|
-
POSTING RULES

-
Donate yearly (please).
-
Advertise in here!
-
Today's Posts
|
Insert Pics
|

08-23-2012, 12:00 PM
|
|
|
|
Join Date: Apr 2010
Location: slc, UT
Posts: 29
|
|
Longeron template (F-718 template and F-721 don't match)
So the answer must already be hidden in here somewhere, but it is not jumping out at me..
So the template for bending the longerons labeled "F-718-l and F-718-r bending template" and the curve of the F-721B-L (and R) do not match ? Huh ? Not the solid line or the dashed line, what am I missing here ? I have the bend nearly complete to the template but in looking ahead at the next step I pulled out the canopy decks (F-712L & R) and lo and behold, they differ by about 1/4" or more (eyeing it).
This has to be some misunderstanding on my part ?
|

08-23-2012, 12:06 PM
|
|
|
|
Join Date: Nov 2005
Posts: 1,256
|
|
Just a question...did you use the original drawing, or did you make a copy of it to cut up? I did the latter, using a large-scale scanner at Kinko's, *but* I held the two up together to make sure the scanner/printer did a perfect 1:1 copy.
If you made a copy and it wasn't exactly 1:1, might that be the cause?
__________________
Steve "Flying Scotsman"
Santa Clarita, CA
PP-ASEL, ASES, Instrument Airplane
RV-7A N660WS flying!
#8,000
|

08-23-2012, 12:22 PM
|
|
|
|
Join Date: Apr 2010
Location: slc, UT
Posts: 29
|
|
I cut the original off of DWG-17, the length matchs perfectly ?
|

08-23-2012, 12:32 PM
|
 |
|
|
Join Date: Jan 2010
Location: Hampshire, IL
Posts: 276
|
|
I did the same as goldbar
__________________
Ed Martin
Bluskydtl
RV7
DKB
Donations 1/19 & 6/19
|

08-23-2012, 01:00 PM
|
|
|
|
Join Date: Aug 2010
Location: Wichita, KS
Posts: 1,958
|
|
Make sure you're reading the drawing carefully. I almost had the same problem on my 9A (longerons are the same) until I realized I was not aligning the canopy decks with the longerons correctly. Once I realized my mistake it turned out the longeron template made a perfect part.
__________________
Kurt W.
RV9A
FLYING!!!
|

08-23-2012, 02:50 PM
|
 |
|
|
Join Date: Sep 2011
Location: Edgewater, FL. KSFB
Posts: 1,118
|
|
From what others have said, the older kits had a "Not to scale drawing". You will need to match the F-721-B not the drawing.
I have a newer kit and mine was scaled perfect. I got so wrapped up in what others had said that I goofed and drilled my F-721-B in assembly in the wrong place. I had to by another longeron.
|

08-23-2012, 03:42 PM
|
 |
|
|
Join Date: Feb 2005
Location: 20km outside of Zurich, Switzerland
Posts: 468
|
|
Do not take the plan as guide!
Hello,
As Ken Krueger told me once, do not take the plan as a guide to bent the longeron! The plan is printet on paper and the paper grow or shrinks depending on humidity, temperature and age.
Take the aft canopy deck F-721B as template, those two parts have to fit together. Maybe start with the paper template, but finish it with the aft canopy deck.
You can also check with the aft canopy deck, if the plane is accurate or streched.
Regards, Dominik
|

08-23-2012, 07:56 PM
|
 |
|
|
Join Date: Aug 2010
Location: Gilbert AZ
Posts: 414
|
|
check the start of bend locations
Just bent mine last weekend, its a perfect match. Double check where you are placing the fwd/beginning of F-721B. It starts at 28-1/4 but the bend doesn't start till 38-7/16.
__________________
Jeremy
ATP, CFI, CFII
RV-7 N424JD KCHD
EAA Tech Counselor
2017 Bronze Lindy
|

08-23-2012, 10:08 PM
|
|
|
|
Join Date: Apr 2010
Location: slc, UT
Posts: 29
|
|
Thank you all for your posts.. It makes perfect sense to match the bend to the F-721, it jast had me concerned that the 721 and template were not the same, I'll finish my bends with the 721.. I appreciate all of your comments and help.
|

08-24-2012, 11:04 AM
|
 |
|
|
Join Date: Nov 2005
Location: Asheville, NC
Posts: 2,692
|
|
Sorry but I'm not convinced that real comprehension has occured yet, Goldbar.
No insult intended. I remember looking at it incorrectly in the beginning too.
The curve shown on the plans only PARTIALLY resides within the 721 deck as Jeremy and another said. See dwg 18
Certainly, you can use 721 as the final arbiter of shape, but make SURE you have it located on the longeron in the correct spot before "correcting" the curve.
My template on dwg 17 and and the 721 placed per dwg 18 matched spot on.
__________________
Bill Pendergrass
ME/AE '82
RV-7A: Flying since April 15, 2012. 850 hrs
YIO-360-M1B, mags, CS, GRT EX and WS H1s & A/P, Navworx
Unpainted, polished....kinda'... Eyeballin' vinyl really hard.
Yeah. The boss got a Silhouette Cameo 4 Xmas 2019.
Last edited by rzbill : 08-24-2012 at 02:10 PM.
|
| Thread Tools |
Search this Thread |
|
|
|
| Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -6. The time now is 12:22 AM.
|