Pitts 48" Edition Fuselage Printing and Assembly
Updated: Feb 18
Here's how to print and build the body.
Make sure to reference the full resolution PDF plans provided in your purchase. It is not necessary to build directly on top of them, but it certainly could be done this way if you that is your preference. The parts have been designed to interlock together to create a jig for accurately aligning all the bits. Where you will start is by printing shapes: ST1, ST2, ST3, and ST4. as shown below.
Once printed and assembled, you will want to turn the assembly upside down and begin printing and installing the (A) series of formers first as shown below. For now, you should omit former F7 and the forward firewall. This assembly should be allowed to lay flat on a table. Use a square to ensure that the formers are all standing perfectly vertically while bonding with CA glue.
Once in place the lower Stringers: ST5, ST6, AND ST7 along with the rearmost former F7 may be installed. For now, omit the ST8 stringer assembly and firewall as a bit of work will need to be done to double up on the main landing gear section first.
Now its time to add the braces. The naming syntax on the braces has to do with wich former the brace attaches to. for example, if it touches former 12 and is on the right side, it is brace B12R
Exploded view of motor mount components:
Note that the frames must install around the 3d printed motor mount. Because of the taper of the 3D printed part it will not go into the frame afterwards.
Assembly of firewall forward:
prior to installing on the model, lay F1 flat over wax paper. using 30 min. epoxy mount the plywood doubler to F1. Use something like a heavy book to apply pressure while epoxy sets. Once setup, place the motor mount into the hole for it. Ensure that the ends of the motor mount are all square and that they sit flush to the tabletop through the doubler and F1. Once this has set, lower the motor mount doubler square on to the face of the F1 doubler and securely bond with epoxy or gap filling CA glue.
Wire Landing Gear:
prior to mounting the main gear mount to the back of the fuselage take this moment to use it as a jig. The gear is made of 4mm. piano wire. It is not incredibly difficult to bend but it is difficult to bend sharply or to bend a single wire exactly the same on both sides. Because of this we have split them up so that they can be compared together. Use the mounting bracket as a jig. Test fit the wire in place to ensure that they both fit exactly. This is the exact same angle as the bend at the bottom where the wheels attach so use the jig temporarily to ensure an adequate bend at the bottom as well. For now, you can place the gear aside.
Firewall landing gear mount:
On the back side of the firewall assembly, mount the main landing gear support using the holes to ensure perfect alignment. Either epoxy or generous amount of CA glue may be used for this step.
Firewall forward now mounted.
Doublers for wing strut attach points added. ST8 added at bottom.
Both sides of vertical stabilizer can now be added along with ST10 and ST11R. Do not install ST11L until both the horizontal stabilizer and elevator have been installed. You will need the access to the control horn and elevator pushrod.
You are now ready to install the Balsa stringers. See the plans sheet for size reference. Why balsa? because it's light and comes in strips much longer than your 3d printer build plate. You won't have to wait hours only to glue multiple segments together.
Now it is time for the plywood wing root Doublers. Dry fit them into place per the image below and mark where the end of the Doubler is on the stringers. You will want to make a very small cut in your stringers at that point and shave balsa away so that the Doubler will sit flush to the face of the stringers. Once happy with the alignment then proceed to bond the Doublers in permanently with CA glue.
Main Wing Attach fitting:
Main Gear attaching.
Cabane center strut assembly.
Conclusion: That is it for the fuselage! Check the main blog here for anything you may have missed, but at this point it's time to go fly! Feel free to reach out to us with any questions. We will attempt to clarify the construction blog including your input as much as possible. Also please check out or new community forum. Feel free to post pics, ask questions, or help others.