S-Bends in stuffing tube?

[shoboat]

Boaters,

We are finding a lot of driveline friction with the current

JAE S-Bend stuffing tube. Over the weekend we tested

Four different JAE's with the standard S-Bend set up. All

Are building a lot of heat in the stuffing tube in the radio box.

One is so hot it melted the epoxy that holds the tube in place.

One melted the foam around the battery pack. The others needed

More shaft lube after just testing two or three different propellers.

We are going to try less bend and see what happens with the heat

build up. I think less S-Bend will help pull more propeller. The H-7's

Were running very well with 3.21", 3.33", or 3.46" of cup on three

different Nova Rossi motors. The 5, 7, and 35+plus all ran very close

numbers, our speeds were all around 68MPH to 74MPH. We had

a very good test session out at the Murany's test lake. I want to

thank them for helping with our testing session. We learned quite

a bit with the JAE design.

Thanks For Reading,

Mark Sholund

 

[Martin Hamilton]

I use wire drives now in my electric JAE Mini Sprint as it gives much reduced friction & no heat problems at all + less rotational weight so much better for high rpm. Im running the motor around 42000rpm unloaded. Martin.

 

[Ron Zaker Jr]

Boaters,

We are finding a lot of driveline friction with the current

JAE S-Bend stuffing tube. Over the weekend we tested

Four different JAE's with the standard S-Bend set up. All

Are building a lot of heat in the stuffing tube in the radio box.

One is so hot it melted the epoxy that holds the tube in place.

One melted the foam around the battery pack. The others needed

More shaft lube after just testing two or three different propellers.

We are going to try less bend and see what happens with the heat

build up. I think less S-Bend will help pull more propeller. The H-7's

Were running very well with 3.21", 3.33", or 3.46" of cup on three

different Nova Rossi motors. The 5, 7, and 35+plus all ran very close

numbers, our speeds were all around 68MPH to 74MPH. We had

a very good test session out at the Murany's test lake. I want to

thank them for helping with our testing session. We learned quite

a bit with the JAE design.

Thanks For Reading,

Mark Sholund

It REALLY matters how severe the S bend is laid out . A GRADUAL S bend will not generate anymore heat than a conventional bend. In fact the S bend allows the shaft to ride on less points of friction than a straighter bend.

 

[Chris Wood]

i would agree with z.. on my boats i have NEVER had a heat issue with the drive line.. even on the new boats with the ski.

i would guess you have to MUCH bend do you have a pic mark?

 

[Terry Keeley]

Boaters,

We are finding a lot of driveline friction with the current

JAE S-Bend stuffing tube. Over the weekend we tested

Four different JAE's with the standard S-Bend set up. All

Are building a lot of heat in the stuffing tube in the radio box.

One is so hot it melted the epoxy that holds the tube in place.

One melted the foam around the battery pack. The others needed

More shaft lube after just testing two or three different propellers.

We are going to try less bend and see what happens with the heat

build up. I think less S-Bend will help pull more propeller. The H-7's

Were running very well with 3.21", 3.33", or 3.46" of cup on three

different Nova Rossi motors. The 5, 7, and 35+plus all ran very close

numbers, our speeds were all around 68MPH to 74MPH. We had

a very good test session out at the Murany's test lake. I want to

thank them for helping with our testing session. We learned quite

a bit with the JAE design.

Thanks For Reading,

Mark Sholund

Bring it down to Thread Lake this weekend and run the oval!

Balloons don't hurt if your driver messes up! :lol:

 

[Grimracer]

Not the S bend thread again... lol

Just yanking ya!

Grim

 

[Ray Sametz]

Not the S bend thread again... lol

Just yanking ya!

Grim

Beats talking about rockets, just yanking ya!

 

[Grimracer]

aha hahaha.... good one Hammer!

Take care!

Grim

 

[SayMikey]

I think Mike Zs rocket has a s bend

 

[Don Ferrette]

It REALLY matters how severe the S bend is laid out . A GRADUAL S bend will not generate anymore heat than a conventional bend. In fact the S bend allows the shaft to ride on less points of friction than a straighter bend.

EXACTLY! 100% spot on the mark!!

 

[shoboat]

Guys,

These boats were built by some very knowledgable builders.

The plans may show just a little too much bend. We are fixing

the shaft problems on a few of the boats that we tested this past

weekend. We also may have found some advantage with a little

less ski out the back of the transom.

Thanks,

Mark Sholund

 

[Mike Larson]

After melting a couple, even on my mentor's build.... gradual was the deal.... well.... maybe not, cause seemingly I was able to get a traditional series tube set in there with a little motor angle and some care.... 2 national champions cant be wrong, with the "s" but, I struggle with it, hate it, and and havent been succesfull yet with one..... aluminum tubing without the log...... dont wanna fight about support points and crap, with all due respect to Z and Chris because their boats back up what they say...... the boat can be built and i'd bet theres more to fessin up than not.... mines got no "S" take your time.... Mike

 

[anthony_marquart]

my 5 port JAE style boat runs 68, real easy sbend,.. never had an issue... now a little missalignment will cause some issues for sure. not suggesting you have that... I'm just sayin...

 

[David Bryant]

can you post sample images of s-bends you guys are using........

 

[Ian Inverarity]

The S bend stuffing tube in my JAE21 hasnt been an issue. Took a while to bend it to my satisfaction when I built the boat tho. I have also built five 44" Seaducers with s bend shafts, no problem.

 

[moparbarn]

my jae .21 is built EXACTLY as to the plans, with all zipp supplied parts & hardware. single tube, no shaft log or stuffing box. i have had zero issues with my flex or heat.i use a synthetic industrial grease from texas petroleum. don't have the part # here. engine is level in the hull, shaft tube is bent to fit the cutouts in the parts from zipp. working great for me in a boat that just barely tops 80...........

 

[TOM DRIVER]

Never had a issue with S bends with all the boats i've built as long as they arn't too radical.

Tom

 

[Rigged]

IMO you should be able to put shaft all the way in dry... flick the prop and have it rotate at least 3-4 revolutions. If you feel any noticable tension when pushing the shaft through once it gets to the bend, it is too severe of a bend.

 

[Richard Dahlheimer]

The only time i saw epoxy melt at the shaft tube, was due to a severe engine/ shaft misalignment issue. I was helping a guy at the pond last summer, and noticed smoke coming from around the shaft tube, of his .20 hydro. Richard D

 

[Mario Hutchins]

I also built my JAE per plans and haven't had any problems with heat. I did fine a good grease to use called Greengrease http://greengrease.net . After a full day of running when shaft was removed it still had a slick coating od grease. Tried wiping off with rag ,still there. Could only remove with break cleaner. It is a little expensive around $7.00 . Mario