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Chat Area => General Discussion Area => Topic started by: 05omegav6 on 01 June 2016, 00:09:30

Title: RC Plane question...
Post by: 05omegav6 on 01 June 2016, 00:09:30
Doing a spot of preemptive research before building an electric rc balsa plane...

Have had a good rummage around and have the basic electrical set up in mind. What I am puzzling over is prop sizing...

Run the numbers through here...

http://flbeagle.rchomepage.com/software/webocalc_1.7.6/html/webocalc_imperial.html

Keeps coming back to an 8"x4" prop which is good because the numbers work, but it doesn't allow for prop configuration, ie two or three bladed... other slight concern is that an 8" prop only allows a quarter inch clearance between the tip and the ground...

So the question is this... Can I drop down to a seven inch three bladed prop? And if so, what pitch?

Would 7"x5" work?

Title: Re: RC Plane question...
Post by: omega2018 on 01 June 2016, 00:31:36
where it says "Maximum Prop. Size (inches)" put in 7 ::)
Title: Re: RC Plane question...
Post by: 05omegav6 on 01 June 2016, 10:52:05
where it says "Maximum Prop. Size (inches)" put in 7 ::)
Yeah, that helps. Not. For a 7" prop, it suggests a much higher speed requirement... thus is a Cessna, not a P51 ::)

Also, as said, it doesn't differentiate between blade numbers...
Title: Re: RC Plane question...
Post by: zirk on 01 June 2016, 11:48:11
This Chap will know -

(http://www.wearysloth.com/Gallery/ActorsR/19827-26530.gif)

or was it Him -

(http://3.bp.blogspot.com/-nsvdlc9W_q8/UjR9GxX5CKI/AAAAAAAAFxg/fKad5QnWp6M/s1600/Kruger.PNG)
Title: Re: RC Plane question...
Post by: steve6367 on 01 June 2016, 12:23:39
Doing a spot of preemptive research before building an electric rc balsa plane...

Have had a good rummage around and have the basic electrical set up in mind. What I am puzzling over is prop sizing...

Run the numbers through here...

http://flbeagle.rchomepage.com/software/webocalc_1.7.6/html/webocalc_imperial.html

Keeps coming back to an 8"x4" prop which is good because the numbers work, but it doesn't allow for prop configuration, ie two or three bladed... other slight concern is that an 8" prop only allows a quarter inch clearance between the tip and the ground...

So the question is this... Can I drop down to a seven inch three bladed prop? And if so, what pitch?

Would 7"x5" work?

Not quite the same, but I have a couple of Electric RC gliders and in my experience you will end up having a play with different props once you have it finished. Assuming you are fitting speed control and the prop is very unlikely to be variable pitch it will always be a compromise.

What motor are you planning to use?
Title: Re: RC Plane question...
Post by: 05omegav6 on 01 June 2016, 12:27:12
An E flite Park 370 brushless outrunner, 1080kv with a 3s 1300mAh LiPo ;)
Title: Re: RC Plane question...
Post by: steve6367 on 01 June 2016, 13:07:29
An E flite Park 370 brushless outrunner, 1080kv with a 3s 1300mAh LiPo ;)

Your going to be in a slightly different performance league to me then!

I using the good old Graupner Speed 600 in my pair  :D
Title: Re: RC Plane question...
Post by: TheBoy on 01 June 2016, 18:14:06
My RC's glider's maiden flight ended in it losing a fight with a rugby post.  But its biggest problem was it was unable to withstand the "garage incident" ;D


After getting reasonably proficient with the glider, I always intended to get a plane, but then places to use started to get more restricted :(
Title: Re: RC Plane question...
Post by: Andy B on 01 June 2016, 22:43:08
This Chap will know -

http://www.wearysloth.com/Gallery/ActorsR/19827-26530.gif

or was it Him -

http://3.bp.blogspot.com/-nsvdlc9W_q8/UjR9GxX5CKI/AAAAAAAAFxg/fKad5QnWp6M/s1600/Kruger.PNG

 ;D ;D ;D
Title: Re: RC Plane question...
Post by: Andy B on 01 June 2016, 22:44:39
I trust you have the requisite PPE  ::)  ::)  ::)