Pitts style biplane scratch build.

DamoRC

Elite member
Mentor
Great job - I really like the color / finish of the final product and it flies well to boot!
 

RacerX

Member
Thank you for all of the positive comments. I finally got around to detailing the plans I used to build this model. They are kinda rough but if you have any questions, please, let me know. I added the PDF plans to the original post, too.

The boundary line should be 20" x 30" to match the Dollar Tree foam board. The overall page size, in the PDF, is architectural "D" or 24" x 36".

View attachment FittsPlans1.pdf
View attachment FittsPlans2.pdf

Just so you know, I haven't had anyone follow any plans I have created. You have been warned. =o
 

matjey

Member
Oh man.. this bipe really catch my heart. Gonna build one soon. Oh ya.. how about the CG, is all correct? Tail heavy? I have view the plan and your post but couldn't know where is the COG for this bipe.

I've build a couple of biplane previously including the Boeing Stearman as features in flitetest article section and end up tail heavy. Not sure where went wrong. But I definitely will be building this bipe for sure.
 
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RacerX

Member
Hi matjey! CG should be pretty close. Just mount the battery where it needs to be - this simple design allows for easily moving the battery around in the fuselage.

I've flown the original quite a few times but I made a mistake when I built it. I mounted the top wing too far forward. That meant that my CG was different from the plans. I haven't built another one of these to check the CG with the correct wing placement. Right now, I have the battery mounted directly behind the firewall as far forward as possible - you won't need to do that if you place the wings how the plan shows.

Good luck and let me know if you have any questions.
 

RacerX

Member
I just looked at the plans again and noticed that I didn't list a CG. Let me check tonight. I used a website for figuring CG and also referred to some other Pitts build plans.
 

foambasher

I do NOT like the ground
That's a nice bibe! Maybe stick some streemers to it? It'll look good! And maybe a vid with some airobatics involved?
Keep it up!
 

matjey

Member
It's been a challenge to build this biplane since you din't have the build guide for it. Since I'm already been building a couple of plane from flitetest and other source, it's easy to figure which is which.

fitts-01.jpeg
fitts-02.jpeg

For biplane, it always a challenging episode in finding the correct COG for it. I'm using a found image on the net to determine where is the CG for your plane design and end up with 2200mah lipo to have a proper balance.
Balance 1.JPG

This lead me to a 780g of AUW for this plane. And I already put the lipo next behind the motor mount. The nose still didn't barge down to make it slightly nose down for safe maiden. Could you please put some picture on how your's balance with the CG? Issit a bit nose down or a level position?

Anyway, mine didn't fly. Taxi take off failed and also hand launch failed.
fitts-03.jpeg
 

matjey

Member
Maybe make it into a tri plane? It will give it a bit more lift.... why didn't it fly?

Triplane would be another side of story of all :) For my case, it might be due to the wing to weight ratio that is too heavy for this plane to lift of and the CG was out of calculation.
 

foambasher

I do NOT like the ground
oh ok. sorry. im still interested in the triplane! dont have the resources to do so though... im just suggesting if someone else can test that for me?
if u have the time though. u dont have to.
 

jpot1

Elite member
Matjey - what motor did you use. I'm thinking of building this but only if the 74g 1100kv motor I have will work.
 

matjey

Member
Matjey - what motor did you use. I'm thinking of building this but only if the 74g 1100kv motor I have will work.

I put a 1300kv motor swinging 9x6 prop. An underpowered setup for this baby. I think 1000kv or 980kv with bigger prop might make a different. But as for me, I'm not worry much on the setup. The COG that's kept me baffled.