Parts reality check for first Quad

[JasonEricAnderson]

I'm building my first Quad, it's based on the 330mm mini frame I got for a steal when Microcenter was putting their DIY quad parts on clearance. I'm hoping someone with more quad experience can look over my parts list and see if it's 'sound'. I'm including links for all the details.

Frame: (purchased) F330 red/white frame link
Flight controller: (purchased) KK2.x link
Motors: Brushless Outrunner 1100kv link
ESCs: Afro ESC 12Amp Ultra Lite Multi-rotor link
Props: Turnigy Slowfly Propeller 8x4.5 Black (CCW) & (CW) link1 link2
Battery: (purchased) 3s 1,000mAh link



I'm studying and reading up on all the great info here as usual.
Multirotor-Top-Tips

 

[airhawk]

I would swap the battery for something more powerful later on but i think 1000 mah will pull but you have a decent setup right now whats your goal for this quad?

 

[JasonEricAnderson]

The goal for this quad is a "I can build something that flies" and get my muscle memory for flying quads

 

[airhawk]

so 1300 minimum is what i would go with but you have the 1000 so why not try it i dont know if that small battery could hall that quad

 

[pressalltheknobs]

1000 mAh isn't the issue, it's the C rating. Smaller capacity (mAH) just means shorter runtime but if you have a smaller capacity you need a higher C rating to get the same amps from the battery. The motors you have are rated to 10 amps so taking that as a maximum you need 40 amps which means your 1000- mAH battery should be 40C or better to provide the max current 1 * 40 = 40 amps) . You probably won't draw anywhere near 10A per motor but you want some room. If the battery is only 20 C you may find its not up to to the task and will fail early. Using smaller props with keep the amp draw down but obviously they need to be big enough to actually fly. If you use a 1500 mAH then (1.5 * 30 = 45 amps) and 30 C battery should work.

I think the ESCs may be a bit underrated for those motors particularly given the props you choose are larger than recommended for 3S. The description says 7X4s are recommended for 3S. Unless you are really sure the larger props work and don't cause the motors to draw more current than they should (ie someone trustworthy has tested them and measured the amp draw) I would stick with the recommended size to start.

If you are going to use a larger prop than recommended, you will draw more amps and 12 amp ESCs maybe not be up to it. 20 amp escs maybe a better choice. Going a little higher on the amp rating for the ESCs just adds a little weight and perhaps a few $ to the cost but won't otherwise cause any problems.

The ESCs you chose have a very wimpy BEC at 0.5A. Personally I would not use the BEC or use BEC'less ESCs (sometimes incorrectly called Opto) and use a separate voltage regular instead of an ESC BEC. Something like this...

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=75603

which provides 5v and 12v circuits and doubles as a power distribution board. 12v is good if you want to add a FPV camera. It may need a 4s lipo for the 12v regulator circuit to work though.

I have one to try but haven't got to it yet so I'm not recommending it specifically, just pointing it out as an example. There are other stand alone 5v BECs you can use. Doing this does add some extra wiring to get 5v power to the FC and RX but it avoids the BEC overheating the ESCs.

 

[Craftydan]

Hey Jason!

Long time, no chat

At 102W, that motor should be pulling just under 10A/ea, so as long as you go for the suitable prop (7x4) that combo should be light-but-good. You won't have much payload capacity with those motors on this frame, but "build something that flies", it will do. Keep in mind, when you upgrade, the motors/ESCs will be the first to go.

I'll agree about the C rating -- WOT you'll be pulling near 40A and hover will likely be 20-25A. On a 1Ah pack, you're looking at 40C minimum. I'm all for using what you've got, but if it's a 25C pack, expect to be replacing it soon

For the kk2's, you'll need a pack of male-to-male servo cables to connect the board to the RX. I'd also recommend picking up a USBASP adaptor to reflash the kk2 board. (you don't need HK's. amazon or ebay has ones that work)

The UBEC in those ESCs are indeed weak, but if all you're running off it is a kk2 and RX, you're just fine.

 

[airhawk]

yeah c raiting matters more but wheres the link for the battery i cant see the link.your escs are fine for now but as pressalltheknobs said get some thing higher

 

[Cyberdactyl]

I'll sound byte it.

The battery is painfully too small.

 

[JasonEricAnderson]

Thanks everyone! Most of the gear I have currently is what I've been using with my foamboard flyers, so quads are a whole new area for me. Based on all I've learned from your replies I'm going to rethink my parts. I'm a cheap bastard frugal so I'm thinking I'll need to throw some more budget to this if I'm really going to start the build.

I'm considering holding off on this build for a while and weigh the Fun/$$$ balance of building my own quad or sticking with fixed wing for now and perhaps getting an off the shelf quad to play with. I still have the Flyplotter project haunting me.

(Good to be back Dan)