HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Nov 19, 2010, 07:18 AM
Registered User
Norway
Joined Nov 2010
5 Posts
Hi guys,

First of all im pretty new to this plane. I have not flown RC's for many years but want to start up again. I have just ordered it and have planned to build is with and ArduPilot autopilot. Hoping it will show up in post tomorrow

I have planned to use a 700W motor and a 4000mah battery and a 11/7 prop. I also have two smaller motors aswell 400-500 watt ones. Same ~kV.

I have a few questions;

Is there any wing polar avalible (Speed/weight/glide) for this plane?

What is the trim speed of the plane with approx 1,5-2kg range? Any thoughts on stability versus the wingload. I want a stable plane, but slow/moderate landing speed is also very important. Probably the flaps can extend to help on that.

Any ideas about stallspeed?

The CG point of the plane. Is that information together with the plane? I read 63 cm some place. Is this correct?

I also see that it recommends 9g HT servos and some mentioning those to be to small. Any feedback or oppinions on this issue?

I will post some photo series and status updates as i go along if someone is interrested.

best regards
Thomas
cumulusnimbus is offline Find More Posts by cumulusnimbus
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 19, 2010, 09:00 PM
Registered User
Damian Couzoff's Avatar
Melbourne,Victoria,Australia
Joined Apr 2010
1,503 Posts
Thomas-this is my asw 28,built for slope only.The arf kit has no flaps,so l added spoilers instead,flaps can be cut,and hinged if you want flaps.The centre of gravity is 60-62mm.I might be buying another kit,and that will have flaps,but l will keep it as a spare kit,if any slope mishap occurs,theyre still reasonably priced.
Damian Couzoff is offline Find More Posts by Damian Couzoff
RCG Plus Member
Last edited by Damian Couzoff; Nov 20, 2010 at 01:15 AM.
Reply With Quote
Old Nov 20, 2010, 07:36 AM
Registered User
Norway
Joined Nov 2010
5 Posts
Hi Damian,

I mistaked about the flaps. As you say it can be "homebuilt". I will try to get my plane flying before i attempt any modifications.

Im not going to use mine for any traditional sailplane soaring or thermaling. Im going to build an UAV with autopilot, gps and gsm telemetry module inside. Im using the sailplane model because it seems like a good choice for a relativly stable body and also with long wings that possibly could handle some load and have good L/D.

Is there a manual with tech specs inside the box? Im very interrested in a wing/plane polar for this model. How mouch load it can take, the ld and speed.

Im really looking forward to picking up my kit early next week I will make a series of photos as i work on my plane if someone is interrested. With a 4500mah battery and 11/7 prop any idea how long time its possible to keep the plane in air. Lets say max 400m alt gain total in entire flight.

Is there any software/calculation programs for this kind of things online? Im pretty new to this, have not been flying rc for 10 years, but im starting again now. Since my edu is microelectronics i have a pretty good idea about the electrical and computer side of things. Been flying paragliders last 8 years aswell so i know a little bit about aerodynamics aswell, but ALOT have happened in rc area last years so im a little newbie again

Thanks.
cumulusnimbus is offline Find More Posts by cumulusnimbus
Reply With Quote
Old Nov 20, 2010, 01:24 PM
Crikey never leave beer behind
steve wenban's Avatar
Mt Annan Sydney Australia
Joined Dec 2003
23,055 Posts
This particular ASW 28 is already a fairly heavily loaded model as it is, Its flys fast but it is predictable .Adding more weight will make it faster and harder to land without any aero dynamic braking system in place. the foils section would be the same as the Salto and the DG1000 that being an Eppler 205 for polars check a program call Profili. The data that comes in the box is very basic indeed consisting of a small drawing of the model and where parts fit together and thats it. Good luck and have fun.
SteveW
steve wenban is offline Find More Posts by steve wenban
Reply With Quote
Old Nov 20, 2010, 01:55 PM
Registered User
viper1's Avatar
Melbourne, Australia
Joined May 2006
483 Posts
Quote:
Originally Posted by steve wenban View Post
"the foils section would be the same as the Salto and the DG1000 that being an Eppler 205 "

Hmmm, I thought it was HQ 3,0-15 ???
viper1 is offline Find More Posts by viper1
Reply With Quote
Old Nov 20, 2010, 02:58 PM
Registered User
Damian Couzoff's Avatar
Melbourne,Victoria,Australia
Joined Apr 2010
1,503 Posts
Hi Thomas-brushless motors have the lipo size recommended-min to max,and prop size-min to max,also esc size to use.For the asw 28,you would most likely need 4s lipo,4s is alot better than 3s,and will give you a good climb,with power to spare.A low kv motor,will spin a bigger prop,and a higher kv motor will be better with a smaller prop.I have 4s/2100 mah/30C lipo and a 14x9.5 folder/60 amp esc, in my 2.65 metre cs discus,flying weight is 2100 grams.The motor is a 770 rpv himark brushless.4s is the best,3s just does not have enough power.
Damian Couzoff is offline Find More Posts by Damian Couzoff
RCG Plus Member
Old Nov 20, 2010, 07:08 PM
Crikey never leave beer behind
steve wenban's Avatar
Mt Annan Sydney Australia
Joined Dec 2003
23,055 Posts
Quote:
Originally Posted by viper1 View Post
Hmmm, I thought it was HQ 3,0-15 ???
Actually your quite correct the DG1000 and the 28 from aerofever have a HQ3015
I have a DG1000 NIB on the bench and my original and my ASW28 hanging in the rack and just had a closer look.
SteveW
steve wenban is offline Find More Posts by steve wenban
Reply With Quote
Old Nov 20, 2010, 08:34 PM
I LIKE WAFFLES....
SENTRY 62's Avatar
Powder Springs, GA
Joined Sep 2010
2,452 Posts
Just ordered one for FPV duties. Will read this thread from cover to cover over the next week.
SENTRY 62 is offline Find More Posts by SENTRY 62
Reply With Quote
Old Nov 21, 2010, 10:36 AM
Registered User
Norway
Joined Nov 2010
5 Posts
Hi again,

Damian;

I have a

Code:
Model: TR42-50A
Max efficiency :38A
Max Load : 43A
Kv : 700
Power: 720W
Weight : 195gr
Pull/Thrust : 900~2100gr
Prop size: 11x5.5 or 12x8
Voltage Range: 9~15v
No Load Current : 3.4A
Shaft: 5mm
Resistance: 0.0327ohms
Max Efficiency: 82%
Power equivalent : .30 to .40 glow engine

Manufacturer recommends 11 x 5.5 or 12 x 8 props.
Ideal for planes up to 5lbs (1~21.kg)  in weight.
Mount holes are 25mm apart and take 3mm screws.
Similar to E-flight Power 32
that i plan to use as the main motor. Have to smaller ones aswell with higher kV. I plan to use a 4S 4000mah 40C to power it.

Have a 60Amp robbe ESC so i think that would work out well.

The prop is a Graupner 10x6 folding prop, but after what you say i probably should use a 14x9,5 or something.

I have a question. Regarding performance the motor,battery,prop,esc should be dimensioned of course to fit together but what is the issues i can run into with a to small prop on a low kV engine? The only problem is that it will turn to slow right? Or might it be overheated due to no/little resitstance?

I also assume that running a engine on high rpm could hurt it/heat it, but is there any rules on how to dimension etc?

Thanks.
cumulusnimbus is offline Find More Posts by cumulusnimbus
Reply With Quote
Old Nov 22, 2010, 12:39 AM
Registered User
Damian Couzoff's Avatar
Melbourne,Victoria,Australia
Joined Apr 2010
1,503 Posts
Thomas,using your combined set-up,the kv motor you are using would still be okay on 4s, with a 13x8 or 14x9.5 prop.10x6 is to small,as is 12x6.A 13x8 or 14x9.5, will have more power for climbing.THIS IS ASSUMING YOU ARE GOING TO USE THE 700 KV MOTOR.regards damo
Damian Couzoff is offline Find More Posts by Damian Couzoff
RCG Plus Member
Last edited by Damian Couzoff; Nov 22, 2010 at 12:44 AM.
Reply With Quote
Old Nov 22, 2010, 02:08 AM
Registered User
Lunns's Avatar
Melbourne, Australia
Joined Aug 2003
309 Posts
Hi Cumulusnimbus,

The prop sizes are 11x5.5 - 12x8 and the voltages at 9-15v.
That would indicate that at 15v (4s ish) the 11x5.5 or at 9v (Little bit under 3s) the 12x8 is ok to keep within the amp rating of the motor. You may well be able to run larger props however from the specs posted you will be running the risk of blowing the motor.
I had a look on the web and could not find a chart of amp/voltage/prop size to confirm, but unfortunately could not find one. Be careful, measure the amp draw and move up in prop size slowly if you are going outside the spec.

Lunns
Lunns is offline Find More Posts by Lunns
Reply With Quote
Old Nov 22, 2010, 02:51 AM
Registered User
Damian Couzoff's Avatar
Melbourne,Victoria,Australia
Joined Apr 2010
1,503 Posts
Thomas-its up to you,what prop to use.A 12x6 will be safe,,my set-up is different from yours,so it cannot be compared.10x6 is to small,you can try it,but l still think it wont have enough thrust.Your on the right track with your motor/esc/lipo-4s,so start with 10x6,and go bigger if required-12x6.........regards damo
Damian Couzoff is offline Find More Posts by Damian Couzoff
RCG Plus Member
Last edited by Damian Couzoff; Nov 22, 2010 at 05:25 AM. Reason: prop size-start with 10x6,then go to 12x6 for your set-up.
Reply With Quote
Old Nov 23, 2010, 04:47 AM
Praying for better weather
Coyote64's Avatar
Joined Dec 2007
4,103 Posts
I tried a 10x6 prop on mine. It flew, but really struggled with power i was on full throttle far too much. I now have a 14x7 prop on with huge ammounts of usable power on tap
Coyote64 is offline Find More Posts by Coyote64
Reply With Quote
Old Dec 02, 2010, 02:34 PM
Registered User
Norway
Joined Nov 2010
5 Posts
Hi guys,

Thanks for all the replies. I have been working on my plane and its now ready. I have got the "flaps" function to work on the ailerons. I will get less effect of them, but i will of course use the flaps during landing so i think it will be ok.

For the motor it seems more than powerfull. I use the 13x8 prop and i tested in in-house by just holding on to the fuselage. Im not sure how good that kind of test is since its just dragging air and not passing it aswell but the motor really did blow the cuirtains I tried holding the plane vertically and on ~50% throttle it lifts itself (approx 2.8kg all inclusive) and the drag/lift was pretty strong on 100%.. i guess a maby 2-3kg thrust atleast.

I have a question. Is it ok to measure current with a regular multimeter when model is in bech or do i need to have a special one that i can fit inside body and that logs max/min/avg values during flight? The ESC is 60A and motor is 42A max. The battery 4200mah 40c.. i think.. if i remember correctly.

I will be flying it tomorrow. I will posts some pics and some vids.

Thanks
cumulusnimbus is offline Find More Posts by cumulusnimbus
Reply With Quote
Old Dec 02, 2010, 03:50 PM
Crikey never leave beer behind
steve wenban's Avatar
Mt Annan Sydney Australia
Joined Dec 2003
23,055 Posts
A word of warning, if you are using Flaperons meaning your Aileron deflect down when applied then you maybe in for a shock as your roll control will be reduced to nothing so picking up a low wing on approach could give you a heart attack ,also using ailerons as flaps forces an aerodynamic washin on the wings increasing the risk of tip stall at low airspeeds. My advise is to land clean a long flat approach into wind will be the answer.
On the other hand if you use the ailerons as spoilerons eg they deflect upward they will increase the decent rate but does have a small effect on airspeed due to the drag they create, but on this model it also make the wings tuck down when applied which can cause a more rapid arrival than planned. Of course you can choose to ignore this and find out through your own experience
SteveW
steve wenban is offline Find More Posts by steve wenban
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
HF models ASW-28 3M soaringMoe Scale Sailplanes 7 Aug 21, 2003 04:49 PM
Asw-27, Asw-28, 82" Carter Scale Sailplanes 14 Aug 03, 2003 11:39 AM
EMS ASW 28 3m Radek Z Thermal 15 Jul 29, 2002 12:58 PM
NSP's ASW-28? Ben74 Slope 5 Jun 06, 2002 11:41 AM