T-crafty

Just like the title says, I want to make a fiberglass Cessna. An 06' Skylane Turbo to be exact. I want to make it about one !QUOT!size!QUOT! larger than the Top Flite Model 182 (about a 1.2 - 1.8 size). Here is what I have been thinking of doing to build a plug given my recourses. Please let me know if you think this will work or not:

1. Generate a model of the Cessna using Pro Engineer - this should only take me a little while and I can be very detailed with the doors/gear/and small scale details.

2. Have the model rapid prototyped in halves out of plastic/nylon

3. Smooth the surface using bondo and sandpaper preparing it for paintwork

4. then I can paint the plug, wax it and all that good stuff...

I have never made a mold before using plugs so let me know if anything looks like it will not work. I see most of the guys here use foam and plywood formers to make plugs I was just thinking this would be faster and I have access to a lot of the tools I need. Will I be able to remove the plug from the female mold in tact or will the plug be destroyed? What provisions are taken to allow for hinging the vertical stab to the rudder - are pieces of wood added to the tail behind the fiberglass for this? Can I add wood pieces in the cabin area for servos and electronics after I have the fuse sides joined? Also once I have the two fiberglass halves how do I join them - just glue them together?

Thanks for helping a newbie! Oh yeah... anyone want to buy a Cessna Skylane Turbo kit when I am done???

Deadstik

My Feedback: (8)

T-crafty,

I applaud your go for it attitude but..... it's a little more difficult than that. I (and I'm sure most of the guys on here) can only DREAM of a rapid prototyper.. but if you've got one GO FOR IT !!!.... now there are MANY excellent threads and how to articles/web pages on making a mold.. but there are certain key factors.

1. The plug has to be perfect... not ok, or good enough, it has to be perfect with no blemishes/scratches/holes... and should look like a mirror. Wax is cheap, repairing a plug that will not release is heartbreaking... so.. USE the WAX.....You can use the chemical mold release agents AFTER you have made the mold.
2. You are NOT going to destroy this plug in the mold making process. You do one half, remove the parting board and then do the 2nd half... then you remove the plug.
3. Waxing the plug correctly is critical to it being removed in one piece..... follow the threads instructions very carefully here.
4.You will insert a piece of wood into the gap in the vertical stab to hinge the rudder. This is done after you have molded the glass fuselage.
5.You add the servo supports and formers into your fuselage using epoxy/microballons and they glue in just like anything else.
6. Two methods are available to join fuselage halves. Personally, I join both halves in the mold using a flange made from the last layer of inner fiberglass. This way the fuselage is perfectly straight and, if done correctly, leaves very few voids in the glass cloth. The second method is to lay up each half, pop them from the mold halves AFTER laying masking tape on the edge of the mold and sanding a PERFECTLY straight edge on each half with a metal sanding bar, and then you tape the halves together and lay in a piece of fiberglass tape soaked with epoxy and lay it right down the centerline. Works very well, but I prefer the first method.


This is one of those processes where it all sounds very simple... right up to the point where you are the one doing everything. One more thing.. GET A HELPER... pay them whatever they want.... if nothing else, they will be more confused than you when something doesn't go right..... there is plenty of help available here and many different opinions on how to do every process.. just read them all and once you decide on a course of action.. do it.

Good luck...and I just might want a kit...


Dan

Carolina Custom Aircraft

A10FLYR

My Feedback: (1)

I prefer to trim the parts while still "green", that is, not quite cured with a slightly dull exacto KNIFE, not the #11 blade but the 2-3" long blade. Slightly dull so as not to cut into the edge of the mold. Join the mold halves back together....you did have locating pins right? And then do the tape and resin bit quickly, to make a good chemical and mechanical bond between the two halves. I've heard of the "last layer" method but have not tried it.

I don't know how well it will work making two halves. I guess you could join them and do the parting board method which I think is the way to go.

T-crafty

Ok, now that I have some feedback this is what I'm thinking.

Deadstik - It sounds like you make the plug as a whole fuse and section it using a parting board, I was going to rapid prototype a left and right half with interlocking pins. After I create the left and right half I was going to lock the molds together using the pins and drill holes straight through the two molds locating the halves with dowels. Then I was going to join them using the last layer of fiberglass like you mentioned. Does this sound like an ok process?

As for the two halve being perfectly semetrical the rapid prototype process is accurate to .002" but the surface finish is a little rough. Thats where the bondo comes in - I can use bondo to fill the surface finish and provide a vary nice surface for paint.

What do you think?

Deadstik

My Feedback: (8)

T-craft,

Sounds very doable to me....I do not know what material your prototyper will be cutting, but if you form 1/2, then the other, then do the locating hole/dowel thing.. you shouldn't need the glass strip to join the halves.... you should just be able to clue them together.

As for bondo.. forget it.. it is too hard to work with ... find a product called ICING... this is a white, polyester filler than is VERY easy to work with and accepts primer well.... As I said, Easy to sand.. and want that plug looking like a mirror... good luck.. sounds like you have access to some equipment I would REALLY like to use...


Dan

Carolina Custom Aircraft

Grumpy1940

Good luck for your project!! here pic my first fuse plug and mold. for easier opening i did 3 pcs mold for fuse. and used iron balls in aligning halfes. about 1/3inch diameter iron balls. very easy and makes parts just fit perfectly. not cheapest way of building. but for sure joyable learning experience. and last pic 1st fuse.

A10FLYR

My Feedback: (1)

Grumpy,
Looks good but you should put some detail in it

Grumpy1940

LOL! i promise next time i will add some details.....

T-crafty

Wow! That is a very impressive model! If you don't mind me asking, what did you use on the plug to make all that detail? Did you just carv the panel lines in with an exacto and what about the rivets?

A10FLYR

My Feedback: (1)

I was hoping you would take that as a compliment See what listening to Leva's Polka all winter looonng will do to you!!

Grumpy1940

i used litho plate in all panels. panel by panel in correct order. and hammered every rivet on panel before gluing it on plug.
on this link u will find perfect way to do it. used same method. http://www.su27.de/
rised rivets hammered from backside of plate with ballend dremeling tool. then sharpened tube from upper surface on hard metal surface. flush rivets just hammered with sharp tube on ply surface. entire plane with wings and tailplane took about 8 months to hammer.
.. keep staing on tango!! lol