Vacuum former and Stealth Versa Wing

Hi, this is my first time submitting an article to Flite Test. I have really enjoyed the videos and build plans. I have been a scratch builder for a long time and like to try all sorts of different types of methods and materials to build from. I really like to recycle anything I can to create RC aircraft. I recently made my own vacuum forming setup. I built a versa wing and used this setup to make some parts. The results were pretty good for a first try and so I thought I would share them with Flite Test and all the people who enjoy this site like I do.

To start this project I built a versa wing in a pusher configuration just as Josh shows in his build videos. The only thing I would add is that I recommend removing to paper in the spot under the servos. Then hot glue the servo directly to the foam. I found the paper delaminated from the foam. Leaving the servo lose inside the wing after I assembled the wing and installed the linkage. The only other difference is I used dollar tree foam that has black paper on it for a stealth look.  

The motor cover, servo linkage covers, and lower fuselage were vacuum formed from .20 ABS. The vacuum former is really just three pieces, shop vac, a heat source, and a vacuum box.

I made my vacuum box from scrap oak boards I salvaged from a dumpster from a nearby business that was being remodeled. I also used a left over piece of peg board for the top and a 1/4 inch piece of plywood for the bottom.  Any plywood or board would work.  The outside dimensions are 12 ½”x 24 ½”. The size can be changed to fit what you plan to form of course. This size allows a 12” x 24” piece of plastic to be used. A hole to fit your vacuum hose is cut into one side of the box.  

The next part of the box is a top frame to hold the plastic sheet. It should fit snugly around the box. Inside the outer frame is another frame to sandwich the plastic and hold it in place while it is heated and vacuum formed. I used ¼ 20 countersunk screws and T nuts to hold the pieces in place. I used window screen frame to make the inner frame, again because I picked it up cheap at a thrift store. Any thin material like hard board or plywood could be used. The last piece to be made is the top of the frame which is another piece of hard board cut to fit over the frame and the center is cut out to match the size of the inner frame.  The last thing I did was to add a piece of screen over the peg board. This really helps the plastic to pull down tight around the lower edges of your form (aka buck), and a strip of dollar tree foam around the edge to make a seal between the box and frame. 

My heat source is made from plywood I had left over from another project. It is also 12 ½” x 24 ½” to allow the frame to fit over it. It is about 12” tall. The height was determined by the size of the leftover pieces I had. But 12” seems to be about right.  Inside it is lined with aluminum roasting pans. It took three of them to cover it. Tin foil or whatever could be used. It is there to reflect the infrared heat to the plastic and it also does to good job of keeping the box from getting too hot. I just cut the pans into pieces and stapled them to the inside of the box. The first try at heating element was a single hot plate but the plastic just didn’t get hot enough.  So I got two elements from a rotisserie I got at the thrift store for 10 dollars. I took it apart. I then wired it to a switch. I also added a switched outlet for the shop vac to quickly switch it on and off. I see many people on YouTube who just put the whole frame in their oven to heat it but my wife would kill me if I tried that.  That is all there is to the heater.

 I got most of the ideas for making the vacuum former on YouTube. RC Groups also has some good information. The forms or bucks as they are called need to be smooth or the imperfections will transfer to the parts you are trying to make. I cut these bucks out on my table saw and sanded them smooth.

Finally, I got the graphics for the decals from RC Groups and resized them to suit my plane with Micro Soft Word. I printed them on label paper but they didn’t stick too well. I found that it worked better to print them on plain paper and brush them on with white glue thinned with water. The windows were a challenge. They started out as SR 71 windows. I had to stretch and paste and crop to get the right shape.

There is one final thought about safety. The heater box is made from wood. The elements get red hot. The sides don’t seems to get hot while heating the plastic sheet but it takes a few minutes to let the ABS get hot enough to start to sag about an inch to two inches before moving to the vacuum box. The heater must never be left unattended when plugged in. The parts get hot so you must be careful not touch the inside of the heater. As with any DYI electric wiring you need to know what you’re doing when you wire it. So if anyone wants to build one for them self, please be sure you don’t get hurt by these dangers and any others that might not be foreseen at this time.

This was a fun project. There are some blemishes in the final result because I came across some unexpected issues, the servos both pulled the paper loose from the foam, so I had to punch a hole thru the wing and use gorilla glue to reglue them in place.  The bottom fuselage took a couple of ideas before I came up with the best way to hold it in place. The graphics took a little tinkering to get them to stick to the paint. And I might have put a little too much weight in the front. A 2200 makes it a little nose heavy. I am pleased with how it looks but orientation is going to be a little tricky. I think I might make another one and try to get the finished product a little cleaner. I still have the bucks so I can remake all the plastic parts any time I want.

Thanks to Josh and all at Flite Test for the awesome plans and a place to share our projects and ideas.