IMAC Build: Dalton Extra 300

[Notorious B.E.N.]

I finally started working on the Dalton again last night. I wasn't in the mood to do a lot of sanding and I really wanted to work on the pipe tunnel.

I started by edge gluing to 2 sheets of 4"X48"X1/16" balsa together. After making many measurements, I came up with what I think the dimensions should be to fit in the plane and also fit both pipes.

The main reason why I'm doing the pipe tunnel is to try an make it easier for installing the pipe mounts later on. I also like the idea of compartmentalizing them.

To help hold the sides on, I glued on some 1/4" basswood. Since there is a small taper at the back, I had to cut some notches to get the basswood to bend. I will eventually put some basswood diagonal pieces in to reinforce the top part of the tunnel but that will come later on once I have the entire assembly ready to install in the plane. Just working through things I was able to get one of the side pieces on before taking a break.

I placed the top and side pieces in the plane to see where they would join up with the rest of the airframe so I could cut some slots to get the tunnel in when I finish it.

 

[Notorious B.E.N.]

The second side has been glued on and the triangle stock to reinforce the back has been cut to size and glued in.

 

[Notorious B.E.N.]

And the final progress from yesterday. I did a dry fit and I'm going to have to make a few adjustments but nothing too big.

 

[Notorious B.E.N.]

I have the tunnel where I can get it in and out and I got the front trimmed. There's a little extra, but not too much and it will be sanded down once I have the tunnel ready to paint.

I also started working on the cross bracing.

 

[Notorious B.E.N.]

Well, I had to help the ball-n-chain rearrange a room tonight. I also got my new heli in the mail so I only got 1 more cross brace glued in.

 

[Notorious B.E.N.]

My back was bothering me yesterday so I just finished up the cross bracing and called it a night.

 

[Notorious B.E.N.]

So I'm starting to think about buying a motor for this plane. There are 2 options.

1) Keep saving and buy a brand new motor (DA 170, 3W 170, GP 176 EVO, or ZDZ 180)

or

2) Buy a used older motor for less than half the cost

I started a thread on this in the Engines forum. Please feel free to weigh in here or there.

http://giantscalenews.com/threads/older-3w-and-da-for-first-40-er.4600/

 

[Notorious B.E.N.]

The current weight of the tunnel is 6.3 ounces so let's say 7 pounces once painted and installed.

What do you guys think?

Install it or scrap it and do something else?

 

[capthis]

You knew adding pipes would ad weight. 7 ounces is significant, but it doesn't look like your tunnel is over built by any means. If you want to run pipe, and as you said compartmentalize them then keep it. If you want the lightest bird out there then run in cowl muffs, and let all the imac guys give you grief about noise! I just tell em to piss off I like being able to actually hear my airplane!

As far as new vs used. It's like anything else. I've had great luck buying used, and have even bought some engines super cheap that "needed work". If you can talk to the seller and know the hx of the engine you can save a lot of money over buying new. I think a lot of folks are lke me and don't fly engines nearly enough to ever worry about wearing one out unless it's just Chinese junk to begin with. There's a few guys I have watched wear engines completely out but they are rare or are competitors that fly all the time to practice.

Used DA 150's go for cheap these days, and used 3W 150-157's are hard to give away. This hobby is probably like other things in that people seem to want the latest and greatest, and forget that the good ole DA 150 was the best there was for years!

 

[Notorious B.E.N.]

So I'm still trying to decide if I want to mess with the pipe tunnel. I looked at some other threads and saw how they did their pipe set ups and I'm leaning that way.

Because of this, I started working on the canopy hatch. Thankfully when I went to the LHS yesterday I picked up some 1/4" spruce. I had to splice 2 pieces together to do both sides. I'll glue on some balsa to reinforce the joint.

To begin, I had to put the cowling back on and so I opened up the 2 lower access slots. Once I had the cowling on, I began getting the hardware and hold down points in place. I used small pieces of wax paper to keep from gluing the spruce to the fuse frame.

To set the proper spacing between the front former and the cowling, I just cut some strips of paper and used it to shim the former back. I glued the former and used triangles to make sure it was at 90 degrees and let it sit overnight.

This morning I got the center stringer and the second former glued in. I took some measurements from the plans but the second former was too far forward so I move it back a little bit.

I need to start thinking about what pilot figure I'm going to install. In the pics is an EF 30% figure and I'm concerned it's going to be just a little bit small. What do you think and what should I look for?

I also like the ones Aircraft International sells but I need to get the sizing information on the helmeted series.