Author Topic: Build threads look fun (Read 80702 times)

Dave_Trible · « **Reply #254 on:** November 25, 2013, 07:23:15 PM »

A few frames tonight....I cut plywood bulkheads for behind the fuel tank compartment and epoxied them in position.

Dave_Trible · « **Reply #255 on:** November 25, 2013, 07:27:43 PM »

I've drilled accurate holes through the fuselage sides to receive 1/16 music wire pins which will help locate the motor mount block. Epoxy is applied and the motor block is inserted between the sides and made to rest on the wire pins. This assembly is blocked and clamped in square alignment and allowed to cure.

Dave_Trible · « **Reply #256 on:** November 25, 2013, 07:30:45 PM »

In the morning after the epoxy is really solid I'll twist the pins out and start cutting the rest of the bulkheads. If it all goes well we'll have two completed fuselage boxes but tomorrow evening.

Dave_Trible · « **Reply #257 on:** November 26, 2013, 01:01:22 PM »

Bulkheads drawn out on 3/32 soft wood.

Dave_Trible · « **Reply #258 on:** November 26, 2013, 01:05:02 PM »

Any method to get a straight fuselage is a good one. I have drawn a center line down on the work surface and centerlines on all bulkheads. I am blocking, pinning and whatever it takes to get the sides in the right position.

Dave_Trible · « **Reply #259 on:** November 26, 2013, 01:05:44 PM »

Dave_Trible · « **Reply #260 on:** November 26, 2013, 04:44:34 PM »

We've got the bulkheads in. I use webbing between sides and bulkheads to eliminate fuselage twisting. I'll put in a little of that to help hold things in shape until final assembly but can't do it all as long as we still need to glue inside joints and hook up the controls.

Dave_Trible · « **Reply #261 on:** November 26, 2013, 04:50:20 PM »

In the process of pinning the bulkheads in I cracked a couple of them along the grain so I put a cross- grain doubler on each to give them a little more stability across the fuse. A heavy handed pit man could crush these while launching.

Dave_Trible · « **Reply #262 on:** November 26, 2013, 06:57:26 PM »

john e. holliday · « **Reply #263 on:** November 27, 2013, 12:34:01 PM »

Well see if I pick up your plane again. I know I'm club fisted.

I do the cross piece of balsa on all formers made of vertical grain balsa. Started cutting riblets for my next project yesterday. This exercising is getting me. But, hope to get in better shape.

Dave_Trible · « **Reply #264 on:** November 28, 2013, 06:50:28 PM »

What? More flaps? Well this is just about exactly the point where I left off with the regular size Desperado set aside to build the larger ones. I've decided to pull it right along with the other two. Finishing three airplanes at once will be a challenge but there is some chance I may have to give up my workshop space for a while in a couple months so ....

Dave_Trible · « **Reply #265 on:** November 29, 2013, 09:37:33 AM »

It's time to join the wings with a fuselage. Since I choose to put my landing gear permanently in the wing as well as mount the flaps, the bottom of fuse gets cut. Wish I didn't need to do that but it's the least of the evils and goes right back nicely with doublers inside.

Dave_Trible · « **Reply #266 on:** November 29, 2013, 09:39:35 AM »

The wing is blocked up perfectly level using the alignment block and incidence meter.

Dave_Trible · « **Reply #267 on:** November 29, 2013, 09:44:03 AM »

The fuselage is put on and then I go through whatever contortions are required to get it aligned in the horizontal plain, perpendicular to the wing trailing edge. When I've got that pinned in place I then put the incidence meter on the motor mount block to get it in line with the wing centerline, shimming as required.

Dave_Trible · « **Reply #268 on:** November 29, 2013, 09:45:11 AM »

Well, I like it! Dabs of epoxy inside to lock it in.

Dave_Trible · « **Reply #269 on:** December 01, 2013, 08:43:36 PM »

Really slow... A little better work schedule next week so maybe we'll make more progress. The wings are in the two big birds and now I need to put the bottom cut outs back. Somehow I always have to trim these a little to fit right. The wing always seem to be about 1/16" thicker than the drawings allow for. I tack glue some scraps as alignment tabs on the pieces.

Dave_Trible · « **Reply #270 on:** December 01, 2013, 08:45:36 PM »

These are glued with a light dab of epoxy.

Dave_Trible · « **Reply #271 on:** December 01, 2013, 08:51:48 PM »

You can see the balsa patterns I made for cutting 1/16" plywood doublers. Didn't mention I traced these off the side earlier before putting the wing in. The doublers are epoxied and clamped to cure. Tomorrow I'll glue inside all around the wing continuous and start getting the small ship caught up to this point. Need to finish the flaps and get them mounted on the wing. The fuse is ready to fit the wing.

MarcusCordeiro · « **Reply #272 on:** December 02, 2013, 04:46:55 PM »

Very nice Dave!!!!

Marcus

Dave_Trible · « **Reply #273 on:** December 03, 2013, 07:41:56 AM »

Thanks Marcus. Looks like the weather might give me chance to get a few flights today- hooray!!!!

Dave_Trible · « **Reply #274 on:** December 03, 2013, 12:15:21 PM »

Moments ago... Straining at the leash.... The FP.40.... Three patterns in so far.... Better N home grown maters!

Dave_Trible · « **Reply #275 on:** December 03, 2013, 12:19:42 PM »

FP at 8700 rpm, 11-5 APC, 60' lines, about 5.3 laps, 3.5 ounces fuel for 7 min.

Dave_Trible · « **Reply #276 on:** December 03, 2013, 01:08:17 PM »

Six in and need to call it a day. The forecast tells me it might not break 40 degrees for the next six weeks. The FP seems to like my classic fuel 10/29 a little better than my pipe fuel 15/23.

john e. holliday · « **Reply #277 on:** December 04, 2013, 11:04:05 AM »

I knew I should have come by the field. Was on the way home from theropy and thought about driving by. Still had the planes in the old Ford. Need to see the plane in person.

Dave_Trible · « **Reply #278 on:** December 04, 2013, 12:45:29 PM »

John I wish you did. Last great weather day for a while I guess, but I'm ready in case.

Dave_Trible · « **Reply #279 on:** December 05, 2013, 01:34:06 PM »

Go Sukhoi at the Aussie Nats Mr. Batty!!!!

Dave_Trible · « **Reply #280 on:** December 06, 2013, 09:24:40 PM »

Thought this was interesting. Here I have the regular Desperado wing on the right with the new 105% version on the left. You can see the difference. The weight difference between the two wings with landing gear, flaps etc., is two ounces. Doesn't sound like much given the size difference.

Dave_Trible · « **Reply #281 on:** December 07, 2013, 11:58:18 AM »

Got the wing in the smaller plane. I'm using 1/4" plywood 'bearings' for the flap horns, epoxied to the fuse sides. Takes the strain off the hinges and greatly extends the life of the airplane.

Dave_Trible · « **Reply #282 on:** December 07, 2013, 04:39:01 PM »

This evening we are mounting the stabilizers. First I fit the rear section of pushrod with a wheel collar.

Dave_Trible · « **Reply #283 on:** December 07, 2013, 04:42:12 PM »

I do the rear pushrods (3/32" mw) in two parts which are soldered together, the only solder joint in the whole system. This allows me to set perfect level on both flaps and elevator, then solder the pushrods.

Dave_Trible · « **Reply #284 on:** December 07, 2013, 04:45:17 PM »

I'm setting the stab square three ways. Here I've made a tool to get both stab tips at the hinge line equadistant from the flap hinge line. When it there it's pinned so as not to move.

Dave_Trible · « **Reply #285 on:** December 07, 2013, 04:46:42 PM »

Now I'm going back to my level reference block to get the airplane set level.

Dave_Trible · « **Reply #286 on:** December 07, 2013, 04:49:43 PM »

The incidence meter is set on the stab so I can adjust it to 0-0 degrees. I know some are using a little positive incidence here. I'm not quite there with that yet.

Dave_Trible · « **Reply #287 on:** December 07, 2013, 04:51:50 PM »

Now I'm trusting my calibrated eyeballs to get the stab parallel with the wing in this rear view.

Dave_Trible · « **Reply #288 on:** December 07, 2013, 04:56:11 PM »

After messing with that I want to check this once more then mix a little 5 minute epoxy to spot on a couple places on the outside where the stab and fuse meet underneath. This is very lightly done. After I finish the fuselage it's possible there might be a little twist and I like to be able the crack it loose and reset if need be the get it straight. This is absolutely critical!

Dave_Trible · « **Reply #289 on:** December 08, 2013, 09:12:56 AM »

While in my waking stupor before coffee this morning I had a revelation about a new look for the airplane. Think I'll keep the 105s the same but give the new look and maybe a new name to the regular sized ship. Going to be really pushing to get these done ASAP. Have a daughter and grandson moving back home from Florida in Feb or March and have to give up the workspace for a while. Think I can keep a work table and the scroll saw up in my bedroom but larger projects will have to wait. Maybe I'll do some smaller old time stuff I've got on the back burner. Life evolves.

Dave_Trible · « **Reply #290 on:** December 09, 2013, 10:46:38 AM »

The goal for today is to get the controls hooked up on all three airplanes. I first get the ship leveled going back again to the level reference block.

Dave_Trible · « **Reply #291 on:** December 09, 2013, 10:48:27 AM »

Now I put the beam back on the meter and span the wing and the flaps looking to get this level.

Dave_Trible · « **Reply #292 on:** December 09, 2013, 10:50:20 AM »

Here you see the balsa block used to hold the flaps in place once level is achieved.

Dave_Trible · « **Reply #293 on:** December 09, 2013, 10:51:26 AM »

The elevators are locked in neutral position.

Dave_Trible · « **Reply #294 on:** December 09, 2013, 10:53:31 AM »

These are pushrod fair leads made up from 1/16" plywood. I'll use two on each airplane- one fore and one aft of the pushrod joint.

Dave_Trible · « **Reply #295 on:** December 09, 2013, 10:55:45 AM »

These will dangle on the 3/32" music wire pushrod until after everything is connected, then glued to the bulkhead. This prevents pushrod flex.

Dave_Trible · « **Reply #296 on:** December 09, 2013, 10:57:51 AM »

Here the pushrods are being wrapped with fine brass wire. This will be soldered with resin core.

Dave_Trible · « **Reply #297 on:** December 09, 2013, 10:59:41 AM »

Here the forward end is retained with a wheel collar. These will get some JB weld to prevent vibration from loosening them down the road.

Dave_Trible · « **Reply #298 on:** December 10, 2013, 09:07:09 PM »

Tonight I did the epoxy all around the wing to fuselage joint inside. I prefer to get no epoxy outside because dope doesn't stick very well to it and will blister pretty easy off it. I am looking at the soon-to- be pipe area.

Dave_Trible · « **Reply #299 on:** December 10, 2013, 09:08:00 PM »