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Old Oct 05, 2010, 12:36 PM
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Originally Posted by Mike Tully View Post
Most planes need a bit of right thrust to counter thrust assymmetry from a clockwise-rotating prop. Look up P-factor.
Thank you, I thought I did come across that before.
So I take it that the motor mount is designed to be that way.

Since I want to use it with floats, I would like more thrust.
If I stay with the stock "3715" motor (kv=?), stock 45A 3s-6s esc and stock 4s 2200 15C lipo, can I improve thrust and efficiency by changing from the stock 3-blade 10x6 to a 2-blade 11x5 or similar?
I hear so many bad things abt the stock 3-blade prop.
Would appreciate any advice for a prop plane newbie. (My experience is in heli and edfs.)
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Old Oct 06, 2010, 07:29 AM
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Methuen, MA
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Yes, the motor mount is designed that way. Most slowish planes that spin big props use about 2 degrees right thrust.

If you read through the whole thread, then you will see that the stock motor (at least in mine) is ill-suited for 4s use in this airframe. I think the motor is around 1150kv - see here: http://www.himodel.com/electric/1150..._3715-01B.html

Running a two blade 11 x 5 on 4s will eventually melt a motor of this kv and mass. The only reason the motor can survive short periods running on 4s with the (horrible) stock prop is that the flimsy blades flatten out to reduce load. I found that the pitch speed on the stock prop with 4s was about 55mph, meaning that you are wasting huge amounts of energy trying to go faster than this plane will go. The prop blades stall and the energy is wasted beating the air and making noise. Four cells on this setup is just stupid. Run three cells and a 12 x 6 APCe for great performance off of water. An 11 x 5.5e on three cells is a great setup for land operations. Mine is fully aerobatic on floats with the 12 x 6 and three cells. Long vertical lines and nice 300' round loops are no problem. Pick up a decent prop adapter when you get the prop, the stock one is dangerous junk.
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Old Oct 06, 2010, 08:29 AM
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Thanks Mike.
Is there a solution if I don't already have 3s packs, and want to use my included stock 4s 2200mAh pack?
You said a 2-blade 11x5 would cause motor overheating, does it help to go 10x5 or 11x4?
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Old Oct 06, 2010, 12:42 PM
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The battery and motor should be able to handle a 10 x 5, which I static tested at 30 amps. That translates to 56 oz thrust and a pitch speed of 52 mph. Not a good fit with the airframe, but with some throttle restraint, should keep things from melting. I still have my stock pack. I cut one of the cells out. Not an option for most people, but I've been using lipos since the days when they could only be purchased as single cells and they came with a warning letter that said they were not to be used for experimental purposes such as powering model airplanes!
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Old Oct 09, 2010, 06:28 AM
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Still with my stock parts

It turns out my included 3-blade prop is marked E-DO MODEL EP-1070 x 3. So this is even more agressive than the 10x6 that is marked on the box, and which everyone else here got?
The included ESC, light green anodized, is "RICCS 45A" burst: 55A, 2S to 6S, switching BEC.
With the freshly charged 4S 2200mAh 15C, (no-name stock lipo), at full throttle, I measure 50A discharge at the battery leads. Dropping to about 46A after a few seconds.
I do have screeching sounds sometimes, seems to be when I increase throttle setting too abruptly.
Waiting for the epoxy on the seams of the floats to cure. I used BobSmith finish cure 20min. with micro balloons. Some seams are very close and the penetration might not have been very good.
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Old Oct 09, 2010, 03:19 PM
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Gold Coast Australia
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G'day all,
just came across this thread and read the lot with much interest.
Have had both version one and two of these models and some of the posts have explained the technical aspects of my love... hate/disappointment
with these models.
Three of us have them at our local field and I have just brought 4 more
in. ( I can buy direct off Edo and have also got a couple of their Yak 54
to play with/ evaluate) Can source parts if anybody needs.
My opinion, a great design, especially version two with ply motor mounts, better hinging and strut mounts BUT let down by the wrong motor/ prop combo.
Fly them with a 12 x 6 on three cells, great scale flying . Keep checking the speedy and battery temperatures , enjoy ...
Fly them on the standard 4 cell and 3 bladed prop ...for all the very good tech specs raised in this thread its all going to be short lived thrills.....I can remember one flying session with the joy of near verticle performance, rolls loops etc shortly followed by total power loss with burnt out speedy !!
Will be trying out the floats this summer and thanks to the guys for relating their mods in this regard.
Cheers
Tony
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Old Oct 10, 2010, 05:39 PM
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Quote:
Originally Posted by Biggles51 View Post
G'day all,
just came across this thread and read the lot with much interest.
Have had both version one and two of these models and some of the posts have explained the technical aspects of my love... hate/disappointment
with these models.
Three of us have them at our local field and I have just brought 4 more
in. ( I can buy direct off Edo and have also got a couple of their Yak 54
to play with/ evaluate) Can source parts if anybody needs.
My opinion, a great design, especially version two with ply motor mounts, better hinging and strut mounts BUT let down by the wrong motor/ prop combo.
Fly them with a 12 x 6 on three cells, great scale flying . Keep checking the speedy and battery temperatures , enjoy ...
Fly them on the standard 4 cell and 3 bladed prop ...for all the very good tech specs raised in this thread its all going to be short lived thrills.....I can remember one flying session with the joy of near verticle performance, rolls loops etc shortly followed by total power loss with burnt out speedy !!
Will be trying out the floats this summer and thanks to the guys for relating their mods in this regard.
Cheers
Tony
hi Tony, fellow banana bender

Let me know how you go with the floats, I bought a set of floats for mine but unsure if it's worth the effort to fit them

my maiden ended in a nose-in when just on liftoff, port side aileron departed company due to crap hinge tape... so- all servos, motor, esc, prop, all changed out with whatever I had lying around home, hinged all control surfaces with pinned dubro's, and fitted dual rudder servos.
11 x 7E prop on 4S seems fine for me, and should work ok on floats I guess. I have a 12 x 7 woody but havent flown with it on this c-185, i get an easy 15 mins scale flying per 2450mah batt, works for me as is.
recently i did a handful of fpv flights, first fpv landing i came in with a bit of a bounce, main gear looks like it's twisting back, i'll remove the ally wheel plate, re-epoxy the ply, then i might run a brace from wheel axles back up to the aft floats strut mount, beef it up a bit

curious tho, what are your thoughts on the e-do yak?
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Old Oct 10, 2010, 09:41 PM
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I've had a myriad of problems with my landing gear. I have changed out the axles on the main wheels, original axles kept bending/binding and twisting. Rear wheel has spun loose a couple of times, currently holding together with a wad of CA. Would love to swap it out for something more substantial, but have no idea what to use.
Len
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Old Oct 10, 2010, 10:16 PM
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G'day Hoppy...
What a crap weekend and still plenty of wind and rain to come.
I have a little profile indoor thing half built, may have to finish it off and find a hall.
I put together the E Do Yak on Saturday, looks real impressive but dubious about the reported quick motor burn outs. Ran it on the standard 14x 7 prop and the motor was real hot real quick. Swapped to a 12x 6 and all nice and cool. Going to try it with this to see if it has enough grunt. Got it all set up with 60% travel adjust and plenty of expo to keep it within my ability first up. Got two of them in and the other one that I am giving to a mate who is going to do the Tunigy conversion. He is a much more experienced areo pilot with a Pulse 32 and same size Zlin 32 so we can compare.
Will keep you posted.
Looks like we will have to do a bit to the floats and play around with flap settings to get the Cessna 185 off the water. Thanks for the info on the 11x 7 on the 4 cell ,ever had it on a watt meter. Did you read all that great technical stuff on Bungymania.
Cheers
Tony
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Old Oct 10, 2010, 10:31 PM
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Quote:
Originally Posted by green_mtn_boy View Post
I've had a myriad of problems with my landing gear. I have changed out the axles on the main wheels, original axles kept bending/binding and twisting. Rear wheel has spun loose a couple of times, currently holding together with a wad of CA. Would love to swap it out for something more substantial, but have no idea what to use.
Len
For the main wheel axles, I went to the local bolt shop & bought the same machine screws, just longer so I could use nyloc nuts & flat washers to both stiffen up the axle and space the wheel away from the ally to stop the tires from rubbing/binding on the ally, I did this before the maiden coz didnt want the risk of nosing over at speed.

In regards to the tail wheel, I've not had any issues with mine at all, but given on my C-185 the actual "axle" part of the bent wire has an amount of length poking past the wheel for the plastic wheel retainer thing... I'd reckon i'd get something like one of the small grub screwed clamp things... the thing on a servo horn that you run your control surface stiff wire through then clamp with grub screw (I cant remember the name of'em)... i'd think that should work.... if you by some miracle understand what I'm talking about...
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Old Oct 11, 2010, 12:34 AM
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Quote:
Originally Posted by Biggles51 View Post
G'day Hoppy...
What a crap weekend and still plenty of wind and rain to come.
I have a little profile indoor thing half built, may have to finish it off and find a hall.
I put together the E Do Yak on Saturday, looks real impressive but dubious about the reported quick motor burn outs. Ran it on the standard 14x 7 prop and the motor was real hot real quick. Swapped to a 12x 6 and all nice and cool. Going to try it with this to see if it has enough grunt. Got it all set up with 60% travel adjust and plenty of expo to keep it within my ability first up. Got two of them in and the other one that I am giving to a mate who is going to do the Tunigy conversion. He is a much more experienced areo pilot with a Pulse 32 and same size Zlin 32 so we can compare.
Will keep you posted.
Looks like we will have to do a bit to the floats and play around with flap settings to get the Cessna 185 off the water. Thanks for the info on the 11x 7 on the 4 cell ,ever had it on a watt meter. Did you read all that great technical stuff on Bungymania.
Cheers
Tony
gawd mate.... between work and crap weather, wind & rain, every damned time i want to fly! lol sooooo much rain... it's like mother nature is bulk dumping all of summer's rain in one lengthy hit!
No I havent put her on a watt meter yet, but I will do... i havent thought to do so coz not only do i get good scale flight times but both motor & esc (non-standard) are almost cold after a flight... but i did make sure there is plenty of air flow for them... i dont use a spinner to improve air flow, and have the esc strapped to the inside of the motor mount.
re: floats, yeah, a bit of dickin around but probably worth the trouble. i'd want to try seal up the float mounted servo somehow. I'll probably use the 12 x 7 on 4S for the floats, better to have reserve power with (hopefully) faster acceleration on water to help get up quicker. I'm still thinking along the lines of longitudinal grooves cut into the fwd portion of the floats, to help break the water surface tension by allowing air under the floats. Only an idea, I'll prob try it at some point.
Flaps work real well, but i honestly dont use them on grass at all, but ya, i'd reckon they'd play a big part in extra lift off water. If you do play with the flaps, could you let me know please what elev/flap mix rate you settle with?

indoor just doesnt do it for me lol i'd rather go play water sports with my 1/5th 300zx if anything but any spare time is dedicated to fpv these days...

I am kinda curious on the Yak, could make for fpv. Read lots on the failures. Before maiden personally I'd be replacing motor/esc & possibly servos, and serious forget aesthetics to make a lot of ventilation around the cowl.
for the money tho (depending on how much you paid i guess) may well be better off going for a non foamy plane.
If your mate has aero experience I'd be real interested to see what he thinks of the difference between the E-Do Yak and a non foamy Yak...

you've lost me on "Bungymania"...?
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Old Oct 11, 2010, 03:09 AM
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Quote:
Originally Posted by Biggles51 View Post
Thanks for the info on the 11x 7 on the 4 cell ,ever had it on a watt meter.
for those who may or may not be interested, my setup...

GC3648-KV600
G&C 50 amp ESC
BEC disabled
Turnigy 2450mah 4S

Note that there is no other current draw off main flight battery:
RC Rx/servos has dedicated 6v 2000mah niMH batt
vTx/cam has 800mah 3S lipo batt

1070 x 3 EP plastic 3 blade
Approx cruise throttle:
4.2 amps
69 watts
WOT:
16 amps
256 watts

This is the prop I use on this Cessna
11 x 7E EMP nylon 2 blade
Approx cruise throttle:
6.8 amps
108.2 watts
WOT:
17.5 amps
260.1 watts

12 x 7 Turnigy woodie 2 blade
Approx cruise throttle:
5 amps
79.6 watts
WOT:
21 amps
325 watts

15 x 8 nylon 2 blade
Approx cruise throttle:
7 amps
106 watts
WOT:
36.6 amps
521 watts

That was static bench test.
No idea on the accuracy of the meter, cheapish eflight
No fingers were harmed during this test... once prop bitten, forever shy...

Interesting results actually, hope it helps someone...
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Last edited by AussieHoppy; Oct 11, 2010 at 04:00 AM. Reason: More props to test :-)
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Old Oct 11, 2010, 05:06 AM
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Gold Coast Australia
Joined Sep 2010
254 Posts
Cheers Hoppy,
Thanks for the data on the Turnigy set up. Could well be how I end up with the Cessna.
Look at www.bungymania.com lots of very technical reviews from French electric flyer crew (make sure you hit the English translation)
What they identified was that the standard PNP set up is not that bad, even though
all the tech stuff pointed to a mismatch in the motor set up, it was more that the 20C discharge rate on the supplied battery was exceeded on WOT.
( I am still catching up on all this tech stuff)
Hopefully some better weather coming up at end of the week. I am going to take a punt on the Yak with the standard donk with smaller 12 x 6 prop. Looked to have sufficient
thrust and cool running on the bench. Have a Mini pulse and a Greens Super Dimona 2400
but like the foamies as well.
Sorry to talk about the "dark side" but also have a Diamond 2500 and a 2m Minimoa to get sorted. I like the power thing first up but then love to fly the glider as the morning heats up and we get some breeze.
Also our field was cored last week and before they could get it "swept up" and sanded it started raining . the place is a real mess, can only get in and out of the carpark with small stuff but think we can get the gliders landing Ok.
Where do you fly in Brisvegas.
My mate looks like he will be a while getting his Yak up.... lots of builds in front of it.
He has his Eflite Duece twin to go again after a very interesting engine coming off the
mount on take off and a couple biplanes , I think one is a Python.
Cheers Tony
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Old Oct 11, 2010, 11:23 AM
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float struts - taller one goes behind? rake forwards?

Hi all,
I did not see any mention in this thread about the struts for the floats.
The shorter one seems to be straight, while the taller one has a "rake".
From the Banana Hobby video of the 185, I see that the taller strut is installed behind, with the rake forwards. i.e. extending forwards downwards.

Has any one tried any other way?

Putting the taller strut in front instead should give the plane a more nose-up stance, would that be helpful?

Also, rudder on the left or right? or doesn't matter?
E-DO manual shows it on the left, Pete-BH has it on the right.
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Old Oct 11, 2010, 01:02 PM
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Quote:
Originally Posted by kaon View Post
Hi all,
I did not see any mention in this thread about the struts for the floats.
The shorter one seems to be straight, while the taller one has a "rake".
From the Banana Hobby video of the 185, I see that the taller strut is installed behind, with the rake forwards. i.e. extending forwards downwards.
It's right like that!
Has any one tried any other way?
Not yet.
Putting the taller strut in front instead should give the plane a more nose-up stance, would that be helpful? No, I don't think so, elevator and upper part of the float should be parallel.
Also, rudder on the left or right? or doesn't matter? both are possible, just check the same direction of the movement as the rudder
E-DO manual shows it on the left, Pete-BH has it on the right.

by m.m.
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