Otter-1.6 (scale model)

rudar · Post by **rudar** » Sun Sep 21, 2008 12:21 am

Well, I promised myself I would not build another boat until my thesis is submitted... But surely, scale models don't "count"?

I've been pondering modifications to the Otter to a) have a sideways-facing bench to sit on while sailing, and b) have somewhere to stow the oars while sailing and the spars while sailing. But I'm not sure I can entirely visualise whether they'll "work", so a model will have to satisfy the BBV urges for now, and let me see modifications in 3D

First panels laid out on 1.5mm baltic birch plywood:

I'm hoping a glue-gun will work for building "fillets" on the model. Or is there a better suggestion? Actual epoxy would probably be a bit silly.

I'm not sure whether an x-acto knife will work for cutting this stuff, or whether I'll use a scroll saw. The latter would probably throw the nesting diagram all ahoo, what with its 3/4"-to-scale kerf

rudar · Post by **rudar** » Wed Sep 24, 2008 1:27 pm

panels cut (turns out scissors were the best way to go...), and a "strongback" made...

Electricians tape did not work. I found some 1/2" wide fiber-reinforced packing tape which seems to hold better. But I'm not convinced that glue-gun glue will be strong enough to hold the twists in the plywood so I can take the frames out... Either I'll have to cut the frames to shape before assembling and glue them straight in, or else use actual epoxy putty, or come up with some other option...

Gramps · Post by **Gramps** » Wed Sep 24, 2008 1:56 pm

Looking great rudar! I can not remember the name of it, but what about the glue used for balsa model building (it is like green elmers)? Or simply super glue, liquid & gel?

Where did you find the 1.5mm wood? I would love to give that a shot.

Tagged · Post by **Tagged** » Wed Sep 24, 2008 2:46 pm

Rudar, for glue, I used superglue when I built my model sailboat. The wood was balsa and some sort of ply from the craft store. I was leary of it at first, but found that model airplane shops were selling a fast drying (!) version for airplane builders.

I used both the Kmart kind and the Hi-Test. Both worked extremely well.

The expensive stuff came in 1.5 or .5 second drying times, if I remember correctly.

Tag

rudar · Post by **rudar** » Wed Sep 24, 2008 3:41 pm

Lee Valley has 0.8, 1.5, and 3mm baltic birch plywoods at around $20 for a 25" square. I figured the 1.5 would be just over a half-inch at scale, so might work. I guess I'll try twisting a couple of pieces of scrap a bit and gluing them with different options, to see if they hold.

JIM M · Post by **JIM M** » Wed Sep 24, 2008 8:47 pm

rudar, super glue will hold, I flew RC airplanes for years everything was super glued and never had a glue joint fail. Made many semi controlled landings, the wood always failed not the glue. Also made a flight box with 3/16th ply and super glue, weighs 15 lbs. when full, it held up for years.
In spots like the bow where the wood barely touches you can use baking soda to make a fillet then add a drop or two of glue, it sets almost instantly and makes the joint much stronger.
Super glue will only fill a very small gap so the better your pieces fit the stronger the joint will be

Jim

rudar · Post by **rudar** » Thu Sep 25, 2008 1:55 am

I decided to test the glue gun glue. First, I cut a piece of scrap with a good curve to it, then taped a second piece bent along that curve. Then, I added a third piece cut at a slightly off angle, so the bent piece also had to twist. Also, a good variety of big gaps (~1-1.5mm) and no gaps. Then I tack-welded the few spots left between all the tape I had to use to force the bends and twists, with the glue gun. It ain't pretty (despite the left-over glitter glue in my friend's glue gun, which I've borrowed...), but it held just fine when I pulled all the tape off:

And I'm sure a razor blade will trim the goobers down into something more reasonable. The bits on the inside are much easier to put down reasonably smoothly from the gun.

Probably won't get to it until next week, but looks like once I re-jiggle all the taping and stuff until I'm happy with it, I'll be able to go ahead and make glue-gun fillets inside and out, and it should work fine.

rudar · Post by **rudar** » Sun Sep 28, 2008 6:55 pm

All glued up and looking like a miniature boat:

Close up of the interior:

So the changes from the plans, thus far, are frames B and C.

In frame B, I've cut out some openings, leaving 76mm all around. Including on either side of the daggerboard trunk. I dunno if I could get away with leaving less there, to make the holes a bit bigger. In theory, oars/spars can stow through these holes when not in use. There's 3m of space between the bow and frame C, but I'll have to get some doweling and see if they can be moved in and out of stowage, at all...

In frame C, I've mostly cut it open as per the plans for the removeable seat, but have left a bit on the sides. I'd like to put small benches so I can sit sideways when sailing. Jacques seemed to think this would interfere with the oars, but he might have been thinking of something different, because I just don't see how...

rudar · Post by **rudar** » Fri Oct 03, 2008 6:47 pm

Here's spars and oars almost-to-scale (not tapered, but about the right diameter and length...)

Looks pretty crowded... Unless I open up frame A a bit closer to the sole, I can't weave them through all the frame openings to the bow of the boat. Would opening frame A further down be "safe"?

I'd imagine having oars on either side of the boat would make for lots of tripping hazard while sailing... Anyone have any bright suggestions?

Boat Builder Central

Builder Forum