fdo300

My Feedback: (1)

Hi

I'm building a CAmodel 27% Extra 300L and I have to take a decision about what hinges to use.
aileron and elevator ar top hinged, I like the radio south CA hinges but I haven't use them in large model before now.

So.... what do you think is better, CA, dubro, robart ???

Regards

Fernando Viollier

caravanflier

i prefer the robarts by far

compute42

My Feedback: (15)

There's a long thread about the CA 27% somewhere in here... do a search for Colombo

Top hinging with robarts looks to be very tough.

jongurley

My Feedback: (29)

I used robarts,,, but my CA is center hinged ,,,,,

Ryans Rebel

My Feedback: (12)

Don't use CA hinges on the CA. The stabs are foam core and the CA will eat the foam. I used robarts but mine was center hinged. It may be worth the time to make your center hinged as well.

Ryan

jongurley

My Feedback: (29)

Yeh Ryan that is what I was thinking, if there is anyway to take a extra afternoon go on and center hinge them..... It will pay off in the long run and the robarts are so easy to epoxy in...

promag

Don´t use CA hinges planes this size. In my 27% Edge I use Robart pin hinges 3/16" (ROBQ 310) and works very well. Glue used Pacer hinge glue.

Abraxxas

My WH Edge came pre-drilled for the supplied Robart hinge points, this was my first experience with them... I installed them using Elmers Probond and I can honestly say I dont think I'll ever use anything else. They are easy to put in, I really like the barbed shaft for security and they look cool too The Probond glue is some amazing stuff as well, just the perfect amount of foaming to fill the voids, and you have tons of working time to get everything perfect.

Good Luck
Brian

davidmor

I just finished hinging my Midwest 80" Extra with Robart hinge points and I have to say, I don't think I will use anything else in the future. I used Probond glue and followed the video tutorial I found on this site. I have used CA, tape, monokote, and flat pinned hinges on many planes in the past, and the hinge points were by far the easiest method I have ever used. The line up perfectly if done correctly, and they seem to be very strong. Using polyurethane glue like Probond or Gorilla glue gives you a plenty of time to get everything together and lined up, and the foaming fills all of the voids in the wood and around the barbs. I was very impressed with them and they look great too!

3dbatixkid

Hope this helps. These are Klett hinges (arent being made anymore from what i hear). Then hinge slots are cut down into the meat of the wing, and are then glued in with epoxy.

TT2

My Feedback: (13)

I built the CA Extra 31% and followed the instructions to the letter during sheeting / hinging at the hingelines. I regret it now. They turned out very nicely but it took FOREVER and was quite difficult to build and keep everything lined up perfectly.

I'm most likely going to build another CA Extra this winter but I'm going to do things differently next time around to speed up the build significantly.

Instead of beveling the foam and capping it at the hingeline (per instructions), plan on using 1/2" thick hard balsa (one for the LE, one for the TE) at the hingelines and Robart hinge points. Increase or decrease the thickness of the hard balsa depending on how much bevel you want. Mark the control surface and allow a gap for the hard balsa. Cut the pieces with a bandsaw using the bottom foam shuck to keep the cuts perpendicular to the wing. Sand the surfaces perfectly flat with a bar sander / 80 grit.

Cut the two hard balsa hingeline pieces to length and tape them together near the ends. Mark the hinge point positions. In a drill press, drill holes for the hinge points through both pieces at once. Remove the tape. Countersink the holes for the hinge points at the face of each piece. Bevel the hinge line pieces with a sanding bar or band saw. Use short pieces of appropriate-sized brass tubing in the hinge holes going into both pieces of hard balsa to keep the holes lined up. These pieces should be just short enough to not protude past the gluing surface of the hingeline pieces. Glue the hingeline pieces into place with Pica Gluit or other sandable aliphatic glue. If you use polyurethane glue here, some might seep into the holes you've created and could make the brass tubing 'locator pins' difficult to remove. I have found that the Gluit sands easier than the poly glue also. Tape the hingeline pieces to the flying surface / control surface carefully centering the hingeline vertically. Alternately you could use some hardpoints in the flying surface / control surface to increase the pull out strength but I feel this is overkill.

Once everything has cured, remove the brass tubing 'locator pins' and sand the hingeline pieces flush with the flying surface / control surface. Bore holes into the foam with a piece of sharpened brass tubing deep enough to allow installation of the hinge points. Cover the hingelines then create holes in the covering at the hinge holes with a soldering iron. Now you're 100% ready to install the hingepoints with polyurethane glue.

Though this method may sound difficult it is QUICK and very accurate. I'm sure that building the hingelines per instructions and using 'flat' style hinges (and the covering problems they create) takes at least three times longer if not more.

-Tom

Geistware

My Feedback: (16)

Use the robert pin hinges