#1
|
||||
|
||||
rounding over a leading edge
rthis may sound like a silly question but how do you get an even roundnes on a leading edge like in the picture? Thanks Chief
|
#2
|
|||
|
|||
First sand a 45 degree angle into the sides of the leading edge. Don't make a wedge; you're shooting for something like this:
_ / \ | | Lay out a sheet of sandpaper on a flat surface. Hold the fin so it is lying almost flat against the paper, with your fingers under the trailing edge. Pull the fin toward you, with the line of the leading edge perpendicular to the direction of the motion. Lift the rear edge so that the leading edge "rolls" as slides along the paper; at the end of the draw the fin should be "standing up". Repeat this with the other side of the fin. Do this, alternating sides, until your angled leading has a symmetrical curve. Then wrap a small sheet of very fine sandpaper over the new leading edge and smooth out the curve.
__________________
NAR #27085 - Oregon Rocketry - SAM |
#3
|
||||
|
||||
I prefer short ogive curves to hemi. I fly transonic a lot.
I use the method stated without the last step of a small piece over the edge. Jerry |
#4
|
||||
|
||||
Take your time and make the end look just right. The rest of the leading edge can be a little off and nobody will notice.
__________________
I love sanding. |
#5
|
||||
|
||||
I just freehand it, but pre-bevelling does sound like a good idea.
BTW, what are you building chief. I can't quite tell from the page.
__________________
Never trust an atom. They make up everything. 4 out of 3 people struggle with math. Chemically, alcohol IS a solution. NAR# 94042 SAM# 0078 |
#6
|
||||
|
||||
Quote:
That would be an Estes EPM-010. I have one in my queue right now. Bill
__________________
It is well past time to Drill, Baby, Drill! If your June, July, August and September was like this, you might just hate summer too... Please unload your question before you ask it unless you have a concealed harry permit. : countdown begin cr dup . 1- ?dup 0= until cr ." Launch!" cr ; Give a man a rocket and he will fly for a day; teach him to build and he will spend the rest of his days sanding... |
#7
|
||||
|
||||
Quote:
Thank you Bill you are correct. THE Estes EPM-010. Jeff EPM sounded like something we know about so I bought it. |
#8
|
||||
|
||||
Quote:
LOL. 3 knots max speed for a Sturgeon Class boat on the EPM!
__________________
Never trust an atom. They make up everything. 4 out of 3 people struggle with math. Chemically, alcohol IS a solution. NAR# 94042 SAM# 0078 |
#9
|
||||
|
||||
Chief, I've built only one EPM so far. The best advice I can give you is to PLEASE paint the little white nose cones and the rest of the rocket separately, and then glue the cones into the BT-5's. It will save a A LOT of extra masking (and naughty words.)
Hence:
__________________
Never trust an atom. They make up everything. 4 out of 3 people struggle with math. Chemically, alcohol IS a solution. NAR# 94042 SAM# 0078 |
#10
|
||||
|
||||
Quote:
Ditto
__________________
Gravity is a harsh mistress SAM 002 NAR 91005 "The complexity of living is eminently favored to the simplicity of not." |
Thread Tools | Search this Thread |
Display Modes | |
|
|