today's work

[Rick Teskey]

No gel coat?

[He Who Shall Not Be Named]

No gel coat?

I make my own gelcoat from the base resin and a spoon-full of colloidal silica. I brush a thin (less filler) coat within the PVA protected tool; once that goes to tac; I apply thickened gelcoat to high-draft areas; and when that goes tac hard, I brush in another thin layer of gel coat. Once all that has cured, I lay in the first layer of cloth and go to town -- typically three laminates, sanding between lay-ups. If the tool is not of weird geometry, I use 3-ounce cloth.

[He Who Shall Not Be Named]

[JHapprich]

Sexy sub! Handy size!

[He Who Shall Not Be Named]

Sexy sub! Handy size!

The ALFA? Yes, if you augment the rudder to tighten up the turn. Here's mine at Rocky Mount, NC about ten years ago.

https://youtu.be/eLap8AP27eQ

[Subculture]

No gel coat?

You can purchase ready mixed epoxy gelcoat from many resin suppliers. Some also use Vinylester resin gelcoat, which you can use with both epoxy and polyester resin systems.

[He Who Shall Not Be Named]

https://youtu.be/ZN-n1sF-r34

[Ken_NJ]

went blank at 2:20

[He Who Shall Not Be Named]

went blank at 2:20

Nuts!........

[Fishb0y]

Not to distract, but are you bringing Danny Webster to Subfest?

[He Who Shall Not Be Named]

Not to distract, but are you bringing Danny Webster to Subfest?

Man! That was the plan, but I got bogged down with some obligations, so I'll just bring boats for camera tows and the like, and one or two smaller ones for newbies to try their hands at this stupid hobby of ours.

Yeah, the Daniel Dumpster-Fire will have to wait till next year.

[redboat219]

https://youtu.be/ZN-n1sF-r34

Looks like the gremlins are back. Didn't you have the same pitch problem in the past?

[He Who Shall Not Be Named]

Looks like the gremlins are back. Didn't you have the same pitch problem in the past?

This is either the fourth or third Bronco 1/35 Type-23 I've assembled and driven. And all of them misbehaved the same: wildly unstable in pitch once submerged. All had a well working angle-keeper, and at least two of them featured a depth-keeper as well. All had the longitudinal c.g. placed at the center of the hull.

Two days ago, I radically changed things by moving weight and WTC forward to place the c.g. about four inches forward of its previous position. This to place the c.g. well ahead of the likely center of pressure, making the boat dynamically stable about the yaw and pitch axis. This change (I hope) will permit the vehicle to 'weathercock' to the flow; getting away from this awful pitch oscillations that likely results from the c.g. and c.p. being too close together. I'm guessing that the c.p., shifting back and forth with each change of angle of attack transits ahead, then behind the c.g. with each pitch swing is the problem. I'm thinking that my type-23's are experiencing a form of the dreaded 'inertia coupling' phenomena some aircraft get into.

[DrSchmidt]

From a physicist perspective: Does your pitch control have an adjustable controller, i.e. the proportional part? Oscillations can be the result of the proportional part of a controller being set to high. If possible, make the controller less sensitive by reducing the proportional part.

[He Who Shall Not Be Named]

From a physicist perspective: Does your pitch control have an adjustable controller, i.e. the proportional part? Oscillations can be the result of the proportional part of a controller being set to high. If possible, make the controller less sensitive by reducing the proportional part.

Thanks. If the current 'fix' does not work I'll vary the angle-keepers sensitivity, as you suggest. That should get out of any stern plane device induced ocillations by getting away of the boats natural frequency about that axis. Good stuff, sir.