Created a Zenith Air brass accent for the air drill I restored last month.
Zenith CH 750 STOL Build Log
Scratch-building a Zenith CH 750 STOL from plans.
80.50 build hours logged across 29 entries since July 2026.
Made a radius shoe out of .032" 3003 for a 12" hydraulic brake targeting the 6.4mm bend radius called for with the thicker 6061-T6. Three layers got there, but four was too large a radius.
I'll try it on …
Remade the last horizontal tail shaping form. Then I coating the edges of the curved forms with several coats of a 50% cut of shellac. I read online that this was a good way to harden HDF without damaging its …
Sanded spring back allowance and flute notches into the curved horizontal tail rib shaping forms. I need to redo one of the front stabilizer rib shaping forms before I can call them all done.
Decided to wait to make …
Finished forming the remaining two rudder ribs, though still need to debur edges. Also formed an elevator rear rib. Built a rigid clamp base for my 48" brake so I'll resume testing the performance of that this weekend.
Drafted blank cutting templates then cut out the part blanks for the remaining rudder ribs.
I got the adjustments dialed in on the 24" brake and formed two of the straight sided rudder ribs with the dimensions landing within tolerance. Also formed the small rudder tip bracket.
I attempted to shape one of the rudder ribs using a brake instead of the form. Or to at least start it that way. The wide end had the target inner width, but the narrow end must have shifted in …
Trimmed the horizontal tail section curved rib shaping forms flush to the patterns, rounded over edges, and angled the straight tail section rib forms to have spring back allowance.
Drafted and cut the part blank for the rudder nose rib. Then deburred the edges and shaped around shaping forms. The 3mm wide front of the nose was challenging and time consuming to form. I can see what people say …
Laid out wing ribs on graph paper. Going to double check all measurements tomorrow before cutting them out.
Transferred the spar and flaperon ribs to card stock. I'm planning to add 1/8" tooling holes on the tiny parts to …
Made progress on the pairs of shaping forms for curved horizontal tail section ribs. Also fabricated a pair of parts for the rudder: the upper hinge angles.
After a productive day, all the pattern template forms for the tail section assembly ribs are completed, and I got a head start on the rough shaping of the remaining curved shaping forms which are now able to be cut.
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Cut a couple more pattern templates for fabricating shaping forms for additional tail section rib parts.
Figured out a better way to cut angles on the table saw for straight sided ribs.
Not a lot of progress the past week as I've been consumed with work and other obligations in the evenings and last weekend.
Today I received the Corvair shop manual which the flycorvair manuals said was necessary to have …
The FlyCorvair manuals I ordered arrived and I read through them. It's going to take a bit of effort and additional research to develop task and parts lists from the format. But I now have a better idea of the …
Based on the earlier metal brake research, I tried using 2 3"x24" strips of .032" 3003 aluminum to create a fully supported 3.2mm radius for a 24" metal brake and it worked successfully. I bend one piece over the other …
I printed more radiuses including two color coded ones that match the ones that most parts in the plans have to allow for adequate bending without cracking of 6061-T6. Planning to always check my form block round-overs and brake bends …
Got referrals to places in Tucson that have long sheet metal brakes, and learned of a better online source for 6061-T6 at airpartsinc.com.
Placed a small tools and materials order with airparts.com including .04 sheet 6061 which they ship …
Drove out to Ryan airfield to attend my first EAA chapter meeting and got some great advice from an experienced plan builder named Eric.
The female part of the flange die ended up needing a different XY dimension adjustment coefficient than the male one, but after the second try it's also well within tolerance and the fit is perfect between the two.
I …
Made progress fabricating rudder rib forms after cutting the front rib template blank last night. Need to start using a taper jig on the table saw to make things easier with fabricating forms for straight edged ribs.
Received my …
Drafted front rudder rib form on metric graph paper. Planning to glue to plywood and shape into to the pattern template piece to cut other the shaping forms from either this evening or tomorrow evening. Collected more tools. Placed sheet …
Received tools ordered from Aircraft Tool Supply
Pressed replacement bearing onto drill vane cylinder with fabricated replacement gasket, and received aircraft plans from Zenith.
Laser cut replacement gasket and applied cold bluing to exterior steel parts.
Restoring air drill while waiting for aircraft plans to arrive. Findings on disassembly: 4 of 5 vanes stuck due to corrosion, 1 of 4 bearings need replacing, paper gasket has a tear, and a badly in need of cleaning, corrosion …
Sourced an air drill, a Scotch-Brite bench grinder wheel (MU-WL), and some small red and green abrasive flap discs at Tucson Tool Shop.