R&D Hex for Survey/Imaging/Conservation

[crayfellow]

fellas, parallel track here: wood props. I think they look awesome, have a historical look, and are well suited to a 'conservation' craft. there seems to be a lot of debate about how they behave in changing weather, and as a guitar player I'm well acquainted with what can happen. But it seems like they should help absorb vibration too. What's the deal? I see AP folks running Xoar and they are cheaper than CF, right?

 

[Motopreserve]

I have some wood props. Xoar is the Cadillac. They are fairly light and definitely rigid. I like them - but I think the CF I have are a nicer ride. Also, the CF are the ones that allow the quick-release, which at this point I'd put on every rig I have. The ease of use and peace of mind (I have to do a nasty dance to get my 900mm hex out the door).

And for the record - my CF props are knock-offs. Probably $20/pair?

 

[ary]

My build, I got 38-40 min with this config. This is an early stage to test in various wind condition, quad config, way point, Eazy uhf, other component for long distance flight.
Next step will be quad with 29inch props

 

[crayfellow]

My build, I got 38-40 min with this config. This is an early stage to test in various wind condition, quad config, way point, Eazy uhf, other component for long distance flight.
Next step will be quad with 29inch props

craziness!! what is the config for that one (I know you said KDE 3510 475 kv earlier), and for the one you are planning? What is the ultimate goal?

For this build I think I have to go 3520 400kv in order to safely haul gimbal and camera (GH4 or similar experimental equipment).

I definitely need to get my HAM license so I have UHF as an option.

and a probably silly question: when not running t-style props with the screws, how are those massive props attached? just lock nuts? any trick to it?

 

[crayfellow]

I have some wood props. Xoar is the Cadillac. They are fairly light and definitely rigid. I like them - but I think the CF I have are a nicer ride. Also, the CF are the ones that allow the quick-release, which at this point I'd put on every rig I have. The ease of use and peace of mind (I have to do a nasty dance to get my 900mm hex out the door).

Yeah. I still don't really understand how the non-t-style props remain attached. Even my little 250 quad is tricky getting the lock nuts just right on the props.

The more I think about the wood, the more I think it's a pretty cool option. I want to be sure of the rig before sending it off with $76/pair CF. Xoar 15x5 seems to be about half the price, right? Not a bad deal for a Cadillac. I just like the organic nature of having some wood on there; maybe it'll be the only folkie/woodsy craft out there.

And for the record - my CF props are knock-offs. Probably $20/pair?

That could be a way to go too, but the wood guys are not much more.

When this is first built, I should be using APC 15" from the local hobby shop anyway for tuning, right?

 

[Motopreserve]

Yes. APC would be a nice choice to save the wallet some pain in the event of a tip over

 

[ary]

craziness!! what is the config for that one (I know you said KDE 3510 475 kv earlier), and for the one you are planning? What is the ultimate goal?

For this build I think I have to go 3520 400kv in order to safely haul gimbal and camera (GH4 or similar experimental equipment).

I definitely need to get my HAM license so I have UHF as an option.

and a probably silly question: when not running t-style props with the screws, how are those massive props attached? just lock nuts? any trick to it?

For commercial purpose.
Multis with 45-60 min flight time with 2-5kg payloAd
Thin electric are less efficient but perform better stability in high wind. Compare to tm cf

 

[fltundra]

My build, I got 38-40 min with this config. This is an early stage to test in various wind condition, quad config, way point, Eazy uhf, other component for long distance flight.
Next step will be quad with 29inch props

35 min is a walk in the park. (4S10000 1oc) It's when you start adding gimbals, strobes, vtx, osd, and cameras it's not so much. and still fit on the front seat of a midsize vehicle.

 

[crayfellow]

35 min is a walk in the park. (4S10000 1oc) It's when you start adding gimbals, strobes, vtx, osd, and cameras it's not so much. and still fit on the front seat of a midsize vehicle.

Yeah. At this point I am thinking KDE 3520 400kv, 15" prop, 6S based on our estimates for gimbal, camera, FPV, and research equipment. What do you think? When I plug it into ecalc it looks OK, and even if we radically reduce the weight it simply increases flight time (in case we are way off on the weight estimate, but I think we are close).View attachment 24673

 

[fltundra]

2x http://www.getfpv.com/batteries/flight-packs/tattu-9000mah-6s-25c-lipo-battery.html
View attachment 24674

 

[crayfellow]

yeah, that seems good. but MAN oh MAN those things are expensive! I know it's another controversial subject, but do you agree with Patrick (KDE) that Tattu are worth it?

 

[Mactadpole]

I think its an excellent suggestion to just get some APC's to start with. Easy to balance and reliable. I just decided after being part of this thread to order some APC 15 & 16's to see how they do.

FWIW - the cheap CF props I have gotten have a variable qualities of surface finish and most hubs are seriously out of balance.

 

[Motopreserve]

I've had the same experience with the cheap CF props. But I have been able to get them balanced - just takes more time. When I got them - I was willing to sacrifice the elbow grease more than the cash

 

[Mactadpole]

I've had the same experience with the cheap CF props. But I have been able to get them balanced - just takes more time. When I got them - I was willing to sacrifice the elbow grease more than the cash

Maybe yours are better than mine. I have literally added a whole bottle of CA to one side of a hub just to see if that would get it balanced. Nope. so I then started adding bits of small steel wire (2) with the CA and still not balanced.

 

[Motopreserve]

I've had more trouble with them than other props - but nothing like an entire bottle of CA.

I also do more on the leading/trailing edge with the t-motor style props than on others where the hub has more meat to balance.

 

[fltundra]

Tattu are worth it?

I don't no, but I just ran into not being able to get RMRC 4s8000mah's anymore. They stopped shipping them a while back because of the new lipo shipping regs.
I ordered the 7000mah tattu 4s and it came today and I must say they look like a lot of care was taken on assembly.
I have 175 cycles, 13 months with my rmrc's and IR has stayed the same since day one. New Tattu tested 1mohm straight across.
It better live up, as it cost me twice as much as the RMRC's did.

View attachment 24677

 

[crayfellow]

tried to get the list in the first post updated to reflect the current state of things.

 

[crayfellow]

I don't no, but I just ran into not being able to get RMRC 4s8000mah's anymore. They stopped shipping them a while back because of the new lipo shipping regs.
I ordered the 7000mah tattu 4s and it came today and I must say they look like a lot of care was taken on assembly.
I have 175 cycles, 13 months with my rmrc's and IR has stayed the same since day one. New Tattu tested 1mohm straight across.
It better live up, as it cost me twice as much as the RMRC's did.

wow. yeah, that is crazy. I just received some batts from getfpv on Tuesday, I wonder why this law did not affect that order?

Is your rig purpose-built for 4S? based on what you know of this build, does 6S seem correct to you? (build list on first page is pretty close if you want to check)

 

[fltundra]

Yeah. At this point I am thinking KDE 3520 475kv, 15" prop, 6S based on our estimates for gimbal, camera, FPV, and research equipment. What do you think? When I plug it into ecalc it looks OK, and even if we radically reduce the weight it simply increases flight time (in case we are way off on the weight estimate, but I think we are close).View attachment 24673

I think the 475's are your best choice, since your limited to 15's.

 

[crayfellow]

I think the 475's are your best choice, since your limited to 15's.

How so? Here is what I get with 3510 475kv:
View attachment 24679

and changing nothing else I get this with 3520 400v, far lower temp suggesting better efficiency, no? Am I missing something?

View attachment 24678