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-   -   Wattage PT-17 modified & ready to fly (https://www.wattflyer.com/forums/showthread.php?t=724)

donjiskra 08-24-2005 09:20 PM

Wattage PT-17 modified & ready to fly
 
1 Attachment(s)
Just completed this handsome Stearman and will give it it's maiden flight tomorrow.

MODIFICATIONS:
* Installed a Plettenberg Freestyle24 brushless motor
* Replaced flimsy landing gear with a 1" wide aluminum unit with an 11" spread, using 2 7/8" wheels for our grass airfield. (Stock 1/4" pieces are too soft and easily bent on hard landings). The 11" spread provides good ground stability.
* A ThunderPower Li-Po 2100mah 3s1p battery
* A CoolRunning A-25 ESC
* An 8x4 Zinger prop (will convert to an APC-E after visit to LHS)

Here's the E-calc data to provide performance data.
* 8x4 Zinger, 16.9 amps, 99watts per pound, 1,523 ft/min at 42 degrees climbout and 17.0 minutes cruise.

I also checked:
* With 8x6 Zinger: 21.7 amps, 122 watts/lb, 1852 ft/min, 47 degrees climb-out,
14.5 minutes cruise.

* With 10x6 MAS electric prop: 34.9 amps, 173 wats/lb, 1904 ft/min at 90 degrees climb out. Certainly produces performance that would probably rip off the wings and would require a higher amp rated ESC.

I choose the 8x4 combination for a more docile maiden flight and longer flight time to sort it out.

Will get back with flight update,
Don

donjiskra 08-26-2005 01:01 PM

Wattage Stearman PT-17 flight test result
 
I tried to take-off with the Zinger 8x4 prop rolling through our grass field was not a problem but there was not enough power, (99 watts per pound), to take off. Air was calm which did not help.
I installed the 10 x 6 Master Airscrew Electric (173 w/lb), the Stearman had plenty of power and no problem getting airborn but it was very erratic and wobbling, after getting up 5 feet. I brought it down to determine the cause. Inspection revealed that the firewall had separated from the fuselage causing the motor to seek other directions.
The firewall has been secured with JB Weld epoxy and another test is scheduled for next week, using an APC-E 10x7 (155 w/lb).
Don

donjiskra 08-26-2005 05:22 PM

Wattage Stearman motor mount
 
1 Attachment(s)
Here's how I fixed the firewall and how I mounted the Plettenberg brushless motor.
The motor mount is available from http://www.espritmodel.com/ the mounts are awesome and can be adapted to your model by selecting the proper length rods.
Don

donjiskra 10-06-2005 09:49 PM

Wattage PT-17 demise
 
Well it roared off in a fury got airborne about 3ft and then nosed in BAMMO!!! Plane is now for parts retrieval. Too bad as it sure looked good until the pilot, (ME), couldn't handle it :mad: :mad: :mad:

Duster52 10-07-2005 06:26 AM

Very distressing! I have many hours on the GWS PT-17 and love it. After a few accidents and repairs, I need a new one. I have been looking at the WattAge model and considering it for my new one. It is much more scale looking and I know it is heavier with almost the same wing area. I was hoping for some flight reports before I put in for the "Christmas hint"!:D

Are you considering another one or have you given up on it?

Thanks and good luck.

donjiskra 10-07-2005 01:27 PM

Another?
 
Well I did like the plane and how it looked but I had to modify too many things about it to make it grass field worthy.
1-the landing was not sturdy enough for rough landingd
2-the wing stuts rubber fasteners were replaced with machine screws (again too flimsy)
3-I didn't like the fact that the wings had to be removed in order to replace the battery. (I inserted through the cockpit).
4-Stock motor not powerful enouigh for grass field take off, so I installed a brushless motor and used a 3s1p LiPo instead of other batteries. (great weight reduction)
5-Reworking the motor mount took a lot of time
6-After doing all these mods I had very capable model which evidently exceeded my flyiny skills

Other than all the above it was a great looking model, but if you keep it stock and fly off a paved runway it will work. I would recommed it for you, if you love the Stearman.

The manual is superb and greatly illustrated, easy to follow.


Good luck,
Don:)

Aviator Wim 01-28-2020 08:38 AM

Building instructions needed
 
Hello,
recently I've bought this lovely plane as a building kit. But the building instructions are not included.
Is there any way that you could provide them?
Many greetings from Belgium 😀


Originally Posted by donjiskra (Post 5403)
Just completed this handsome Stearman and will give it it's maiden flight tomorrow.

MODIFICATIONS:
* Installed a Plettenberg Freestyle24 brushless motor
* Replaced flimsy landing gear with a 1" wide aluminum unit with an 11" spread, using 2 7/8" wheels for our grass airfield. (Stock 1/4" pieces are too soft and easily bent on hard landings). The 11" spread provides good ground stability.
* A ThunderPower Li-Po 2100mah 3s1p battery
* A CoolRunning A-25 ESC
* An 8x4 Zinger prop (will convert to an APC-E after visit to LHS)

Here's the E-calc data to provide performance data.
* 8x4 Zinger, 16.9 amps, 99watts per pound, 1,523 ft/min at 42 degrees climbout and 17.0 minutes cruise.

I also checked:
* With 8x6 Zinger: 21.7 amps, 122 watts/lb, 1852 ft/min, 47 degrees climb-out,
14.5 minutes cruise.

* With 10x6 MAS electric prop: 34.9 amps, 173 wats/lb, 1904 ft/min at 90 degrees climb out. Certainly produces performance that would probably rip off the wings and would require a higher amp rated ESC.

I choose the 8x4 combination for a more docile maiden flight and longer flight time to sort it out.

Will get back with flight update,
Don



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