I recently completed a Review of the E-flite Carbon-Z T-28 for RCGroups and thought I should post a link here on Flying Giants. I know the 78" wingspan falls a little short of the 80" minimum "Usually" reserved for big bird status, but this past weekend the Waco HEART OF TEXAS MINIATURE AIRCRAFT CLUB held it's annual Big Bird Event and specifically exempted the Carbon-Z T-28 to allow it to participate. By mid-day there were 7 Carbon-Z T-28s flying and more expected later in the day. That says a lot about the popularity of the this design. Many of the club members have several larger gas powered big birds, but the T-28s were getting the lions share of the airtime.

Here's the link to the Review:

http://www.rcgroups.com/forums/showthread.php?t=2658890

Here's the video from that Review if you want to take a peek:

E-flite Carbon-Z T-28 BNF Basic - RCGroups Reveiw (6 min 43 sec)

...and here's a picture form the big bird event:

The T-28 is a Favorite plane my grand son loves to fly it's a big pussy cat and fly's better than most. I use the T-28 as a trainer easy to see and easy to fly The one I have has logged over two Hundred hours, and still looks brand new. I just traded it for a wood carving of a Buffalo being attacked by two wolves. I have even flown it in 40 mph wind and just hover it around and stay in one spot then hover it down and land like a chopper leave some power on and with my grandson's help go pick it up and walk it back to the pickup

My lovely son gave me a NIB giant T-28 for Father's Day and I was in Alabama at the time. BIG BOX eh? Whereas we were flying, I paid $30 for a 'second bag' and flew to Arizona I'm using a 5000 6S battery and love to do those slow touch and goes!!!!

Jerry

I put a 16x8x3 Master Airscrew on mine. Looks good and flies great. Got a ton of flights on mine. Love flying it.

The three bladed prop makes a world of difference.

A three bladed prop will roughly draw 50% more current and 50% more power.

Current drawn is proportional to #blades, pitch, voltage², Kv³ and diameter⁴.
Increase in current with one or two cells added, simple table - RCG
(a.k.a. "why did my controller go up in smoke?" )

So even small changes in setup can have quit an impact.
Always measure current in a new/changed setup.

Some silly examples:
Doubling voltage would 2²=4 fold current, doubling Kv would 2³=8 fold current, doubling propdiameter would 2⁴=16 fold current.
Real life examples:
Adding a mere 10% to those parameters would respectively 1.1²= 1.2 fold (+20%), 1.1³= 1.3 fold (+30%) and 1.1⁴=1.5 fold (+50%).


Vriendelijke groeten Ron
• Without a watt-meter you are in the dark ... until something starts to glow •
• e-flight calculators • watt-meters • high power motor tips&tricks • Cumulus MFC •

Thanks for the theory. The reality is that I have been flying this combination with the stock motor and ESC for over 4 years with no issues. Works much better than the stock 2 blade. Nothing hot, nothing glowing, 7 minute flights to 30% capacity on my 5,000 mAh 6S packs.

One thing I've learned through the years is when the results don't prove out the theory, believe the results and invent a new theory.

Originally Posted by Judge

Thanks for the theory. The reality is that I have been flying this combination with the stock motor and ESC for over 4 years with no issues. Works much better than the stock 2 blade. Nothing hot, nothing glowing, 7 minute flights to 30% capacity on my 5,000 mAh 6S packs.

I get the same results with mine.

Originally Posted by Judge

Thanks for the theory. The reality is that I have been flying this combination with the stock motor and ESC for over 4 years with no issues. Works much better than the stock 2 blade. Nothing hot, nothing glowing, 7 minute flights to 30% capacity on my 5,000 mAh 6S packs.

No worries Judge, my post was not intended as an exact calculation, but as a general heads up because of all the exponentiations, smalll changes can have surprising results, always calculate and measure after a change/new. Not as a statement about your powertrain. Apparently your battery, controller, wiring and motor have enough headroom
The calculations are worst case, I did not take into account the higher voltage losses in battery, wiring, controller and motor due to higher current.

Vriendelijke groeten Ron
• Without a watt-meter you are in the dark ... until something starts to glow •
• e-flight calculators • watt-meters • high power motor tips&tricks • Cumulus MFC •

Anybody try a three bladed prop for this stock set up?

Jerry

16x8x3 Master Airscrew.
Works like a charm. Stock motor and ESC.

Looks great and performs way better than the stock prop.

Thank You Judge!

Originally Posted by Judge

16x8x3 Master Airscrew.
Works like a charm. Stock motor and ESC.

Looks great and performs way better than the stock prop.

I second that. I've been using that prop for a couple of years. Just be careful with prolonged full throttle

I have a switch that limits normal full throttle to about 85% of full. When I need the extra power I flip a switch to get it.