New to Quads - Asking For Advice.

propflux01

propflux01

Member
Hello,
New to the forum, and new to quads. A couple months ago a co-worker bought one of those small quads. Well, he brought it to work, and hooked me right along. I got me one, a husban H107 X4 and having a blast with it.

Then....

We both decided it was time to build ourselves a larger quad, totally with home-built frame parts. We each have our own idea on what to make our frames with, and have already started the race. Since I am new to this, I need some advice on what engines to use on this. My frame arms will be 1/2" aluminum round tubing, about 24" tip to tip (his will be the same length as mine using different materials, something we both agreed on) and the craft should weigh about 300 to 400ish grams bare. I would like to use a 10" prop on this build. It is to be solely used for learning to fly, simple, no cameras, not super fast yet not slow, just general, gee-wiz type of flying. I am trying to learn about engine sizes VS weight VS speed, etc. The best I can figure right now is an engine in the 900-1000KV range. Am I far off on this? I understand there is some 'fuzzy math" involved in this but have no clue how to figure it.

So based on the approx. weight, size (length) of frame, is this a feasible start?

Thanx in advance!!
 
Hi mate welcome to the forum , ok ( not engines lol , Motors are better) the maths is the flight weight x 2 and half divided by how many motors it has so if you say 400grms x 2.5 =1000grms divide by 4 as its a quad = 250 grms of thrust needed for each motor , now high kv need smaller props 1100kv would turn a 10x4.7 prop ok but your want a 30amp ESC on each motor to have head room so you dont over load ESC
Low kv motor will turn larger props like a 650 kv will turn a 14x5.5 prop easy
I am trying to not over load you with info ,but high kv with the wrong set up will get no flight time ,also a low kv with wrong prop battery set up will do the same
Your need to mount the motors to the arms so your need to look at whats about or what can you make to mount motors to the arms , now they will have to be made right and all the same , for the FCB to work right, the motors all need to be the same point from the centre of the FCB a 450mm quad has the centre of the motors 450mm apart from each other so its square , this is why dead cat frames fly strange as front legs are at a different angle and legs are longer , so make sure its square
Now the lighter you can make it the better it will fly and the longer it will fly , if you look at mine in the pic its a 700mm quad with 650kv motors 14x5.5 props 2200mah battery flight weight of 42grms flys for 8 mins and is fast if i want it to be but has the kk2.1.5 FCB with steveis pro firmware and is super stable
ESC = electronic speed controller this converts 2 phase DC ( battery) to 3 phase AC for the brushless motor and gives a 5v output for FCB power
FBC= flight control board
Kv = rpm per volt of power ( 650kv on a 11.1 volt( 3 cell) battery gives you 7,215 rpm ) at full throttle
Your going to need a 4 to 6 channel transmitter and receiver
Sorry its a bit long and will prob make you need to ask more questions but thats good ask away
 
Ok, Motors, not engines!! lol!! I understand the math portion on that, and consider my build to be about the average weight of most newb builds using frames such as the '450' and such. The math I was referring to was for matching the motor to the prop. Before you replied, I spent more time looking and come to conclusion that something in the 850-900KV would suit my needs so far. I'm particular was looking hard at the sunnysky 850KV. I have seen several engine mounts that would fit on the ends of my 1/2 tubing, and if needed I have a way to attach them with a cross-mount as well. I have determined that the motors will be 600MM from centre to centre, and I will be doing a straight even design (an "X" or "+" design). Very much like the quad in your avatar, but with a different centre. I plan on getting the frame done, then weighing it to go from there. After this comes the rest of the questions as far as what to buy and how to use. I am still learning all the different acronyms used throughout the hobby and have a basic understanding of 'what is what', just not how to match up 'what is what'. I know some components have to be bought after others, and some before. I do appreciate your help and would like to get more knowledge from you on this. Thanx!
 
Hi mate no problem ask away , if you use ecalc.com put in the frame weight then click on without drive, it will work out the weights of esc, motors, battery, if you go for the kk 2.1.5 or the kk2.1.5 Hard Case you will be best to flash it as the Hobby king firmware is not that good
The sunnysky motors are good but also the emax and agm motors are as good they will all spin a 10x4.7 prop , when you know what motor your getting see if they give you amp loading for a 10 inch prop this will help for ESC amps , I run 30 amp ESCs and even my 650kv on a 14x5.5 prop does not get warm , so a 30 amp esc will give you loads of head room so you wont max it out
 
I pretty much settled on 30A ESC's no matter what engine I used, I like to have wiggle room! Now just need to get a basic parts list of necessary items regardless of brand. then choose my branding and go from there.
 
Ok great!!

I know I need motors, esc, radio, controller, battery, and charger. What else am I missing?

I did some more research and have the following parts decided:

The sunnysky 980 motors,
10" 4.5 nylon blades
AFRO ESC 30A
KK2.1.5 board.

Now as for radios, trying to decide between the Orange, and the turnigy 9x

I'm leaning towards the orange, but I do not know what, in addition to the radio itself, that I need?
 
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Hi mate on the props I would fit carbon fibre as the nylon snap in flight , check the afro has a power out for the kk 2.1.5 , get a flash tool for the kk it will fly much better on Steveis1.18si pro
As for radio orange is the clone of the spektrum DX6I your need a receiver too good radio ,the 9x is good to but your need a module for spektrum or futuba , the only other difference is orange is 6 channel, 9x is 9 channels , i would have the orange but i like spektrum i have the DX6I and DX9
To add to list your need blue lock tight ,servo leads so you can connect the receiver to the kk , battery strap power board ( unless frame has one already), heat shrink , i dont use bullet connectors as i have had then fail in flight before so i just solder the wires and heat shrink over the joints
 
Hi guys, total newb here! A good friend of mine who is a pro flyer gave me an old setup of his last weekend. I knew virtually nothing about multi-rotor vehicles before yesterday and know little more right now. I was browsing threads and came across this one and like the info here because it is basic. I'm a pretty handy guy, equipment engineer, mechanic, motorcycle racer, etc, so there isn't much that's outside my capability but I still need to learn.

The rig he gave me is already built and running, I just needed to buy some batteries and a charger. I went with some LiPo cells and a Thunder AC6 charger to start with because that's what he was using. It came with a Spectrum DX8 radio and Naza-M already installed and ready to go. Basically it's ready off the shelf.

I think right now my biggest "problem" is understanding system architecture as I have never seen a diagram. On the surface I understand how the radio works to input signals to the receiver. I think I understand the purpose of the Naza unit but probably could use a little explanation. I get the ESC's and the motors, again, from a basic understanding of how they work.

Some of the stuff I don't quite get yet is motor and prop sizing, a detailed explanation of how the Naza works, and all of the bells and whistles on the radio. I intend to do a bunch of reading over the next few days but I was wondering if you guys could point me to a primer on a basic system. Then after reading that, I think I would get more out of my reading and be able to ask some intelligent questions. I've heard and subscribe to the theory that the only stupid question is the one you don't ask, but there has to be a good FAQ somewhere that would prevent me from asking the same basic questions as everyone else has asked over the past few years.

Of course I can still ask my friend some questions too. But I'm trying to build some other relationships in the community, and also not bombard him with the basic stuff. I want to mainly rely on him to help me learn how to fly.
 
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Best way I learned was to browse, read, browse again. I kept my questions to one forum to avoid confusion and asked the questions here to get the answers I needed. I now have a fully home-built copter that I just programmed my KK2 on tonight, with limited test hovers in the house ( too windy outside right now for a full flight test). Just slow down, absorb the info, and go one little thing at a time until it all falls in place.
 
Hi mate Go to a you tube channel called rcmodelreviews its run by a guy called Bruce go through his videos it will teach you loads on RC , The naza m is a really good FCB i hope it has the GPS , if it has you need to learn how to set up and use the GPS , never have GPS active indoors due to if you hit return home or fail safe it will go to its last known GPS location and that can be miles away .
Ask if your not sure on any parts your not sure on
Keeping things easy low Kv motors run bigger props, high Kv motors run smaller props , KV is rpm per volt put in from battery , prop size say 10x4.7 , 10 is size of blade 4.7 is how much pitch the blade has , if you run a tri blade you reduce the size by an inch and will still get same lift
I have seen some really good set up videos on the phantom is has the same FCB just make sure it has the same as your ,so if you have GPS then make sure video cover this , your need to download naza assist from the DJI web site this will allow you to program the naza , but as its flying it all set up any way
AS for learning to fly i tell every one to do the training for a CP heli as the quad flys like a cp heli does , but the hover will be very easy
Have fun my friend there is no rush in this hobby
 
Thank you propflux and holtneil, I appreciate the feedback. I remember reading a description of the motors and how they are "sized", meaning the voltage to RPM that you described. But just to make sure, a 1200 kV motor is 1200 RPM/volt input, so if my current commanded voltage to the motors was 3.0 volts they would spin at 3600 RPM, right?

I also figured out last night that the QC is an HT-450 with Quadframe 200 mm landing legs to accommodate a camera gimbal suspended underneath. He also gave me a bunch of spare chassis parts which from everything I've been reading I will need at some point (probably soon). I do have the gear for the GPS for the Naza, but it is not installed or set up yet. I removed the clear dome over the Naza to get a look inside. Here's a question: Why the dome? Protection in a crash? Keep debris out of things?

Oh yeah, my radio is a Spektrum DX8. There's more darn knobs and switches on that thing than the F-16 I crewed in the Air Force! I think getting to know that thing is going to be my biggest challenge.

Another thing I've been wondering about is regarding props. I've read something about some people preferring carbon fiber props to nylon props because of problems with breaking nylon ones. In looking around last night, I've seen some fiberglass ones as well. My assumption is that in terms of breakage, they would be more similar to carbon fiber, but they would probably weigh a little more, right?

One last note, I've been reading horror stories about people's rigs getting out of control when they are working on them because of various GPS things or whatever, and the admonishment to remove your props when doing certain types of maintenance. I'm pretty sure I will get the full scoop when reading the radio and Naza manuals, but are there any very basic rules that I should follow? I'd hate to have it spin up to full tilt and run into the ceiling in the garage and take out a flourescent light! Let alone scare the pants off the wife from the racket and the potential run to the ER because I have a prop embedded in my forehead.

There's a picture of my quad below. I'm itching to fly the darn thing! WHERE'S MY BATTERIES?!?!

IMG_3539 50PCT.jpg
 
HI mate most of what i told you is to help with back ground knowledge as I didnt know how much you know , Yes working out 3,6v at 1200kv is right , The Dx8 does have lots of switches but not all are used unless you assign some thing to it i have the DX9 which has more but I only use gyro , duel rates , hold ,idle up , Looking at the quad the most you will have is a switch for stable mode to acro mode , and the dome is to protect the FCB
As for props plastic flex when flying so quads wallow a lot , the prop you have found are prob nylon fibre reinforced they chip very easy on the tips are a little tougher then plastic , carbon fibre does not flex are strong in a crash can still snap but not as often
Run aways are like i said about never arm GPS in doors ,always remove props when doing anything on the quad , and if and when you fly if you have GPS fitted always calibrate it before flying if you can get GPS lock DONT FLY your get a fly away
PS nice looking quad
This may help there are 9 videos on set up in the DX8
 
Thank you holtneil. I'll start giving the videos a look tonight.

I was wondering if that was the case with the switches on the radio. I need to spend more time with the manuals. But as I said in my first post, there is sooo much that it's a little overwhelming. Then start throwing around unfamiliar acronyms and things really get dodgy. This is going to take a little time, so I just need to be patient.

Thanks again for your help!
 
First, thank you, holtneil, for the information on the Naza setup. I don't quite understand it yet but I'm getting there one step at a time.

Back on line, I was out of country on business for a week so I took some time to read through the manuals while I was out. When I got back yesterday, I sat down with the radio, which my friend had already programmed, and looked through the settings. That tied a lot of things together for me.

This is probably old news for you guys, but it was very interesting for me because the settings told me some things and cleared up some assumptions/questions I had. Please bear with me while I work this out, but I'd like to know if my assumptions are now correct.

He has the radio programmed for a fixed wing aircraft. That surprised me a little at first until I re-read the Naza manual and led me to my first conclusion: the Naza is acting as a signal mixer to traditional elevator, aileron, and rudder controls. Right? In other words, on my quad x type multi rotor, the Naza mixes those signals and varies motor RPM to give me the required pitch, roll, or yaw response. As an example, I figure if I want pitch forward (elevator input) then the Naza might speed up the two rear motors and slow down the two forward rotors. Roll would be similar to pitch except it would be a right to left differential. For yaw/rudder input, I'm guessing the Naza slows down the two props rotating in one direction and speeds up the two spinning in the other direction.

BTW, I also figured out about 60% of everything on the DX8 doesn't do much for me with my rig. May be able to use more of it on a different bird.

Another assumption based on my first one is that changing the D/R & Exponential settings will change the outputs from the radio/inputs to the Naza, thereby speeding up or slowing down the response in any given axis of rotation.

One thing is still confusing me on the DX8 though. Can someone give me a plain English explanation of the difference between Mode 1 and Mode 2?
 
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Hi Now be careful what do you mean by mode , there is 4 modes that are the sticks Mode 2 which has throttle and rudder on left and cyclic on the right Dont change this Ok
Now there are flight modes this will be easy if we talk helicopters for a min , mode 1 will give you zero to 100% throttle on the stick ,so zero stick is zero throttle ,full stick full throttle.This is like normal flight
Then mode 2 ( normally called idle up ) this gives you 100% no matter where stick is so now flight is just pitch
So with your quad he may have it set up in switch position 1 is normal flight no GPS mode ,then when you go to position 2 gives you GPS mode or return home , you have to look at the transmitter and software at the same time to see what turns on and off with the switch ,the software should show you
PS your doing well my friend just take your time and your get it right
 
Hi your doing fine :D It takes time to get to know your quad and transmitter is what i was going to say but put answer from other thread lol
 
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