Dusting Off a Fine Design 32 w/ Graupner Z-drive

[ShapeShifter]

Hi everybody.

New to this forum but not new to the hobby. I have had my boats on the shelf in the garage for about a decade and I decided to start rebuilding them. I used to run this FDM 32" with 12 or 16 nicads cells and it always ran great - except for turns. It likes to spinout real bad and I have always assumed that I mounted the outdrive a little too high.

The Zdrive has the output shaft exactly in line with the bottom of the hull. There is some tilt up and down adjustment but I have never been able to dial the spin-outs out. This drive is probably a little big for this hull and it may be time to find a different hull for the drive, but until then, I am about to get this thing wet for the first time since the Bush/Quale administration (assuming my 10 year old hatch tape is still good). Its a lot lighter now with 4S lipos. I usually balance right a 30%.

Just by looking at these pics, can anyone recommend a tweak to reduce spinouts? Any input would be great!

[Newboater]

Longer and larger turn fins would be my thought

[Heath M]

Cut off what ever is sticking out under the hull. It just increases drag and may even add to your turning issues.

[oscarel]

Where is your COG?

[ShapeShifter]

Like I said in OP I balance a 30%

As far as whatever minimal drag the Octura pickups may or may not cause, Im not racing this one. Really effing fast is good enough for sport running.

[oscarel]

Your OP say you usually balance at, it doesn't say where you've balanced this one at. You also said its lighter now.

Sent from my SAMSUNG-SM-G930A using Tapatalk

[ShapeShifter]

Your OP say you usually balance at, it doesn't say where you've balanced this one at. You also said its lighter now.

Sent from my SAMSUNG-SM-G930A using Tapatalk

Thats weird I see it.

Anyway, yeah it should be considerably lighter than the last time I ran it with Nicads. I'll set the balance a little more aft but I still suspect the drive is too high.

[Newboater]

If the drive is to high why not get longer adjustable trim tabs to compensate.

[Fluid]

We discovered decades ago that steerable outdrives were more prone to spinning out in monos, particularly in tight turns. Drive height had some but minor effects. The problem is caused by the outdrive lifting the transom as the boat leans over in a turn. The bow digs in and the vectored thrust along with prop walk cause the spin. What we didn't understand was the role of turn fins in holding the boat locked down in turns. This may have helped.

The first thing to do is to install a BIG fin. You can always cut it down, but if this helps with the problem you can experiment with size. DO NOT cut off the outdrive skeg! That is all that holds the hull against prop walk and helps to anchor the transom against slipping sideways and spinning the boat.

Raising the the drive height (not lowering it) may help some too, but you will probably come to realize that you just can't turn very tightly at high speed. Understand that, limit the outdrives deflection by the servo, and enjoy that classic boat. It looks so cool with the outdrive!



.

[ShapeShifter]

Well it looks like I'll be sharpening up some aluminum....

Thanks for the input guys.

[Tamelesstgr]

Oh my gosh, I am just finally getting my FDM 32 in the water the past few weeks, so glad to see another!

[iop65]

Maybe by making the strakes smaller at the back , hull creates less lift and you get more hull in the water?

[JohnZ]

I had one of those a number of years ago. Bought the FDM gearbox to use with it along with their SS 700 brushed motor. Ran it on 16 cells and I don't remember having any turning issues with it.
Wish I could find another one of these.

[DRMead]

WOW,I thought I was the only one left with one of those czec brushed motors in the old stuff box............If you want another one give me a shout.

[ShapeShifter]

I had one of those a number of years ago. Bought the FDM gearbox to use with it along with their SS 700 brushed motor. Ran it on 16 cells and I don't remember having any turning issues with it.
Wish I could find another one of these.

The FDM 32 hull turns fine when not rigged with a giant outdrive.