Balsa Rain

A newbie to electric with intermediate-level glow experience...and more questions than ever

Picked up a used EStreak with stock (550)motor; re-timed the motor and put the following in the plane:
Futaba 127DF receiver,
HS81 servos (3),
Astro 217D ESC (no BEC in this),
4.8V 480mahreceiver [email protected] oz,
6-cell/3000Mah NiMH pack @ 13.3 oz.

AUW is 3.25 pounds (!)

I've already heard that the stock motor sux, and apparently it sux a *lot* when on only six cells and toting this much weight!

Maiden flight, as you might imagine, very short; with a really stout hand-launch, it just settled to the ground politely without enough thrust and with too much wieght.[&o]

I really like the looks of this plane and I want the aerobatic capabilities. I'm determined to make it go, however, I am not going to pay the added expense of brushless at this time.

This is one o' those swap meet bargains that 'snowballs' into a chunk o' money in a flash![X(]


I have some options and would like some advice on which way to go. More and lighter batteries, maybe and I have a couple of motors that I could try: an Astro Cobalt 15 geared FIA motor and a Trinity "jaguar" 11T "Mod Motor".

I think my options are these:

1. Get more cells in a smaller size...say, two 6 cell 1200Mah packs in series or a 10-cell pack on the stock motor.

2. Do #1 above AND use the Jaguar motor.

3. Use the Astro 15 without the gearbox... What prop and prop adapter? (Offset gearbox won't fit in the fuse.)

4. Get a planetary gearbox for the Astro 15 ...Which g-box and what prop?


I do have a Triton charger already; I bought it because I will someday get some Li-Polys but don't yet have any. Could some one tell me which liPo pack(s) I would use for this plane and it's high amp draw? Please be specific as I haven't found any with high amp ratings that seem affordable.
Thanks for your help.

Ricky

blvdbuzzard

here is my setup. I have a Magnetic Mayham I retimed, ($20.00) a gd600 gear box($14.00). I am running the medium ratio and a 10X8 prop. I have a Dymond 50 amp ESC. I picked up two packs of 2 6 cell 2400 mah nicds for Hobby People when they have a good sale. I solider them up in a 10 cell pack. To get the gear box in there you will need to do some trimming of the wood in the nose. You could also use an inline gear box but they are a little more money.

When I hand launch it, it climbs at a near vertical climb out. I guess that I get around 5 minutes of flying per charge. I am to bussy flying to watch the clock.

Dru.

Balsa Rain

Sounds good...mine wouldn't "climb out" or even climb at all!

Do you happen to know how the Jaquar (11 turn) would compare to the Mayhem (17 turn)? What is the weight of your set-up?
Are the cells that you are using of the "sub-C" size? Where do I get a gd600 gearbox?
Thanks
Ricky

Peter Khor

My Feedback: (4)

GD-600:

http://www2.towerhobbies.com/cgi-bin...?&I=LXSL79&P=7

Kyosho Mayhem and Endo are generally your best bet to use due to their 5x5mm brushes, and they're only $20 a pop.

You could also try 6x6 folding on a Endo on only 6 cells (high amp draw though, 40A or so) and get very nice performance (setup taken from Kwik-E)

Matt Kirsch

My Feedback: (21)

I suspect that the attempt to retime the motor did more harm than good.

3.5 pounds is a lot. The Kwik-E's weight is listed as 2 pounds, and the E-Streak ARF is listed at 2 pounds, 11 ounces.

Between these two issues, I think you can see why the plane doesn't perform well, and probably why it was for sale at the swap meet, AND probably why its previous owner will never own another electric for as long as he lives. This plane was probably "beefed up" by an experienced glow flier who didn't understand that most of that extra beef isn't necessary because of the smooth electric motor.

You can save some weight by dumping the receiver battery and going with a lighter ESC with a BEC, like a Great Planes C-50. That might get you down to 3lb 4oz. A lighter receiver will shave off another ounce. Using a pack made of HR4/5FAUP NiMH cells instead of Sub C NiCds (car packs) will shave off a few more ounces. Poke around inside and see if there is any lead stuck anywhere. If there is, remove it. You should be able to fix the balance by moving the pack around. Replace the 550 motor with any of the aforementioned rigs. I think with just these simple modifications, you ought to be able to get the plane down to 3 pounds even. That's a reduction of 1/7, or 16.7% of the plane's weight.

The solutions discussed so far in this thread involve adding power, which adds weight. The plane is too piggy now; adding weight will only make it worse.

Balsa Rain

I certainly agree with the points presented but I have more questions (of course)

1. <I suspect that the attempt to retime the motor did more harm than good.>

You may be right as this was my first attempt at this. The raw data is this: Stock folding prop on 6cell pack(static)RPM increase = 550, current draw = no change

2. <Kyosho Mayhem and Endo are generally your best bet>

Is the Jaguar (11 turn) that I already have useful here, or should I just put it back on eBay?


3. <3.5 pounds is a lot. The Kwik-E's weight is listed as 2 pounds, and the E-Streak ARF is listed at 2 pounds, 11 ounces. >

its actually 3lb.s, 4oz. (3.25) but still piggy, no argument here! I'm wondering about the Estreak @ 2/11...is that s'posed to be all-up weight?


<Between these two issues, I think you can see why the plane doesn't perform well, and probably why it was for sale at the swap meet, AND probably why its previous owner will never own another electric for as long as he lives.>

I agree with you on these points, the owner actually implied the same thing.


< This plane was probably "beefed up" by an experienced glow flier>

This plane is the ARF with the glass fuse and as far as I can tell, it's unchanged from factory build. I haven't found any lead yet, but the silly thing is definitely too heavy!

<You can save some weight by dumping the receiver battery and going with a lighter ESC with a BEC>

This is something I will probably have to do. I got the 217D primarily for the astro cobalt motor (for whatever I end up using it in)

<A lighter receiver will shave off another ounce.>

I have a Hitec "Feather" and a GWS receiver, but am concerned about range/quality issues with these. Should i use either one, retain the Futaba, or buy something else?


<Using a pack made of HR4/5FAUP NiMH cells instead of Sub C NiCds (car packs) will shave off a few more ounces.>

This is definitely needed...now tell me, how many cells should I run?

<Replace the 550 motor with any of the aforementioned rigs.>

Does the Astro Cobalt have a use here? Is there an inline gearbox for the Astro (or the Mayhem/Endo) Would any of these work "direct drive"?

<The solutions discussed so far in this thread involve adding power, which adds weight. The plane is too piggy now; adding weight will only make it worse.>

No argument on this point...so what about shedding weight while adding power (speculating here)
What if I used the Astro 15 (save about an ounce) with the feather receiver (another ounce or so) with the Sanyo cells (3~4 oz?)
an ESC w/BEC, lose the receiver pack (3oz)

And the next step: What about Li-Polys?

It looks like a great illustration for how NOT to jump into electric! Most of the pieces that I've bought for this project are not actually suitable for this plane. A lesson to be learned, for sure! My determination will not fade, though.[>:] I WILL make this thing fly, and fly well! (with the help of all of you here!)

blvdbuzzard

From what I have tried with mine, the gd600 has helped the flight times. Yes the batterys are sub "C: size. To get a ten cell pack I had to use 2 servos for the alierons. Mine feels pretty heavy when it is ready to fly. I have not weighted it so I do not know how heavy it really is. I also have the landing gear on it. I do not have grass to fly from so I need them. I am using 4 HS-81MG servos. Hitec Spectrum 6 Rx. I had to do some surgery to get the gear box to fit. If you run DD there will be no problems.

I do not know anything about the Astro so I can not tell you anyting.

Dru.

Matt Kirsch

My Feedback: (21)

The El-cheapo "feather" type receivers should be limited to small, slow-flying park fliers. The E-Streak, once you get it up on step, will cover a lot more distance in a lot less time, perhaps going out of range of these little receivers. A glitch, which both the Hitec and GWS are prone to, would be fatal with the E-Streak. I would go for a full-range micro receiver like the Hitec Feather or FMA M5. However, one ounce either way should not make that much difference, and I'd just stick with the Futaba for now.

From what I've read and seen, 16 turns is about the "hottest" car motor you'd want to even think about running direct drive. An 11 turn motor will draw far too many Amps turning a prop of any useful size, and the gear ratio would have to be unbelievably high, like 6:1 or more, to get the Amps down.

That's a 15 Cobalt, right? According to Astro's website, on 10 cells (3S LiPoly), the motor will draw 25 Amps with a 9x4 prop, 20 Amps on an 8x4 prop. Sanyo makes a 1700mAh HR4/5AUP (notice no "F") that's good at 25 Amps, and a bit lighter than 4/5FAUPs. You ought to be able to cram ten of those in the fuselage. It'll be heavier, but there should be lots more available power. With the 8x4 prop, you can drop down to 10 KAN1050s and lighten the plane signifigantly, by 1/4 pound or more over the 'AUPs.

The Astro looks promising because it's a low current motor, and there are several lightweight NiMH options that can handle that kind of current.

Balsa Rain

Dru: I really would like to know how much yours weighs with ten sub-c's on board and an extra servo. I'm hoping to avoid having to do that mod to make room.


Matt:

<However, one ounce either way should not make that much difference, and I'd just stick with the Futaba for now.>

Agreed.

<From what I've read and seen, 16 turns is about the "hottest" car motor you'd want to even think about running direct drive. An 11 turn motor will draw far too many Amps turning a prop of any useful size, and the gear ratio would have to be unbelievably high, like 6:1 or more, to get the Amps down.>

Thank you for this explanation; this finally makes sense of the 'turn count" issue and what it means in practical application.

<That's a 15 Cobalt, right?>

Yes, its a '615G' and its the FAI version...but I'll have to remove the offset gearbox.

What do you think about available inline gearboxes, and what ratio and prop size would you suggest?


<The Astro looks promising because it's a low current motor, and there are several lightweight NiMH options that can handle that kind of current. >

I don't have any batts right now which seem suitable; If I have to buy new packs anyway, I'm wondering if I can 'rationalize' buying Li-Pos (?)
I think I would have to use 3S2P to get enough current???? Or 3S3P??

Ricky

blvdbuzzard

Mine is a PIG!!. It weights in at 3 ponuds 6 1/2 oz. I am a little on the cheap side so I can not justify the cost of the lipoly batterys and a charger for them. If I had more of the batterys I would go that route. I am thinking of, trying to pick, a brushless motor of my FFF Ulimate bipe and I want to go lipoly with that one so I may get them for the E streak too. It is just hard to spend so much on batterys when I can get the 2400 nicds for a good price.

Dru.

Matt Kirsch

My Feedback: (21)

The numbers I quote are for direct drive. Check it out for yourself: http://www.astroflight.com.

What brand LiPolys are you considering? With Etec 1200's, you'd need at least 3S3P. Kokam 1500s, you can get away with 3S2P as long as you don't run full throttle all the time, but this is a speed plane, so you probably should get 3S3P. Thunder Power, you should be okay with their 11.1V, 4000mAh pack (i.e. 3S2P, 2000mAh cells), again if you don't fly full throttle all the time.

Also consider that the E-streak has a narrow fuselage, and certain LiPoly cells will not fit. The Etecs are pretty narrow, and will fit in the same width as two Sub C cells side-by-side, as are the ThunderPowers. I don't know about the size of the Kokams. Tanic/Irate packs are definitely too wide, and aren't available yet anyway.

Balsa Rain

Matt:


<The numbers I quote are for direct drive.>
Understood. I'm wondering, though, if there would be any real advantage or purpose in using a gear drive for this application....say, a 5~6:1 with a huge prop? Waste of time/money?

<What brand LiPolys are you considering?>
I truly don't know; just looking for the best value overall.

<but this is a speed plane, so you probably should get 3S3P>
This makes sense to me.


<don't fly full throttle all the time>.
Unfortunately, I'm a full-throttle kinda guy(!) I can't imagine this plane being able to "cruise" along at half-throttle since the wing loading is so high. Probably best to go with the upper end of the recommendation. Of course, I may have to wait till spring to get enough coin together!


<Also consider that the E-streak has a narrow fuselage, and certain LiPoly cells will not fit. The Etecs are pretty narrow, and will fit in the same width as two Sub C cells side-by-side, as are the ThunderPowers.>

Another good point; I hadn't even considered that any of the LiPos were that wide! The fuse holds two sub C's side-by-side but there is *NO* spare room; You'll never find an ElectroStreak rattling....there's just no room for that!

Now taking a little bit different approach.....the next issue: Apparently this plane can fly well with the Mayhem or the Endo. I'm assuming it will fly even better with the Astro 15....but now I'm wondering if that wouldn't be a waste, of sorts.
I've read that the Astro 15 Gear motor will fly a ".40 size" conversion and I'm considering this. If it's true that it'll work for this (I've got a SureFlite P-39 on the way and a TT42 ready for it) then maybe I'd better off to just get the Mayhem for the streak(?) and stick the Astro w/ gearbox on the P-39? Too many options!

foo

I have 5 e-streaks,one has an af sport 15 dd,8-8 prop,8-cp-1700 cells.One flight so far,it was fast ;but I had too much aileron on so I cut it short before I dork it.Wind /rain so far.With a Kavan soft prop,8-6,a 60 size plane had trouble staying with it.

Balsa Rain

Foo, sounds impressive. I think I may try just that setup or maybe the Mayhem motor. The idea of usng the astro 15 to convert a glow plane is tempting me too!
Let me know How it works when the rain quits...it will quit...someday

foo

I have a e-s with a mm dd,7/6 tornado prop.Goes good,but need to keep the amps about in the low 20s on 8 cell or you'll have to rebrush and turn the armature rather soon.I went to Trinty brushes and heavier springs on it.One had a Endo,GPgb,8/8 torando prop,went very good,that set up is now in a bubbles.

Balsa Rain

I think I'll follow your example; I'll get a Mayhem and an 8~10 cell pack of some sort for the 'streak. I guess some 2/3 A cells might work....the sub-c's are just too dang big.

I think I'll keep the Astro Cobalt 15 with its gearbox together and use it to do a conversion. I have a Sureflite P39 on the way, but it might be too heavy. I've been thinking of getting a "Hot Knife" from Global and its really light...under 4# AUW with a .46fx! That one ought to be a great spot for the astro.

Ricky

foo

I do not know about 2/3 cells, I am using cp-1700 cells in 8 and 10 cell paks.With which still leaves me with a 3# e-s.

Balsa Rain

It Flies!!!!
Details to follow, but the dang thing really flies!

10CP-1300SCR @ 12 ounces and Astro 615G without the gearbox

Ricky[8D]

Balsa Rain

I seemed to be going 'round in circles trying to get this pig to fly; trying to get as much info as I could while avoiding throwing (more) large piles of money at this thing.
Made the trip to the BIG hobby shop in Dallas and spent the afternoon buggin' those guys. We talked over every combo that didn't involve more than two hundred dollars and came up with this plan:

Buy the ten cell 1300SCR pack ($60) and try it with the astro with the gearbox removed and using a Graupner "Cam" 9X5 Folder. I picked up an 8X4 as well. If that isn't enough, add more cells. then change the ESC to one with a BEC to save weight. Then LIPolys, then mabye brushless....

Then we looked at this setup in MotoCalc. It said it wouldn't fly! Not convinced, the guy set up the G2 flight sim and picked this setup from the options. The Sim said it would fly and in fact, indicated a LOT of vertical. Hoping the Sim had it right, I bought the pack and props and then I swore to my self (many times during the loooong drive home) that I wasn't gonna spend another dime on brushed equipment. If this setup won't fly it, I'm bustin the piggy bank and going brushless.
Fortunately for me and the plaster pig, this thing has PLENTY of thrust. Hand launching is just a matter of not getting in the way; no need to actually throw the thing! I had a problem with an aileron torgue rod that prevented me from fully checking out the set up, but the gist of it is that the 'streak now is one![8D] Looks like flight time is about four minutes, but that may improve as I have added some cooling vents to the fuse. The pack got so hot in that unvented cabin that the shrink now has a buncha holes!
Hoping to get another shot at it on Sunday as I now have the aileron issue repaired.

BTW: I re-timed the Astro for direct drive. It pulls 4.00 amps no load.
Loaded with the 9X5, the Astro pulls 26 amps and the original 550 pulled 36 with an 8X5.
My cheap-ass Hobbico tach is refusing to see the prop, so, no info on RPMs yet.


Ricky

foo

Good for you,you are now a e-streak junkie.I have 5 of them with gear set up and dd.On the AF-15 dd i'm trying a 8/8 Torando,don't remember the amp draw.If the weather ever gets better i'll try it again.

Balsa Rain

The good news is that your weather is getting better right now!
The sky is powder blue here since noon. My weather will make it to you in a couple of hours.
I would love to see a pic of your gear setup. I picked up a main gear of a generic type, but undecided about using it. I would actually like to try the gear from my Firebird XL. Extremely light for a three-pound-pig, I know, but maybe just the ticket if I can absolutely nail the approach.
Also thinking of a sailplane-type single wheel.
I have the aileron problem fixed now. Im hoping that today I can test the vertical and also learn if my added cooling vent will be enough.

foo

I,m using a torson bar type landing grear set up that they used on the plans just ahead of the wing,sorry no dital camera.I led you astray when I said gear,I should have said GP gear box.The plans are from AMA Electro-streak,#569.My AF-15 is pulling 25 amps on a 8/8.

Balsa Rain

Got the tach working tonight; 10,400RPM w/ 9x5 Cam folder @ 26mps This makes me veddy veddy happy!
Playing with MotoCalc (whole lot I don't yet understand about it)
and M/C says 10,297 RPM @ 30 amps and 31 oz. of thrust with a top speed of 47MPH. The program misses the measured amps, but is pretty darn close on the rest as far as I can tell. Didn't get a chance to fly today, but maybe tomorrow.

Now, according to Moto Calc...If I wanna make this thing prop-hang.....

Ricky

pilotnow

Hello gentlemen, I've got an E-streak that I built with a Thunder Power 2S3P 6000mAh battery, FMA super 30 ESC and M5 receiver and the stock goldfire motor w/8X4 electric prop that weighs in at just over 2 pounds (2.07), and it flies great. I wouldn't call it great vertical, but I never worry about losing altitude doing maneuvers because it’s so easy to gain it back. With this setup, I get tired about the same time the battery does. I haven’t timed it yet, but I’m guessing flights are at least 15 minutes. With a fresh pack, the Whatt meter is showing about 225 watts full tilt. After a few minutes it settles in at around 200 watts for most of the pack. How does it fly? It’s pretty much like they say. If you can get 100 watts/#, it’ll fly nicely.

Pilotnow