Scratch-building a Nexor Pro - Page 2 - RC Groups
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Jan 30, 2010, 08:36 PM
The Junk Man
Great photos, but I don't understand. 3 mates, a shed, building a nice plane... and not a Crownie in sight?

Tom
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Jan 30, 2010, 09:07 PM
Come out swinging
sporter's Avatar
What is the green "gel coat" composed of?

Sean
Jan 31, 2010, 05:40 AM
Thermal Wrangler
DrFragnasty's Avatar
We're on a strict training regime of cups of tea, cucumber sandwiches and croquet on the green afterwards Tom ;0)

As for the gelcoat Sean, I can't recall the chemistry. I'll check with the other guys. It was off-the-shelf marine gelcoat I got from Hobart in a 1 litre can.

Chris.
Feb 01, 2010, 08:30 PM
Thermal Wrangler
DrFragnasty's Avatar

vinylester ranson


Vinylester Tooling Gelcoat.

PVA your plug.

Dam walls should be covered with tape and lightly waxed
(can't recall if we did or not but reccommend it)

At warm 20c conditions 3 guys with brushes stippled
their way around an entire top wing in 10mins.

Aim for a 2-3 mm depth. Lay-up with epoxy resin/ fabrics and filler
over that. Although I can't recall if we let it go off before proceeding
with subsequent layers.

Result was excellent; no pinholes, no air pockets, easy release.


Chris.
Last edited by DrFragnasty; Feb 01, 2010 at 08:34 PM. Reason: typo
Feb 02, 2010, 09:47 AM
Come out swinging
sporter's Avatar
So, it's a polyester resin based gel coat?

Sean
Feb 05, 2010, 02:11 AM
Thermal Wrangler
DrFragnasty's Avatar
It's apparently vinylester Sean acording to Bruce.

A good explanation of vinylester properties:

http://www.redrockstore.com/resin.htm


Chris.
Feb 06, 2010, 06:21 AM
Registered User
Thanks for the info and photos from the deeeep South
John
Feb 09, 2010, 01:44 PM
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Upvector's Avatar
Hi Chris
Sweet build...drooling over the keyboard here...thanks for the posts.

Hoping to get a couple of Supras in the air this season.

Saw the pic of your wing joiners...are they CF over white foam..?
...intrigued by your idea.

Thanks
Ray
Mar 04, 2010, 01:43 AM
Thermal Wrangler
DrFragnasty's Avatar
It's just blue foam cut with a hot wire Ray.

A couple of dry runs to see if the cloth fits then wet out the cloth on plastic sheet and layup the top face, add the foam, fill the sides then close the mold allowing excess resin to wick out the ends. It sounds imprecise but with the steel mold I'm using results have been top notch.

The project is waiting on more cloth (carbon sock for the boom) so should be back in the shed next week sometime.

Chris.

Chris.
Mar 08, 2010, 05:23 PM
Registered User
Upvector's Avatar
Quote:
Originally Posted by DrFragnasty
It's just blue foam cut with a hot wire Ray.

A couple of dry runs to see if the cloth fits then wet out the cloth on plastic sheet and layup the top face, add the foam, fill the sides then close the mold allowing excess resin to wick out the ends. It sounds imprecise but with the steel mold I'm using results have been top notch.

Chris.
Hey Chris, thanks for that,...that process is a little down the road for us, but I do like your idea.

BTW....got a response from your build bud, Steve, who has certainly helped us with a little dillema on rolling a boom. Some words of wisdom from Phil Barnes and I think we may have it solved. Hope to be able to take some photos, so just incase we epoxy our a$$ to the work bench, there will be some record of where we dissapeared to..

keep on track
Thanks
Ray
Mar 13, 2010, 04:47 PM
Registered User

which resing to mix the poraver


[QUOTE=DrFragnasty;14195749]The mold filler is Poraver. Cheap. Lightweight. Works. We'll use it again.

Hi DrFragnasty,

I read that your gelcoat is a vinylester-based one; is also a vinylester or a polyester the resin you used to mix the poraver? If so, is it safe in terms of deformation during the curing process?; does it become very hot?

Thanks

Rafael
Mar 13, 2010, 05:10 PM
Thermal Wrangler
DrFragnasty's Avatar

nose job


Poraver was mixed with epoxy Rafael, 100ml to 1 litre of Poraver which keeps heat down.

MDF plug was machined last week at Nyecam for the new F3B nose.

What are you making Rafael?

Chris.
Last edited by DrFragnasty; Mar 13, 2010 at 05:27 PM.
Mar 18, 2010, 02:10 PM
Registered User

foam wings


Hi DrFragnasty,

Sorry for not replying earlier. Please have a look to this post.

https://www.rcgroups.com/forums/show...59&postcount=9

This is one of the kind of planes I like to build up. I also have made F5J and F5G competition planes.

I hope you like it

Rafael
Apr 03, 2010, 02:38 PM
Registered User
Upvector's Avatar

The Boom...


Quote:
Originally Posted by DrFragnasty
It's just blue foam cut with a hot wire Ray.

A couple of dry runs to see if the cloth fits then wet out the cloth on plastic sheet and layup the top face, add the foam, fill the sides then close the mold allowing excess resin to wick out the ends. It sounds imprecise but with the steel mold I'm using results have been top notch.

The project is waiting on more cloth (carbon sock for the boom) so should be back in the shed next week sometime.Chris.

Chris.
Hi Chris...
Saw the pic of Steven with the boom mandrel...and was wondering how your boom turned out. We have had a measure of success with using layered 12k tow, but our outside finish is more like a barber pole. We used VHS tape, and electrical tape to wrap and squeeze...but ended up with a giant CF worm gear..!! The good part is that we hit 58.7 grams, for the piece, only a couple grams above M. Drela's...so happy with that.

Would appreciate any
info on yours, (when you get a chance to get out of the shed..)

Thanks
Ray
Apr 04, 2010, 04:07 AM
Thermal Wrangler
DrFragnasty's Avatar

glacial progress


Nice planes Rafael!

Ray; progress is glacial at the moment ;0)

I did however email Soller Composities asking if their tubualr heat-shrink could work on the boom but no, it can't shrink down from 44mm at 1 end to 22mm at the pointy end.

We're still working on solutions for making it neat.

Your boom weight sounds great.

Our 2" carbon sock arrived so we have all the fabrics we need. Just need a spare day to lay one up.

Chris.


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