Apr 01, 2024     Right Wing Main Spar - (28.5 hours)       Category: Wings

Prep the Right Spar Web and cut the Spar Caps to length for drilling. Drew straight lines on the Spar Webs along the rivet line at plus/minus 3.5" from centerline. Studied the plans regarding the deviations in standard spaced rivet holes around the center splice due to the strut and aileron pulley attachments. Marked out the rib locations and the lightening hole locations. Marked out all of the rivet locations on the top and bottom line on the spar web. In the future, should have only marked out the rib rivets and then used the rivet fan to drill the others. Used an optical punch to center punch the rivet locations in the Spar Web. Initially drilled with 1/16", then increased to #40... and every sixth one I drilled to #29 (to fit #6 machine screws). CAD designed and 3D printed plastic washers to use with the #6 machine screws. CAD designed a 5/8” offset jig to use with a fine point Sharpie to draw the lines on the spar caps for match hole alignment. Match drilled the rear top and bottom spar caps. Then used them to match drill the front top and bottom and the front and rear doubler spar caps.

  Mar 18, 2024     Spar Web and Caps - (46.5 hours)       Category: Wings

Planed the 2x4s and mounted them across the top of the big table for spar building. Took the Spar Web blanks to Collin's. He helped bend all of the Spar Web flanges using his 10' sheet metal brake. Designed Main Spar Splice Plate and cut out with CNC. Trimmed the excess flange material from the Spar Webs with a router. Scotch-brite'd all of the Spar Web edges. Drove to Wick's Aircraft to pickup Spar Cap aluminum. They couldn't source the 1-1/4" Spar Caps, so we had to buy a 4x12 sheet and use their shear to create the Spar Caps... which created an edge polishing problem. After trying multiple ideas, Collin's recommended double-flat aluminum file arrived and did an amazing job at removing the tool marks and dressing the edges. Drilled the center holes for the lightening holes to use as referenced when aligning the Spar Caps.

After realizing that the Bearhawk engineering drawings are NOT real engineering drawings, as they are not accurately drawn to scale. I had to redo a couple of edges of some of the Spar Plates. I was very happy to find that I could simply re-design the Plate in CAD and then create the jig mounts on my CNC and re-cut the critical edges.

  Feb 19, 2024     Wing Tip Ribs - (24 hours)       Category: Wings

Thought I was done with Chapter 2... but then realized that the plans and the build guide had said nothing about the Wing Tip Ribs (full-length). And, saw them included in the end of Chapter picture. So, started at the beginning of the process for building ribs and created the two Wing Tip Ribs. Full-length template, cut out aluminum, cut out lightening holes, bent edge flanges, fluted and flattened, bent lightening hole flanges, re-fluted and flattened, Scotch-brited the edges, surface prep'd, cut out rib stiffener and attach angles, bent, drilled, Scotch-brited the edges, surface prep'd, 2-part epoxy primer, match drilled angles, and riveted them together.

  Feb 11, 2024     Priming and Riveting Wing Ribs - (26 hours)       Category: Wings

COVID slowed me down for a bit. Then, erected my inflatable paint booth and primed the remaining ribs. Then, match drilled the Rib Stiffener Angles to the Nose and Center Ribs... deburred the holes... and riveted them together.

  Jan 17, 2024     Cutting Spar Web Blanks - (9.5 hours)       Category: Wings

Studied plans and created the Wick's order list for the Web Spar Cap Strips, etc. Laid out the plan to cut the Spar Webs out of 032. The build book and on-line research was NOT helpful. I used a 8' Rockwell straight edge guide and then ordered a couple Johnson straight edges from Amazon, because I needed at least 9.25' for the Flap Spar, to guide a trim router with a 1/8" 0 flute end mill (offset 1.7"). I also used 1/4" fold foam as a sacrificial layer under the aluminum. Ensure you measure YOUR rib heights and do NOT trust the drawings. Collin hinted that the web blanks do NOT need to be exact at this point... in fact, he recommended that they be cut over-size and then trim the flanges after bending them in the sheet metal break. I completed the project by cutting out the 4 Main Spar Webs, 4 Rear Spar Webs, 2 Flap Webs, and 2 Aileron Webs.

  Jan 01, 2024     4' x 18' Table - (17 hours)       Category: Workshop

Built a 4' x 18' Bearhawk Assembly Table. Used four 18' long manufactured I-Joists for the framing... 2 of them for the long sides... then cut to 43" for cross-span joists every 2'. The top is covered with 1/2" plywood... and then 1/2" MDF (a replaceable wear-item). The legs are currently 40" long to create a working top height that is comfortable for me for building the spars. I will later create a set of 24" legs for assembling the fuselage. I purchased a set of 3" retractable casters to enable me to easily move the table.

  Dec 12, 2023     Wing Attach Spar Plates - (35 hours)       Category: Wings

Deburred about 800 holes in the new attach angles. Scotch-Brite'd the angles, aileron, & flap ribs. Trips to TN and CO. Designed and CNC'd the 16 wing-to-fuselage spar plates. Ordered and picked up the 18' I-beams and other materials for the 4' x 18' table.

... 17 Jan 2024 note... I probably should NOT have done these prior to building the Wing Spars... as I found that the drawings are not really engineering drawings... but are closer to good "hints" as to the specific dimensions and shapes of parts. In other words, I suspect I'll need to redo these in order to ensure they fit my wing spars.

  Oct 31, 2023     Ribs and Strength/Attach Angles - (38 hours)       Category: Wings

Went to ArkanSTOL to volunteer. CNC'd balance tube holes in "mirror" aileron nose ribs. Went to Kentucky and SD. Spray painted the first set of ribs and angles with two-part epoxy (EP420). Built the first set of angles for the aileron and flap nose ribs and pocket rib... then realized that there was a difference between the "stiffener" angles used on the nose and center ribs... and the "attach" angles used to attach the ribs to the spars. I had incorrectly trimmed the exterior angles on the attach angles (like the stiffener angles) ... so, had to start over and remake about 150 attach angles... almost done. Prepped the Aileron, Flap, and Pocket Ribs for spray painting. Built the C-Frame Dimpler table. Designed and 3D printed a "jig stop" for the sheet metal brake to make consistent 90-degree bends.

  Sep 26, 2023     Aileron & Flap Ribs - (29 hours)       Category: Wings

Well, it has been a while since the last update... in the interim I went fishing in Ohio, assembled and tested the CNC, two week flying trip to the Northwest, jury duty, and a trip to Texas. Designed the Aileron Nose Rib and Form, Aileron Pocket Rib and Form, and Flap Nose Rib and Form in CAD. Converted the CAD to CAM. Used the CNC to cut out all of the Nose and Pocket Rib Blanks and Forms and Pinch blocks. Scotch-brited the edges of the Rib Blanks and then pinched the Rib Blanks between the Rib Forms and Pinch Blocks and beat them into shape. Designed the Form to hold the Aileron Nose Ribs on the CNC and the 7/8" diameter Balance Tube Hole to be cut into the Aileron Nose Rib.

  Aug 13, 2023     Aileron & Flap Ribs - (12 hours)       Category: Wings

Bent the outer flanges on the aileron and flap hinges. Cut the lightening holes and started to make the MDF templates... but, the ribs were too small for that technique. Found the flange dies from Collin that would work on 3 out of 5 holes. Created two 3D printed flange dies... waxed them prior to each use and they worked great. Finished the flanges on the lightening holes. Used the RV flanging tool and fluting pliers to straighten all of the ribs.