Quickie 500 Fuselage layup and mold building pics (Full Version)

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Scorpion Racing -> Quickie 500 Fuselage layup and mold building pics (5/5/2008 10:02:24 PM)

I have a question. I am about to start laying up some fuselages for 428 and would like to know what you guys use.

I have seen some use all fiberglass, fiberglass & carbon as well as fiberglass & wood. What seems to work the best, and what weights of glass and wood do you use?

I also see some of you bond the seams during fabrication. Is there a reason you don't vacuum bag it (like a wing) and then join the halves?

Thanks for the help!



diggs_74 -> RE: Quickie 500 Fuselage layup question... (5/5/2008 10:23:10 PM)

Well Scott, welcome to what could be the most frustrating thing you've ever done. [:D]

So far I've found that a layer of 3oz, 6oz then 3oz again yields a very stiff fuse and the weight seems ok.. I've tried with less cloth but I don't think it's stiff enough.. I was told by Terrance (manufacturer of the Neme Q+) to shoot for around 7 - 8oz with the firewall, hold blocks and paint..

As far as joining the halve goes, I'll let someone else answer because I haven't been able to get a single one to turn out a good seam yet.. I always end up with some voids.

Have fun...



Scorpion Racing -> RE: Quickie 500 Fuselage layup question... (5/5/2008 10:48:48 PM)

Thanks Lee, talking about fun? I spent 15 hours making a parting board for the fuse alone! Anyone who thanks this is the easy way out is sadly mistaken!!

Do you think the fuse could benefit from vacuum bagging and either carbon or balsa added?



Ed Smith -> RE: Quickie 500 Fuselage layup question... (5/6/2008 12:11:57 PM)

Maybe it is too late but I would recommend a "Bathtub" type mold. The sides, top and bottom of the finished part have no seams. The seam is along the bottom corner of the fuselage, it is much easier to produce and correct any voids. I use one layer of 2oz and one layer of 6oz with a layer of 1oz carbon from the firewall back to the landing gear plate. I take a couple of strings out of that heavy "Waffle" weave cloth and add to the top corner to act as longerons, that and the joint overlap at the bottom provide all the stiffness required. I mold and join everything at one time while the whole layup is wet, this includes the firewall, landing gear plate and wing mounting blocks. Weight when it comes out of the mold is 6oz.

See picture.

Ed S



Scorpion Racing -> RE: Quickie 500 Fuselage layup question... (5/6/2008 1:55:46 PM)

Thanks Ed,

It isn't too late,... because your method is the one I used! [:D] Your method seemed logical to me and allowed easy access to the seams, so I copied it. My fuselage makes a drop to the gear, then a reverse curve up and a sweep after the v-tail. Did I mention the sides and top are also Coke bottle shaped? Not the easiest shape to create a parting board for to say the least! [:@] I have the fuselage mounted on 3/4" wood, with 3/4" supports under 7 stations at points down the bottom to create the curves as well as in front of the firewall, and then mounted the parting board to this structure. I need to add some registration bumps and then lay up the mold on this. If all works out as planned, I should end up with a mold that looks quite close to yours.

Ed, where do you get 1oz. carbon cloth? 6oz. finished weight sounds great!

Does anyone think vacuum bagging the fuselage would give a stronger/stiffer product?

Thanks for the replys, keep them coming if you have any ideas...



diggs_74 -> RE: Quickie 500 Fuselage layup question... (5/6/2008 2:35:39 PM)

The problem I've had trying to bag the fuse sides is getting down in the fuse mold all the way.. It gets difficult to make sure the bag isn't hanging up on the flanges of the mold or whatever.. Ed's way would be fairly easy to do the bottom but the top would have issues I would think.. However, the nice thing about a mold, as long as nothing sticks you aren't out much if something doesn't work..

I'm going to be tackling the second version of my quickie shortly.. Starting from scratch again.. I to copied parts of Ed's technique.. I may part mine the same way this time..



TeamSeacats -> RE: Quickie 500 Fuselage layup question... (5/6/2008 6:50:47 PM)

Strechlon!

[image]http://www.fiberglasssupply.com/Product_Catalog/Vacuum_Bagging/Stretchlon_200.jpg[/image]



Randy Etken -> RE: Quickie 500 Fuselage layup question... (5/6/2008 6:57:18 PM)

Hi Scott
This is just my opinion on RC Q-500 fiberglass fuselages. I have build over 100 the last 8 years and change something each year to make them better. I race mine and see the points that need to be reinforced. If you a using fiberglass and carbon fiber you do not need to vacuum bag. If you use balsa and fiberglass, I think you need to vacuum for a good bond. Here is how I do it.
1. Wax mold twice with dolphin wax.
2. Paint with PPG concept DCC.
3. One pump of epoxy, mix with capbosil to the consistence of ketchup.
4. Brush this on the inside of fuse mold with extra laid in the corners and curves.
5. Lay in style 120, 3.16oz crowfoot weave fiberglass, wet out with epoxy.
6. Lay in a half piece of 3.16oz from firewall to trailing edge of wing saddle, wet out. Add a couple of fiberglass pieces around tail.
7. Lay in Carbon Fiber 5.7oz strip 2” to 1” from fire wall to tail, on each side. Add a couple 1”by 3” for landing gear. Wet out.
8. Final layer is 6oz soft weave fiberglass. Wet out. I also use this for the lap joint.
The firewall and landing gear blocks are ¼” plywood. Weight is 6 1/2oz.
I have used West and EZ lam epoxy, did not like either one. MGS is great but hard to get and expensive, I am now using Adtec Pro Built from Cass, works good.
Good Luck, and hope to make your race again next March.



Scorpion Racing -> RE: Quickie 500 Fuselage layup question... (5/6/2008 7:53:33 PM)

Thanks Randy,

I was glad to get to talk to you again at the spring race and hope you can make it again. I hope you will be racing against a Scorpion in 428 next March!

I will be using MGS resins for the molds as well as the parts, but I will pull a few parts before I try to tackle painting in the molds. My plan is to lay up the molds next wekend, and start pulling my first parts within a month. I will try a few different lay ups, and modify as I see what is needed for my design. That's how I had to do it with the woodies in 424, so I am used to the trial and error process! [)]

It's great to have guys like you who are willing to pass along what you have learned to help others out. I really appriciate your help. Any more help you guys have would be great! [:D]



Ed Smith -> RE: Quickie 500 Fuselage layup question... (5/6/2008 9:19:06 PM)

This is the shape of my fuselage.

because I join the top and bottom while they are still wet vacuum bagging is not possible. I would not bother anyway.

Ed S



Kevin Matney -> RE: Quickie 500 Fuselage layup question... (5/12/2008 10:56:45 PM)

Here is what I do. To make the fuse.
1 Layer or 2 oz glass. A pice of 2 oz Kevlar in the LG area, 4.3 uni, carbon from the FW to 1/2 of wing, Then a last layer of 6.0 glass, and a wet lap seam. With a weight of 7.0 to 7.5 oz.
With a molded in V stab saddle and FW, and other wood



jeffk464 -> RE: Quickie 500 Fuselage layup question... (5/13/2008 12:33:01 AM)

Kevin, is that the Mad Dog or the Dawg gone it?



Scorpion Racing -> RE: Quickie 500 Fuselage layup question... (5/13/2008 1:17:19 AM)

Thanks guys. I think the general formula I am coming up with is:

1.) Some combination of fiberglass & Carbon in 3 or more layers (beginning with a 2~3oz. layer of very plyable fiberglass) equaling about 12~14 oz. in total thickness.

2.) Extra reinforcements in the landing gear & tail mount area, add all formers (LG, Firewall & wing mounts) and do a wet lap joint while the fuselage is curing. Additional carbon tow can be added in corners if needed.

3.) Target weight with paint should be 7~8oz.

I am beginning the waxing process on the fuselage plug on, and will lay up the mold next week. So if you have any corrections to this formula, it isn't too late yet! My fuselage has a lot of curvature in it, so I think that will add to a natural stiffness in a composite structure, right? I am sure I will make some changes after test flights are completed, but this will definately give me a head start.

Thanks guys [;)]



Kevin Matney -> RE: Quickie 500 Fuselage layup question... (5/13/2008 7:21:53 AM)

I do all the Q/500 fuse this way. The Pit Bull has no kevlar for LG, it is in the wing



jeffk464 -> RE: Quickie 500 Fuselage layup question... (5/13/2008 4:11:37 PM)

I have a salvaged v tail from a crashed predator II, do you think it would fit the mad dog's vtail saddle?



Kevin Matney -> RE: Quickie 500 Fuselage layup question... (5/13/2008 10:31:13 PM)

I sure it would with a few shims. just set the wing to 0 degrees and then line up the tail.



Scorpion Racing -> RE: Quickie 500 Fuselage layup question... (5/27/2008 8:27:05 PM)

Here are some progress shots of the molds. These are of the Fuselage plug, sitting in the parting board structure. You may be able to see the white clay I used to fill any last minute gaps.



diggs_74 -> RE: Quickie 500 Fuselage layup question... (5/27/2008 8:37:30 PM)

Wow Scott, that looks great..



Scorpion Racing -> RE: Quickie 500 Fuselage layup question... (5/27/2008 8:41:40 PM)

Here are the various resins, additives, fillers and mold relese wax that I am using. The parting board and plug were waxed and buffed once a day for 9 days prior to molding.

For the base coat (Gel coat) on the mold I used:
30 Ml. MGS 285 resin
15 Ml. MGS 285 hardener
7 Ml. West Systems 423 Carbon Powder
7-8 Ml. of Milled Fibers
30 Ml. of Fumed Silica

The resin is mixed well, then the carbon and milled fibers added. I then added in the fumed silica slowley till it was about like mayonaise. I think it took about 7 batches of this to cover it all.

For a radius filler prior to laying in my glass, I used MGS resin, hardner and cotton flock. Seemed to work real nice.



Scorpion Racing -> RE: Quickie 500 Fuselage layup question... (5/27/2008 8:51:35 PM)

I used Aerospace Composits 2 Oz. cloth for the first layer over the gel coat and the cotton flock. After the 1 coat over the entire mold and some extra pieces to round off some corners, I used a 6 Oz. "surfboard" cloth to build up the thickness. You can see I really piled it on the tail section notch where the tail will sit. I didn't want to have this high stress area messed up, and it was a real P.I.T.A. to keep triming the cloth here. I built it up, and grinded it flush before I went on.



Scorpion Racing -> RE: Quickie 500 Fuselage layup question... (5/27/2008 9:06:01 PM)

Here are some shots of the moment of truth! I was very relieved with how easy it poped loose from the parting board. I used two mold wedges and went around the edges by hand and it was free. The only issue I had was some of the primer stuck to the gel coat. I will cleaned that up, and its back to waxing for a week or so to finish the remaining two parts of the mold!! [;)]




Scorpion Racing -> RE: Quickie 500 Fuselage layup question... (5/27/2008 9:12:34 PM)

Thanks Lee! It is a real learning experience, but I really want to learn this stuff. I am trying to take my time, and learn from you guys and my own mistakes along the way! [:D]



Scorpion Racing -> RE: Quickie 500 Fuselage layup and mold building pics (7/12/2008 4:55:01 PM)

Today I am as happy as a schoolboy! [:D] I pulled my first test fuselage... and it looks GREAT! I will tell you it wasn't too easy to get here, and I made some mistakes along the way.

The first and WORSE mistake I made was to use that primer for the final surface! Had it been PPG or a good quality paint, it probably would have been fine. What I used was rattle can (total crap) auto primer and it seemed to fuse with the resin gelcoat. I had to clean about 40% of the primer off the mold to reveal it. In case you wonder how the plug came out of the bathtub part of the mold with the primer melting,... it came out in confetti sized pieces!! [:@] I spent 2 weeks cleaning primer out before I could start polishing the mold. On a good note, once the primer was all cleaned out, the suface was beautiful. [;)]

I had 1 small area that looked like a bug got trapped under the gel coat, so I filled this area with the same gel coat mix I used for the mold in post #19, minus the silica. Wet sand with 400, rubbing compound then polishing compound and it flat disappeared. I used rubbing compound on the entire mold, followed by polishing compound. I then waxed the mold with Partal #2 - 3 times; Buffing it out and allowng it to harden for 24 hours between coats. The first coat was a bear, but gave the mold a nice shine. The next 2 coats were much easier, and you could see your reflection in the mold! Nice...

I made 3 templates to cut my glass by. 1 for the TOP, 1 for the SIDE and 1 for the BOTTOM. When I cut the glass, I added the firewall piece to the first and last layers of the sides and top pieces. The middle layers had no firewall glass and ended at the firewall. The last 2 side pieces also had the extra flap of cloth for the wet lap joint to join the bottom piece. Took about 1/2 hour.

For the first test, I used 3 layers of 3.7 oz cloth only. (I wanted to see the finish, and make sure I could get the part out!) I used Randy Etken's method of MGS resin and fumed silica (carbosil) mixed like ketchup to paint the mold with. I then layed in 3 layers of cloth, alternating top & sides for overlaps and used straight MGS for the laminations. I built the layers in the bathtub section up EXCEPT the final sides with the wet lap joint. I then layed up the bottom, added the sides with the lap joints and clamped it all together. About 2 hours to lay it all up, but remember I didn't add the wood parts to this test.

I will get some pictures to show it to you and add them.



Scorpion Racing -> RE: Quickie 500 Fuselage layup and mold building pics (7/12/2008 5:32:04 PM)

Some pictures of the mold:




Scorpion Racing -> RE: Quickie 500 Fuselage layup and mold building pics (7/12/2008 5:36:07 PM)

A Picture of the mold with the test, and the fuselage prior to clean up:



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