Windscreen

[DCASonex]

Aside from eliminating porpoise nose, raising the bow usually increases forward visibility. If you decide to make a new bow, one trick I used when forming it was to tap the ends of the tube 7/16-14, plug one end with bolt, fill with sand, bounce it on end till sand well settled, fill to near top and install second plug to compress the sand. This helps keep tube from collapsing. it is much less expensive to buy and ship a straight piece of tube than a formed one from Sonex. Be sure tube is long enough to leave about 8-12" of straight tangent on each end as that makes forming easier, and the tapped ends will be cut off. I made a big tube forming jig by simply saw cutting a half moon shape from a 1-1/2" thick board and running 1/2" ball end router around the edge. Radius does have to be significantly smaller than finished radius due to spring back. Same rig is great for tweaking the canopy bows to match front and rear. E-mail me if want photo of that bending rig.

David A.

[ScottM-Sonex1629]

Could someone who is near their set of plans (or have a great memory) let me know what the radius is specified for the windscreen bow on the plans?

I recall something like 17-13/16" +/- and the last 3 deg. is straight.

Want to draw this in cad and plot a full scale template today (I'm already at work and forgot to get the dimension before I left home)...

Many thanks,

[Rynoth]

I recall something like 17-13/16" +/- and the last 3 deg. is straight.

Scott, I just looked and you nailed it. 17 13/16" to the inside radius of the bow, with the last 3 deg straight.

I've done most of my windshield in the last week, and will note that I ended up needing to put an additional small bend an inch or so down the straight part (just above the top of the longeron) in order to smoothly insert the bow through the longeron holes. Otherwise it wanted to put a twisting force on the longerons. This probably depends a bit on the longeron holes themselves, but I tried enlarging them slightly and still needed to add the bend. Fits well now.

[Gripdana]

Check your PM. I can go look at my plans right now.

[ScottM-Sonex1629]

Thanks Ryan, and Dana. I guess my memory is better than I remembered...LOL