J21 Hornet

[J21Hornet]

Originally this project was posted in the Welcome Mat forum. Checkout the Welcome Mat forum for the beginning story.

Since I am working on my gyro again, I am moving my posting here to the Builder's Corner where it belongs.









As seen in these pictures, this project has been setting idle since 1997 ........

Above pictures are of the frame with mock up enclosure, basic frame on wheels with the enclosure, plugs and molds in background, fuel tank installed and the enclosure panels ready to assemble.

[J21Hornet]

Believe it or not this project is not dead ........

Actually I had time to make paper, than heavy cardboard and now plywood templates of the bulkheads to attach the body to my gyro. I hope this very rainy Spring is over and tomorrow I start making the bulkheads. After that I can resin them in and FINALLY attach the body to the frame. Picture shows plywood templates in place and my very cramped work space.

[J21Hornet]

I'll also bring over from the welcome mat forum the last question I received in regards to shock mounts.

The engine, drive and prop are soft mounted to the frame. Don't want those bad vibrations running out to the tail! Test runs to try different prop blade setting have demonstrated and very smooth system. When I designed my gyro, I was still working in the submarine business. We had all the latest vibration test gear and software and I could get my hands on the good mounts. My boss always thought I was working through lunch on company stuff ..........

Also note the prop pulley bearings are keyed to the motor mount shaft. There is no drive system contact to the tailboom. With the tailboom removed, you can look through the prop pulley, motor mount shaft and see the frame! About a 1/2" gap all around. Yes, there are two very large diameter truck bearings in the prop pulley.

[J21Hornet]

Working on the firewall / seat back bulkhead. My problem is when the J21 Hornet was designed between 1992 and 1994 the software of choice was Intergraph. Great program because I could take each bulkhead out as a single plane like a slice of bread, rotate and print full size sheets. After 1994 the software was changed out to Autocad. I converted my drawings over but can no long remove slices. The bulkheads are not solid planes but are now only pixels ............ I have the lower half of the seat back where I want it. Just need to get the upper half curvature where I like it.

I did get the front bulkhead done today,

[All_In]

Hi Dana
Thanks of posting the build thread here I've been watching your project with great interest ever since you first posted and been wondering on the progress!!

Thanks of sharing!

[egyptman51]

hello ur project its very good ( ma shaa Allah )
can u learn me to built same ur plan ?

[J21Hornet]

I need to finish the prototype first, than fly it to ensure it will be safe for others to build from plans.

Painted the bulkheads this past weekend. Next to build seat bottom and glass in.