Getting Ready for SHTP 2021

[AlanH]

The 2 x 4 that the lumberyard gave me sat out in the rain for a few weeks, so it's wet. -- Really wet, and it weighs a ton. The cassette, right now is heavier than the rudder. I bet it'll lose 5 pounds when it really dries out. To help that along, I'm putting the cassette inside the house, tonight....in my bathroom, which is the warmest room in the house.

[AlanH]

Today started off with sanding down the side I slathered with microballoons in epoxy, yesterday. Truth is, I should have waited another day for the epoxy to harden some more, but I did what I could.

The next order of business was to get out the circular saw and cut back the leading edge of the blade, the part that sits in the cassette.



Measure twice, cut once!...I measured about four times! I wanted 1 1/2 inches of cutback, which is half of one of the boards that make up the core.



Next was to trim the very top of the rudder, flush. Easy peasy. Oh, that's the "before I cut it" photo....

[AlanH]

Now I flipped the rudder over and mixed up more microballoons in epoxy and slathered that all over the parts of the blade that will be underwater.



As I write this, it's catalyzing outside, hopefully it will be firm enough for me to bring inside, around 6:30..

I got the itch to see if the cassette and rudder play nice together. Since I added that little shim strip, I figured that everything would fit, now... Drum Roll, please! TA-DAAAA!



Here it is, pushed forward in the cassette. The cutback is exactly the same as the thickness of the forward piece of solid wood in the cassette, so the leading edge of the underwater blade is right in line with the front of the cassette. The gudgeons will place the axis of rotation of the system about an inch forward of that, which is not ideal, but it's not that different from, say a J-27 or J-29/J-30 rudder. If I hadn't cut back the upper part of the blade, the leading edge would be 2 1/2 inches behind the axis of rotation. Can you say "unbalanced"? The very first emergency rudder that I made was like that, and it steered the Ranger 29 I had at the time, but Damn that thing was hard to move.



The plywood for the cassette has a bit of warp to it, so the box is smaller in the middle and a scooch wider at the aft end. That means the rudder, as it sits right now, would have some slop to it, inside the cassette. I need to get fiberglass around the aft edge of the blade in the upper part, anyway, I'll just just use leftover heavy triaxial, instead of the lightweight 6 ounce I have lying around. That will add a bit of thickness back there, and tighten up the fit.

That empty space in the cassette at the back end of the rudder is where the "jammer" will go, to push the rudder forward in the cassette.

[AlanH]

Today I rounded off the edges of the cassette...the top four inches, the bottom four inches and a four-inch wide area in the middle. The cassette got wrapped with 4-inch glass tape, 3x around at the top and bottom and 2x around in the middle. I wet out the wood, first...as I did for the rudder, and then laid on the tape. Pics as soon as my cell phone charges up.

This thing is bombproof.

I'm almost out of epoxy... It's sitting outside under a "tent" again, as the weatherman says there's a 50% chance of rain, tonight.

[AlanH]

the BEFORE pic...



As you can see, I didn't put down a sheet of plastic on the ground under the sawhorses....and sure enough, I knocked the cassette off, twice, no less, while I was fiberglassing. You'd think I'd learn, but NOOOooooo. That's where the dirt came from.

It'll still be very strong, but gaaaaa...

[AlanH]

Today was spent on two things...

1.) getting the upper part of the blade "wrapped" on the front and back edges, and

2.) making the gudgeons for the cassette and attaching them

Starting with #1... two days ago I went up to TAP Plastics in San Mateo and got plenty of 4-inch fiberglass tape. That went 'round the front edge. Do you remember that I needed to thicken the aft edge, that goes into the cassette, because the cassette plywood has a bit of a warp to it? I used a layer of 24 ounce triaxial cloth....had some left over from covering the body of the rudder with it... with the glass tape over that to cover most (not all) of the aft edge. The back 2 inches of the rudder will be 1/4 inch thicker, now. This was all covered with wax paper (epoxy doesn't bond to wax paper) and then clamped to make sure the glass went 'round the hard corners.


That's a motley assortment of clamps. The thick boards on the bottom of that photo (which is the aft edge) are leftovers of the redwood used to make the body of the rudder from.

Oh, I got a few scraps of 6 ounce cloth onto the very bottom of the blade, just to help protect it, and water-seal it. It'll need sanding.

[AlanH]

#2...making the gudgeons...

I made these out of the same douglas fir that the cassette pieces are made from. This sat in my study, just below the heater in the ceiling so it dried out a little. You can see the shape pencilled in. The holes are for short lengths of s.s. thick-wall tubing that will be what the pintle pins go through. I got one of them a little off center, so I trimmed the piece a bit. It's now about 1/4 inch narrower than the other one, so that will be the top gudgeon.



Here they are, trimmed, sanded and stuck on the cassette with epoxy. The distance between the bottom surfaces has to be 504 m.m. I know because I have the class rudder in my garage, and measured that. I must have checked that 504 m.m. distance fifteen times.



The gudgeon edges/corners where it meets the cassette have now been faired a bit with epoxy and wood dough. It's been tabbed in with pieces of 1-inch glass tape. When the epoxy kicks off, they'll be pretty solidly attached....nowhere near solid enough to take a rudder load, but solid enough that a random knock won't dislodge them.

The wood gudgeons are 1 1/8 inch thick. Actually the top one is 1 1/8. The bottom one is 1 1/4. Yeah, well...my table saw isn't the most accurate tool in the whole world. The thicker, wider gudgeon will be on the bottom.

The piece of aluminum is just a sighting guide to help me eyeball that everything is straight and lined up.

[AlanH]

Finally, here's a view of my sophisticated workshop.



I'm out of epoxy, darnit. Allan Steel has been closed for the holidays so I couldn't get the s.s. pipe. Ah, well... I can make another run to TAP Plastics and Allan Steel this week, and there will be an essentially complete system ready to view for the E-Rudder seminar.

There won't be a tiller, or tiller brackets, there will still probably be a few bits of glassing to do, and it won't be painted yet, but folks will be able to see exactly what I did.

[AlanH]

I went by Allan Steel this morning and got the s.s. thick-walled pipe inserts that will be attached to the gudgeons and slip around the pintle pins. I have some plastic material that I know fits nicely over the pintle pins on the Wildcat, I'm using it for pintle bushings right now on the "regular" rudder. These sections of s.s. pipe have just big enough an inside diameter that the plastic slips inside, so I can use a couple of inches of this stuff for bushings on the E-rudder. The holes I drilled in the wood will be enlarged....they're probably about 1/8th of an inch too small (on purpose)...with a rasp and my Dremel, and then I'll epoxy the inserts in there, and the plastic bushings into the inserts.

[AlanH]

I set things in place, traced lines and so on, this morning. whooiiie...the s.s. pipe inserts are big-gish. I'll have to place them a little further "out" on the wood gudgeons than I might have liked, due to their size. That's all right, They'll be wrapped 2x with fiberglass and 6x with unidirectional carbon fiber.