Which one?

[voyager_663rd]

I've recently found the thread on the Tutor electrics that are being sold by TeamGad and I have a couple of questions.

I've only recently got interested in electric foamies (an F22 a buddy made up for me from scratch 'cuz it looked like loads of fun to fly :) ). I found out it was fun-surprise surprise-and was thinking of getting either the pusher Tutor or EDF Tutor.

Can't decide. I like the "bigger" EDF but I've read that the pusher version would generally be a better plane (more efficient to use a prop than EDF).

The price difference is negligible so that's not an issue.

And I don't necessarily want to get both in case someone was going to suggest that.

So the question is:

Which one should I get and why?

[Flyboy76]

If you not in a big rush, wait until some of us here that have the pusher and have spoken for an EDF get the EDF then we can give more info. Also Peter should be able to give the pros and cons of each.

geoff

[inhissteps]

If you like to do a bit of building, the F22 raptor foamy on RCGroups is a really easy build, and it flys great! It was my very first build and it went together very easy. I used cellfoam88 and reinforced it with CF Rod. plus it was REALLY cheep to build. If you have a small electrics already, pop them in and you have a great flying 20 buck jet that goes vertical.

[voyager_663rd]

Geoff, as said I'm in no rush (no flying till spring for me anyways) so I can wait. It wasn't so much these specific planes->pusher or edf<- but pushers vs edf in general I was interested in comments on.

Obviously I'd like to get opinions on these two specific planes but initially, just pusher vs edf in general.

Inhissteps, I believe that is the one I have already. But I only have the guts for the one I'm flying and the tutor I would get the motor, etc at time of purchase. I've never been into electrics so this is all initial outlays.

[millet_flyer]

OK, Here Goes…..

Performance……given the constraints of the airframe……55mm EDF is the max you can fit, however, you can go with better motors, more cells etc…..but you are still limited.

In bigger EDF`s you can put huge power in, however this comes at a cost. Power = Money + Weight. Newton’s 3rd law applies here, every action has an equal and opposite reaction….Lighter wallet, heavier airframe, better penetration, higher landing speeds.

Pushers by definition, a prop is always more efficient and the costs are lighter. Single motor, single prop….leaving the only variable as the Cells….of course bang for the dollar, you will always get more power on a prop compared to EDF……however….EDF will always have the edge as far as speed is concerned.

Your EDF is almost always pitching at 100+mph Efflux, mostly with big power systems you’re looking for 3 x stall or about 160mph efflux…..given the drag factors of the airframe and the relatively low thrust to efflux ratio, you would get maybe 120mph, obviously as the thrust goes up the effective Efflux increases…..

Prop Jets, Cheap motor $20, cheap cells $30, cheap ESC $20. Power to weight 1.5-1 goes vertical and accelerates….but prop pitch is limited to 90mph….so the max you will ever reach is 70mph…

EDF….Pricey EDF system, Combo say $70, ESC $40, 4Cells $70 (rpm = thrust and speed) Efflux is at 140mph… aircraft struggles away with .9-1 power to weight…..but when she bites….straight up to 120mph…wont accelerate vertically, but will hold speed for say 300 feet until the pitch speed is over the airflow coming in……then the EDF starts to stall…speed drops off….

Long and short both have their upsides, however EDF is still magic, and you need to understand airflow, FSA ratios, output ratios, and generally be excellent at all things sad and geeky to make them work to their potential.

Pushers generally work right off the shelf….and perform pretty well, even in the hands of inexperience!!! Just got to watch for those that mismatch prop to motor and motor to Aircraft, huge torque reactions and generally poor slow speed performance…..

As it was explained to me. Thanks Mike.

Hope this helps………

[voyager_663rd]

Thanks. A good starting point for me. I'm sure I'll have more questions soon enough. Thanks for taking the time.

BTW, Merry Christmas & Happy New Year :)

[voyager_663rd]

A couple more ? then:

Your EDF is almost always pitching at 100+mph Efflux, mostly with big power systems you’re looking for 3 x stall or about 160mph efflux…..given the drag factors of the airframe and the relatively low thrust to efflux ratio, you would get maybe 120mph, obviously as the thrust goes up the effective Efflux increases…..


Would you explain a bit more please: "pitching", "Efflux" "obviously as the thrust goes up the effective Efflux increases….."

And this:
you need to understand airflow, FSA ratios, output ratios, and generally be excellent at all things sad and geeky to make them work to their potential.
Do you mean by this just that you need to fly them "hotter" ie they fly more on the engine than on the wings so to speak?

Does the EDF tutor you're selling fit into this category? I guess what I'm asking here is: is your EDF tutor more for an experienced EDF flyer (I fly glow & gas so am not inexperienced flying per se, just a noob at pusher electric and no experience at all with edf).

[millet_flyer]

Ok,

Pitching actually refers to impeller pitch. Works the same as a prop.

Efflux is the equivalent to Pitch speed. More closely, the discharge velocity of the EDF.

The Tutor EDF flies well with a 3S pack. It has a lighter wing load in this configuration. As a result, the glide ratio is a little too good. Using a 4S pack will definitely turn up the heat. Higher RPM, Higher Speed (Efflux) and increased weight (extra cell).

Fly it hotter... no, it's a trainer platform. It's flown on the generous wing. Fast or slow.

You'll have to forgive me, I'm just getting into EDF myself. Hope I'm making sense of this for you. I had to ship my Tutor EDF to California so I'm at a loss. Flight performances were forwarded to me from the testing that took place in the UK.

[voyager_663rd]

still not clear on the efflux etc but as it's trainer-like and flies on 3s (which is what I'm using now, all I need to know is the other question (wheel size on grass).

With your stock wheels at 1 1/2, going to a 3 is not really practical from a weight p.o.v. (I only fly off grass).

Hopefully it can be hand launched/will wait for an answer as nothing is happening till the end of Jan anyways.

[millet_flyer]

Len,

Sorry missed that one, yes it hand launches.

I roll off soccer pitches with 2 inch wheels. Works on my old stock e-starter, it weighs about the same.

[voyager_663rd]

Len,

Sorry missed that one, yes it hand launches.

I roll off soccer pitches with 2 inch wheels. Works on my old stock e-starter, it weighs about the same.

You didn't necessarily miss it. It was asked in the other (long) thread where the tutor was introduced.