On to the wing...

I set up my adjustojig to build this wing... First problem... the wing is too wide for it if I built the ADM5 version. By doing the rounded tip A6M3, I could have fit it, but I am ornery... and wanted the A6M3, but not with a 6" solid balsa wing tip...

After studying things a bit, I realized it was possible to simply extend the 5/32" jig rods beyond the outer limit of the jig for the outside ribs. This seemed to work out OK. The second picture shows more clearly how the oustide ribs extend beyond the jig. With this setup, I sacrificed being able to completely invert the wing on the jig, but it worked out fine.

To do this, however, I had to figure out a way to support the center rib without the rods, so I glued on a jig that fit neatly into the adjusto jig's center slot. Looking back on this, I think it would have been smarter to get longer rods because at one point in the build, I realized that the center rib was slightly misalligned, which reguired some sawing a regluing, regrettably.

Dave's plan calls for building each half of the wing at a time on the plan using a piece of balsa to raise the trailing edges to the right washout height.

It tooka while to settle on where to drill the jig rod holes to allign things according to plan, and it also took awhile to figure out what dihidral to set up on the jig (forced me to recal some junior high geometry) since the hight at rib 11 on the plan is <u>the height above the plan plane to the bottom of the rib</u>. On the Adjustojig, I needed to figure the equivelent heights based on the "jig dowel points" which are not at the bottom of the rib... this confused me for a while... it took a couple extra days of thinking time to figure it out.

Picture 4 shows the ply/basla dihidral brace with the pencil marks I drew to maintain sanity...

I decided to install the optional flaps. They are not needed for flying, but I think they look really cool....

Here's a sequence of making them. I found that cutting a template and then using a light spray paint mist to mark for ribs and voids saved me some time (it's a "labor of love" right...)

The humidity this summer was very high, as can be seen by the warp in my balsa when I got home the next night to add the ribs to the flaps. But no worries... that's what ribs are for, right?

The final picture shows me cutting out the 1/64" ply "top" piece. When those flaps drop, this bird will look realy nice from the rear! Thanks for a terrific plan Dave Platt!

Here's one more of the flap toppping and then installing the 1/4" brass contol/hinge.

I toyed with using a CF or alluminum tube instead of brass to save some weight behind the cg, but in the end decided to follow Dave's plan. I figured it was important since he clearly wrote "braised, not soldered" on the plan (and I don't have a mig welder). It will certainly be rugged! I'm using a high-torque HS-645MG Ultra Torque servo to activate the flaps:

Here's all the servos I'm using:
<h2><span class="mw-headline" id="Platt_80.22_A6M_Zero">Platt 80" A6M Zero</span></h2><ul>[*]Flaps: HS-645MG Ultra Torque (32645S)[*]Aileron: Hitec HS-625HB (32625S)[*]Rudder: Hitec HS-635HB (33635S)[*]Elevator: Hitec HS-635HB (33635S)[*]Throttle: HS-81MG Sub Micro (31081S)[*]Drop Tank:GWS "el cheapo"[*]Main Gear (air switch): HS-81 Sub Micro (31081S)[*]Tail Gear (mechanical): HS-75BB Low Profile Retract (31075S)[/list]

Resonding to Numblock's question:

<span style="color: rgb(0, 0, 255);">"How large of a wing will the A-Justo-Jig accommodate? And was there a jig included for the holes you drilled into the ribs?

Thanks,

Bob I. <span class="info"> </span> "</span>

Hi Bob,

The Platt Zero has just barely under an 80" wingspan. With the A6M3 wingtips option built as per plan, it will just fit the jig. I wanted the A6M3, but decided not to use such a large solid wingtip, so I extended the jig's rods out a couple inches beyond the jig to hold a last rib #11 per the A6M5 square tip version, but I trimmed it down to the A6M3 profile with a much smaller wingtip block that way.

A-justo-jig rod holes: The plan does not provde drill points for a-justo-jig rod holes. I picked a location that would allow me to use one of the rod holes for the aileron control after I pulled out the rods. This worked great.

I also had to cut two of the jig's rib braces in half so I could remove it with the wing still on the jig where the aileron control horn support goes. I had to do this so I could mount the horn before covering the top of the wing. I made a 1/8" ply plate that fit inside the jig profile and screwwed it together. This turned out to be a neat idea I think... (if they remake a-justo-jigs, as I have seen talk on other forums, this would be a neat standard feature to allow removal of some ribs early...

I hope these pictures make sense after reading this... (grin)

PS. I just found some earlier photos I made when I was figuring out where to drill...

Finished sheeting the wings tonight. I'm fitting it to the fuse now. I'll take some pix tomorrow night and adit them into this post!

Great thread, thanks for taking the time. Looking forward to more.

Hollow the wingtip block out.....I've done that on many planes.

Total awesomeness!

Questions...

1. Will you be glassing it?
2. Have a spray gun? I do if you want to borrow it.
3. Have you considered electrifying your pneumatic retracts via "Down and Locked" ? I think it was about $375 for a pair of mains.
I did this for my latest project if you want to stop by and take a look. Yeah..another expense but no more worries about the retracts failing.
4. There is the NVRC Auction on 10/22 in Fairfax (I think)...you going?

Bob I.

Bob,

Thanks for the encouragement. I am planning to glass it. I have a roll of 1/4 oz. I'm at that stage where you just have to grunt through the sanding and filling...

I did some glass work today making the retract covers. Here's some shots of how it went. I used two layers of 3M matt, one layer of CF weave, sandwitched between two layers of 3M weave (feels like about 6oz). I was surprised that my polypropeline plastic stuck to the layup, it was supposed to peel right off. I guess it made a mechanical bond. I should get some proper film.

They still turned out pretty good, and the thickness feels about right (about 1/8" to 3/16"). The CF strip really stiffened the narrow part nicely the wheel covers should be rock solid with no buffeting.

One thing, I'm leaning toward a steel 1/4" wing pin instead aluminum - I know that aluminum is stronger than the wood it's glued into, but the steel just seems safer. What do you think?

P.S. Yes, I'm going to the auction. Last year's was great, and that's where I got the Zenoah G38 for this zero! I'm sure I'll leave much poorer than when I arrive (grin)!

Wingtips came out good. I hollwed them out a little bit as recommeneded by sebo.

I'm kinda bored with sanding... I think I'll take a break from sanding (need to work up some steam to get it done and glassed).

In the mean time I may work on the drop tank for a bit. Has anyone done a drop tank that worked right? Any pictures? I have a glass tank in two halves (you can just see it in this picture...)

Got a little time this week to work on the Zero. Built the drop tank and started on the wing fairings using the "green florist's foam" technique I found in other RCU posts. This stuff is light and easy to work with but dusty! I'm going to shape it and then fill and glass it.

This is a fantastic build thread....Keep up the great work....
It takes a great deal of effort to do a build thread....I know.
You give a person great incentive. Thanks.....

Made some progress on the Landing gear.

I found a pair of Robart RoboStruts on eBay made for the Top Flite Giant P-51 (ROB675L and R). These have 1/2" shafts and fit my Platt retracts perfectly. This allows me to mount them as per Dave's plan so they are closer to perpendicular to the wing when extended. They are not perfectly scale. but much better than the simple oleo strut I already had.

I had already mounted the straight-strut retracts with a tapered spacer to keep the wheels from retract into the wing too far (crunch!)... and I was also going to have to jigger the door covers. I found a picture that kind of shows this (see the last shot).

It was bugging me too much... so $84 later, here's the result, and I am much happier with this setup (as long as no one is keeping track of cost overruns...)

When I replaced the old struts, I also had to shift the entire assembly about 1/2" closer to center for the wheels to retract into the right place. This required redrilling the mounting holes and gluing in new blind nuts but now the nuts can "snug-up" straight into the mounting wood since the bolts are going straight through less chance of stripping screws.

I included a picture of a terrific plastic model I found online that shows the landing gear well.

I'm working on a cowl and battery mounting solution.

Dave's plan has a box installed just below the glow engine to place the battery weight as far forward as possible. I will follow this principle, however, my box needs to be above the gas engine (grin). I am planning to use a decent battery, and would rather have useful weight rather than lead ballast...

I am wondering if it would be a bad idea to put the receiver here since it would be so close to the magneto... I'm thinking if I do that, I'll need to line the bottom of my box with foil.

Any feedback?

I'm also wondering if I can make the cowl open in a scale-looking way for access to this area for charging, air-tank refilling, and refueling....

In any case, The cowl will be attached to mount points along the bottom of the box and at points on the first fuselage former.

I was planning to incude air-deflectors as shown to force the airflow down past the muffler and out the cowl bottom.

For the top of the box, I am thinking 1/64 ply, or even aluminum sheet from a large beer can (probably Fosters - grin). I should have planty of lattitude weight-wise.

I was looking through my build pics and saw a few other cool ones to post... in no particular order.

hey skip can u help me i still need moldings for the tail and gun hood and cowl and i dont have a canopy eithier. your thread is very helpfull i worked a little on my zero that i am scratch building and got a good ways of it built before i stoped so i could complete my shrike. please keep posting pictures and i will post some pictures of my zero. oh i also dont have a engine and i will b using a glo engine so if you are interested in selling yours let me know...

Got some time today to get down to business with some sand paper! Was an awesome day, with several WW2 and Korean War aircraft regularly buzzing my house while the nearby airport hosted an air show.

Here's one shot of a DC2 passing directly overhead!

I really liked having so much room out on the deck in the fresh air to do the pre-glassing sanding.

One thing that is bothering me a little... take a look at the port flap... the upper skin has slightly warped away from the flap edge. I used 1/8" x 1" basswood (rather than balsa) at the trailing edge, but it seems to have warped a tiny bit. I'm thinking that I'll need some way to stiffen it and straighten it begore glassin0.? Anyone dealt with this before?

I'm wondering if some 1/64" ply strips under the trailing edge, where the flap will close over them, or should I do some glassing under the trailing edge and clamp the edge to teh flap to cure straight...

Hi Bryan,
I was able to get a hood, canopy and cowl from Dave's site. It seemed like he had more. You should email him, he's [email protected].

Good luck!

-Skip<br type="_moz" />

I've been able to spend a little time on my zero lately! Here you can see the exta hinge I have to add to the inner gear door to allow it to open all the way when carying the drop tank.

I included a picture from a museam which I used for my guide.<br type="_moz" />

Got tyje wing glassed and am in process of finishing it..

After you sand the primer down as you have, do you give it one more coat to cover the wood that is showing?
I'm espeacially concerned because I am shooting white paint....Thanks, Ron

Hi Ron,

There's a few more steps before that, but yes. The last primer coat will be fully opaque. It will get a wet sanding with 400 grit, and then I'll paint it with rustoleum aluminum. And then a thin coat of the the war colors (I still havent decided if it will be green or white), which I'll weather a little bit, to let the silver show through in just a few places. I little bit of that treatment goes a long way, and regular hangar-rash will do more "weathering" for me over time.

I have all the materiels to build a second one later after I have some time with this one. That one will get the benefit of all the ideas I had on this one, but too late. Grin.

Before those steps, however, I'm going to tape some panel lines and primer it to set them. Then I'll pull the tape and do some "rivet" marks. It's amazing how cool those panel lines and rivets look on the final plane.

One other option I have, is FlightMetal. I was just given a spool by a friend to try, and I may do so on this plane. If I use that, then I'll probably just do one more coat and wet sand it before the flight metal...

Thanks, that's good information. I'll probably skip the aluminum paint. Mine is a civilian aircraft and they don't get the abuse that warbirds got.
I really appreciate your response.......Ron

What brand retracts are you using? I see you are using Robart struts but can't find any where that you mention whose retracts they are. I built one of these years ago with Dave Platt retracts and had nothing trouble with them. He may have improved them over the years but just wanted to give you a word of caution. The plane flies like it is on rails, you couldn't ask for a better flying war bird. With the wide stance gear it is good on the ground too.

I have Dave Platt retracts in a Lancair that I am building.....Hope they fare me well.
Had them In a Dave Platt Spitfire that I never had the chance to fly.....Sebo. They worked well on the bench.