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General control line discussion => Open Forum => Topic started by: bob branch on November 08, 2009, 03:24:55 PM

Title: Electirc T-Rex weight
Post by: bob branch on November 08, 2009, 03:24:55 PM

Just thought I would post that the electric T-Rex ARC build thread I have been doing on the electric forum has pictures of the finished airplane now. Final weight WITH battery is exactly 60 ounces.

bob branch

Title: Re: Electirc T-Rex weight
Post by: Alan Hahn on November 08, 2009, 05:59:13 PM

Bob,
Was that with the battery charged? ;)

Title: Re: Electirc T-Rex weight
Post by: bob branch on November 08, 2009, 06:15:35 PM

Alan
Yes it was completely full of electrons.  y1

bob

Title: Re: Electirc T-Rex weight
Post by: Alan Hahn on November 08, 2009, 08:42:15 PM

Quote from: bob branch on November 08, 2009, 06:15:35 PM

Alan
Yes it was completely full of electrons.  y1

bob

Well of course you have the same number of electrons in a discharged battery as in a fully charged one. The only difference is that in the charged case they are all "up the hill", instead of sitting around at the bottom!.

So you should worry  n1 about that 2 nanogram change in weight and how it will affect your cg in the clover. ~^

Title: Re: Electirc T-Rex weight
Post by: bob branch on November 09, 2009, 05:17:59 AM

I'll dial in another rpm.

bob

Title: Re: Electirc T-Rex weight
Post by: bob branch on November 09, 2009, 05:25:17 PM

I must amend the weight. The wide fuse and blunt airfoil required a bit more rpm and current than I had expected. I am currently therefore flying with a 3000 mah 4 cell pack and the all up weight with battery onboard is 63 ounces.

bob branch

Title: Re: Electirc T-Rex weight
Post by: Alan Hahn on November 09, 2009, 06:46:34 PM

Well fortunately I was using 3000 mAHr for my calculation, so you won't gain any extra weight there! y1

Title: Re: Electirc T-Rex weight
Post by: Bradley Walker on November 10, 2009, 04:57:16 AM

Quote from: bob branch on November 09, 2009, 05:25:17 PM

I must amend the weight. The wide fuse and blunt airfoil required a bit more rpm and current than I had expected. I am currently therefore flying with a 3000 mah 4 cell pack and the all up weight with battery onboard is 63 ounces.

bob branch

That is still crazy light...  in fact that should be the perfect fighting weight.

My prototype was 67 oz DRY, with the 76 installed it was more like 69 oz DRY.  Add 5 oz of fuel and take off weight is 72+ oz and it was downright FRISKY at that weight.

PS:  Joe Gilbert's PA 65 and pipe ARF, weighs 63 OZ DRY with no fuel.  So, I guess you have your apples to apples IC/electric comparison...  and Bob added a pilot.

Title: Re: Electirc T-Rex weight
Post by: Bob Reeves on November 10, 2009, 08:54:00 AM

Saito 62 ARF is also 63 ounces with 2 ounces of tail weight..