RCU Forums - View Single Post - Cutting and Prepping Lightweight Foam Cores
Old 09-11-2013, 02:56 AM
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sensei
 
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Originally Posted by Viper1GJ
I started this thread to expand discussion from my previous "1.4 oz vs .75 oz Fiberglass Cloth For Balsa Finishing" thread that morphed into other building discussions. Great ideas there but many of follow up questions were off topic.

I like scratch building but have been
severely limited by time the last several years. Retirement is approaching and I want to start again. So I want to pick the brains of you builders that use composite materials that I want to use.

Specifically for this thread the techniques for cutting and prepping foam cores for large 100" plus aircraft.

What type of foam do you prefer and where do you get it and what it costs?

What type of foam cutter do you use for large cores? Many online ideas show glider wings with short chords. What works well with chords of 24" and larger and thick airfoils? Hand bow, suspended bow, double wire, swing arm,etc. Photos would be great.

How you cut channels for wing spar tubes, wood spar channels, wire channels, etc?

How you make lightening holes, servo well, gear well, etc in the foam cores.

Bob (Sensei), if you are there, how do you make your panel templates for cutting the lightening holes? Do you jig saw, router, etc the templates. Do you have a photo of one of your template sets in use? I see in your gallery a foam core with lines on it for the lightening holes. I assume you would have to reapply the template to top and bottom to make the foam cuts. Do you have a photo of your foam cutter for the lightening holes? Bow, hand held wire, etc.

Surface prep of foam before glue, sanding, sealing, etc.?

Materials other than balsa for skinning the foam.

What type glues

Looking forward to collecting all your ideas.

Gary
I make my templates by laying them out, cutting the out close to the line with a jig saw, and sanding to the line with an oscillating spindle sander. this sander can be purchased from Harbor Freight for around $100.00. I don,t have any pictures of templates or my bows. You are correct, I apply a template to both sides of the core, use a soldering iron and burn through the center of each opening of the template, string my wire through and reconnect to the bow, make my cut, disconnect and remove core plug. I repeat over and over until my core is finished.