HEY GUY'S
I just picked up a Mode Tech Saphir,what or how are you guy's, what mounting method are you using for the aileron to the wing, elevators to the stab?, from what I see is
that they are top hinged mounted

Thanks for the help

Jarvis,

yup, they're top mounted. I plan to use Robart hinge points drilled into the hinge line angled down forming an open "A" shape. I also plan to make mine electric powered with ~1700W on 6s.

Mine is a Saphir I with two pieces of glass: one to form the chin under the fuse and the other to form the wing belly pan. Of course, there is also the glass cowl. I'm thinking of painting the fuse and vertical along with the glass and wing center section and then cover the wing and stab outer panels.

Is yours a current build? I'd be interested in seeing your progress.

David

Think mine is the 2, it only has a belly pan and chin cowl, I'm going to go with glow, but all my 2 meter pattern planes a E-power, I wanted to use CA hings, do you do them the same way?
Just checked WS 70'' and fuse is 63'', if it was a kit that I had to build, then it would be e-powered, but it's a ARC, I picked it up at the swap meet at the AMA EXPO, this past weekend.

Jarvis,

yours does sound like the Saphir II. It was designed for a 120 4-stroke I believe. The bottom pan is a single piece - chin cowl and fuse bottom? If so, it is a II.

I don't recommend CA hinges on foam core surfaces (wing & stab), CA will eat the foam. There is foam safe CA but personally, I find it doesn't work that well. I also find that the design of the surfaces doesn't lend itself well to CA hinges but it could be done if you really want to. I just don't know how well the foam safe CA stuff holds on to the hinge material. One is supposed to use thin CA and foam safe ain't thin!

I'd suggest using poly glue or epoxy. You can use DuBro or Robart type hinges. If you haven't tried the hinge points, you might want to give them a try. It is very easy to install them and they are solid. It's a fairly large bird and the controls are not light which is also a reason why I prefer plastic hinges.

If you don't use hinge points but use flat hinges whether plastic or CA, install the hinge just under the sheeting of and along the top airfoil. I really can't see CA working though. Fine on the rudder though if you wish - it's solid balsa.

David

I have the Saphir II ARF from Modeltech, and it has separat cowling and bellypan. I used std. DuBro hinges. It's tricky to slot, but it worked out OK.
Pictures here: http://www.flickr.com/photos/aerowold/tags/saphir/

Jon,

It looks like you modified the hinge line to use center mounted hinges and a V-shape control LE. Were you able to do this simply by sanding the existing wood or did you have to add some?

David

Jarvis,

I knew a Jarvis Johnson who used to fly in the Kansas, Oklahoma, Texas area in the 90s. Any chance that's you?

David,

I've never worked on a Saphir II so I can't speak to that model in particular. However, I guess we're going to have to agree to disagree again on CA hinges. I've used CA hinges - I prefer Radio South 1/4 Scale hinges - on every pattern plane I built since the LA-1 in the mid-90s. I have found them to be the fastest, cleanest installation, and easiest to use hinges that provide the tightest hinge line gap when done correctly. They are also the easiest to repair when needed in my experience. Here's the technique I use.

- Mark the hinge lline on both fixed and movable surfaces.
- Cutslot with a #11 XActo blade just slightly longer than the width of the hinge itself but <span style="color: rgb(255, 0, 0);"><span style="font-size: larger;">NO WIDER THAT THE THICKNESS OF THE BLADE</span></span>. This will provide a SNUGfit for the hinges without excess gap. Do this on both fixed and movable surfaces.
- Position the hinges in one surface - I prefer the control surface itself.
- Run just a very small bead of thin CA right along the line where the hinge and surface meet. Do this on both sides and no more.
- After all hinges are glued into the control surface, assemble it to the adjoining surface. Start all hinges one at a time, then press the surfaces together as tightly as possible.
- Deflect and hold your control surface a bit farther than the maximum throw for the surface. If throw is supposed to be 1/4", deflect it 5/16" or so.
- Tack the outer two hinges with 1 drop of thin CA on the inner and out hinges. Another tack may be needed on long surfaces like ailerons.
- Run just a very small bead of thin CA right along the line where the hinge and surface meet. Do this on both sides and no more. Deflect the surface while doing this.
- Wait a minute or so and give the surface a good tug to be sure it's secure.
- Done.

This works for me and I have never had a hinge failure. Your mileage may vary.

Jim

I had a 60 sized Saphir back when they first came out (20+ years ago) (still have a SaphirII NIB). I used CA hinges on the stock surfaces (asymmetrical hinge line). There is plenty of wood for the hinges to adhere to, BUT you must make the hinge slots at a downward angle on both surfaces to provide lots of wood above and below the hinge. It is a good flying airplane (I had about 200 flights on mine when I sold it), however it was a bit overweight; in hindsight I wished I had powered mine with a YS 91AC. Someday, when I finish my SaphirII I will probably modify it for fixed gear.
Good luck with yours!
-Will

I'm glad to hear the CA hinges work on the MT Saphir's. I have nothing against CA hinges per se, my concern was more when used in conjunction with a foam core wing. Often there is a 1/4" TE thickness and large CA hinges will go deeper than this. If one slots past the wood and uses thin CA, it will penetrate the core melting the foam somewhat. Granted, given the amount of CA, it probably doesn't do too much harm.

I've seen thin hinges installed like Will describes in assymmetrical controls. Provided the sheeting is at least 2 mm thick, I've also seen them installed under the sheeting at the core/skin interface. Probably wouldn't work with CA type though given the lower surface is foam so Will's method is better.

I guess I'm just keen on hinge points but they do require a semicircular filing in the control to allow the control to butt up tight against the surface and pivot.

Will, when I get to mine, I plan to build it with e-power hoping it will alleviate the weight and size which is a little large for a 60. I'll bump up the power to ~1700W or more if possible on 6s. I believe John has an electric Saphir II conversion thread here. It appears to fly very well on and off the beach no less!

David

Mr Jim John
Yes indeed, I'm one of the same. It's been a long time, are you still flying pattern?, I got station in California, about 12 years ago. I miss flying back in Dist 6. But there are more
contest out west here. I'm flying in the Master Class, and the first contest this year is in 3 weeks, can wait.So what have you been up to ?

Sent you an email, Jarvis.

Hi, I've not modified it. Elevator and wing are top hinged as it came out of the box, using Dubro std. pinned hinges. Works like a charm for me [8D]