SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Apr 19, 2001, 04:59 PM
Registered User
NY NY USA
Joined Jun 2000
715 Posts
Anybody use two packs for speed 400 twins?

I was thinking on making a twin speed 400 plane and using two power systems mixed together on the radio. How does this sound? Two speed 400 6V on 8x600AE each?
Dan
Daniel English is offline Find More Posts by Daniel English
Reply With Quote
Sign up now
to remove ads between posts
Old Apr 19, 2001, 05:08 PM
Registered User
Texas
Joined Aug 1999
5,110 Posts
Heavy
dave_lilley is offline Find More Posts by dave_lilley
Reply With Quote
Old Apr 19, 2001, 05:09 PM
Registered User
Larry Dudeck's Avatar
Williamsville, NY, USA
Joined Sep 2000
4,503 Posts
Sounds like a lot of additional work, esp. if you plan on 2 ESC's.

What benefit do you perceive?
Larry Dudeck is online now Find More Posts by Larry Dudeck
Reply With Quote
Old Apr 19, 2001, 05:33 PM
Registered User
NY NY USA
Joined Jun 2000
715 Posts
Well I have a lot of 600mah packs.....
Daniel English is offline Find More Posts by Daniel English
Reply With Quote
Old Apr 19, 2001, 05:34 PM
Single-task at best...
tim hooper's Avatar
Telford, UK
Joined Feb 2000
7,501 Posts
Dan,

Digging deep here.....I think someone has done this with a Twinstar. A seperate ESC for each motor, somehow mixed into the Tx.

He was able to throttle each motor independently, and induce such tricks as high-speed flat spins.

I'm sure that somebody will be able to shed more light.

tim

Bingo! Email Jim Myers;

KMyersEFO@aol.com

and ask for a file of the Ampeer newsletter from July 99.

[This message has been edited by tim hooper (edited 04-19-2001).]
tim hooper is online now Find More Posts by tim hooper
Reply With Quote
Old Apr 19, 2001, 05:38 PM
Registered User
NY NY USA
Joined Jun 2000
715 Posts
I just checked the specs and 2 8 cell 600 AE packs works out to 10.4 ounces. An 8 cell 2400 pack weighs 18 ounces, and a 8 cell 1200 pack weighs 12 ounces.
It would just be the extra weight of a controller which is less than one ounce. It could actually be lighter.
Dan
Daniel English is offline Find More Posts by Daniel English
Reply With Quote
Old Apr 19, 2001, 05:46 PM
Registered User
Ireland
Joined Apr 2001
4,031 Posts
earm what if one pack discharges faster then the other?
cmulder is offline Find More Posts by cmulder
Reply With Quote
Old Apr 19, 2001, 06:22 PM
Registered User
Sabrejock's Avatar
Winnipeg, MB Canada
Joined Jan 2000
2,419 Posts
Dan: If you want to use your 600 packs and don't want to go series, 'Y' your packs in parallel to give you 1200 mAh and still use BEC. You can charge them as individual packs. Tex.
Sabrejock is offline Find More Posts by Sabrejock
Reply With Quote
Old Apr 19, 2001, 06:31 PM
Registered User
NY NY USA
Joined Jun 2000
715 Posts
Thats theother otion, but then I need a 16 cell controller.
Daniel English is offline Find More Posts by Daniel English
Reply With Quote
Old Apr 19, 2001, 07:20 PM
Registered User
Sabrejock's Avatar
Winnipeg, MB Canada
Joined Jan 2000
2,419 Posts
Dan, if you join your packs pos to pos, neg to neg, and take the power from there, you still have 8 cells in reality. That's parallel. Tex.
Sabrejock is offline Find More Posts by Sabrejock
Reply With Quote
Old Apr 19, 2001, 07:36 PM
Senior Member
Oxford(ish), England
Joined Feb 2001
389 Posts
Good question, what happens if one flattens first? Assemetric thrusts, that's what. With a pinwheeling prop on the other side (heaps of drag) this COULD be dangerous!

You could wire them up in parallel. This is the option i'd choose as you only need one ESC and that can be a standard 8-cell one.

If you're interested in assymetric thrust for steering, you'd need to wire things up so you had a Y lead like a delta. You'd have throttle on the "Elevator" channel and rudder on your "aileron" channel. I don't know how you'd go about sorting the power supply for the radio, though. Obviously you could use the BEC's in the ESC, but i haven't a clue how it might be effected by this extra complexity!
gdb1973 is offline Find More Posts by gdb1973
Reply With Quote
Old Apr 19, 2001, 11:06 PM
Registered User
NY NY USA
Joined Jun 2000
715 Posts
Parrallel like Sabrejock says would probably be theeasiestway, I was thnk series together weoud be 16 cells, or series seperately would be 2 8 cell packs. Maybe I should just buy some 1250's
Dan
Daniel English is offline Find More Posts by Daniel English
Reply With Quote
Old Apr 20, 2001, 12:51 AM
Registered User
Austin, Texas USA
Joined Mar 2001
848 Posts
I read somewhere about a Twinstar with the motors wires in parallel and 2 battery packs wired in parallel. This would be the simplest way to do it and use your existing equipment.
sf_247 is offline Find More Posts by sf_247
Reply With Quote
Old Apr 20, 2001, 06:37 AM
Old age is not for sissies
Azarr's Avatar
Dayton Intl, Ohio, United States
Joined Jan 2000
7,987 Posts
I've done the mixing twice now, but both times with two speed controls and only one battery. The systems worked well, with all mixing done in the transmitter, mixed to the rudder stick so that rudder stick movement causes one motor to speed up, the other to slow down, depending on the location of the throttle stick, it can be quite dramatic. I did this successfully on the TwinStar, but my attempt at converting a JC Hobbies fun bat was not as successful, not because the mixing didn't work, but because we never could get it in the air, even with a bungee. There was obviously enough power to fly, it wanted to pull out of your hand, I think the airfoil was so thick that we just couldn't get it going fast enough at launch. It looked OK though, here's a pic.

Azarr
www.azarr.com

OK, for some reason I can't get the photo to appear, let's try this:

<a href=http://albums.photopoint.com/j/View?u=94931&a=12646387&p=46897672>See my photo, twinbat1 at PhotoPoint</a>

[This message has been edited by Azarr (edited 04-20-2001).]
Azarr is offline Find More Posts by Azarr
Reply With Quote
Old Feb 27, 2004, 03:22 PM
[intentionally blank]
fprintf's Avatar
Cheshire, CT, USA
Joined Jan 2001
1,528 Posts
So this was this first post in this forum eh? Cool!
fprintf is offline Find More Posts by fprintf
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Looking for a cheap lithium capable ESC for speed 400 use... papasmurf Power Systems 5 Apr 24, 2004 11:38 PM
Has anybody USed Vario Props What size for speed 400? DPupko Scale Kit/Scratch Built 7 Mar 05, 2003 09:08 PM
Cheap Battery Packs for Speed 400 Fliers SchiessCo Aircraft - Electric - Airplanes (FS/W) 4 Mar 02, 2003 10:35 PM
Anybody use Tape Solder for battery packs?? saint152 Foamies (Kits) 4 Apr 30, 2002 12:54 PM
Radiator for a Speed 400? Tim Seidenstricker Electric Plane Talk 22 Jun 02, 2001 02:02 PM