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This thread is privately moderated by pmullen503, who may elect to delete unwanted replies.
Mar 08, 2018, 08:57 AM
Registered User
Sheeting.

I've been working on the sheeting. The EDF ducts were a challenge. I first tried one big sheet of balsa but there was no way to clamp it without distorting the duct so I decided to plank it.

I made a template of the shape then taped together the planks and transferred the shape to the planks. After cutting, I taped the inside surface with 1/8" strips of packing tape to hold the planks together and allow them to follow the contour of the duct. I removed the tape from the top side. After final fitting, I glued the taped planks to the duct with canopy glue. This gave me the smallest possible diameter of the duct.

I added a laser cut plywood ring to stiffen the end of the ducts. I'll need to make a tail cone ring to finish it off. The duct ends are pretty fragile at this stage. That will be either bent plywood or maybe I'll make a mold and do them with CF/fiberglass.
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Mar 15, 2018, 08:27 AM
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Gear Doors

The main gear doors have a subtle curve. While the mount will easily take this curve, the door reverts to flat once it's cut free leaving an unacceptable gap.

So I made the door plate from two layers of 1/32" ply. First I cut the outline from two pieces of 1/32" ply, epoxied them together and screwed them into place. Once the epoxy cured I had a nice curved blank. Then I partially cut the doors, mounted the pin and tube hinge as shown in Ian's plans along with the horn and servo mount. Then I cut the door free. It worked perfectly with free motion and a tight gap. The nice thing is that the servo and door are both mounted on the removable plate so it's easy to set up and service.

The rear part off the doors will be attached to the gear leg and open and close with it.
Mar 16, 2018, 10:52 AM
Registered User
Nice work & progress, Pat!

Phil
Mar 16, 2018, 11:27 AM
Registered User
Hey Phil,

When you coming back?
Mar 16, 2018, 12:33 PM
Pro Hoarder
turbonut's Avatar
Great work ..Between you guys and karl the Vulcan should be well sorted out by the time I start on mine...
Latest blog entry: In flight
Mar 16, 2018, 01:32 PM
Registered User
That's true, having Karl posting his progress has been invaluable to me. And building the 2 planes as we have also has helped sort a lot of things out.

As good as Ian's plans are there is still many details to work out.
May 18, 2018, 01:35 PM
Registered User
Got the nose and tail shaped and Styrosprayed. I ended remaking them completely with 6mm foam replacing the balsa cruciform. Just to difficult to get a fair curve with the balsa against the foam.

Fitting the removable rudder to the tail cone . Once that's done I can glass the center section.
May 21, 2018, 03:42 PM
Registered User
Finally to the point where I can glass the center part of the plane. The Styrosprayed tail was glued on and the fiberglass extended past the joint. That will be sanded flush with the rest of the tail cone.

After glassing the top I cut the battery hatch out. The edges of the cut planking are reinforced with more 1/8" balsa. I colored the freshly cut edges of the hatch and fuse cut out with black magic marker. That way I can plane the freshly added 1/8" balsa reinforcement strips flush with the cut edge. When the black on the cut edge starts to disappear, I know it time to stop.

The small rudder fairing was glued on as well.
May 23, 2018, 05:43 PM
Pro Hoarder
turbonut's Avatar
Very Nice...nothin like a balsa lumber yard
Latest blog entry: In flight
Jun 11, 2018, 10:29 AM
Registered User

rudder servo


Mounting the rudder servo.

I wanted to put the nose gear steering servo on the same channel as the rudder but I had already planked the fuselage and thus couldn't check to make sure what direction is was working so I wasn't sure what side of the rudder servo needed to be on so it would match. That meant I would have to add the servo mount after the rudder was already sheeted.

I cut a hole for the servo and then glued in the mount to the skin. A pedestal of foam was glued to the opposite side to support the bottom of the servo. I'll secure the servo to the foam block with double sided tape and a little hot glue around the perimeter.
Jun 11, 2018, 10:34 AM
Registered User
Nose gear doors

I decided to make the nose gear doors from fiberglass rather than trying to use the fuselage cut out. I laid up a door blank from 2 layers of 2 oz and 2 layers of 6 oz. cloth. I covered the fuse with plastic, laid down the glass and epoxy, then another layer of plastic and a cardboard caul and lots of sandbags. The blank turned out good with only a couple small bubbles to fill.
Jun 14, 2018, 05:04 PM
Registered User
Nose gear doors cont.

Make the cutout in the fuselage and trim the blank to fit. I partially cut the door blank in half. Gear door hinges were glued into place. To keep them aligned, I removed the screws that hold the hinges together and inserted a rod through the holes, forcing the hinges to be aligned. I glued the part that is attached to the fuselage first. After adding the rest of the hinges, I taped the door blank in place with sticks to hold it level. Then I glued the door part of the hinge to the door blank. When the glue set, I cut the doors apart.

The center line is perfect but I had to sand the side gaps more than I would have liked to get the doors to open fully.
Jun 14, 2018, 05:27 PM
Registered User
Covering the outer wings.

The outer wings are covered in kraft paper and WBPU. First I added 1/16" false ribs to the root so I could fit it to the fuselage. Put the wings into place and slide a piece of sandpaper between the wing and fuselage and sand the high spots until no gap shows.

1. mist water onto the precut paper to get it to relax. It will expand so pick up the corners and make lay flat again.

2. Brush on a liberal coat of WBPU. Also brush on a good coat of WBPU onto the wing.

3. Place the wing onto the wet paper and start to adhere the LE.

4. Now turn over the wing with paper stuck to it and stick down the rest of the paper.

5. Chase any bubbles out by lifting a corner and working the paper down from the middle out.

6. When the bubbles are gone, trim any excess to about 1.5 times the thickness of that edge.

7. Cover the other side.

8. Stick the excess from the top and bottom together and tuck and roll the excess so the paper is snug to the top and bottom. Put a small binder clip to hold the paper while it dries. Work your way around until all the edges are snug. (The paper it overlapped at the LE so clips aren't needed.)

9. Give the entire wing a final coat of WBPU. The goal is to wet everything evenly. Avoid getting it too wet.

10. Hang it vertically in still air and let it dry overnight.
Jun 14, 2018, 09:16 PM
Registered User
KarlHeinz57's Avatar
Quote:
Originally Posted by pmullen503
The center line is perfect but I had to sand the side gaps more than I would have liked to get the doors to open fully.
I have a supply of the same type of hinge and would have loved to use them except for the same problem you encountered. The thicker the material, the more of a gap you have to leave.

Someone very kindly educated me to the fact that the needed gap was a function of how close to the outer surface the pivot point was. As a result, I used pin hinges flush with the surface to get a nice tight gap. It may not be ideal but in my case it worked well. Of course, it's a bit late to be sharing this now. Sorry.


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