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Dec 28, 2010, 09:01 PM
Registered User
Thomas Wang's Avatar
Quote:
Originally Posted by krikkens
hi,

rohacell cores are almost done.

aileron, spar and wingmount holes are cut into the cores , the first one i'm gonna make is without rds , that will be machined too on future cores.
mould is waxed and painted .

i'm gonna use carbon tow for sparcap wich hopefully fit the cnc'ed slots well.
if the wing has no sufficient bending stiffnes i'll cut a thin slot all the way thru and glue a thin piece of hardwood in , this should do the job, no doubt.

here are some pictures , more to come...
This is great, what concern me is if the rohacell core weights too much?

Thomas
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Dec 28, 2010, 11:51 PM
Registered User
Hi Kristof,
Is the rudder going to be a pull-spring setup or normal pushrod system?

Regards
Rudolf
Dec 29, 2010, 01:17 AM
1 revolution and throw!
hi,

weight of the cores = 40.1 gram (for both halves)

rudder is ment to be pull-spring, this is what i've been doing last year witouth problem's so...

but it would be very easy to install a rod/tube also...

-kristof-
Dec 29, 2010, 01:26 AM
Registered User
I just read through the old thread.
Well done.
I'm at the point where you started.
Busy making a plug for fuselage.

Rudolf
Dec 29, 2010, 04:23 PM
1 revolution and throw!
hi,

i pulled the first wing today!

i was a little to impatient and opened the mould after 20 h , result : delamination

it had to do with the pva i used too, normally i spray it on ,(a relatively thick coat ), now i used a pva sponge to do the job , but the layer of pva was way very thin .
the upper side of the wing is much better then the bottom side ,(had troubles with the pva on that side ,probably not properly degreased or something...)

at least now i know the exact weight of the part's:
rohacell cores: 40.2 gr
CF for spar and LE reinforcement: 55gr
glas skin : 43 gr
rest : 10 gr

it should be 20-30 lighter , the spar is waaaay to much

-kristof-
Dec 29, 2010, 04:29 PM
ThomasLee's Avatar
Kristof,

I love that color scheme, good job!
What airfoil is that?
Latest blog entry: Vibe Assembly Instructions
Dec 29, 2010, 04:44 PM
1 revolution and throw!
Quote:
Originally Posted by ThomasLee
Kristof,

I love that color scheme, good job!
What airfoil is that?
hi,

edge series by GT

-kristof-
Jan 04, 2011, 02:00 PM
1 revolution and throw!
hi,

new mould's for vertical and horizontal are done .

vertical has the edge vertical airfoil and a 2.1dmē area

horizontal has the ht 22 airfoil and also 2.1 dmē area.

vertical is bigger than the one i used last year , this should get the plane quicker into a straight climb (can't wait to find out on the field)

horizontal is slighly smaller than what i used to fly to compensate weight of the vertical and it should be better balanced according to wing area too.

hope to pull the first part's next week...

-kristof-
Jan 04, 2011, 02:02 PM
Team Swallow
Jonas M.'s Avatar
Why do you use the HT22 on the horizontal instead of the Edge foil?
Jan 04, 2011, 02:08 PM
1 revolution and throw!
hi,

edge is ment for full flying...

-kristof-
Jan 04, 2011, 02:09 PM
1 revolution and throw!
i forgot the pictures....
Jan 04, 2011, 02:12 PM
Team Swallow
Jonas M.'s Avatar
Nice molds!

Hinged Edge stab airfoil can be found here:

https://www.rcgroups.com/forums/show....php?t=1238997
Jan 04, 2011, 02:47 PM
1 revolution and throw!
jonas,

yeah , i know that one , the fixed hinge location bothered me . i like a big moving surface but that one leaves very little for mounting it on the boom .

-kristof-
Jan 05, 2011, 07:49 AM
Registered User
Traian's Avatar

CNC Advice


Khristof you can get it faster yet.
I noticed that you use a small 1/8 or 3mm end mill. May I suggest using the largest ball nose end mill you can fit inside the router. 3 flute ball nose work great. If you need help with programming I can help you if you use G Code in your machine. I use Master CAM and I can import IGES DXF STEP files etc.
Another idea here is for you when you cut the top of the foil. It looks that you are cutting the bottom first then you cut the top. The issue here is that the bottom of these wings is not flat and when you flip it over and place it on vacuum it changes the shape and the foil. You need a negative to place the wing in to before you cut the other side. If you make this negative pay close attention to the trailing edge and maybe add a removing feature to it with some pins for alignment so you can put it on the table and remove it when you do not need it and make a note for your offset position. Then next time you need to make another wing just place it in position recall the offset, load the program and go. A faster spindle will work too here with faster travel too.
I like your machine and just by looking at the ways it tells a lot about the quality of the machine. I was thinking of building one just like that with 48 in of travel by 24 by 6 in of travel but I have no money.
Jan 05, 2011, 11:28 AM
R&G
R&G
Composite Technology
Quote:
Originally Posted by krikkens
at least now i know the exact weight of the part's:
rohacell cores: 40.2 gr
CF for spar and LE reinforcement: 55gr
glas skin : 43 gr
rest : 10 gr

With precured UD material you should be in the range of + 5-10 g for the spar. The required groove could be milled in the core. Try our range of carbon rectangle high modulus profiles and carbon rectangle profiles
Last edited by R&G; Jun 20, 2011 at 02:28 AM. Reason: Wrong link


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