Mike, Do not cut into these depressions. They’re perfectly good glass (structurally), they just may have delaminated from the core. If the depressions fail the tap test, get a big syringe. Drill a sma

Hahaha! Who will carve *that*?

I’d suspect those parts are generic from Aircraft Spruce, although I no longer see the spun aluminum spinners in their catalog. ☹

I strongly recommend that you install the Belleville Springs specified here: http://www.cozybuilders.org/Prop_Bolt_Bellville_Washer/index.html

QCSM4? Isn’t that just a standard oilite shoulder bushing? It’s a press fit into a 5/16” hole into a 1/8” thick 2024-T3 Aluminum part (CS-17) and supports the 3/16” (IIRC) QCSM3 headless AN-bolt. Shou

Did you ask about “Fabrication Billet?” It generally comes in larger sizes and is cut to size by the distributor….

See page 11-3 in the plans. It’s this thing right here: David J. Gall

Ben, That's pretty much exactly what I've been saying; To use degree-two single-span (degenerate) splines is, mathematically, exactly the same as to use conic Bezier curves. It's just a choice of term

Danged email down sampled my picture so it’s all fuzzy looking. Here’s a better image:

Johannes, Here's a start on a Q-200 firewall using the method of conics that I suggested. (Rhino CAD file attached.) As you can see, either the original drawing or the scan is not symmetrical, particu

Johannes, My apology! When I referenced Appendix Sheet 3 I was looking at the Q-200 Engine Installation plans Appendix Sheet 3. The Q2 plans appendix sheets have no such annotations. I've attached the

Johannes, Please note that all the side view drawings of the Q2/200 throughout the plans are not accurate representations of the silhouette of the actual airplane. The lower silhouette line of the sid

Johannes, Try to stick to degree-two curves (conic sections) as much as possible, and fit them piecewise with tangent continuity at the joins. Use the control point "weight" on the middle control poin

Johannes, Page 8-2 shows the 2.9" dimension on the firewall. Page 8-4 repeats the image with the "Shell Split Line" explicitly labeled. The firewall template on Appendix Sheet 3 shows WL 12.1 explicit

Oops. I should've addressed this to Johannes, not Robert. David J. Gall

Robert, If your intent is to duplicate the existing QAC shape I would caution you that, although "CAD is fun" it can also lead you astray. The state-of-the-art in the early 1980s was compass and protr

Jay! I took that course, too! By any chance do you still have Hollmann’s flutter and vibration analysis program? David J. Gall

Rick, It would likely be fairly simple to reconstruct it (or build it in Excel) from the description given in the Waddelow canard documents. More robust codes are already available – I was interested

Thanks Jay. David J. Gall

Jay, The Waddelow document makes reference to a computer program called Q2ANALYSIS. By any chance do you have a copy of that program? I assume it was written in BASIC or QBASIC so source code should b