E550 Radikal ? Lets try it

[Dennis P]

I was going to do this well over a year ago but it just was not getting done. So here we go with a 6s 550 blade size Radikal E series. I am starting with my favorite heli which is my stretched E640 which I have ran 690 and wide cord 660mm blades on. This heli was bought crashed and rebuilt into a stretch from the start. I have about 150 flights on it presently and has been flawless. So with that being said lets see if we can mess it up. I am not shrinking the boom at this point but a stock E640 boom is going on as well as stock tail gearing. I did some simple testing with a 6s 5000mah pack and it balances fine with it just about as far forward as it can go before it hits the radio tray area, so we will be fine with balance and it mounts up to the tray fine. I have chosen to use the Hacker A50-6s V3 which is there new 1100kv motor that is rated at 3000 watts.

[Furious Predator]

Interesting project, keep us posted!

[ngin]

It certainly sounds like an interesting project. I have always hopped that Century would come out with a 550 version of this.

What blades are you planning to use?

[Dennis P]

Originally Posted by ngin

It certainly sounds like an interesting project. I have always hopped that Century would come out with a 550 version of this.

What blades are you planning to use?

I will be trying the RotorTech 560mm FBL blades to start . I am just getting the ESC and motor connectors finished up so I can get them installed. The new Hacker is a lot lighter with the hollow upper motor shaft.

[MotorRotor]

OOOeee Dennis, I for one will be very interested in how that turns out!!

[Dennis P]

I did a little mod that Distructor had done with his E640.If you are not using futaba servos it is very likely that you cannot run the balls on the underside of the servo arm for the elevator servo in the rear. I had sanded the servo mount down until I had just a hair of room between the servo and the frame and it worked. Later I seen that Distructor had cut out the side of the frame and then cut the servo mount down so the geometry was correct. Being that I was right there with the transmission removed I did the mod to the frame and mount. I need to find some new mounting screws and do a little final sand on the frame but it looks like it should be perfect now. I set the mesh ,ran up the motor and programmed the Jive .With any luck the tail should be back on tomorrow and some blades mounted back up.

[rotorsport]

Looks good Dennis. I might do that mod to my 2 E640s

Charles

[helinutz2]

Just curious, guys.

Isn't the whole premise of an E640 the ability to have 700 class performance from a 600 size heli?

So, what is the upside to 550 size blades and powerplant in a 600 size heli? Is it the ability to run only 6S?

[Dennis P]

Originally Posted by helinutz2

Just curious, guys.

Isn't the whole premise of an E640 the ability to have 700 class performance from a 600 size heli?

So, what is the upside to 550 size blades and powerplant in a 600 size heli? Is it the ability to run only 6S?

Yes the E640 is going to be a better performing heli with a 3300 12s setup and 610 to 640 blades but there are some that may want a single battery setup or they may have some 6s 5000 packs and do not want to buy a new HV setup. The simplicity of a single pack setup really appeals to some. For myself this is a test to see how it performs and if this can be sold comfortably as a 6s heli to customers knowing that it will perform and treat them well. The share packs things seems to go with 700 class heli owners have a 550 to share the packs with and 600 owners have a 500 heli to share packs with. Sparks and I PMd about doing up a 550 version of the E640 a long time back and I just never found the time to do it. The heli is feeling reasonably light and I think it will be fine .We shall see shortly !

[helinutz2]

Got it. That's kinda what I thought but wasn't sure.

Pack sharing between the 2 would surely help with the operating costs.

Thanks for the explanation, Dennis.......

[Dennis P]

Well it is basically ready to fly and with a Thor 5000mah 45c 6s pack installed , the 560 mains and 92mm tails on and a canopy it weighs 8.16 pds which I do not think is to bad as I just weighed my E5s with the same battery in it and it was 8.29 but with 610 blades on it so they are about identical weight wise. I think it should perform very well and I will have headspeeds of 2150 , 2300 and 2440 .I would guess it will be at the 2150 the most. Some assembled pictures will follow and if it ever warms up again some flight reports. Nice balmy -35 deg this morning

[Dennis P]

Well I think we are coming out of a very long and miserable cold spell and I hope to get some flight reports this weekend if it quits snowing. I had some issues with the Kontronik 100LV esc and my new hacker A50-6S motor . The version 9 esc would not start the motor normally (inductance to small) and after some phone calls I found the later Version 13 esc has repaired this but I need to send the esc back to Germany with a good amount of funds for a update. Long story short I have a Edge 100 in there now and all is working well but my headspeed will be limited some due to castles governor and pinion options presently. Fingers are crossed for some weather now.

[Dennis P]

Well we had lift off and I would say a very successful first flight. Being that I left all settings untouched in the V bar and radio, I was very comfortable with the heli flying well and it did. The power was very good and the only change I have planned before I fly it again is some more pitch in my N and stunt 1 flight modes. It still climbs out great but there is no sign of a bog anywhere and I find I am hitting full pitch regularly in these modes. Heli feels nice in the air and it sure does not feel heavy at all ,but not as floaty as it did stretched which is expected. I will snap some pics and add to the flight story once I have some more time on it. I was planning on putting it back to it's stretched status soon after testing but I think it may spend some time as a 550 6s machine. I flew 5 minutes and I used 68% but this did include a few spool ups on the bench with no blades.
Happy Happy happy

[MotorRotor]

Well done Dennis!!!! Two Thumbs Up for sure!!!

[MotorRotor]

Dennis, have you had a chance to try it with more pitch yet?

[Dennis P]

Yes I did put a couple more flights on it with more pitch and flying it harder. It does perform very well but being a HV guy I am a little shocked with the data logs as I hit a high of 185.7 amps on it. I would say the 560 mm blades and the weight along with a somewhat aggressive fight makes this combo consume some power. Do not get me wrong this fly's very well and has proven to be a very viable option for someone. I would say it will be great for a sport or below flyer and scale applications that do not want a high head speed and max performance out of the unit. If you want high performance and stick banging with higher head speed go 12s from the start as you will get lower temps , longer flights and you batteries will last longer . This is a fun combo though and feels very good in the air.

[ngin]

I am sure the 186 amp reading was a very temporary one (maybe a tenth of a second or so), so your continual flight average would have been a lot less then that. A 6 minute fight that required 4000mah to recharge would mean your average continuous draw was only 4 amp hours (4000mah) x 6/60 = 40 amps.

This 186 amp peak on a 6S pack with the 560 blades at those relatively high head speeds, means the momentary peak wattage draw was 22.2 x 186 = 4129 watts. So if one configured it for two x 4S packs (29.6V) then that peak amperage would drop down to 139 amps and the average would drop down to about 30 amps. For the same flight, one would only need 2 x 4S/3750 packs to get the same performance and flight time.

With a 10S (37) pack that peak amperage would drop down to 4129/37 = 111 amps and the average to only about 24 amps and one would only need 2 x 5S packs of 3000mah for the same flight and flight time.

The 12S pack would drop that amperage peak down to 4129/44.4 = 93 amps. The average would drop down to a miserly 20 amps. Two 6S/2500 in series would give the same flight with the same flight time.

Of not is that with these higher voltage packs, you would need an HV type of Speed controller, but it cold be one of relatively low amperage (e.g. an HV x 50 amp ESC). On the other hand, with the 6S pack, one would need a standard ESC with a high continuous amperage rating (e.g. at least 80 and preferably higher.

Of course all of the above is for an all out 3D type of flying. If you are going for a sport type of aerobaics (loops, rolls, flips and inverted flight or scale type of flying, then you will not need the high head speeds required above. Dropping your head speed down to just 1700 will drop the amperage requirement to less then HALF!

[ngin]

Originally Posted by Dennis P

Yes I did put a couple more flights on it with more pitch and flying it harder. It does perform very well but being a HV guy I am a little shocked with the data logs as I hit a high of 185.7 amps on it. I would say the 560 mm blades and the weight along with a somewhat aggressive fight makes this combo consume some power. Do not get me wrong this fly's very well and has proven to be a very viable option for someone. I would say it will be great for a sport or below flyer and scale applications that do not want a high head speed and max performance out of the unit. If you want high performance and stick banging with higher head speed go 12s from the start as you will get lower temps , longer flights and you batteries will last longer . This is a fun combo though and feels very good in the air.

Your readings prompted me to check out some of my Eagle Tree read out graphs I recorded this past summer, on my lighter Swift NX with 530mm FunKey blades and 6S 5000 packs set up to turn at 2150 using an 1110 KV motor and 80 am ESC.

There are a couple of very brief millisecond peaks showing at 110 amps with the average draw over the complete flight being only 30 amps. The total draw over a 5 1/2 minute flight, with two autos, was only 3000mah.

So it does not sound like your battery draw is all that much more, But I would emphasize that a 6S configuration set for a high rotor speed would need a high amp ESC with some good high C battery packs.

[Dennis P]

I have done some more flights and have it is working well now. The gov gain needs to be dropped a few points but other than that it is working well. I dropped the pitch down to 11 deg and ran a flight at 1900 with the 560mm blades. The max amps was 86 so that is fine with a average of 35 amps . I the flew a flight at 2100 and had a max of 98.6 amps and a average of 42 amps . These where not real hard flights but strong sport flying as it was windy and cold with the sun just down . It is a much better setup for 6s now and at 1900 I used 66% of the 5000mah pack in 5 minutes so that is not bad . Motor esc and pack where just warm if that. So for those that like the simplicity of a single pack and are not after the wildest smack setup but still want something that performs the E640 with 6s and 560mm blades can fill the bill .

[MotorRotor]

Thanx for the report Dennis. Sounds like a good size consideration for many.