pcastine

My Feedback: (8)

I received my 42% Aerotech Yak kit and wanted to post my pics and thoughts here as I build it. I'll probably end up posting more questions than answers, but hopefully this will be helpful for others. I know that there's another extensive thread already here on a Yak build, but everyone has there own issues, opinions and tips when they build so it should be worth another thread anyway.

Three giant boxes showed up on my doorstep just after Christmas (they wouldn't have fit under the tree anyway). One box was mostly foam, with the wing & stab cores, and some wood. The other box had foam for the fuse, and more wood. The third box was just the canopy and some other misc. parts.

Unfortunately, upon unpacking I discovered that a number of parts were missing from the kit. This was pretty frustrating, but an email to John at Aerotech yielded another box on my doorstep the next morning. So while it was disappointing, the customer service response was excellent!

Also, some of the wood was less than perfect, as you can see by looking at the balsa sheeting. Additionally, the sheeting was not trued, so this took me an hour or so to true up the sheets before I could start the wing skins.

pcastine

My Feedback: (8)

I used Elmer's carpenter glue to put the sheeting together. First was to lay the sheeting on a flat surface, and scarf joint the sheets together to get the length required for the wing. You need to do this for four sheets for each side of each wing panel (so a total of 16) extended length sheets.

After the panels were glued and taped, I put some magazines on them to hold them flat on the board.

pcastine

My Feedback: (8)

While waiting for this stuff to dry, I started on the fuse. The laser parts look great. One of the things you need to do with laser cut parts though is to sand off the "laserburn" so you can get a good glue joint. I found a popsicle stick with sand paper was just perfect for the former cutouts for the stringers.

pcastine

My Feedback: (8)

The motor box/wing tube structure forms up quickly and pretty easily. I found that a few of the ply parts were slightly bowed, but this shouldn't matter as you can straighten them as you glue the stringers in. Also, this plane has a really beefy gear plate structure. You could probably reduce some weight here by swiss-cheesing the parts, but then you'd have to be sure that EVERY landing you made was PERFECT! You can see that the fuse formers have been already swiss-cheesed with the laser, this looks cool and definitely helps to reduce weight as well.

pcastine

My Feedback: (8)

Now I'm scarfing together the bass wood stringers to get the length of the fuse. It's a little wierd, because the scarf joint on the plans is right where the side of the fuse starts to angle in toward the tail. So when you cut the joint, it can't be a straight scarf joint; you've got to take into account the angle of the fuse as well. I think I'll probably laminate some 1/32 ply to the joint just to be sure it won't fail.

Well, that's it for now, back to the shop!

rcnutmd

My Feedback: (2)

ha pete cant wait to see your new yak this season . i will be watching your thread they look to be real nice planes when there finished . well good luck with the build. john morisi

pcastine

My Feedback: (8)

More work on the fuse. Had a couple of issues. First, the wing socket caps didn't fit on the fuse. First the cap was too wide to fit through the slot in former F-3, so I had to cut a small notch in it to get it to fit. I thought maybe I hadn't lined it up correctly, but it lined up perfectly with the wing tube. Anyone else have this issue?

The other issue with the socket cap was that the front of it didn't mate up to former F-2. The reason for this was because F-2 was bowed, so I had to bend it straight to meet the wing cap. After bending it, it lined up perfectly with the plans to be square.

pcastine

My Feedback: (8)

The other issue I had tonight was with ST-1 plate, which is in the tail of the fuse. I'm presuming that it just glues between the bass wood top stringer, and the balsa bottom stringer (at least that's the way it looks on the plans). I thought it would be better to glue this in place before the fuse sheeting.

But with the plate resting on the bottom stringer (the bass wood one) the plate appears to be about 4mm (1/4") too wide to fit between the stringers. Do I shave some off the plate, or do I notch out one of the stringers so it will fit? Not sure what to do here, because if I change the positioning of the plate, that would change the location of the stabs. Maybe 4mm isn't enough to worry about?

pcastine

My Feedback: (8)

Well this is the fuse after tonight's building session!

RobT

My Feedback: (17)

Starting to look good Pete. I wish you the best with her. I assume you are going to fly it in unlimited yes?

Rob

P.S. If you move out of the N.E. we will never find a N.E.R.D. ASS. as good as you.

pcastine

My Feedback: (8)

I doubt it. I'll probably sweat out the year in Advanced, since everyone's saying the Unlimited sequence is easier than the Advanced sequence this year. Are you flying Unl? Going to the JR Challenge?

And hey, it's ASS. N.E.R.D. - not the other way around! So get it right!

RobT

My Feedback: (17)

I have flown both. I do not think the Advanced is harder then the Unlimited. I cannot see why people feel that this years advanced is any harder the past years.

I don't think I will be able to make the Challenge due to work.

as722

My Feedback: (1)

John said the sheeting comes trued on his kits. Was this not the case? Goo luck with the build.

Albert

as722

My Feedback: (1)

Almost forgot, You've done more work in a few hours than Paul P. has done on his ARF in two months!
Do you think you'll have it done by spring?

Albert

pcastine

My Feedback: (8)

The sheeting is supposed to be trued. All of the 1/16" sheeting is trued; somehow my 3/32 sheeting for the wings & fuse sides was not.

Got the gear plate glued in tonight; didn't take any pics. The only thing I'm doing different there is I'm not using metal screws to bolt the plate & supports to the box sides. I'm pinning it with 1/8 dowels instead.

I talked to PaulP the other day; Barry & I are thinking we should bring his SupX down to Joe Nall again this year so we can finish it for him! I was just thinking tonight that I may have this Yak built before he has his Yak ARF put together!!

I should have it for spring. I don't know if I'll have it for Mike's contest (hopefully he's still having one in April), but I should be close.

Leardriver

My Feedback: (12)

YOU freakin guys are are unbelievable! And for your info I have only HAD the plane for 4 weeks! Another week for the engine to arrive, measured for the exhaust and waited for that to come in....plus I still am waiting on the batteries, switches, ext. Couple that with the new job started Nov 1 and the Holidays...so SHUT UP! Geez!

P

jmiracle

My Feedback: (9)

I started on the 35% version a few weeks ago....none of the sheeting in my kit (1/16 or 3/32) was trued.

OnTheEdge

Hmm.....You started your other post on Tuesday 12/6 and today's the 10th. Let's see that makes it at least 5 weeks (assuming you started the thread the day you got the plane delivered.) So..... 5 weeks to your 4 weeks....that makes ONE full week differnence. One week equals TWICE as long as Baxternick and NdFrSpeed took to assemble AND fly thier 35% Yak Arfs.

as722

My Feedback: (1)

Pete, I don't see any pictures. Don't let me call Paul on you!

Abert

pcastine

My Feedback: (8)

Ok, ok! Geez, take one night off and look what happens....

Was back in the shop tonight, fully fueled and ready to go. All you need is Starbucks and Sirius, and you can build all night!

pcastine

My Feedback: (8)

Well, I cut down the ST-1 plates, and glued those in. Then epoxied in the tail wheel support and mounting plate. Then it was off to install the 3/8" square balsa. As you can tell by the pics, I suck at cutting the angles!

pcastine

My Feedback: (8)

Spent the rest of the evening pinning down the gear plate. It was glued in with West Systems epoxy, and I pinned it to the box and rails with 1/8" dowels and carpenter's glue.

Starting to run out of things to do. I really need that vacuum pump system that I ordered from Aerospace Composites to show up on my doorstep. 3 of the 4 wingskins are ready, guess my next step will be the fourth wingskin and then the fuse and empennage skins.

pcastine

My Feedback: (8)

B**ch and ye shall receive! My vacuum pump showed up on my doorstep on Friday! It's amazing how that worked! Let's see, let's try this: I really need that 3.3m Composite ARF Yak to show up....

pcastine

My Feedback: (8)

So, I started my favorite task in the building process...sanding the balsa skins! NOT! Had to do this in the garage with the door open to keep the wife happy. Blew the skins clean with my air compressor at 150 psi. Also sanded the foam cores with 220 grit paper to take out the wire lines and any other small imperfections.

This was the first time I'd ever tried vacuum bagging parts. Special thanks to as722 and RobT for the advice on tackling this. I was very worried it was going to be complicated and I'd screw it up, but it was really simple (at least so far!). Aerospace Composites also gives you a video when you purchase their system which has a lot of good information. The best tip Albert gave me was to do a complete dry run (setting up the piece, putting it in the bag, and drawing your vacuum) before putting your glue on the wood.

I'm sheeting the turtle deck first, as my test piece. I figured if I screw this up, it would be cheaper than a new wing core. I'm using Probond for the fuse pieces. I'll use West Systems epoxy for the wings. Has anyone used the "uni-web" carbon fiber reinforcements that Aerospace sells when sheeting the wings? Looks like a negligible weight, and a great way to stiffen the wings. Wondering if it is worth it.

pcastine

My Feedback: (8)

I set the vacuum to draw 7 inches, which is what Aerospace (and Albert) recommended for white foam. After the part is bagged, the 7" of pressure is something like 18,000 pounds! The foam core doesn't look compressed, but it feels very solid inside the bag. After the pics were taken I put some small weights on the bag just to make sure the deck couldn't warp or anything. Let it sit for 24 hrs, and we'll see how it is!