DJI F550 Build

My next project is the DJI F550 hexacopter. I have most of the parts now. I am planning to use the 6400 mAh 3S batteries I already have.

Wait a minute, you've only just barely finished the GAUI 500X. 

That looks like a cool project. I've been eying the DJI 450 and F550. The videos I have watched of them are pretty impressive. The frames are quite tough and the DJI electronics very good.

The GAUI 500X is a great machine.  I like the way it flys and the way it looks.  Unfortunately I discovered it won't carry the weight of the gear I want to load it up with.  After testing the 6400 mAh batteries again with a better mount that was centered I found the GAUI 500X still struggled.  The DJI F550 should carry more weight.

I intend to use the GAUI 500X now more as a sport flyer and use the DJI F550 as my video and FPV vehicle.

There are some other attributes that the DJI F550 has that are interesting to me after having flown, and crashed, the GAUI 500X.  I will point them out in the build photos and comments.

I'll be watching. These things have my interest. 

One of the things that is not spoken about enough in my opinion is the DJI motors. The GAUI 500X, and most of the other multirotors that I have seen for that matter, all use a prop adapter. Below is a photo of the DJI motor on the left with a GAUI 500X Scorpion motor on the right. What you can't tell from the photo is that the $65 Scorpion motor has a bent shaft. I have been looking for a replacement shaft with no success so far so I had to purchase a entire motor.

Another issue is the GAUI 500X prop adapters. They are made of aluminum and fixed with a set screw to the Scorpion motor shaft. The prop adapter is hollow and once I over tightened one and it broke. Luckily I noticed it on the ground and not after getting the quad in the air.
As a interim solution I picked up a E-Flite prop adapter (part number EFLM1922) which is a great product, but it left a lot of the motor shaft exposed and the prop rode higher than the stock GAUI 500X parts. What is good about the E-Flite EFLM1922 is that it is a collet type and therefore no set screw to affect the balance and also potentially bend the motor shaft. If I had a machine shop I would cut down all the GAUI 500X Scorpion motors and use the E-Flite EFLM1922 prop adapters.

As you can see in the photo the DJI motor design incorporates the prop adapter into the motor housing and it is very strong looking. I would guess that it will be significantly more difficult to damage the shaft on the DJI motor compared to the GAUI Scorpion motor.

Not sure but isn't this the shaft you need ??

http://rcflightstore.com/product_info.php?cPath=295_259&products_id=3724

Thanks for looking w00d, but those are for the GAUI 330X GM-410 motors and I have the GAUI 500X Scorpion motors part number GM-412S.

If they would publish the specifications we could see if they are the same, or similar.  The GM-412S that I have are 48mm long and 3mm in diameter.  I have not measured the positions of the set screw flat spots on the shafts.  Randy at RC Dude (http://www.rcdude.com/) told me he has been unable to locate the shafts for the GM-412S so I more or less have given up for now.

NEVER Give up NEVER surrender

Try this one --->

GAUI 222414 3mm Motor Shaft for 222412 GUEC GM-412S Scorpion Brushless Motor 400W 960KV

http://www.dronesvision.com/gaui-222414-3mm-motor-shaft-for-222412-guec-gm-412s-scorpion-brushless-motor-400w-960kv/

EDIT: Only other is from GAUI Taiwan Page not the English Vs ... Either way both from Taiwan  which just set-off my BS detector

http://test.gaui.com.tw/shop/%E9%A6%AC%E9%81%94%E8%BB%B8%E5%BF%83%E5%8C%85guec-gm412s-960kv%E7%94%A8-p-611.html

Thank you w00d!  That looks to be exactly what I need.  Sure will beat $65 for another spare motor.

I maidened the DJI F550 tonight in very strong wind.  I used the 6400 mAh 3S LiPo and it can lift it without problem but it was a tad twitchy but could very well have been the wind.  I used a Traxxas battery connector on this model because they are easier for me to grip and I was getting tired of the EC3 connectors I have been using getting loose in the blue plastic housing.  Because of the Traxxas connector I was unable to test fly a lighter battery until I make a adapter or cut off the EC3 on the other batteries.  Not sure I will do that yet though.

It looks like other folks are using Turnigy 6000 mAh 4S batteries in their DJI F550s so I am looking into that as a possible option.

Yeah it does look exactly like what you need and there in lies my problem ... Why are THEY the ONLY Links who have this shaft? ... And the second link don't seem to work, when trying to make a purchase ... Looks like a broken site

Anyways as I said they Set-OFF my BS-Detector so be careful Yoda

[size=1.1em][shadow=grey,left]w00d[/shadow]
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What's with big deal this shaft problem?  The 3mm is probably the most common shaft out there.  You can buy them anywhere.  You can buy them at Al's!  They almost all have the snap ring groove on the bottom so the worst problem you could have is needing to make a flat with your Dremel or a file in the right place.  Am I missing something here?  I must be.  This seems so trivial.

...Tiger

Actually they are not common.  Most are 3.175mm which is 1/8 inch not 3 mm which is the shaft of the GAUI 412S motor.

Yeah 3.17, same as my 450, but what tiger is getting at is you can buy either size at McMaster Carr and zip tie a drill to a table, chuck the raw shaft in the chuck and use the little cut off wheel of a dremel to score a snap ring groove in the spinning shaft stock, then part it off with the same method.

Why is it that guys with CNC mills and lathes always have easy solutions for making metal parts?

I maintain that 3mm is very common, but if you are going to McMaster, buy a 3mm drill blank.  It's insane strong and very precision.  I've made plenty of motor shafts out of those.

...Tiger

That's because before we had a CNC all we had was a hack saw and a hammer. One time I fixed a broke down motorcycle out in the mountains with a stick and a rock.

Right!  And once I made a motor shaft out of a rusty nail. 

...Tiger

I've found that the DJI with a Naza wants a lower gain than the GAUI 500X with a Naza.  I don't know why that is, I was expecting to see similar values plus/minus a tad but on the GAUI I am using 150% and on the F550 I am at 100%.  150% on the DJI makes it fly kind of jittery.

The F550 really likes the 3S 6400 mAh battery and I got a solid 18 minutes flight time.

18 minutes? Jeeeeez, 3 batteries for an hour? With a good charger and only 10 batteries you could fly non stop all day.......

You'r going to need a lawn chair with flight times like that.