HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old May 19, 2008, 08:55 PM
Registered User
Joined Feb 2007
3,657 Posts
Guys, I know this is all about thrust and not the intent of the airframe, but have any of you tried smaller props higher revs on the nb to see how it would perform? Just wondering...
tymbrewolf is offline Find More Posts by tymbrewolf
Reply With Quote
Sign up now
to remove ads between posts
Old May 19, 2008, 09:23 PM
flyin' fool
goldguy's Avatar
Vancouver Island, Canada
Joined Jul 2003
7,214 Posts
Haven't tried it on a NutBall, but I know from experience that small props are for speed and large props for torque. You could never get the volume of thrust (or moving air) from a small prop spinning at tens of thousands of revs as you could with a large prop spinning at 1/3 that. Just try it and see, but you'll need more volts to make it work, so now your adding weight and will end up with a parkjet with no real slow speed capabilities. That's because the big prop, acting as a brake, allows us to fly slower and keeps generating thrust when a small slow turning prop will not.

Electric flight is one big compromise after another............
goldguy is offline Find More Posts by goldguy
RCG Plus Member
Last edited by goldguy; May 20, 2008 at 12:10 AM.
Reply With Quote
Old May 19, 2008, 10:45 PM
Registered User
Joined Feb 2007
3,657 Posts
Frank, that is what I was wondering. If you have the same motor size but different Kv's and and the proper esc, could one conceivably have a slowflyer or an RET parkjet thingy sing a firewall mount and just switching out two different motors for both kinds of flight from the same plane.

For instance these two motors: http://www.hobbycity.com/hobbycity/s...idProduct=5482 or
http://www.hobbycity.com/hobbycity/s...idProduct=5353

or these two:
http://www.hobbycity.com/hobbycity/s...idProduct=2069 or
http://www.hobbycity.com/hobbycity/s...idProduct=5453

if one could use 2s or 3s batteries of similar weight.

What got me thinking was when I reread your post in rcuniverse about mild to wild as you compared it to an RET park jet. I just wonder what the maximum flight envelope could be. We all know its the cats meow for slow fun RET, I just wondered what the airframe's limits would be with a turbo charger. I know it can nearly outfly my skills in a spiral dive on WOT.

It is already perfect, why change it... just thinking outloud as I have no real speed demons and this thing just flies so well as it is, just wondered if it would fly just as well really fast.
tymbrewolf is offline Find More Posts by tymbrewolf
Reply With Quote
Old May 19, 2008, 11:04 PM
Registered User
Joined Feb 2007
3,657 Posts
Gotta say one more thing about your plane, Frank. As I was going to shut down, I noticed that today this thread is 60 days old. Everybody gets knocked off the top of the heap sooner or later, hopefully this thread will be on top for years. Just can't imagine what foamies was like before this plane as this fall/winter and now spring has been my reentry back into this hobby for real again. Starting with the dart, moving over to my own "killer bunny" design and then the NB along with all these new small brushless outrunners and inexpensive 20C lipos etc... Just think what the people that got out of the hobby even less than six months ago are missing.
tymbrewolf is offline Find More Posts by tymbrewolf
Reply With Quote
Old May 20, 2008, 12:33 AM
flyin' fool
goldguy's Avatar
Vancouver Island, Canada
Joined Jul 2003
7,214 Posts
The only two threads I started that have staying power are this and the Dart. Shows you what people like, simple, cheap, fun and flyability.

My 17" NutBall is powered by the 16g motor on 2S turning a 7 X 4 can not only prop hange, but keep up with any parkjet at our field.

I often use the same motor in different applications. An example is the 10g motor. I use it on a small 3D machine turning a GWS 7 X 3.5 moded to a 6" on 2S and on my fast tiny delta turning a GWS 4.5 X 3 on 3S and it's very fast. Although it doesn't put out the thrust at low throttle, I can do some pretty silly high alfa stuff with it.

I do this with most motors that are factory built, but mostly wind my own to get exactly what I need........the GB Custom, Komodo, Rocket, VL and the Blu Wonders. I'm going to get a few more 16g to rewind and play with.

Modifying props and winding motors needs a watt meter to get it right.
goldguy is offline Find More Posts by goldguy
RCG Plus Member
Latest blog entry: Flyin' Fool
Reply With Quote
Old May 20, 2008, 12:36 AM
flyin' fool
goldguy's Avatar
Vancouver Island, Canada
Joined Jul 2003
7,214 Posts
Art: How about a NutBall decoration contest? No flying, just paint jobs.
goldguy is offline Find More Posts by goldguy
RCG Plus Member
Latest blog entry: Flyin' Fool
Reply With Quote
Old May 20, 2008, 05:38 AM
Registered User
davereap's Avatar
Ashford. Kent. England
Joined Feb 2005
6,809 Posts
Finally finished the 32" nutball...It looks BIG... this has a 50% KF step...and weighs in at a massive 20oz with a big lump of a battery and a heavier U/C .... Wing loading still only 3.6oz sq ft.. Waiting on some better weather here...too much wind.. for comparison the 24" nutball is shown..which flys great at 3.3oz sq ft

the motor on the bigun is a 10 large blue bell from overlander.co...
this uses a 9x5 to give 26oz thrust at 11A on a 11.1v lipo...

On the big nutball I could reduce the wing loading by using a smaller battery, and removing the UC. I will just have to see how it goes
davereap is online now Find More Posts by davereap
Last edited by davereap; May 20, 2008 at 05:50 AM.
Reply With Quote
Old May 20, 2008, 06:44 AM
London Ontario Canada
artlane's Avatar
London Ontario Canada
Joined Apr 2004
1,045 Posts
Pretty NB's

Quote:
Originally Posted by goldguy
Art: How about a NutBall decoration contest? No flying, just paint jobs.
Hey, that sounds like a good idea...... Now, what do you propose for rules (there's that stupid word again, "Rules")
Got a question regarding older Lipos... Got 3-7.4V ones, without the balancing connector. They need balancing!!!!! Is there a way to add that 3rd line to em and use my E-Flite, Blade, balance charger???? Or, do I just continue chargin, and using till the become defunct? They are the older Kokham batteries...
Hummmmm, best decorated NB... hummmmmm...Where's my spray gun?
artlane is offline Find More Posts by artlane
Reply With Quote
Old May 20, 2008, 10:52 AM
Registered User
Joined Nov 2006
1,067 Posts
Quote:
Originally Posted by artlane
Hey, that sounds like a good idea...... Now, what do you propose for rules (there's that stupid word again, "Rules")
Got a question regarding older Lipos... Got 3-7.4V ones, without the balancing connector. They need balancing!!!!! Is there a way to add that 3rd line to em and use my E-Flite, Blade, balance charger???? Or, do I just continue chargin, and using till the become defunct? They are the older Kokham batteries...
Hummmmm, best decorated NB... hummmmmm...Where's my spray gun?
I personally have taken the batteries apart and changed around the balance connecting tabs when 1 cell went bad in a pack. Adding a balance connector isn't terribly hard if you know your way around a soldering gun and are careful not to short out or heat up the pack.
Kurpal is offline Find More Posts by Kurpal
Reply With Quote
Old May 20, 2008, 05:20 PM
Registered User
Joined Feb 2007
3,657 Posts
Thanks as usual for your knowledge Frank.
tymbrewolf is offline Find More Posts by tymbrewolf
Reply With Quote
Old May 20, 2008, 07:11 PM
Registered User
Joined Apr 2006
87 Posts
Yeah, I realized it when I figured it as a 21 X 21 square. NOW, if I could get it down to 1.57 at I could get it to fly as slow as i walk.

However, I am still very happy with the 2.4 loading.

Thanks for correcting me a bit on that.


I do have a question though. Mine seems to be flying in fairly high alpha and needs a fair amount of rudder imput to steer. I was thinking tail heavy, but then I would think the controls would be touchy. Elevater seens normal but Rudder is very sluggish to respond.

Quote:
Originally Posted by goldguy
All up weight is 4.8 ounces, and 440 square inches of area. 3.05 square feet of area with a 4.8 ounce weight works out to WOW, 1.57 ounces/Sq. Ft.!!!!
The area of a circle 21" in diameter, R x R x 3.1415, is 346.35 sq. in. for 2.40 sq. ft.[/QUOTE]
fomieforme is offline Find More Posts by fomieforme
Reply With Quote
Old May 20, 2008, 10:42 PM
flyin' fool
goldguy's Avatar
Vancouver Island, Canada
Joined Jul 2003
7,214 Posts
Check the down thrust, very important.
goldguy is offline Find More Posts by goldguy
RCG Plus Member
Latest blog entry: Flyin' Fool
Reply With Quote
Old May 21, 2008, 05:25 AM
Registered User
Joined Apr 2006
87 Posts
Got the down and right thrust.

I guess that is good advice, I have just been building long enough to have that much figured out and was hoping it was something to do due to the lack of an air foil or such. lol

Quote:
Originally Posted by goldguy
Check the down thrust, very important.
fomieforme is offline Find More Posts by fomieforme
Reply With Quote
Old May 21, 2008, 02:48 PM
flyin' fool
goldguy's Avatar
Vancouver Island, Canada
Joined Jul 2003
7,214 Posts
It's got an airfoil, a thin fully symmetrical one

Not sure what your problem may be, but you may notice is some of the videos we posted that I had no problems with rudder control in high alfa or even prop hanging. Maybe your rudder is not tall enough.
goldguy is offline Find More Posts by goldguy
RCG Plus Member
Latest blog entry: Flyin' Fool
Reply With Quote
Old May 21, 2008, 07:09 PM
Fighter of Gravity
woolebugr's Avatar
Joined Aug 2007
316 Posts
Got a question, with the 16g and 24g motors from Hobby City, what esc are you guys using. I really like the price of the "Super Simple" esc's, but are they worth a toot?
woolebugr is offline Find More Posts by woolebugr
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question What is THE best free plan foamy? 3Dude 3D Flying 27 Oct 13, 2009 10:48 PM
Best R/C Day yet! R/C~Mev Electric Sailplanes 3 Nov 22, 2004 10:35 PM
Best Simulator for Foamy 3D Flying ? knut 3D Flying 10 Nov 02, 2004 12:51 PM
Best AXI for Foamy Factory 44" Extra? Doug Cronkhite 3D Flying 10 Mar 16, 2004 11:11 AM
Q: Best covering for foamy scale warbird? dimple Foamies (Kits) 4 Feb 05, 2003 06:14 AM