today's work

[redboat219]

Would be great to have access to a hydrodynamic test facility to test the theory on David's actual boat or the 1/144 scale Type XXIII modified to mimic David's.

[redboat219]

There were a few running at Subfest that did not seem to have the problem... Just something about your boat perhaps.

I wonder if the modifications David did to the limber holes on his boat has some effect?



Like the holes in a flute, cover one and the pitch changes.

Maybe repositioning and changing their size results in some turbulent flow which causes the oscillations

[He Who Shall Not Be Named]

Ugh, not something I wanted to hear. Don't know what to think about it except proceed on my XXIII and hope for the best. There were a few running at Subfest that did not seem to have the problem. Steve's I think. Just something about your boat perhaps.

I'm looking forward to your results. If they are good, then do chronical all pertinent information as to c.g-c.b. placement, amount of fixed ballast weight, etc. I would apply all those conditions to this screaming pile of **** I'm currently burdened with.

[He Who Shall Not Be Named]

Still got the see-saw effect with the leveller disconnected?

Didn't try that. If, and when, I ever re-visit this boat I'll try that. Thanks, Andy. Right now I have to distance myself from that project... or someone's gonna get hurt!

[Ken_NJ]

Ugh, not something I wanted to hear. Don't know what to think about it except proceed on my XXIII and hope for the best. There were a few running at Subfest that did not seem to have the problem. Steve's I think. Just something about your boat perhaps.

[Subculture]

Still got the see-saw effect with the leveller disconnected?

[He Who Shall Not Be Named]

Tested the Type-23 at the lake yesterday. Terrible results, u/w pitching is the worst yet. This is the third longitudinal change in c.g.-c.b. location on this boat. The hull goes into storage and the WTC will be re-purposed eventually. Total frustration. I don't have a clue as to what I'm doing wrong with this particular hull. Total defeat on this front.

[Subculture]

They all tend to operate on the same principles- accelerometer chip linked to a microcontroller, with adjustable gain sometimes continuously variable via a small trim pot or in steps by jumpers or button presses, and finer tweaking via the servo arms.

[redboat219]

What if you try a different brand like Engels, Microgyros or the old Subtech levellers?

[biggsgolf]

I tend to agree with you, Andy; seems that the evidence points its bony finger of guilt at the angle-keeper. After this Sunday's deep water run, after this severe c.g.-c.b. change, I still get the wild pitching underwater, I'll swap out the angle keeper with a different unit. Your input always welcome, pal.

Yup, that's why I asked you what sensitivity it was set to

[He Who Shall Not Be Named]

No improvement with the leveller bypassed I take it?

All these things come out of the same jelly mould.

I tend to agree with you, Andy; seems that the evidence points its bony finger of guilt at the angle-keeper. After this Sunday's deep water run, after this severe c.g.-c.b. change, I still get the wild pitching underwater, I'll swap out the angle keeper with a different unit. Your input always welcome, pal.

[Subculture]

No improvement with the leveller bypassed I take it?

All these things come out of the same jelly mould.

[He Who Shall Not Be Named]

Did you try turning the leveler feedback down, Dave?

Yes, went through all three sensitivity settings. No joy.

[DrSchmidt]

Did you try turning the leveler feedback down, Dave?

[He Who Shall Not Be Named]

I believe this Tom's Chalfant's Type XXIII with your 2.5 SD. No porpoising whatsoever.

Unfortunately it was lost out on patrol.

First time I've seen this video. Thanks for sharing. Now, I have hope!