Paint all the way. Oratex takes it quite well without primer.
1/4 scale Piper PA-22 Tripacer Restoration
- Thread starter willsonman
- Start date
Did you test-fit the wing struts with the aileron servos and pushrods mocked up? I ran into a problem after "fixing" a 1/4 scale Cub a few years back where the pushrod ran directly into the strut. The final fix wasn't too bad, but it did take some time.
The aileron servos are in the same bays as before so not issues there.
While I'm behind in my video uploads because... editing videos is not as productive as building... I've made some major progress on the front end of this bird.
The front support for the nose gear was saturated with fuel at some point and was not salvageable. With that, I decided to make the front end that would serve three purposes. I need a new support for the nose gear that is more robust, a motor mount, and a battery tray. I came up with this.
Everything was test fitted and I did build in a touch of right-thrust into the front wall. There is now ample room for batteries at the front and I can position them a bot more aft if the CG dictates it. I'll make a hatch in the top of the cowl for battery access.
I've epoxied in the structure and put in the motor and gear. I lopped off the corners as they would interfere with the cowl. The placement of the motor gives 1cm of clearance from the cowl to the base of the motor, The spinner should go backward about 5mm toward the cowl so there will be about a 5mm gap between the cowl and the rotating assembly. Plenty of clearance. The idea here is that the forces from the landing gear will transfer to the entire inner structure of the model, not just at the base. The firewall is TWO laminations of 1/4" ply with 1/4" ply sides for the transfer. This should be plenty stout enough for some rough landings and I also used beefier screws for the gear mount.
The front support for the nose gear was saturated with fuel at some point and was not salvageable. With that, I decided to make the front end that would serve three purposes. I need a new support for the nose gear that is more robust, a motor mount, and a battery tray. I came up with this.
Everything was test fitted and I did build in a touch of right-thrust into the front wall. There is now ample room for batteries at the front and I can position them a bot more aft if the CG dictates it. I'll make a hatch in the top of the cowl for battery access.
I've epoxied in the structure and put in the motor and gear. I lopped off the corners as they would interfere with the cowl. The placement of the motor gives 1cm of clearance from the cowl to the base of the motor, The spinner should go backward about 5mm toward the cowl so there will be about a 5mm gap between the cowl and the rotating assembly. Plenty of clearance. The idea here is that the forces from the landing gear will transfer to the entire inner structure of the model, not just at the base. The firewall is TWO laminations of 1/4" ply with 1/4" ply sides for the transfer. This should be plenty stout enough for some rough landings and I also used beefier screws for the gear mount.
Finally took time to edit some video footage:
The overall condition isn't too bad, at least compared to some of the stuff I've run into. You've probably already done it, but if not, dig deep into the firewall and make sure it's securely mounted to the rest of the plane. Especially if glow fuel has been used as that stuff softens wood and leaves a nasty slime that glue won't stick to well.
I've been temped to keep track of how many times I have to stop and say "WTF" on some projects.
I've been temped to keep track of how many times I have to stop and say "WTF" on some projects.
Yeah, the penetration of fuel was limited to the nose mount area. Everything else was as it should be. Truth be told, that footage is about a week old and I've been struggling with the front end all week, see post #25. I FINALLY got things sorted last night so I can finally proceed with things.
Was it gas or glow powered in the past? It's sometimes amusing to try and figure out how many different powerplants a plane has had based on the old holes.
I'm not entirely sure but I do know that the fuel that was left in the tank (about a half tank!) was black... does that help?
I'm not entirely sure but I do know that the fuel that was left in the tank (about a half tank!) was black... does that help?
I'm guessing glow then, also because it looks like there was a film of dirt like I've seen on glow planes. Plus it could have been the glow residue that softened the front end up like that.
Welcome to the world of rescue and restoration (the wing and most of the rest of the work was too easy up until now)! About this point you start to wonder WHY you volunteered for this gig, but it all pays off in the end. Your Piper tail gives me flashbacks to the Cessna 152 I did, although yours still doesn't appear that bad.
My assumption for that sheet under the horizontal stab is that it not only sets the incidence but also gives a solid vertical surface to attach covering to. I agree that cutting the surfaces loose of the fuselage is the best bet, as once the covering is removed you're going to find stuff to fix which will be far easier on a flat building board.
The heavy cowl may work to your advantage - the plane was designed for IC and electric will probably weigh less, even with the batteries. I wouldn't worry about it at this point, even if some nose or tail weight is needed for proper CoG it'll be minimal on a plane this size.
Your A-Pillar has about a bazillion holes in it, probably from attaching the rear edge of the windshield. I'm guessing you already have thought about this, but now is the perfect time to patch those up and to make sure the A and B pillars are structurally sound and attached well to the fuselage and wing. Some CF layered in wouldn't be a bad idea based on the age and general quality of the build.
My assumption for that sheet under the horizontal stab is that it not only sets the incidence but also gives a solid vertical surface to attach covering to. I agree that cutting the surfaces loose of the fuselage is the best bet, as once the covering is removed you're going to find stuff to fix which will be far easier on a flat building board.
The heavy cowl may work to your advantage - the plane was designed for IC and electric will probably weigh less, even with the batteries. I wouldn't worry about it at this point, even if some nose or tail weight is needed for proper CoG it'll be minimal on a plane this size.
Your A-Pillar has about a bazillion holes in it, probably from attaching the rear edge of the windshield. I'm guessing you already have thought about this, but now is the perfect time to patch those up and to make sure the A and B pillars are structurally sound and attached well to the fuselage and wing. Some CF layered in wouldn't be a bad idea based on the age and general quality of the build.
All good thoughts there. Yes, The a pillar will get filled with spackle and I'll drip some thin CA in it to make it nice and hard. I may lay some carbon tow over top but as-is it feels pretty good.
As an update over top of the video series, I've already disassembled the tail planes and uncovered them. Lots of WTH moments, especially in the rudder. Looks like the rudder was pieced back together after it reversed into a combine. I'm exaggerating of course but I was able to get things reinforced and corrected. The rudder, V-stab, and H-stab have all been re-covered with Oratex and the elevator is all that's left there.
For those endeavoring in these balsa-y waters... have a spare covering iron on-hand. My iron died mid-job and had to order a new one, despite my best efforts to repair. They are pretty cheap devices so having a spare will save you headache and aggravation WHEN it happens, not if.
As an update over top of the video series, I've already disassembled the tail planes and uncovered them. Lots of WTH moments, especially in the rudder. Looks like the rudder was pieced back together after it reversed into a combine. I'm exaggerating of course but I was able to get things reinforced and corrected. The rudder, V-stab, and H-stab have all been re-covered with Oratex and the elevator is all that's left there.
For those endeavoring in these balsa-y waters... have a spare covering iron on-hand. My iron died mid-job and had to order a new one, despite my best efforts to repair. They are pretty cheap devices so having a spare will save you headache and aggravation WHEN it happens, not if.
+1 on this. I normally try to have two irons, two trim irons, and two heat guns on-hand. They're cheap at swap meets, and they'll only fail when you're using 'em. I'm actually down to 1 heat gun and 1 iron now, as I haven't been to a swap meet to replace the ones that failed over the past 6 months.
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