today's work

[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.

[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

[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.

[Subculture]

Slots won't make much difference, a little drag but that's all. Moving the the c.g/c.b aft will make the boat less stable, as the c.p is dialled in by the design, and that should always be behind the c.g for stability.

All these boats are the same, and with the original configuration largely the same as other Type23's, then by deduction the issue must lie with the hydroplane control.

[He Who Shall Not Be Named]

Slots won't make much difference, a little drag but that's all. Moving the the c.g/c.b aft will make the boat less stable, as the c.p is dialled in by the design, and that should always be behind the c.g for stability.

All these boats are the same, and with the original configuration largely the same as other Type23's, then by deduction the issue must lie with the hydroplane control.

Agreed, Andy. If I ever revisit this boat, first thing I do is, as you advised, and take the angle-keeper out of the loop.

[goshawk823]

Hey David? Do you have another boat you could drop the Type XXIII cylinder into, just for ****s and grins? Just to see how it behaves in another hull?

[MFR1964]

To my opinion it has to do with the CG and the hydrodynamics of this hull, like Andy stated it's design is made around that, mine only takes the dive at higher speeds, want to take the AFD out, just to see what the result would be.
Leaving the model alone at this point is a good decision, did the same with the Ko Hyoteki, had to dive her up from the swimmingpool at Germany,, i hate that, for now she will be a static model untill i find working solutions for this model, some things work another things not.

Manfred.

[He Who Shall Not Be Named]

Hey David? Do you have another boat you could drop the Type XXIII cylinder into, just for ****s and grins? Just to see how it behaves in another hull?

I do. An almost completed 1/96 STURGEON. But, I have many obligations (I'm teaching regularly now) to address so I want to clear those off the table first. Still 'legacy building'. The Type-23 has been banished to upstairs storage, and the cylinder has been post missioned and socked away in the shop 'ready service' pooka under the heavy-duty bench.

[He Who Shall Not Be Named]

[Ken_NJ]

Assuming the 'bad' servos are cheap China servos. How many of those are you replacing?

[He Who Shall Not Be Named]

Assuming the 'bad' servos are cheap China servos. How many of those are you replacing?

It varies from source-to-source, about 10-15% failure rate upon initial receipt (I used to buy them in bulk), testing was dynamic with a stall-load. Failure after installation, not so much. Usual point-of-failure was the feed-back potentiometer, which was the case with this unit.

[goshawk823]

I do. An almost completed 1/96 STURGEON. But, I have many obligations (I'm teaching regularly now) to address so I want to clear those off the table first. Still 'legacy building'. The Type-23 has been banished to upstairs storage, and the cylinder has been post missioned and socked away in the shop 'ready service' pooka under the heavy-duty bench.

No rest for the wicked. :)

It’s a beautiful boat and it’s too bad it’s giving you fits for several years.

[redboat219]

Back to the Chinese Type 92 SSBN and Italian CB.

[DrSchmidt]

And the S.M. U-1 ...

[Subculture]

MG90s are very worthwhile upgrade over SG90 servos. The difference in price is small, but the MG90s has metal gears with a finer pitch, so they run smooth and are torquier. Same footprint as the SG90, so a straight swap.