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Electric Stunt => Gettin all AMP'ed up! => Topic started by: David Shad on November 05, 2010, 05:58:40 AM

Title: Heavyweight!
Post by: David Shad on November 05, 2010, 05:58:40 AM
So...I have this stunter that was built for the PA .65...had a .75 in it too...but I don't have the
powertrain and Randy is out of stock for the forseeable future on them...and I am thinking...$600
for that or...an electric conversion that would probably cost less or if nothing else the same and I
would have several batteries for it.   I have read the current set-ups listed here but technology
changes all the time.   With the PA setup the plane weighs 70 ounces....What do you guys think?

What are the options?
Title: Re: Heavyweight!
Post by: Robertc on November 05, 2010, 09:54:24 AM
How many sq. in?  I'd venture a guess and say the same basic system as Paul Walker.  Look under List Your Set up.
Title: Re: Heavyweight!
Post by: Mark Scarborough on November 05, 2010, 10:03:55 AM
If you copy Pauls setup, you would want to use his first setup, not the current one. The current one is streamlined for a smaller lower drag airframe and wing.
Title: Re: Heavyweight!
Post by: Dean Pappas on November 05, 2010, 11:31:16 AM
Hi Dave,
Yup, how many squares? what does it weigh without the powerplant? Thick foils, fat foils, super-fat foils?
Landing gear: will the ship accept a 13" prop?
It does sound like a 5S, 3300 to 4000 mAH battery coupled with a motor that will probably weigh areond 8 ~ 10 oz with a Kv of somewhere between 720 and 850 will do.
I don't remember which Pletty or Hacker number to recommend right now, but I'll look them up at home. These two motors have the 3-rd bearing which should allow you to keep the firewall that is in the ship, if that's what you would do.

later,
Dean P.
Title: Re: Heavyweight!
Post by: Dennis Adamisin on November 05, 2010, 01:51:29 PM
David:
Lots of big power choices out there, I have no quibbles with what others have already said here - just offering up one more variation.  We have been flying flying an 80 oz Strega with LOTS of power.  It uses a 6 cell pack to help keep the current draw lower and reduce the HEAT.  It can also use packs that are physically small.  Kenny Stevens recently converted an old PA-65 powered SV to the same power system and is very happy with it:

Arrowind 3526 Motor (Brodak BH-1841) http://www.brodak.com/shop_productdetail.php?ProductID=8844

Battery: depending on "dragginess" & final weight, 62x2200 mah or 6Sx2800 mah.  We have been flying the Strega on 2800's but believe we could use the 2200's, especially if it had a thinner wing or a little less weight.  THe 2200 pack saves 3 oz versus the 2800's: http://www.brodak.com/shop_productdetail.php?ProductID=8999 or  http://www.brodak.com/shop_productdetail.php?ProductID=8849 

ESC: Castle Phoenix 45 or Ice 50 Lite, in "Set RPM" mode

Timer: Hubin FM-2SR (Brodak BH-1870)  http://www.brodak.com/shop_productdetail.php?ProductID=8860

Prop: APC 13x4.5EP (electric series pusher prop) turning about 9800-10,000 RPM


The biggest problem with CONVERTING an existing airframe is that it will likely gain a couple ounces - though compared to the old "gassie" with a full tank of fuel the weight differences get pretty small.  Building from scratch will let you make up any penalty...
Title: Re: Heavyweight!
Post by: David Shad on November 05, 2010, 04:22:02 PM
I should have thought to add the squares...756. 64 in span.

PW's setup lists a Plettenberg 30-12 with a 5s 4000 Battery.  Same size and weight.