Originally Posted by GCplane

I almost finished my Stearman. I cut about 1/2 inches out of the middle of the wooden motor mount box and glued it back together using 1/4 by 1/4 inch pine blocks in the inside corners and little pieces of plywood on the outside sides. This made room for an Eflight power 10. The recommended motor is slightly weaker than a 480 size (according to Scorpion's comparison chart). The rudder control rod tube has a sharp bend in the last 3 inches at the tail of the plane and causes the rod to bind. I pulled it with a spring scale and it takes 6 oz to move it. Elevator rod moves freely. Did you notice your rudder rod binds?

The Kv on the E-Flite Power 10 (1100Kv) is lower than what Great Planes recommends (1250Kv) so, I commend you on that and selection of this size motor brings needed weight up front where it is needed for good balance.

Can't wait to see your flight report!

Here is the rough estimate on the Power system using 10 X 6 propeller and 3-Cells.

Originally Posted by GCplane

Did you notice your rudder rod binds?

Is it binding before you even hook it up? I had that issue on another GP model - the Spad, once it was hooked up. I pulled the rod in and then bent it slightly making the rod roughly parallel to the fuselage after it exits. This really relaxed the binding.

The rod binds in the rear 3 inches of the tube. I have not hooked it up yet because I am still trying to do something for the binding. I have put in as much graphite as I can for now.

On KV. More powerful motors trend to lower KV. Look at this chart and see the kv go down as power increases. All brands.
http://innov8tivedesigns.com/Scorpio...ison%20Web.htm

Originally Posted by GCplane

The rod binds in the rear 3 inches of the tube. I have not hooked it up yet because I am still trying to do something for the binding. I have put in as much graphite as I can for now.

On KV. More powerful motors trend to lower KV. Look at this chart and see the kv go down as power increases. All brands.
http://innov8tivedesigns.com/Scorpio...ison%20Web.htm

Yes, the lower Kv, the higher Kt (Torque), however, the Scorpion (very good quality built motors) are just too heavy when you try to go lower in Kv.

In any case your selection of the E-Flite Power 10 is alright just keep that propeller diameter nothing over 10 inches and keep the pitch low to keeps those AMPs (Current) draw down.

Carlos

Carlos, Thanks for the chart above. What is the name of that calculator? I am working on 3 planes and with winter coming I may not fly the Stearman for a while but when I do I will report on how it flies.
Gary

Originally Posted by GCplane

Carlos, Thanks for the chart above. What is the name of that calculator? I am working on 3 planes and with winter coming I may not fly the Stearman for a while but when I do I will report on how it flies.
Gary

Gary,

There are other Free On-Line calculators and they offer some nice features more than the one I usually use but, it is my opinion that the accuracy that the one I use and lack of features do not hinder the ultimate decision to find a good power system setup for purposes in this hobby.

It works on Pull down menus and if your motor selection is not listed then the need to select "Custom" will be required and manually input the motors parameters.

http://brantuas.com/ezcalc/dma1.asp

Happy Landings!
Carlos

I happened to have a piece of an old control rod laying on my work bench with a threaded end. I put the threaded end in the rudder tube and kept working it at the two binding spots about 3 and 5 inches from the rear exit of the tube. After that my rudder rod would slide with only about 2 to 3 oz of force instead of 6-10 oz. I was satisfied and hooked up my servos.

Hey guys, saw your thread and read it for some good info.
I am in the middle of putting my beautiful Stearman together. She's a looker for sure! I thoroughly love the job they did building/covering this plane...perfect. The lines just speak to me?!
Glad I found your thread...I just happen to have an old Eflite Park 480-910kv motor that has been looking for a nice home. Perfect! I just cut the stock firewall off the fuselage tonight and will cut a new one tomorrow so it will fit the X-mount for the motor. I didn't want to try and rig something out of the stock firewall. I want the mount solid and drilled correctly to fit.

Other than that, everything has gone great. Just the motor and top wing and she's about ready to go.
Hope there are still some folks flying this nice plane. This thread seems to have died. Hope all the Steamans didn't develop "crash-itis" or something?
Ken

I got my Stearman last week and started reading about all the motor issues. I have a Rimfire .10 1250kv from a previous plane that I was going to put in the Stearman and now I am reconsidering. Whats the opinons on this cheaper setup:

Optima 480 3010-910KV Brushless Motor
http://www.hobbypartz.com/75m50-opti...0-910kv-2.html

GENS ACE 2200mah 3S1P 11.1V 25C Lipo
Dynam Detrum 40A ESC(3A BEC)

Since mine went down a little while back, I haven't tried putting her back up since I've into other planes. Will like go back in a month or two if I am in the mood.

For those comsidering 480 or not, I would switch if you can. Although I am using rimfire .10 in the GP SU-31M, I would use EF 480 1024k if I do it over again or at least get a bigger esc.

I may actually put EF Raphodsy up before the stearman.

If you already have the Rimfire .10, wouldn't that be a cheaper setup?

I have no issues with mine (rec. setup used) at all. It flies like a Super Stearman, it is not a PT-17.

The thread may be slow, but the SS isn't!:cool

Have fun!

Actually my rimefire went to GP Sukhoi which worked out good with EF 40 AMP ESC.

Depending on what's available in my "stock room", i may go either direction. However i would lean toward EF just b/c I have more planes with that motor and i recalled some mentioned it may actually may be more efficient with more or less same amount of power.

I missed my stearman....hopefully i'll get her back in the air in the not so distance future.

Well I finally did it. I just finished rebuilding mine (a new one ). All throws checked according to spec. CG also checked. Looking forward to maiden this beauty again this coming weekend .

Setup pretty standard with a few mods:

• Motor rimefire .10
• EF 40 amp ESC
• Futaba S3157 for all servos
• APC 10x7 prop
• Replaced standard front wheels with Dubro no bounce wheels
• Strenghten landing gear with epoxy and fiberglass cloth. Epoxy motor mount for extra strength.
• Cut slots between plastic motor mount for better airflow. Applied a little epoxy on plastic motor radiator for added strength. Not sure this might have been the cause of my issue last time (insufficient airflow to ESC).
• Used plastic control horns with screws instead of what was provided.

Fingers crossed as I don't want a repeat like the first time around.

I actually dremeled out between the cylinders for air flow. Had to add push rods after I seen how well it looked.

The wooden 9x6 prop is just for display purposes....

that's actually what i did. should have been clearer. i like your added touch of silver paint. i may add the little detail to mine later on.