will loose gps and 99% of pilots fly in the acro mode which has no assistance. You don't want to rely on gps or auto level for too long so make sure you have the ability to fly in acro on the flight controller.

Most of all though above everything... ENJOY! Welcome to fpv racing

 

[IceFyre13th]

I like the combo of value priced items, Very good choices.
I might add a pair of something like this Clover Antenna set. but not critical
And I'd be curious as to how much latency(Delay) you might get from the Mobius Live out to the googles, but you're not racing this thing, its for practice. You could use a TVL600/700/800 instead, for the FPV, But I think the Mobius should work too, with possibly better quality.
Can't wait to hear your first impressions

Yes a clover leaf antenna set will be used, I have a few dozen of them from my other birds......

As to the latency of the Mobius, I do not see any when directly hooked up to a monitor.....with GoPro's I always do....but I am going to see what happens when hooked up to the transmitter and sent to the googles this weekend on the bench testing. Call me picky, but I bench test every bird before first flights....everything from range checks, Tx power, interference testing, simulated loss of signal ( small Faraday cage around the antennas )......I have had too many things go wrong in the past with the early multi-rotors ( think "Parrot" and "DJI" crap ). So being safe by testing has become my norm.....

The picture is great at 1080P 30 FPS, but there are other settings too..( 720P can go as fast as 120 FPS, might make for some cool slow motion videos ).

I will post a build log too................

 

[Chris G]

I have an older Contour Cam, that records 720 in 60fps, and the video is really nice compared to the 1080p@30fps, the 120FPS footage should be pretty nice, but would obviously like to see how it handles the compression.

 

[IceFyre13th]

ReadymadeRC.com had a 4th of July sale......so the Mud skipper is on the bench being built.

I will say this about the parts I ordered (the Mud Skipper frame and Seriously Dodo flight controller, would it be too hard to include a set of instructions....they said they were included but are not. And the instructions are missing way too many steps and information.

Frame, nothing said about the power distribution board.......and some of the braces will be in the way of the connections that need soldering, might be nice to show some recommended electronics mounting locations too.....sure you have YouTube videos posted....but have you ever tried to build by watching those, its a real pain in the you know what.

Seriously Dodo flight controller, really no printable instructions anywhere......and trying to read the picture of the pin-outs on their website is next to impossible. (I copied and pasted the web page to word and was able to scale the pictures up to a readable size. Still have too figure out how it all works though.......and again I hate YouTube video instructions...especially the ones for this item.

Other items for this build.

V-Good ARM 32 30 amp ESC V-Good RC - ARM 32 - 30A Lite ESC [30A-0-LITE(2-4s)] - $14.99 : Ready Made RC LLC, The Leader in All Things FPV, RC, and Beyond

Scorpion M-2208-2000kv (Stealth Edition) Scorpion M-2208-2000kv (Stealth Edition) - Scorpion Power System

I will be running a 4 cell Lipo with GemFan 3 blade propellers, size 5 X 5 X 3..