Composite racing wing  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       



All Forums >> RC Airplanes >> Pylon Universe - RC Pylon Racing >> Scale Racing >> Composite racing wing Page: <<   < prev  1 2 3 [4] 5   next >   >>  

Login
Message << Older Topic   Newer Topic >>
Composite racing wing - 2/24/2002 10:35:04 AM   
flugzoid


 

Posts: 40
Joined: 2/21/2002
From: Boise, ID, USA
Status: offline 		I have a stupid question....any trouble with your molds deforming under the pressure of the vacuum bagging? Maybe not since there's an equal amount of pressure on both sides of the mold?

John

(in reply to Mluvara)
       Post #: 76

Composite racing wing - 2/24/2002 10:57:49 AM   
Darrinc



Posts: 1028
Joined: 1/22/2002
From: Piqua, OH, USA
Status: offline 		flugzoid,

Yes, that can happen as the air is sucked out at different places at different times.

Made your mold strong!!!!!!!!!

Darrin C

(in reply to Mluvara)
       Post #: 77

Composite racing wing - 2/24/2002 11:00:38 AM   
flugzoid


 

Posts: 40
Joined: 2/21/2002
From: Boise, ID, USA
Status: offline 		Yes, good point. I'll have to keep that in mind to try and make them strong AND figure out how to prevent leaks. Thanks for the reply Darrin.

(in reply to Mluvara)
       Post #: 78

Composite racing wing - 2/24/2002 11:34:27 AM   
Mluvara



Posts: 1425
Joined: 1/14/2002
From: San Jose, CA, USA
Status: offline 		My mold is pretty strong, but I think it could be better. I've feared coming out the next day to see a crack in it. It also depends on the vacuum applied. I generally use less than 10" for everything, including most of my molds. 5" or 6" is plenty (more than enough!) for white foam.

Leaks are a major problem as the edges of the mold seem to puncture the material very easily. My homemade vacuum system cycles whenever it senses a 2" drop in vacuum. This bag (brand new) is leaking and making the pump cycle every minute. This bothers me as it is bad for the pump to do so a lot and potentially shortens its lifetime. Generally, I can get 10 to 15 min cycles. I think there are some small leaks in my system, but the bag is the most noticeable.

Michael

(in reply to Mluvara)
       Post #: 79

Composite racing wing - 2/24/2002 7:35:37 PM   
AV8TOR


 

Posts: 427
Joined: 12/28/2001
From: Mount Vernon, OH, USA
Status: offline 		[QUOTE]Originally posted by Mluvara
Fuselage in bag and all set for the evening. [/QUOTE]
Mluvara

Did you trim the excess fiberglass flush to the parting line while it was wet before vacuum bagging it?
Also is there any problem with the bag sucking down at the firewall? That seems like a long pull.
I am going to pull out my plugs from my Edge molds today. The top removable hatch was finished yesterday.

(in reply to Mluvara)
       Post #: 80

Composite racing wing - 2/25/2002 7:37:39 AM   
Mluvara



Posts: 1425
Joined: 1/14/2002
From: San Jose, CA, USA
Status: offline 		Didn't cut the glass. It hangs over and then I can trim it before joining. I've got it down now where very little is hanging over.

Not a problem near the firewall. Hardest part for it to pull down is the scoop.

Hopefully, this will be my lightest fuse yet. I used only 11 oz of resin in layup and the best combination of glass/composites that I feel will work. We'll see. Probably won't even join the fuse till later in the week. I have three midterms in my engineering courses this week. Gotta lay off the models.

Michael

Attachments
Click to see fullsize image.
Click for fullsize

(in reply to Mluvara)
       Post #: 81

Composite racing wing - 2/25/2002 7:53:59 AM   
flugzoid


 

Posts: 40
Joined: 2/21/2002
From: Boise, ID, USA
Status: offline 		Nice job Michael. Good luck on the midterms too!

(in reply to Mluvara)
       Post #: 82

Composite racing wing - 2/25/2002 5:34:30 PM   
AV8TOR


 

Posts: 427
Joined: 12/28/2001
From: Mount Vernon, OH, USA
Status: offline 		[QUOTE]Originally posted by Mluvara

Hopefully, this will be my lightest fuse yet. I used only 11 oz of resin in layup and the best combination of glass/composites that I feel will work. Michael [/QUOTE]
What weight cloths did you use, and how many layers did you use?

(in reply to Mluvara)
       Post #: 83

Composite racing wing - 2/25/2002 9:04:48 PM   
Mluvara



Posts: 1425
Joined: 1/14/2002
From: San Jose, CA, USA
Status: offline 		Layup from outside surface inward-

primer/3oz/misc reinforcement around wing mount, tail, firewall, & other areas/aeromat/3oz

Basically it's two layers of 3oz with carbon near the firewall, and areas of reinforcement. There's a strip of glass near the stab area, some on the fuse near the te of the wing, etc.

Michael

(in reply to Mluvara)
       Post #: 84

Composite racing wing - 2/28/2002 1:32:05 AM   
TiGuy


 

Posts: 81
Joined: 1/9/2002
From: Denver, CO,
Status: offline 		Mike,

just came across your thread. I am another one of the people you sent the reflex airfoil to. I am in the process of making plugs for a Q-500 using a thinned MH 18-B and a Q-40 design of a Caudron 460 with your reflex.

The guy that taught me how to mold doesn't bother to bag the fuse. It's a very similar process to what you have documented here, but we just lay up glass and CF in each half, trim the overlap while it is still green, with the exception of an inch or so all the way around on the second half to be layed up. This inch is then used to secure the two halves together once the molds are bolted together (wet lap) (instead of using tape). It's a much faster process since it all gets layed up molded and bolted together in one (long) sitting.

TiGuy
aka V-Raptor

(in reply to Mluvara)
       Post #: 85

Caudron C460 - 2/28/2002 9:24:48 AM   
matchlessaero



Posts: 1288
Joined: 1/6/2002
From: Cordova, TN, USA
Status: offline 		TiGuy, What are the chances of getting some pics of your Caudron? I have been modeling that plane for many years. I even have a 15QMidget wing built, and a fuse plug made that I have never put to use (fuse plug is probably of too poor quality to use).
I would really love to see your Caudron, and would be interested in possibly getting a fuse and wing from you someday.

Matchlessaero

[url]www.geocities.com/matchlessaero/[/url]

[email]lagrue@hotmail.com[/email]

PS. Mike-wonderful info!!!! I have really enjoyed looking at your pics even though I will probably never be capable of doing what I have seen in them

_____________________________

Go fast turn left-----3D is life-----Fly S.M.A.L.L. I'm having an RC identity crisis!!!!!!!!!

(in reply to Mluvara)
       Post #: 86

Composite racing wing - 2/28/2002 10:43:45 AM   
Mluvara



Posts: 1425
Joined: 1/14/2002
From: San Jose, CA, USA
Status: offline 		TiGuy-

Let me know how it goes with the airfoil. I'll be interested to see how it does.

I've done wet layups on the Tsunami. It comes out good, but the benefit of using the composites and bagging is that I need NO other formers except for the firewall in the fuselage. Once the stab is mounted, that is it. Makes life simple. Granted the bagging takes a little longer, but seems to have some benefits.

matchlessaero - It's not as difficult as you would think. I only learned how to do it in the past two years myself. I caught on pretty quick. It's almost addicting.

Michael

(in reply to Mluvara)
       Post #: 87

Composite racing wing - 2/28/2002 9:26:24 PM   
TiGuy


 

Posts: 81
Joined: 1/9/2002
From: Denver, CO,
Status: offline 		matchlessaero,

All I have right now are the plugs in semi-primed form for the fuse, and the wing needs to be re-done (I made a big mess on the first one). The biggest problem right now is that I am in the middle of packing to move into a new house (where I get a 300 sq foot shop all to myself...woo hoo!) I'de love to show off what I have right now, but it is going to take some imagination to envision it in final form.

It is being built to qualify for approval for AMA 422 racing, so I have kept as much of the scale shape as I can. I blew up 3-view drawings to the fuse length I want (33" and then stretched the wing planform out to cover the needed 400 sq" required.

I just had my hands on it last night as I rearranged some things to go into "fragile" storage so it's not burried. Give me a day and I'll take a couple of pictures with a sheeted foam core wing that was the first prototype (I'm now on my third before it has even flown once).

As far as your fuse plug is concerned that you mentioned is probably too poor to use, as long as it is symetrical, it would probably be a great first venture into mold making, and once you get a fuse out of the mold, you can then massage that one for a second generation plug. I think this is an easier way than trying to get a complex design perfect the very first time. It may take longer this way...but it gives a more instant gratification rush! And you don't have to worry about ruining that plug that took months (years) to shape!

Go ahead and give it a shot...what do you have to lose?

(in reply to Mluvara)
       Post #: 88

Giving it a try.... - 3/3/2002 8:22:28 PM   
matchlessaero



Posts: 1288
Joined: 1/6/2002
From: Cordova, TN, USA
Status: offline 		Thanks for the encouragement ya'll!!

I may have to just break down and do it. I think I will wait until we (wife and I) get into a house first, a single bedroom apartment is a pretty awful place to glass the center section of a wing. I can't imagine how bad creating a mold and then using it would be.. I can't wait until I have a garage again!!!!! : )

I pulled the plug and wing out of storage back at Christmas. Even took some pics of it, I will post them if I can get them developed soon.
The plug is fairly symmetrical. I have some tools that will allow me to check that for sure.

I think a q500 fuse might also be a good experiment for learning plugmaking and layup because of the relatively simple shape.

Thanks again Mike for the neat posts, I know we all look forward to seeing the end results.

[url]www.geocities.com/matchlessaero/[/url]

_____________________________

Go fast turn left-----3D is life-----Fly S.M.A.L.L. I'm having an RC identity crisis!!!!!!!!!

(in reply to Mluvara)
       Post #: 89

Caudron Plug Pics - 3/4/2002 8:05:12 AM