Looking for more info on pods

OK,

Still don't understand why the Zeus system needs tunnels. The trim tabs are connected to the pod unit and would not care about a tunnel shape. Although difficult to envision, the only thing I can think of is that they have designed themselves into a situation were, from a mechanical standpoint, the pod can not be installed in any other orientation than vertical.

The IPS system from Volvo is equally complete and does not need a tunnel. It appears that IPS in a twin installation is always installed perpendicular to the deadrise but in a triple installation they use a tunnel shape of some sort for the center unit. If I understand that correctly it would appear that the IPS pod can go either way.

Karl

 

Well,

from Merc.s point of view it is enough that they understand their setup, and that includes tunnels. period

The rest is not worth to argue about, one either buys what the manufacturer offers, or one goes for another propulsion.

Wild guessing, which and what and why, does not answer the original question.

In this special case, a redesign of the hull would be just nuts. Selling the junk and buying one matched to the pods (no matter Merc. or Volvo) would be the solution if the pod is a must.

Regards
Richard

 

Thanks, I Get it, No one seems to have looked into these pod drives, nor do any of you guys feel that an improvement through rediesign is a viable option, Thanks again for your thoughts. Kevin

 

As bold as your first reactions..........

Do´nt ask for experts opinions when you do´nt like them!

 

Dash,

I'll try to help here... The Zeus pod only refers to the mid-size pod 3500 and 3800 series. Which your current horsepower you would be much better off with the ZF small pod 2500 and 2800 series. It does not have the inegrated trim tab. It's 200 pounds lighter for the pair and 3" lower which from my experience fits much better especially in fishing boats with limited height under the cockpit sole. Zeus and ZF pods do required a tunnel but not for the obvious reasons. They will tell you that's It's for stability and reduced draft, which is all good, but the real reason is patent infringment on the Volvo designs. ZF,CMD and Volvo all want sucessful projects so you must have them determine if the boat is suitable for pods. With a re-fit I believe the Zeus (ZF) is a better choice mostly because regardless of your bottom shape you'll have to use the tunnel provided by them. Hulls designed specifically for pods have no rocker. Some of this can be overcome by adjusting the angle of the tunnel flat to acheive the desired running trim angles. Since your boat is alloy I wouldn't be afraid to do the modifications. ZF will provide you with the tunnel surfaces and a jig can be put together to build it off the boat, you did mention that you're handy... By the way, nearly all the effecency is due to lower apendage drag the rest from the flat thrust angle. Don't automatically assume you'll acheive their marketing economy and speed numbers... Again, the first step is to contact the manufacture and fill out the application to see if your boat will even work with pods. One thing is for sure, in many cases Pods are the future.

 

They need the trim tabs because they use tunnels
What part of a pair of duo props under a boat make them required to be in tunnels?
Other than lower the bouyancy and maybe reduce draft with a larger prop, certainly increase hull drag and create a massive coanda effect and create much more noise what use is a tunnel?

 

I'm simply making the point that Zeus is a package and that the tunnell's are part of that package. Merc decided to incorporate tunnell's - perhaps for the reasons you suggest, perhaps not... but regardless of the reason, they are an integral part of the package and no doubt there are aspects of their design that are tied to them.
As Apex said - if you don't want tunnells, you buy something else.
Clearly tunnel's are not a necessary component of pod systems per say... there are plenty around that don't have them - IPS being just one of them. But if you want Zeus, you get tunnels

 

I cant imagine what patent Volvo could have as azipod thrusters have been around since the 60's
Every body selling them ( large ones) today and with duoprops are not putting them in tunnels?

 

Flyingtime, Thanks for the info, I'm currently involved in several projects for other people as well as trying to juggle the boat & Lodge, so my internet time has been limited to a few minutes here there. I'm curious if you or someone else might be able to steer me towards the people at ZF that could assist me in getting this application process started. I do have a question that I'm sure the experts will find amusing and this will certainly fuel the ( this idiot has no business even putting fuel in his boat fire) What are you refering to as a rocker? The hull of my boat has a very sharp entry with a progressively widening flat chine and all the way to stern. The bottom is smooth without any strakes. The deadrise in the stern is in the nieghbor hood of 20 degrees.

 

Dash,
Imagine taking a slice longitudinally along the length of your vessel, some way between the chine and keel. When looked at from the side, the resulting line is called a buttock. If the buttocks curve up as they approach the transom, then this is called rocker (FYI if the curve is the opposite - convex - it is called hook)
I've attached an image of a boat of my design, Graphite. The buttocks are the dashed lines. You will see that for the aft part of their run they are straight and parallel with the waterline, which is typical of a planing hull.

 

Thanks williamson, My hull is definetly not a rocker or hook style planning hull, The buttocks are parallel to the waterline from about 1/3 back from the bow. Kevin

 

Kevin,

The NA that I work with at ZF is Wayne Wingate. He's a super guy and I'm sure he'll get you headed in the right direction.
Headquarters 954-441-4040
wayne.wingate@zf.com

 

I know it doesn't make any sense but after pushing repeatedly to try to mount them on the deadrise that's what I ended up with. They probably just wanted to end the debate...