Chachi639's blog View Details
Posted by Chachi639 | Aug 05, 2014 @ 06:13 PM | 7,497 Views
RCG user graham1234's DLG designs:

Posted by Chachi639 | Feb 04, 2014 @ 11:56 AM | 7,328 Views
Zone --------------- June 2009
Edge -------- November 2009
Zone V2 -----December 2010
Synergy --------January 2012
Synergy II ----------April 2014
Posted by Chachi639 | Aug 20, 2011 @ 05:54 PM | 6,617 Views
Posted by Chachi639 | Jun 14, 2010 @ 05:04 PM | 5,635 Views
Posted by Chachi639 | Jun 01, 2010 @ 02:47 PM | 6,280 Views
Godden's boom construction page
SuperGee Thread posts by jirvin
Shaper Dave's
Posted by Chachi639 | May 21, 2010 @ 01:31 PM | 6,294 Views
"Crank-slider" linkages:

Vegas Ray's
On a Superhawk
On-spoiler servo mount for AVA
Another example from jcpatrick

"Four bar" linkages:

Atjurh's Linkage Implementation
Skybench Aerotech spoilers
Bubble Dancer spoiler
J-Bird 662's 4 bar linkage is driven from the opposite side
Posted by Chachi639 | Mar 31, 2010 @ 06:02 PM | 7,233 Views
From lower tech to higher tech:

1. Put the plan sheet over the balsa and stick pins through the plan into the balsa, laboriously tracing the outline of each part

2. Trace the parts on to freezer paper. Iron the freezer paper onto the balsa. Cut out parts. When done, peel off the paper.

3a. Photocopy or print the part plan using laser printing technology. Lay the plan upside down on the balsa, then iron with a covering iron to transfer the printer toner image to the balsa.

3b. Photocopy or print the part plan (laser only, not inkjet). Lay the plan on the balsa, rub lacquer thinner through the plan, image soaks on to the balsa.

3c. Same as 3b but with acetone.

4. Make a copy of the plan, lightly spray the back side of the plan with 3M77 then stick to the balsa. Cut out parts right through the paper. Remove the paper.

5. Copy or print the part on to iron-on transfer paper.

6. Print the parts directly on to the balsa (requires a laser or injet printer with a straight paper feed path.)

Several threads on the subject follow:

Lacquer Thinner Method
Various methods
Direct Printing
Pros and Cons of Different Methods
Posted by Chachi639 | Dec 21, 2009 @ 12:54 PM | 7,092 Views
I made an edit to Martin Brungard's EDA spreadsheet, generalizing to accept as many as 24 panels.

It's an Excel file but since RC Groups won't accept those I zipped it. To expand zip files you can use Just Zip It
Posted by Chachi639 | Oct 06, 2009 @ 11:28 AM | 10,051 Views
This Foam Properties Table is copied from the Allegro-Lite Yahoo Group, the file is called Foam_modulus2.txt and it's in the Skin Stress folder. Based on contemporaneous posts at the group, it appears testing was performed in early 2003 as the last file update was in May of 2003. Testing was performed by Mark Drela, then supplemented by Phil Barnes. It's been posted many times before on RCGroups, posting here for reference:
               Rho       E11    E22    E33   E33/rho
Foam type    (lb/ft^3)  (psi)  (psi)  (psi) (in/10^6) Data source     AKA

Spyder foam    2.30     4000    6900         5.18     Mark Drela
Spyder foam    2.36     1218    3358  7027   5.14     Phil Barnes
Hi-Load 60     2.25     1100    3400  6000   4.61     Mark Drela     Plazamate
Hi Load 60a    2.30     1229    2819  6212   4.67     Phil Barnes    Plazamate
Hi Load 60b    2.30     1412    2888  6412   4.82     Phil Barnes    Plazamate
Dow blue       1.75     2000     640  2500   2.47     Mark Drela     Square Edge
Foamular 150   1.5      
Foamular 250a  1.63     2317    1899  2372   2.51     Phil Barnes
Foamular 250b  1.63     2430    1972  2476   2.62     Phil Barnes
Foamular 400a  1.98     2788    2946  2941   2.54     Phil Barnes
Foamular 400b  1.98     2920    3088  3087   2.67     Phil Barnes
Formular 600a  3.04     4927    4927  5108   2.90     Phil Barnes
Foamular 600b  3.04     4716    4807  5251   2.98     Phil Barnes
Grey Foam a    1.54     2894    1054   640
...Continue Reading
Posted by Chachi639 | Sep 16, 2009 @ 09:55 AM | 10,998 Views
This post gathers up some different references on how to protect handlaunch gliders in the car and as checked baggage.

1. Cheap and quick, the corrugated cardboard transport box made from refrigerator or bike box is the first listing. I've built two different ones of these and checked as luggage with no problems yet.

2. Lots of boxes and Sportube insert examples are included in this RC Groups thread from 2005.

3. Mike Seid's unfortunate experience where an airline crushed his Sportube-packed DLG prompted this RC Groups thread from 2008, also with many good examples.

4. This RC Groups thread from January 2009 shows some more examples.
Posted by Chachi639 | Jan 17, 2008 @ 12:02 PM | 9,002 Views
Geode's Hyperbolic Manta thread has hijacked my brain. I'm looking at design parameters and have made some preliminary drawings for a 3.2M, built-up, continuous curvature, Drela foil wing using the same fabrication techniques Geode demonstrated there. This is just about the coolest looking wing form I can think of. As soon as I can figure out how to export line drawings from AutoCAD to pdf I'll post three-views sketches to get comments.
Posted by Chachi639 | Aug 16, 2007 @ 10:31 AM | 15,270 Views
This post is a placeholder of all the "raw content" of the "Hand Launch Links" thread's top post. I'm posting it here for archival reasons: if I stop keeping the list up-to-date, this text is a starting point for another user to continue keeping this information up-to-date. To do so, copy everything below "START HERE", then paste into the edit box of a new post or thread.

This handlaunch link thread is a reboot of my [URL=""]Hand Launch Links - Updated[/URL] thread, inspired by (and originated from) Adam Neat's [URL=]Hand Launch Info[/URL] thread. Thanks Adam for the great idea! The list has evolved due to helpful suggestions from RCGroups users: please let me know of additions, dead links, or errors. I'd let the list go dormant for a while, let's see if it's still useful.

As before, I'll try to keep the list short enough to be meaningful and useful. Therefore, I'm listing only only suppliers, build logs, plans, building supplies or reference materials related to handlaunch / discus-launched RC gliders. New links/recent changes are highlighted with a big red [COLOR="Red"][B][SIZE="4"]*New*[/SIZE][/B][/COLOR] or [COLOR="Red"][B][SIZE="4"]*Updated*[/...Continue Reading