Originally Posted by jofro

Another rarity EDF jet of my fleet, highly modified not only frame-wise, but power-wise with its unique only 4S powered 90mm EDF unit off the 80A speedy.
To reduce the current draw I have cut out 3 of the 12 impeller blades spaned by the "Emax -36/60", 1650kv motor. Running off the 4S/2.65/45C pack it pulls some 2.2 kg at some 35-40A/550-600W.
At 1250g. AUW, it is pretty lively flier, either off its simple removable landing gear with steerable nose gear, or off the catapult launch, as my preference.

Took it out again to finish off the year.

Perfect EDF set up.

2020 1231 221450 023 Thunderbolt in action (6 min 25 sec)

(Thunder catapult)

I have just gotten a 28" dumas air boat, Years ago I ran .035 supertiger, but the lake I sail on now no gas motors are allowed. So I would like to know what electric motor would be a sub for a 34 gas. Speed isn't super important , as We are planing to use this boat as a rescue boat for our sailboat fleet.

Batteries and esc recommendation also welcome.

I'll sticky this for a while to see how it grows.. Hydraulic steering system Dubai . Simply contribute what has worked for you - start another thread to discuss a particular setup if you'd like..

There is a plane with a wingspan of 80cm. What motor and battery should be installed to fly at speeds up to 150 km / h? 4s or 6S? It is desirable that the currents be up to 30A. thanks

Originally Posted by unixoid26

There is a plane with a wingspan of 80cm. What motor and battery should be installed to fly at speeds up to 150 km / h? 4s or 6S? It is desirable that the currents be up to 30A. thanks

Show me the plane.

Originally Posted by unixoid26

There is a plane with a wingspan of 80cm. What motor and battery should be installed to fly at speeds up to 150 km / h? 4s or 6S? It is desirable that the currents be up to 30A. thanks

The following it wrong! I had some kind of brain fart in converting cm to inches... :>)

I'm not sure that is practical, that would be a wingspan a little less than 12" and flying at about 93 MPH.

If you look at the propeller test data here:

http://www.flybrushless.com/

You'll find it is hard to find a prop that might work on a plane that size that has the 100 MPH or so potential. If you find one you want to try, you need to choose a battery voltage and Kv specification that will get the prop up to over 100 MPH in speed and then build for minimum drag...

Good luck with it, if it works come back and show us the plane and tell us how it went.

Jack

80 centimeter span is not 12, but 32 inches. Check your math. LOL.

Originally Posted by jofro

80 centimeter span is not 12, but 32 inches. Check your math. LOL.

Thanks for correcting me, I don't know how I came up with that and posted it without recognizing the blatant error!

Jack

Following the format from OP:

Model/subject: Great Planes RV-4 (Quarter Size) 70-inch wing span
Motor: Leopard LC5065-520Kv
Speed Control: Hobby Wing Sky Walker 80-AMP (BEC Disabled)
External BEC: Castle Creations BEC PRO (20-AMP) - Dual Power Output to Receiver
Cell type/count: GENS ACE 5-Cell, 5,000mAH, 45C, Lithium Polymer
Prop: APC 14 X 8.5-E
Reduction method and ratio: Direct Drive
Amps: 48.76 AMPs @ Wide Open (27-AMPs cruising at 1/2 Throttle)
Watts: 1,003.22 WATTs @ Wide Open
RPM: Approximately 7,773 RPMs
Weight Read to Fly: 11.2 lbs.
Comments: This is a Glow-To-Electric Conversion Project.

The selected power system and prop selection was perfect. I did go to GravesRC (Hobby Shop) here in Orlando, Florida and purchased a brand new GENS ACE 5-Cell, 5,000mAH, 45C, Lithium Polymer as they were on sale plus two APC Propellers. One propeller was the APC 14 X 10-E and the other APC 14 X 8.5-E of which I selected the APC 14 X 8.5-E and it flew just magnificently and was mostly 1/2 throttle and when I increased to two (2) clicks above 1/2 throttle that motor spooled up and you can hear the propeller cutting through the air.

Very pleased on the Vented Spinner as it is very well balanced and didn't exhibit any vibrations or ugly noise coming from that business end.

At one point, I tried to slam the throttle and kicked in some rudder and up elevator and this RV-4 almost behaved like a 3D with a few snap rolls. I didn't attempt another one of those and glad I was UP 5-mistakes High!

Without any further delay, I will be sharing the Flight (Maiden) Video, thanks to Gerry Rivera who recorded it and along with the Still Pictures during the 2nd Flight.

Great Planes RV4 70 Inch Wing Span Glow To Electric Project Maiden Flight 09 04 2021 (3 min 55 sec)

Originally Posted by jackerbes

The following it wrong! I had some kind of brain fart in converting cm to inches... :>)

I'm not sure that is practical, that would be a wingspan a little less than 12" and flying at about 93 MPH.

If you look at the propeller test data here:

http://www.flybrushless.com/

You'll find it is hard to find a prop that might work on a plane that size that has the 100 MPH or so potential. If you find one you want to try, you need to choose a battery voltage and Kv specification that will get the prop up to over 100 MPH in speed and then build for minimum drag...

Good luck with it, if it works come back and show us the plane and tell us how it went.

Jack

It's incredibly easy to go ~100mph on that size model with modern power systems.

Another successful power set up I have created while converting couple of micro kids gliders to full RC control EDF jets.
60 hours plus, of TLC for each to create, with the great reward at the end.
30mm EDF power, running via 30A speedys on 3S of various capacity highest C rated packs from 0.5 to 0.85Ah.
AUW of each is some 265 grams, with tremendous thrust improvement of my #2 model after internal more efficient air duct re-design.
Just love it.

hello jrb - is this the right place to ask?

I'm thinking of a twin - high wing, T-tail - like the Dash 8
not scale... 840mm span, 33 inches... foamboard

twin props and motors is obvious, but what about the power options?
- twin motors, twin esc's, twin batteries - only the control signal in common
- twin motors, twin esc's, single battery
- twin motors, single esc, single battery

and there's always differential thrust - two esc's on separate Tx channels - can the Spektrum DX6i do ths?

please remind me which is better?
- shortest leads battery to esc
- shortest leads esc to motor

interested in advice and actual, flying, examples
thanks

Better give your questions their own dedicated thread(s).
More people see/read/answer them that way.
This sticky is intended for posting successful power systems.
In your case say after a month or two from now
Some Dash_8 threads, the prefab advanced search needs activating.

Vriendelijke groeten Ron
• Without a watt-meter you're in the dark ... until something starts to glow •
• E-flight calculators • watt-meters • diy motor tips&tricks • Cumulus MFC •

Ron,

Thanks for that reply!

It would be helpful if people keep the OP's Format so, people could see "Successful" Power Systems and not weed through tons of other stuff like questions and other posts.

Please use the OP's Format!

If you visit the very first post you will see his format!

Model/subject:
Motor:
Speed Control:
Cell type/count:
Prop/fan:
Reduction method and ratio:
Amps:
Watts:
RPM:
Weight Read to Fly:
Comments and links to other forums for more info, video