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-   -   Twister 40 Outrunner? (http://www.Wattflyer.com/forums/showthread.php?t=73954)

Davethebluessinger 06-23-2014 07:13 PM

Twister 40 Outrunner?
 
Hi,
Just bought a scratchbuilt PushyCat Clone.
It's fitted with a 60A ESC and a "Twister 40" outrunner.
I suspect the motor is quite old, I've googled it but can't find any details.
I'd like to work out prop sizes etc. Anyone know the specs for this motor please? :confused:

thepiper92 06-23-2014 07:37 PM

There is a motocalc table that shows up of an EM Twister 19/40, showing 1000 kv. Prop all depends on voltage, 3s would be okay with a 7 inch to 9 inch prop I would think.

Davethebluessinger 06-23-2014 07:41 PM

Thanks!

thepiper92 06-23-2014 08:13 PM

That may be the wrong motor, but it's all that shows up. Sizing is close to a 2836 motor, longer but less diameter, or at least that's what I would think of the 19/40 part, so a 9 inch prop is probably what you want for the max size, or maybe a really low pitch 10 inch.

Davethebluessinger 06-25-2014 10:18 PM

Down on power....
 
OK so I weighed the plane tonight and it's around 2.15Kg (4 3/4Lbs) including motor, ESC and battery. When I bought it it was running a 10 x 6E prop on a 4S and it wasn't particularly quick, I had a 10 x7 APC Thin electric in the garage so tonight I put that on with virtually no effect. I'm not looking for supersonic speeds but can anyone suggest anything other than motor change to speed her up? If required I will buy another motor (suggestions welcomed) but HK and the like don't have a big stock of these larger motors in the UK warehouse.:cool:

solentlife 06-26-2014 05:26 AM

Any joy with giantshark.co.uk ?

thepiper92 06-26-2014 05:47 AM

Quote:

Originally Posted by Davethebluessinger (Post 951411)
OK so I weighed the plane tonight and it's around 2.15Kg (4 3/4Lbs) including motor, ESC and battery. When I bought it it was running a 10 x 6E prop on a 4S and it wasn't particularly quick, I had a 10 x7 APC Thin electric in the garage so tonight I put that on with virtually no effect. I'm not looking for supersonic speeds but can anyone suggest anything other than motor change to speed her up? If required I will buy another motor (suggestions welcomed) but HK and the like don't have a big stock of these larger motors in the UK warehouse.:cool:

With that same motor, a 5s and smaller prop is about all you can do, if your setup can do 5s. You can try a 10x8 or 10x10. Not sure if the motor would handle it. How hot is it getting with the 10x7? 4s sounds like a lot for that motor and prop to me. Of course specs aren't exactly available, but I don't think it is anymore that a 300W motor. I have a 1200kv 2836 in my mini switch, 3s and 8x6 and 8x8 prop, and it hauls. Your plane is 3x the mass though, so with that a bigger motor, bigger prop and higher pitch seems the path for speed.

First, see what weight you can dump, like a smaller 4s. Second, check your temps, or better yet a wattmeter, to determine if you can go the easiest route of a 10x10. If that is a no go, then maybe 5s, and a 7 inch prop I'm guessing, although not sure how much more speed would be gained. I would sooner pick up a larger motor, put 5 or 6s, and play around with the props maybe allowing you a 9x9 prop or something.

Davethebluessinger 06-26-2014 01:40 PM

Thanks for the advice, thinking of changing the motor to this http://www.giantshark.co.uk/product/...er-outrunner-m

Any thoughts

solentlife 06-26-2014 03:00 PM

It needs a lot more info about the model .. as the Pushycat as sold by HK etc. is a lot different ...

http://www.hobbyking.com/hobbyking/s...earch=pushycat

It is rated at 475gr for a start !!

Or clone of this PUSHY-CAT :

http://www.hobbyking.com/hobbyking/s...rSearch=Pusher

You are really out on your own as the weight is a lot higher and needs serious power.

So go on ... ??

Wingspan ?
Length ?
Motor supplied ?
LiPo supplied ?
ESC supplied ?
Prop size supplied ?

The whole has to be evaluated to get an idea of what motor is best ... but at 2.15Kg - that's some motor you will need.

Nigel

Davethebluessinger 06-26-2014 03:51 PM

Solentlife, it's a model twin boom pusher built from a scaled up plan in the RCME published about 2010 so not really a pushycat.

Wingspan 52" Length (nose to trailing edge of elevator) 51"
Motor used by previous owner EM Twister .40
Prop 10 x 6E
4S 3700 mah Lipo
Hobbywing Pentium ESC

I will measure and post the Length later.

thepiper92 06-26-2014 05:02 PM

Quote:

Originally Posted by solentlife (Post 951454)
It needs a lot more info about the model .. as the Pushycat as sold by HK etc. is a lot different ...

http://www.hobbyking.com/hobbyking/s...earch=pushycat

It is rated at 475gr for a start !!

Or clone of this PUSHY-CAT :

http://www.hobbyking.com/hobbyking/s...rSearch=Pusher

You are really out on your own as the weight is a lot higher and needs serious power.

So go on ... ??

Wingspan ?
Length ?
Motor supplied ?
LiPo supplied ?
ESC supplied ?
Prop size supplied ?

The whole has to be evaluated to get an idea of what motor is best ... but at 2.15Kg - that's some motor you will need.

Nigel

I noticed that weight too. I couldn't wrap my head around what was making the plane so heavy. Definitely gonna need a bigger motor.

thepiper92 06-26-2014 05:08 PM

Quote:

Originally Posted by Davethebluessinger (Post 951451)
Thanks for the advice, thinking of changing the motor to this http://www.giantshark.co.uk/product/...er-outrunner-m

Any thoughts

This is a heli motor, so it looks like it can be mounted one way. 1600kv and 4s will scream and at almost 900W, it can take a good sized prop, but you would have to play with props to find the max for this motor.

thepiper92 06-26-2014 06:46 PM

This one seems good. http://www.giantshark.co.uk/product/...rushless-motor

Davethebluessinger 06-26-2014 06:58 PM

Added length of plane to my previous post!

thepiper92 06-26-2014 08:37 PM

I scaled up your wing area using specs from a 36inch wingspan PushyCat, getting 517 sq. inches for wing area. For weight, all out yours is 76 oz, subtract 16 oz for battery and motor, 60 oz. This is likely a bit more than empty weight, but it will work I think.

Results: best is a Turnigy Aerostar 4340 720kV, with a 12x10 prop, max airspeed is showing 81mph, level at 56mph

A slower one: Scorpion HKIII 4025 890kV with a 11x7 prop, 65mph max

For your prop size: Scorpion SII-3020-1110kV, 65mph max.

thepiper92 06-26-2014 08:53 PM

Here is the beast you need: http://www.hobbyking.com/hobbyking/s...ner_900w_.html

Davethebluessinger 06-26-2014 09:24 PM

Thanks thepiper92 however I think I'd have to go with the third option Scorpion.
Reason being if I go up to a 12" prop it'll hit the ground as the nose comes up on take off!

thepiper92 06-26-2014 10:06 PM

That would be a problem on a pusher. 60mph should be fine though, certainly not slow. If you can't find the motor, find a similar one in kv, and max wattage. You may be able to get a similar size and slightly more wattage, allowing a higher pitch.


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