R&D Hex for Survey/Imaging/Conservation

[crayfellow]

how far off do you guys think I am with this setup (KDE 3520 and 15" prop, added 400g over our 3200g for good measure)? Am I going to get into trouble and need even longer arms/bigger prop? Or maybe barking up the wrong tree and should be doing an X8 or something?? Or am I close?

View attachment 24663

I will say this 13min flight time estimate is a pretty big bummer, hoping to do better.

 

[Mactadpole]

You could always run a 16" prop. Also, I went and looked up the weight of the Tattu 16000mah 15c and it is 1931.7 g. So I adjusted the weight per cell on ecalc configuration.

View attachment 24664

I know your pretty set on KDE motors, but when I was putting my build together I spent hours running different motors (including KDE) and props on ecalc and was also really tempted to go with the Tiger motor U5.

U5 w/15"
View attachment 24665

U5 w/16"
View attachment 24667

 

[Motopreserve]

It's been a while since I used ecalc - but are you including the weight of the gimbal in the AUW? In the past - pretty sure I only listed the AUW of the craft - then the program spits out the payload capacity - which would be where your gimbal is included.

 

[Mactadpole]

It's been a while since I used ecalc - but are you including the weight of the gimbal in the AUW? In the past - pretty sure I only listed the AUW of the craft - then the program spits out the payload capacity - which would be where your gimbal is included.

I include the weight of the gimbal and camera in the model weight.

Here are their definitions for: All-up Weight: Calculated Flying weight (Basic Weight + Drive Weight, add payload is NOT Considered.) add. Payload : Maximum additional payload possible to hover with 80% Throttle to garantee maneuverability. (We recommend below 50% throttle for arobatics and below 80% throttle for Photography)

From my experience with eCalc is I pretty much get out of it what I put in. For the current copter my results on flight time and current are slight better. My real-life AUW is just under what I had input in eCalc.

 

[Mactadpole]

@Motopreserve - I am deviating from the topic but is relevant since OP is considering this gimbal.

How are you doing with the quadframe v2 gimbal and CP? I can't seem to get my dampening system (v3 from quadframe) to allowing the camera to bounce/wobble. I finally got the chance to test it without the CP connected and both axis locked in place and it just appears to bounce/wobble alot. This is with a Nex 5t onboard. I see it in my analyzer results with the CP too. I think the camera is not heavy enough or that damper system is crap as you suspect I believe. I have modified it to hang with different dampers but it continues to rain. We can take this into a private conversation if preferred.

 

[Motopreserve]

add payload is NOT Considered

That reads to me that the payload is not to be entered in the top section, and that the calculation should show you what the additional payload (gimbal???) would be. But that also seems that it would make the throttle percentage completely off if you were not using the payload capacity.

Not very straight forward...

I think in the past I did not include gimbal - and worked it so that the payload matched my gimbal - and was shocked when the flight times very very close. With the heavy lifter they didn't have my motors, so I did calculations on my own.

 

[Motopreserve]

I ended up giving up on the CP... all together really.

I have another gimbal I will still mess with - but ultimately, it did not play nice at all with 3 gimbals I tried. I now believe the CP wants HEAVY to be happy. I put it on a DYS with a Canon camera and it got better values than it ever had - but it also freaked out at a certain point. So really that is a fairly uneducated guess.

 

[Mactadpole]

That reads to me that the payload is not to be entered in the top section, and that the calculation should show you what the additional payload (gimbal???) would be. But that also seems that it would make the throttle percentage completely off if you were not using the payload capacity.

Not very straight forward...

I think in the past I did not include gimbal - and worked it so that the payload matched my gimbal - and was shocked when the flight times very very close. With the heavy lifter they didn't have my motors, so I did calculations on my own.

I should have separated the add. Payload definition. There is nowhere to insert payload (that I see), it just outputs that add. Payload number on its own. That's why I include it in the model weight.

My interpretation of add. Payload is that is the amount of extra weight you can put on it and still fly at 80% throttle. No?

 

[Motopreserve]

You may be right. But it's confusing with them throwing in the mention of 50% as recommended - that throws me a bit. How would you know it's 50%??? It seems it would make more sense to state what the rig would handle and then allow you to tailor the payload to fit what it says it has in reserve (as additional payload).

EDIT: Just ignore me - you guys seemed to be ding just fine before I piped up. I'm just muddying the waters!

 

[crayfellow]

You could always run a 16" prop.

I'd be limited to 15" with the 400mm arms, and really probably should not go bigger than that as this is going to be difficult to travel with as it is. Would you run 16" prop on your SIX with 400mm arms?

I know your pretty set on KDE motors, but when I was putting my build together I spent hours running different motors (including KDE) and props on ecalc and was also really tempted to go with the Tiger motor U5.

I'd do whatever is the optimal combination of safety, stability, quality, and cost with a personal bias toward US companies. T-motor still could win if it's got the right combination. BTW isn't that $108 deal you linked to a heck of a deal or is helidirect not trustworthy?

Thanks guys for sharing your experience, it's immensely helpful even to see the dialog back and forth.

 

[Motopreserve]

I don't want to give you a heart attack by suggesting more spending, but.... If you are concerned with transport - I've found that the quick change adapters used with the 3-hole style props was a huge advantage. Not only does it make it easier to move around, but it also ensures you don't nick expensive props getting out the door/into the car etc.

 

[crayfellow]

I don't want to give you a heart attack by suggesting more spending, but.... If you are concerned with transport - I've found that the quick change adapters used with the 3-hole style props was a huge advantage. Not only does it make it easier to move around, but it also ensures you don't nick expensive props getting out the door/into the car etc.

hmm - yeah. I hadn't seen those, and that does sound useful. Better than folding props, potentially. Seems slick.

Speaking of props, isn't going to a 3-blade prop an option too, if I am at 15" and need more flight time for some reason?

 

[Mactadpole]

I'd be limited to 15" with the 400mm arms, and really probably should not go bigger than that as this is going to be difficult to travel with as it is. Would you run 16" prop on your SIX with 400mm arms?




I'd do whatever is the optimal combination of safety, stability, quality, and cost with a personal bias toward US companies. T-motor still could win if it's got the right combination. BTW isn't that $108 deal you linked to a heck of a deal or is helidirect not trustworthy?

Thanks guys for sharing your experience, it's immensely helpful even to see the dialog back and forth.

I can run 16" just fine of the 400mm arms, they are close but I don't think too close. I'm getting ready to right now as soon as the rain and wind stop.

That$108 is a heck of a deal. Helidirect is good as far as I know. I have ordered things from them in the past and not had a problem. It's worth checking around on the forums to see if anyone else has.

 

[Mactadpole]

hmm - yeah. I hadn't seen those, and that does sound useful. Better than folding props, potentially. Seems slick.

Speaking of props, isn't going to a 3-blade prop an option too, if I am at 15" and need more flight time for some reason?

I am still a bit confused on the 3-blade prop thing myself. I read great things about them and that if you use the 15" DJI props it is like flying a 16" prop but there is a loss of efficiency. But with my setup I get slightly longer flight times with lower throttle hover position with 2-blade 16". I need to do some more research on how all that works so can't comment on it.

 

[Motopreserve]

The three blade option gives you more thrust/lift, but you give up some efficiency. If you are also going for long flight times, that's something to consider.

 

[Mactadpole]

I don't want to give you a heart attack by suggesting more spending, but.... If you are concerned with transport - I've found that the quick change adapters used with the 3-hole style props was a huge advantage. Not only does it make it easier to move around, but it also ensures you don't nick expensive props getting out the door/into the car etc.

Do you have a quick link to those?

 

[Motopreserve]

These are reasonable: https://aerialpixels.com/shop/uncategorized/quick-release-prop-adapter/

I didn't realize the U5 was such a monster. 900g thrust at 50% with a 15" prop! You'd be over powered at that point

 

[Motopreserve]

The 3-blade deal is just more surface area for lift. I think it's the equivalent of adding 1.5" to your prop. But of course it needs more juice to spin it with the added weight, resistance etc. so that's where the efficiency loss comes in.

The balancing of them weird me out a bit. You can only "balance" by weighing each blade. But that doesn't take into account the specific problem areas of hub vs blade, leading edge vs trailing edge etc.

 

[Mactadpole]

I didn't realize the U5 was such a monster. 900g thrust at 50% with a 15" prop! You'd be over powered at that point

Thanks for link!

Look at the eCalc screenshot on previous page with the projected AUW and 15" on the U5 it has you hovering at 50% throttle.

 

[crayfellow]

Look at the eCalc screenshot on previous page with the projected AUW and 15" on the U5 it has you hovering at 50% throttle.

yeah I thought it looked pretty good, no? good efficiency, and better flight time all things being equal?

are those restrictive about ESC's they are happy with?

I may still go KDE 3520 but I want to make sure I understand the comparison.