Power my Zagi

[Phil May]

Hi all.

I thinking of fitting a motor to the back of my old Zagi sloper.

I know this has been done in the past but have no idea what set up to use.

Any ideas, it must have some umph.

 

Cheers all

Phil

[Ben B]

If it's the 48" version then I had great times with a HET 2w25 inrunner on a 6*5.5 on 3S 2200mah Turnigy cell.

About 450 watts By this point I'd added a spar to beef it up a bit.

 

Before that it was running a 2200kv 2835 turnigy inrunner on again the 3S 2200 pack. Around 250w on a 6*4 I seem to recall. Not slow but you know how it is

 

Now I'm running a 40" Slipstream on the 2W25 with 4S on a 6*5.5. 1200 watts, lots of noise and silly fast.

 

 

[Ben B]

The correx elevons tend to flutter so it's worth adding some mass balancers (or some carbon rods down a flute to stiffen them) otherwise it breaks the spar and then the above happens. This is why I've now got the Slipstream!

[Erfolg]

I do not think it matters very much, what motor is used.

 

There were a few some years back that managed on 400 brushed motors and Nicads. Possibly 80w power in, at best.

 

Most now use at least use a brushless of 120w in. The odd one uses very high Kv, inrunners, these tend to b unacceptably noisy. Most use outrunners of modest Kv. One at least used a low Kv outrunner. All are now Lipo powered, most on 3s, just one 2s. which is distinctly underpowered.

 

I guess Zaggi types are owned by at least 20% of the club, maybe as high as 50%.

[Ben B]

Mine had 80W to begin with but was woefully underpowered. Talk about slow..... Good for re-learning but it quickly got boring.

 

The other issue is that with 80w it takes about two or three circuits to get two mistakes high.....

[Tim Mackey]

Sorry Erfolg -but it sure does matter to someone who has - quote - "no idea".

You will be pretty much forced to having to use a high Kv inrunner due to the proximity of the elevons - its just not possible / practical to fit a large prop.

[Tim Hooper]

My old Zagi currently tuns one of those cheap'n'cheerful 2801-21 'bell' motors. 3S 1800 li-po.

 

Mind you, I had to trim away a goodly proportion of the centre trailing edge and elevons to clear the 8x4 prop!

 

It originally started life with a 6v S400 and 8x500 nicads.

tim

[Erfolg]

Tim

 

The one thing about Zaggis and type, they go on and on.

 

You are correct of course to say that , using more moderate Kv motors can require, some part of the ailerons to be removed. In our club, what has been modified and why is virtually lost in the mist of time.

 

Removing some of the trailing edge seems to have no impact on roll rate at all, or the glide. There is no impact on the aileron linkages, as these all seem to be driven by servos at about 1/3rd half span.

 

With respect to speed, moderate Kv with a suitably coarse propeller, seems to produce a really fast model, when the taps are opened. They are certainly quieter.

 

The real issue with larger propellers is that conventional launches can appear hazardous. Most are side arm launched, a few prefer an inverted launch, as there can be a bit of fus to almost hold. Until a few weeks ago i would have said that conventional launches, just look and feel hazardous. That is until a member cut his fingers, with a conventional, self launch, requiring hospital treatment. I was not there so I am not aware of all the circumstances.

 

I do find it very surprising how tough Zaggi types seem to be. I have seen a few go in, both from loss of control and misjudged manoeuvres. They just keep on going, seemingly just shrugging of impacts.

 

They also seem to be very amenable to power train modifications, some apparently so changed, no one remembers how they once were.

 

I totally agree that 80w is the absolute minimum.

 

I do not know about other clubs, everyone in our club seems to have a Zaggi type. It could be that they are quite forgiving as a type, stalling not being such a big issue as with some model types. Try and climb to fast, they all seem to mush, and loose height. They also seem to be cheap, although I have not seen any new ones recently. The Parkzone stryker seems the current favorite, not quite a Zaggi, but a brilliant wing.

[Tim Hooper]

Erf,

 

I always launch my Zagi motor off, in the classic 'pizza toss' throw, and then power up as soon as it leaves my hand.

 

Not so my SO who, out of habit with other models, throttled up as she threw the model, and spent some time with a St John's first-aider as a result!

 

tim

[Erfolg]

Yep, I think I have seen that too.

 

With respect to firing up after launch, that seems the standard approach with Strykers, I guess that there is so much power, they just streak into the distance.

 

 

[Phil May]

Thanks all for the replies,plenty for me to work with there.

 

Cheers all

Phil

[Phil May]

Morning all.

I've just been given one of these:-

 

E Max BL2215-25 950kv brushless from BRC (sorry, I could not get the link to work )

along with a 30 amp esc.

 

Will this do the job,

I understand it will need a larger prop than a motor with a higher KV and a bit of modification to the wing is required.

Has any one got a couple of photos they can post for me to have a look at of the conversion.

 

Thanks guys

Phil

 

 

[ken anderson.]

anybody interested-theres a powered one for sale(2nd hand) in the model shop(gladstons) north shields......

 

ken anderson ne...1.... powered zaggo dept.....

[leccyflyer]

For ease of installation, getting hold of a Zagi motor pod, and using an inrunner is the easiest way to go brushless with a Zagi, IMO.

 

My venerable old Zagi has been going since 2000 and has had at least five different power sets by now, starting off with a 6v sp400, Gunther prop and 7x500ars, going to 8x800ARs, then to an Irvine Cobalt and 8x800ARs with a 6.5x4 prop, then to a Permax 450T and 8x800ARs, then finally to a Keda inrunner.

 

My Zagi now has a Keda KB28-47-17S 2300kv 25A Brushless Inrunner, a 30 amp E-tronix esc and Maxpoly 2500mah 3s1p lipos, driving a 5.5x5 Camspeed prop. More performance than you can shake a stick at..

 

Along the way the Zagi picked up a carbon spar and is currrently stripped, awaiting a second carbon spar after a bit of a flutter developed. She does have pukka balsa elevons though, not Correx ones.

 

Remember a Zagi is for life, not just for Christmas.....

[Erfolg]

There was one used in our club. It is necessary to use it as a 3s as when tried as a 2s, just not enough guts. It sank gracefully to the ground. It was mounted onto a "L" bracket, where the bracket was packed to achieve enough up thrust. Or put another way t, the correct thrustline.

 

It is at the lowest end of performance as a 3s,

 

Some want rocket ship performance which they (zaggi) will handle, that requires a lot of watts.

[Ben B]

Posted by Big Phil on 11/12/2011 10:42:12:

Morning all.

I've just been given one of these:-

 

E Max BL2215-25 950kv brushless from BRC (sorry, I could not get the link to work )

along with a 30 amp esc.

 

Will this do the job,

I understand it will need a larger prop than a motor with a higher KV and a bit of modification to the wing is required.

Has any one got a couple of photos they can post for me to have a look at of the conversion.

 

Thanks guys

Phil

 

 

 

 

It will work on 3s (in that you'll be giving it about 160 watts on a 10*5 prop) but it's not going to be a rocket ship.

 

Here's my Zagi's journey:

 

Version #1 : standard brushed motor. 80 watts. Poor performance

Version #2: HXT (hobbyking) 2835 2200kv motor,6*4, 3s. Acceptable.

Version #3: HXT 2835 2700kv motor, 4.5*5.5, 3s. Nice!

Version #4: HXT2835 2700kv motor, 6*5.5, 3s. Fast but COOKED THE MOTOR!

Version #5: Added spar, HET 2w25, 3s nano-tech, 6*4. Fast

Version #6: HET 2w25, 3s nano-tech, 6*5.5 Silly fast. Folded the wing when flutter broke the spar.

For an unmodified 48 inch Zagi I'd heartily recommend a 2835 2700kv motor on a 4.5*5.5 prop on 3s. You shouldn't need a spar at that wattage (350 watts approx) and it will be plenty fast.

 

As mentioned, inrunners are easier to mount too Just get an "L bracket" as discussed and pack up the back the get some upthrust. If you find the packed bit lifting under power a 28mm plumbers copper saddle clamp bolted through the wing holds things down nicely. Only had to do this above 500w though at which point it's definately good to have installed spars.

 

For launching I use a programmable mix via the "retract" switch as a throttle kill switch so I just chuck it (with full throttle but the kill switch on) then after it leaves my hands flip the kill switch and off we go.

Edited By Ben B on 11/12/2011 17:02:26

[ken anderson.]

club zagi... this site is worth a look for all things zagi...

 

ken anderson ne...1 ..... WWW zagi.... dept.

 

[Erfolg]

The site Ken has pulled up is interesting. What interested me particularly was the site is still showing 400/480 type can brushed motors.

 

I know that some seek very high speeds and rocket like climb.

 

My position is very much influenced by our club and its fields. Flying from NT farmland, adjacent to a bird sanctuary, excessive noise is not acceptable to club members. We recognise no fields, there is no club.

High reving pusher wings are generally very noisy. To the extent that some members have been tactfully encouraged to ensure that the there noise profile is not intrusive.

 

A very potent zagi model can be constructed without very high watts and revs. Strykers are capable of more than many can manage without excessive noise, I know that some are taking fantastic watts in. Yet I have noted that for all there +500wattts, the difference in capability is not much better than 160-200 watts.

 

I sometimes think that the comparison is with the 1970,s USA muscle cars, all sound and fury, yet a much less powerful European sports car would beat them on most if not all aspects on a race track.

 

[Ben B]

That website has remained unchanged for a little while. Check the (c) date at the bottom. The problem with trying to go fast is you have to massively increase the power to get a relatively small increase in top speed. After a while it's true you do get more noise than speed increase.

[Phil May]

That's what I thought Erflog,

 

I'm sure the motor I have, along with a 3 cell lipo will be better than a 400 brushed - I hope.

Not that I am dismissing anything you guys have said.

 

As I said, I have no idea on this subject and I would have saved my pennies and bought a higher KV motor, but, when this one came along for free (cheers Kev) I thought I'd give it a go.

 

Thanks for all the input.

 

I hope to make a start today and I'll keep you informed.

 

Phil

 

 

[Phil May]

I'm at the thinking stage with regards the conversion and a thought popped into my head regaring the prop.

With the motor facing backwards, obviously the model wants to fly backwards, now as much fun this would be it is not the desired affect.

Is it a case of just turning the prop around, or buying a pusher prop, reversing the motor or a mixture of both.

 

Cheers all

Phil

 

[Ben B]

Yes, just turn it round so that any writing on it faces forward and obviously make sure it spins up the right way but either reversing it via the ESC or swopping two of the leads (I suspect you know that bit!). You don't really get electric pusher props, just for IC planes where the direction of rotation is fixed.

[Erfolg]

Phil

 

The motor you have chosen is not the most expensive, it has quite a good performance and is light.

 

As has been suggested a 400, will take a fair number of circuits to get to a couple of accidents high. A motor delivering about twice the power will take considerably less.

 

Originally the Zagi type was a slope soarer, which later had a low powered motor strapped on the back, yet essentially still a glider.

 

A little later modellers started to strap far more powerful motors on. Most were not interested in pure gliding. Much of the emphasis being on fast runs, low passes at speed, rolls etc. All of this can be done with 200-250 watts.

 

Others have strapped very powerful motors on. The irony is that the model has little duration, most seem to be piled into the ground or some such mishap. Above all they are often noisy. We have had them at the club.

 

If the motor you have suggested does not provide the performance you want, it will be easy and cheap to re-motor, using the same Lipo and probably the ESC. I do not think there are many easier models to re-motor.

 

The Zagi type must be one of the most versatile models that have been conceived and again low cost. We have some basic film covered models, some that seem to be a collection of wrapping tape and works of graphic art. Yep, must be a classic concept.

[Phil May]

Here's a couple of photos of the conversion up to now.

 

and

 

Only a small portion of the rear has been cut away... 11 " wide to clear the prop and only 1" deep at the outer part of the T/E .

 

I'v mounted the motor to a light ali bracket which is yet to be bolted to the wing, I plan to bolt straight through the foam and use small bushes as not to compress the foam to much - unless any one has a better suggestion.

 

The lipo and r.x will be placed hopefully in a position that will balance the model.

 

Any advice greatly excepted

 

Phil

 

[BB]

Enjoying this thread. I have been given a Zagi (type) kit. No power train recomendations included, apprx 48" span. So am viewing with interest.

 

A group of us at www.flambirdsmfa.com are hoping to hold a combat meet soon.

 

BB