[smchale]

Originally Posted by Dutkoski

Attached is a concept drawing I whipped up, not to scale just some thoughts on the screen. Any constructive input is appreciated. I believe I can actually make these in the home workshop. I might even do the aluminum structure out of molded carbon fiber and that would make it a one piece frame work.

Cool project! On the retracts I'd suggest extending the pivot rod out past the strut and put it in some sort of bearing block to support it. There will be a lot of the force on that rod and a cantilever setup is prone to bending. Better to support the strut between to bearings. Years ago I built a couple P-51 mustangs from Brian Taylor dwgs and he used a cantilevered setup to get the pivot in the scale location near the wing LE and they were forever bending. I finally extended the shaft into a block in the LE and never had an issue. Of note, my bvm 80" Sabre retracts also have a similar pivot block for support.

[smchale]

Here is the retract unit for the Sabre.

[smchale]

Here is the retract bay, note the support plate in the trailing edge spar (in the Sabres case it's to move the strut rearward).

[smchale]

And here is the retract installed, note the extra support this gives the strut.
Hope this is helpful.

[Dutkoski]

That was my intention in regards to a support block, I have a friend whose hobby is machine work, has all the toys to do everything involving metal work. I've already "informed" him that he's been volunteered to do the machine work for me and he's quite interested. I have to make a plywood mock-up first and see how to make the darn strut twist during retraction and pull the two main wheels into position so they will fit into the wheel well. I think I'm going to put aside the fact that the strut also has to shrink about .375" but I do have an idea to make that happen. And it will be electric driven but I think it will have analog type micro switches instead of the computer type circuit board as I am not that great when it comes to electronics. However, if I can find a source for just the motor and electronics, I won't pass that up so long as it is reasonably priced.

This week I actually found time to work on the project, got the nose section fitted to the main fuselage and got it screwed in place. The canopy section was also fitted, had to sand off a lot of bondo to get it right. Now I have to do a final fitting adjustment, which requires more bondo being added . . . . . .

Once everything is fitted, I'll post a couple of pictures.

[Dutkoski]

So the plug is coming along pretty good, for those who wonder, from the tip of the nose data probe to the end of the tail cone stinger, the model will be 122.5" in length. I had to sand away quite a bit of bondo that I had put on top of the forward section after I had cut it off. I over estimated the thickness. But the canopy fits flush with the surface so all I now need to do is fatten up the top of the forward section by about 1/8" on either side so the fuselage and the canopy will blend properly. All in all, it's working out really well. The master fuselage plug for the 90 mm EDF Arrow is on the bench at the right, quite a different in size.

Since I have it already made, I might use the vertical fin that I made back in the 1990's when I started the project. Still seems to be in very good condition, structure wise.....it's straight and no de-laminating that I can see. Cannot remember if I used any carbon in it though for where the spars will go. Maybe best to make a new one.

Would be kinda nice if I could get a copy flying this coming season, it's possible as the wings will be foam cores.

[thedeuce]

Looks great John

[DarthAnal]

John, the retract sequence and the gear structure is covered in the original Arrow book (Arrowheads, Boston Mills Press, 1980) page 176. The sidee and back stay provided the twist action during the cycle so that the main shaft rotated enough to bring the boggie into the right position to be flat in the wing. A chain that ran down the inside of the shaft and passed over the trunion block (pivot point) provided the pull needed to compress the gas shock sufficient to shorten the gear the needed length.

That's why the stock landing gear setup didn't work in Arrow models -- the boggie was off angle and the gear hit the fuselage. Not sure what Sammy is doing for his version but I think that MADDOG (Brad) or "Mike Emilio" should be able to tell you what they did for their verions.

Thread for that one is https://www.rccanada.ca/rccforum/show...ght=Avro+ARROW
Post 353 for first flight and settings.

You Tube

You Tube

[Dutkoski]

I have the CG set on both my pusher and my EDF Arrow set at just forward of the dog tooth, about 22% - 21% and that seems to work really nice. The elevator is set so there is lots of movement but I have the expo set at 75% which tames the model down but give me lots of control at the slower speed when needed, same with the ailerons. I tried to use the same total throws as shown on the scale drawings. I'll be transferring these over to this one when the time comes.

As far as the main struts are concerned, well, I'm going to give it a shot, went to Busy Bee today and looked at some small metal lathes and a small milling machine that will do the trick if my machine shop buddy is too busy to help out. They own a cottage and spend a lot of time near Huntsville and I don't like relying on others to help out when I'm on a time line. It never seems to work out.

Right now the plug is on it's back so I can get the rear portion sculpted and fashion those two large vents on the bottom.

[thedeuce]

John,

I'm thinking you might know of Doug Hyslip? The one who made the models for the movie? I'm sure if you have questions regarding any issues you come across you could contact him with questions. He has been through it all.

www.actionhobby.ca

cheers