APC Thin experiences

[i love nachos]

I am very familiar with balancing props. What I am looking for is some advice on diameter and pitch. For planes I alway split the diameter to get pitch. I just dot know what the happy formula is for a hex.

 

[DucktileMedia]

I'm curious if there is some weird oscillation that can occur when using 2 different props in a coax setup. I know there are tons of people using all kinds of varying props top/bottom so it's unlikely but my results are showing under load that the heli shakes to pieces.

 

[Bartman]

yuri,

i'm running the same motors and props on arms that are 1/4" smaller in diameter with a heli that is about the same weight (maybe heavier) without any of the problems you're having. have you tried taking all your motors off to see if the bearings are shot from your encounter with the band saw?

been flying all sorts of prop combinations for over a year now and haven't seen any weird oscillations like what you're experiencing.

 

[DucktileMedia]

I replaced the motor that had issues. Thats not it. It also flies perfectly fine on slow flys. The APC thins I tried tonight had no issues. it's most likely a balance issue. As most who have tried unbalanced props, they generally arent so bad out of the box you cant fly them, they just dont work for smooth video. Well these, after 4-6 hours of balancing and centering are stil making my arms jump around like I was missing a blade!

 

[kloner]

I am very familiar with balancing props. What I am looking for is some advice on diameter and pitch. For planes I alway split the diameter to get pitch. I just dot know what the happy formula is for a hex.

that is a hover thing and these hover so most the prop choices we make when setting something up counts on guessing the right kv to make it happen. almost all props made for mr's are the 50% rule you note,,,,, 9x5, 10x5, 12x6 and so on

when were fitting a rig for props, were looking at how it hovers throttle wise. You want to aim for 50% throttle for a hover. the weight of the craft, how well the kv matches said craft all have a say in what size you need. Your arms usually dictate a max size..... but smaller and faster props are usually better in wind

 

[Breezemont]

I am very familiar with balancing props. What I am looking for is some advice on diameter and pitch. For planes I alway split the diameter to get pitch. I just dot know what the happy formula is for a hex.

I highly recommend getting yourself a watt/amp meter and build a simple test stand.
When you are buying at least 3 props at a time it's really frustrating and expensive to be guessing.
Here is some basic multicopter prop rule-of-thumbery:

At the same prop speed and diameter the higher the pitch the more amps drawn.
For slow flying and hovering use the lowest pitch and largest diameter you can for torque and efficiency.
For fast flying/acro the higher pitch is more dynamic has a higher top end speed.
There is also the issue of weight, and prop blade design, KV, etc.
The thin prop is, well, thinner which means it doesn't have as much torque as a fatter blade SF.
It's heavier, so there's more load on the motor to spin it.
If the pitch doesn't match the KV you can get magic smoke.

Like so many things, it just depends on what you want to do.

May I recommend some light reading as well?

 

[Breezemont]

Well these, after 4-6 hours of balancing and centering are stil making my arms jump around like I was missing a blade!

Have you checked the tracking on all of them?

 

[tahoelight]

@Iris
This is not APC TE specific as I now use wood props, but I thought I would bring it up since you are getting wierd vibes or occilations. It is easy to overlook the basics with the amount of time we spend on these rigs. Even though the props are balanced on a balancer, there are more steps to take if you are shooting video. Have you tried strapping a vibration meter to one boom at a time. (iPhone app.) First, spin each motor one at a time without prop and add a tiny bit of tape to one spot. Move the tape around the prop until you find the sweet spot and add more tape if needed to get reduced vibes. (this is balancing the bell) then spin up each motor with the prop attached. Check the vibes. Turn prop 1/8 of a turn on motor and try again. Do this until you find the least vibes and make a mark on the prop and bell to be able to reference every time you put the prop on. Number the prop and the motor and the boom. For coaxial, you may want to even check vibration variation with one prop spinning vs both props and make some changes to prop placement based on what you find. I truely believe there is more to balancing that just balancing each item individually. Yes, it takes hours! But we'll worth it.

I did this late one night on a shoot in Baja when my video went from smooth to vibes earlier that day. I was taking the props off for transport to each location. The next day after going through the process I had buttery smooth video and could take off the props without worrying about balance issues since they were marked.

I think the wood props and thin electric APC both need major balancing sessions for Hub balancing. I gave up on Thin electric APC for this reason, but gave wood a chance this year and have been happy. Not Xoar, but JFX since I am a cheap a$$. I think they are the same, but have not had Xoar to compare. This post just reminded me I have not done this on my X8 since rebuild. I know what my project is today....

 

[Breezemont]

Along those lines, some interesting info from OMM (when he speaks, I listen...):

 

[DucktileMedia]

this much work I might as well get a SRH! I am looking out for those tiger carbon props, see how those do with balancing out of the box. I dont think to balance motors since the slow fly's work fine on there. They arent perfect but they do a pretty good job. And yes, the thins are just as much a PITA to baance but one thing I like is that I can sand away material without having to re seal anything. For whatever reason my personal experience with the Xoars has not been as good as others out there. It's unfortunate as they look like really nice props all around, other than the balancing act and oversized bore.

 

[i love nachos]

Thanks guys. I appreciate the response. I will read through all the information and see what I come up with.

 

[tahoelight]

A SRH has more vibration issues than just props. They are a constant battle. Gears, bearings, balance, motor etc... Then they all change when you try to go to a different head speed.

 

[DucktileMedia]

Yeah, true. I've honesty never got good enough results with my 2 SRH but I didnt put much time in it before switching over to multis. But even a friend who has been doing it for years had tons of jello. These thins seem to be pretty good so far. motors not even warm. Using 12x6 tops and 13x6.5 bottoms on tiger 2814's 4s.

 

[Bowley]

I think the vibration isolation is very important on SR's, talking speculatively ie (out my arse): knowing what I have learnt from MR's and building and flying SR's just for fun flying, the idea of getting a heli's vibration down to that which it takes to get jello free video on my multi's seems like a gargantuan task. when I look at SRH setup they seem to step up a level when it comes to vibration isolation. I like the look of the new Align G800 Gimbal which has a similar sort of mounting method to the PS1 2&3X pro.
There are people using gassers and getting good video, the key there has to be isolation, as you are never going to balance out vibrations from an IC engine.

 

[DennyR]

The Align S800 gimbal looks like very good value for money. If it can compete with the Zen on pointing accuracy then its a winner. I just hope the dedicated stabilizer is not a rebadged typical load of crap. To get Zen type of performance requires two IMU's. Indirect servo drives are not great at the best of times but who knows what they have. Maybe their FC ballparks the camera and the high sensitivity bit comes from this little box of tricks. Align do make some nice stuff at times. What I like about it is the ability to carry heavy cameras like the Epic.

 

[DucktileMedia]

I'm gonna duct tape a cx760 to the head of a hawk and just tie a leash to the bird. Super stable. Balancing would be a quick meal.

 

[Lanzar]

That's what I wanted to hear. Thanks! Seems everyone is sold on Xoars, which may be the bee's knees when balanced. But they are hard to get, expensive and take a good amount of balancing. It will be interesting to see how a 12x6 thin compares to a 12x3.8 slow fly.

why are xoar hard to balance. 1min max with 1 prop and sandpaper. the best and easyest prop ever. we have them all in shop and we always use xoar. Maybe your method off balancing is just not that simple or you balance them too much.

 

[DucktileMedia]

Ok. I was planning on sending all my xoars back to their master- Bart. Maybe before I do so I will post s video of me balancing them. Clothing optional.

 

[helloman1976]

Where are you getting them from? Are these the Hobbyking knock-off versions? I use those, balance them and they are excellent and very stable. I use the 10"x5 pitch versions. Hope that helps...

 

[DucktileMedia]

We put in an order many many months ago with a few people. It took a long time to arrive and came straight from the source.