I found first couple mistakes in the files I posted.

Of the vertical fin formers, F1 needs to be 1/8th, not 1/16. F2 was missing completely so I added it in the 1/8th bin. I also added some fillets to help align the formers at the correct angle to the TE of the fin.

New V2 of files posted here, and V1 has been removed. I will continute to make adjustments if I find something wrong as I build. Cheers!

Very cool. I have a set of 480 plans and was going to build one. But I would rather start with a lasercut plans. I would recommend beefing up the tail a bit. I own the original 600 size one and the tail has twisted. I hope to have time this winter to fix it.

Originally Posted by Gonzo007

Very cool. I have a set of 480 plans and was going to build one. But I would rather start with a lasercut plans. I would recommend beefing up the tail a bit. I own the original 600 size one and the tail has twisted. I hope to have time this winter to fix it.

Which part of the tail ended up twisting? Fuselage? Stabilizers?

I added some reinforcement for the nose gear area including cross-braces per the plan, and doublers on the bottom. I'm using a spare 1/2A dubro nose gear mount and will bend my own wire to meet the plans. I mostly used Gorilla glue here for the gap-filling foamy effect.

I also finished sheeting half the bottom.

The next step that I've been putting off is building of the vertical stabilizer. Because it's profiled, its not as easy to pin to the plans. Heres the steps I used:

1. Take 3/16" stock and cut trailing edge piece that is the width of the widest part of the tail. In this case 7/8" was the widest at the aft of the fuselage.

2. Measure and mark the former stations on the TE according to the plan. Repeat for leading edge stations. Also draw a line up the midpoint of the trailing edge piece.

3. Make angled fillet to align the bottom former to the LE and TE. Then I used the laser cut vertical fin tip to complete the outline of the fin and pinned it to the plans with the LE hovering above.

4. Mark the centers of former at the TE, and line them up with the station markings on the TE. Pin and glue.

Pictures:

Jeff
I Am Enjoying The Build Thread. Is There Another Way Of Sending The Cut Files.. I Dont Have A Program To Read Dwg Files. Thanks
Carl

Originally Posted by CARL SCHIMNOWSKI

Jeff
I Am Enjoying The Build Thread. Is There Another Way Of Sending The Cut Files.. I Dont Have A Program To Read Dwg Files. Thanks
Carl

The .dwg is the cut file. There are free viewers available.

Jeff,

Looking good!

Your framing method for the fin is a very good idea. On all my Ivan builds, I have preshaped the spar prior to framing. This then requires some imaginative shimming/pinning to get the ribs aligned. Never occured to me to do this after the ribs are attached.

I'm working on converting all the parts into correct sizes for the 600 size Twotter in CorelDraw. It will probably be a few weeks but I will post the cut file once it is finished for anyone interested. Importing a .dwg file into CorelDraw results in some funky looking shapes that required a bit of smoothing but since I have zero experience with TurboCAD, I felt more comfortable editing the file in a CorelDraw thanks to what I've learned on Milfahre's Gull thread.

John

You have my interest as well... Always liked the Otter.

Mike

I spent some time this weekend working on the Otter. I finished the vertical stab and almost completed the front hatch.

Here is the vertical stab. I decided to depart a bit from the plans and I capped each former with a thin sheet of 1/16" balsa to add some strength and make it easier to cover.

I've been procrastinating on building the hatch because it is one of the busiest areas of the plans. I found it difficult to discern some of the details and when I cut pieces 5D and 5E from the side view, they did not line up with the top view. In the end I mostly winged it, and it turned out okay.

I started by building the frame of the hatch in place using saran wrap on the fuse to prevent gluing the hatch and fuse together.

Then I cut the pieces that form the forehead/roof of the cockpit and sheeted that. I added support window-frame struts to the 1/8'th hatch sidewall.

The bulkheads, longeron, and sheeting were added next, but I found that the window-frame struts I started with would be in the way of the sheeting, so I cut them free and secured the sheeting hatch to the fuselage with tape.

I sized the window frame correctly using 1/8 x 1/8 square sticks. To make the bottom of the front window I soaked some squares stock and curved it around the sheeting between the vertical sticks that form the window. It all looks a bit messy, but balsa-filler cleaned up the gaps and made it look a bit better.

Anyway, here is lots of detail shots, so hopefully the next n00bie to build the Twotter gets some ideas.

I agree with doing the caps on the tail. But I would put some more strings in to help with strength. I am cutting off the tail on the original because of a large twist.

Colin

I could add some diagonals between formers.

I will take a picture of the tail now and show you what can happen if you don't beef it up.

Colin

Originally Posted by JeffElecRC

In the end I mostly winged it, and it turned out okay.

That sounds about par for the course on an Ivan build! The good thing is it makes you more confident and indepedent on future builds.

It's looking really good!


Luke