Quad Paul's Quad project

Stambo

Well-Known Member
Well I have everything but the frame. Order status has been "processing" for the whole week. Going to call Monday if they don't answer my email.

In other news I balanced the props on my 350qx. First time. Used a dubro. Nice unit.

Test flight was good. Seemed there was a noticeable change in timbre of the noise. Less chaotic. Smoother. Need a calm wind day to do some test recording.

Balancing makes a huge difference to quads.
I do it like this, it means props and motors are balanced as a unit.
I found a balancer made a difference but laser works even better for me.

 
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pvolcko

Well-Known Member
Might try that.

Pulled out a motor, esc, and a Rx I had here from the DX7s I bought last year. Soldered up connectors and put a temp deans on the ESC. Got endpoints set on the ESC and did some test spin ups (motor mounted/screwed into my work table). All good.

Half temped to build a balsa/plywood frame. :)

But I have enough bench testing and connector soldering to do for the moment so I'll hold off on that until I nail down whats going on with this qav500 frame.
 

Stambo

Well-Known Member
With a bigger quad it's a good idea to keep the arm off the table, anything with landing gear will be fine.
I found with a friends DJI hex with no landing gear, the bottom of the arm touching the table dampened the vibrations so it was not as easy to see the changes.
And also while you hold it down, don't hold too close to the motor mount as that has the same effect.
I use a servo tester on mine when I do it. Makes it easier to isolate the motors.
 

pvolcko

Well-Known Member
So, bunch of stuff showed up today all at once.

QAV500 frame (place I ordered from never indicated it was shipped!)
Down side is that they sent me the aluminum arm version, their site description indicated it was the G2 version so I got the tall legs for those arms. So I'm stuck with a set of legs I can't use (at least not without some mods).

KK2 board, minim osd, a power distribution board (before I knew I was going with the QAV500 which has a power plate), new OrangeRx 9ch Rx, an AR7000 DSM2 7ch spektrum reciever (in case this OrangeRX craps out too), and some cheapie OrangeRx sat rx units. I don't recall what I ordered them for. Maybe for the KK2's? Do they support sat rx direct? Or maybe I got them for the 3GX? can't remember.

There is a GPS antenna pole/mount on the way still. Otherwise I think I'm set to start building this quad.

I got another motor and ESC setup with connectors and tested. Also balanced the prop for it (keeping everything together in matched sets as I go). I'm finding that the props are easy enough to get balanced blade wise (so they fall horizon level on the dubro). But getting the hub balanced is a challenge. I'm trying fuzzy velcro with CA on it for the first go, but am finding I can't get enough weight on it to make it balance out.

What other options are there? What about drilling a pilot hole into the hub and using a setscrew or small hex head? Can grind off what isn't needed?

I've read it is generally not a good idea to remove material from the heavy side of the hub. At what point is it reasonable to do so?
 

WyDiablo

Member
I have used a dremel tool to remove stock from the heavy side of the hubs. Remove a little at a time and balance in between. I do this until I have a perfect balanced prop. So far I have not had any bad effects from doing this and the jello and vibes are at almost zero.
 

pvolcko

Well-Known Member
Work continues, slowly. Day job has been getting a lot of hours lately and my free time job is chewing up a good deal of the rest. Busy weekend so not a whole lot done since last update.

Props: I got some extra thick CA and some kicker from my LHS and started going to town. Finally got one the third prop to balance out. Went back and got the other two to balance out too. May need to touch up prop #2 again. My spin up bench test seemed to still have some vibration that the other two did not have.

ESCs and Motors: third set soldered up and ready to go.

Now that I have the heavy CA and Kicker I can make pretty quick work of it. Before I was using medium CA without kicker so it was a long adjust, wait to cure, test, adjust, wait to cure, etc. process. I've got pretty significant globs of CA on the hubs now. I don't care much about what things look like, but I am a bit concerned this stuff will crack and break off in flight, especially due to the layers of CA I put on. I dried the kicker off before each application of more CA, but I can see it maybe throwing a chunk in flight and putting things pretty seriously out of balance. Might hit the stuff with a black permanent marker that way if it does crack off I should be able to see it.

So one more prop and motor/esc combo to go and I'll have that all taken care of.

Frame is still in the box. That will be going together soon. Also need to order up the metal arm landing gear.

This week will be busy too, but this coming weekend I should hopefully be able to put some time into this and maybe even get to the point of programming the flight controller and all that.
 

pvolcko

Well-Known Member
Yeah, just placing the order now. I'll put the G10 gear up for sale. Or maybe hold onto them. I wanted the G10 arm version to begin with, but the place didn't have the right description on the item I ordered.

Separate issue:

Finished up the ESC/Motor soldering, setup testing, and prop balancing. Only to discover that one of the pusher props I have is not a SFP just a P. This is odd considering the place I ordered from does not have a non-SFP/MRP option in this size. I don't know if this makes a difference or not for flight. Airfoils look the same. The rest are SF and SFP. APC props. 9x4.7. I also, when I ordered these, didn't know the difference between SF, normal, MR, E etc. These SF/SFP props are rated at 65000/prop dia, which comes out to 7222rpm max rated RPM on these guys. My setup is 3S on 900kv motors, which is about 11.6K RPM, even accounting for inefficiency of .85 we're talking just short of 10K RPM.

So I placed an order for MR APC props which are rated at 105000/prop dia which gives 11.6K RPM max which is right where I need it.

My question is, will the SF/SFP props work even though I'm over rating on them by about 38%? That rating is for max speed. In general I'll be flying 50%-75% throttle which should keep me under limit most of the time with occasional quick bursts into full throttle. So I shouldn't be stressing them very often or for sustained periods.
 
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