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Old Jan 23, 2013, 05:21 AM
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Brazil, SC, Florianopolis
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Quote:
Originally Posted by dougmontgomery View Post
r u going to ramp up clay or bondo to the wing leading edge since it does not look like your splitter plate is not level with the LE?

I have done that before- but the clay ramped up does not leave a very nice finish?

doug
Hi Doug!

Negative, I wonīt use clay!

The platform is 3mm beneath the centerline. I will use a 3mm sheet of MDF over it.

My idea is to use very few glue in this layer of MDF, to facilitate getting the mold out.

The platform is really strong, to support the weight over the flanges and it does not touch the plug. It is made of 9mm MDF.

Today I will work on the flanges and use epoxy to make a perfect join on the seam.

It takes a lot of job, but I am using all the techniques that I have been studying on this plane.

I donīt want to make it in a hurry and as is my intention to sell some planes to pay all the material that I am using, it must get well done.

Thanks!
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Old Jan 23, 2013, 07:35 PM
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Brazil, SC, Florianopolis
Joined May 2008
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Help with the mold reinforcement

Hello!

I am finishing the steel structure that will reinforce the mold. Maybe tomorrow I will have some pictures to show.

Is it necessary to make this structure on both halves os the mold?

I imagine that if one half is reinforced, and the other one is tightly binded with bolts, it should not be a problem.

Does anyone have some experience with this and give some hints?

It been more difficult that I thought to build this steel skeleton...

Thanks!
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Old Jan 25, 2013, 04:00 PM
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Brazil, SC, Florianopolis
Joined May 2008
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Hello!

Today I finished the steel structure to support the mold.

Now, the only thing that lacks to do is the flange on the seam line.

I left the things on my parentīs house and returned to home.

I will have to wait several days to begin the lamination of the mold.

Charles
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Old Jan 25, 2013, 04:23 PM
Caution:Makes sharp left turns
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United States, CA, Lake Forest
Joined Feb 1999
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Quote:
Originally Posted by charlespereira View Post
Hello folks!

This weekend I hope to finish the plug and want to clarify one thing.

Do I need to make a down e right thrust for a pylon?

I have read some topics here and I think that 2 degress down and 0 degress right will be my choice.

Any advice on this subject?

Thanks!
Most electric pylon planes do not add down thrust or right thrust. It is common in some motor-gliders or Hotliners to add down thrust (because they may have higher camber airfoils) but I have never added down-thrust to a Speed 400 size airframe up to 200+mph F5D planes. I have added right thrust only to EF-1 style pylon planes because they have short tail moments and large diameter propellers that create a lot of "P" factor on takeoff.
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Old Jan 30, 2013, 09:40 AM
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Brazil, SC, Florianopolis
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Quote:
Originally Posted by Troy View Post
Most electric pylon planes do not add down thrust or right thrust. It is common in some motor-gliders or Hotliners to add down thrust (because they may have higher camber airfoils) but I have never added down-thrust to a Speed 400 size airframe up to 200+mph F5D planes. I have added right thrust only to EF-1 style pylon planes because they have short tail moments and large diameter propellers that create a lot of "P" factor on takeoff.
Thanks Troy!

I have done the plug following what you said.

It is now finished and waxed.

I applied 5 coats of wax. I believe it is enough, because I will use PVA also.

Now will start working on the flanges.

My work schedule for February has only 40 hours of flight and I think that will be able to finish the mold.

Charles
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Old Jan 31, 2013, 05:13 PM
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Brazil, SC, Florianopolis
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Hello folks!

All the structure that I built to make the mold is at my parents house, about 110 km far from here. I think that I will be able to go there and finish the mold only in two weeks.

Until there, I would like to discuss the ideas to make the lamination.

To help, the tissues that I have:

- 26g/mē fiberglass
- 85g/mē fiberglass
- 200g/mē Kevlar
- 200g/mē carbon (I couldn't find a less heavy carbon here in Brazil)

Today I cut some sheets of balsa wood on the shape of the wing. THe four pieces have 29g. I don't know if it is heavy or not.

On the first layup, I want to make like this:

- one layer of 26g/mē fiberglass
- one layer of 85g/mē fiberglass
- the balsa wood

Everything cured on vacuum.

The spars made from carbon and the hinges made of Kevlar.

I appreciate any help on this issue. I don't have much experience on the layoup.

Thanks!

Charles
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Old Jan 31, 2013, 08:19 PM
Just fly it!
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Cody, WY
Joined Nov 2007
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I would put the 85 gram on the outside, then the balsa, then the 26 grams glass on the inside. You may be able to just use the 26 gram on the inside and outside. If you don't sandwich the balsa between the glass then the wing will not be structurally stable (hold the proper shape).
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Old Feb 01, 2013, 02:31 AM
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timbuck's Avatar
gold coast australia
Joined Aug 2008
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+1

Lay up.... 85/balsa/25..for a light build that will be ok.

Tim
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Old Feb 01, 2013, 07:04 AM
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Brazil, SC, Florianopolis
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Thank you Adam and Tim!

I will follow your advice! It will be fiberglass, balsa and fiberglass again, maybe a 26g/mē on the internal layer.

Between these layers, the carbon, that will be acting as a spar.

Now I ask: is it necessary to make a spar that goes trough the center of the fuselage?

Or using only carbon along the shape of the fuselage is enough.

I don't know if I made myself clear.

Thanks!

Charles
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Old Feb 01, 2013, 02:44 PM
Just fly it!
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Cody, WY
Joined Nov 2007
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I think you will be o.k. if the carbon goes through and follows the contour of the fuse. I would add a few more layers staggered in the area.
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Old Feb 05, 2013, 04:15 PM
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Brazil, SC, Florianopolis
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Quote:
Originally Posted by wyowindworks View Post
I think you will be o.k. if the carbon goes through and follows the contour of the fuse. I would add a few more layers staggered in the area.
Thanks Adam!

The flanges are now ready.

The next step it to fix them on the mold platform and fill the gap with epoxy.

Today is the last day of my vacations, but on the next week I will have some spare time and will make the mold.
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Old Feb 05, 2013, 05:29 PM
Arrarrar!
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Australia, NSW, Wagga Wagga
Joined Jan 2010
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Hey charles, why dont you want to use clay to set your plug into the mould? its much easier than epoxy and seems to give very similar results I have found. Also less chance of wrecking your plug surface being damaged on release.
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Old Feb 06, 2013, 04:48 AM
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Brazil, SC, Florianopolis
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Originally Posted by josh18 View Post
Hey charles, why dont you want to use clay to set your plug into the mould? its much easier than epoxy and seems to give very similar results I have found. Also less chance of wrecking your plug surface being damaged on release.
Hi Josh!

In fact, I never used the epoxy approach! I wanted to use it to learn a new way.

It seems to me that it should take longer, but the result should be a bit better!

I never got a good seam using clay, maybe lack of experience or patience! :-)

Thanks for your consideration!
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Old Feb 06, 2013, 08:17 PM
Just fly it!
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Cody, WY
Joined Nov 2007
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For pristine parting lines I always use thicken resin to fill the gap between the plug and the parting plane. After it cures I remove the parting plane/plug and block sand the thickened resin flush with the parting board. This makes a nice sharp corner.....although the sharp corner gets rounded out if you are using PVA. If I use PVA I just use clay to fill the gap.
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Old Feb 14, 2013, 02:00 PM
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Brazil, SC, Florianopolis
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The mold is done

Hello folks!

This week I was off-duty for three days and finally finished the mold!

It was about 30 hours of work in two days and a half.

Even using wax and PVA it was not easy to pull off the plug, but I am happy to say that it survived with only some minor scratches.

Thanks you all that helped in this job.

Next week I will polish the mold and make the holes for the bolts.

Hope you enjoy the photos!

PS: I will make a movie with subtitles in English next week explaining the details.
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