saw boats

[Glenn Quarles]

To some extent yes. The "long" helps out with stability which is often needed to get a light boat with lots of HP and a big pitch prop to take the power. Too long is bad also because you are just dragging around more boat than you need. I have found that a good SAW boat can actually be shorter than a heat racing boat (with same size motor), but because all of the other dimisions are smaller too it makes it look long and skinny.

The "narrow" helps out because you need less lift for a lighter boat running at a faster speed. And again, you are looking to get rid of anything extra that is "just along for the ride" to cut down on weight and drag. Just like the length part, it is possible to get too narrow and actually get rid of too much lift...been there, done that!

Glenn

 

[Don Templeton]

Glenn,

I am going with non adjustable strut, so that info helps a lot. Pretty

much what I had in mind but I feel better hearing it from you. Not

really an SAW boat, just trying out some different things. I just checked

my old .67/40 Crapshooter and the rears are a good 3/8" shallower

than the strut. ;D. However that's a solid shaft with 13 ball bearings

encased in a center wooden strut.

Don

 

[Hammerhead]

Hey Don! I have heard you talk about that strut before, I really would like to cop a picture from you for my album. Please mail me one if you have one.

Glenn! I love reading your thread. I'm just sitting back absorbing the info. At least you don't speak french like those guys at RC.com. They loose me with all their techno babble.

Hammer

 

[Don Templeton]

On it's way Hammer!

 

[Grimracer]

Gang

I do not get much of a chance to post with you guys about the Rigger stuff, the SAW stuff and alot of other cool things on the Board. And i have to side with Hammer on this one.. This board is easy to follow. The information is straight forward and fun to read. Having Glenn here, Hammer, Mike CFMASTER P, and RZ looking over our sholder, makes this one of the best sources for information we could ever have.

Three Cheers to the 400 + members of INTLWATERS

Hip Hip..

THIS GOES FOR ALL OF THE MEMBERS rigger dudes, tunnel dudes and mono guys alike..

Grimracer ;D

 

[Propjockey]

Yup...and don't forget Jerry D, Randy R, Ian and ALL the people that pour their experience and knowledge into this effort. (and that guy that keeps winning with those tunnels--Mike something-or-other )

We couldn't do it without ya! (Ok, maybe we could, but it wouldn't be nearly as much fun)

[move][SIZE=22pt]THANKS!!![/SIZE][/move]

 

[Don Templeton]

"DITTO"

 

[nitro2]

Ian, Can you describe how you set up the needle, thrust bearings and shft assembly on your 90 mono. Also where did you get the bearings. I would like to try it on a gas boat. Thanks George

 

[Ian Inverarity]

George,

The benfits of such a system are greatest for high revving low torque motors like 21's and least for high torque low revcing engines like gas engines, but there still should be a benefit. After reading what is below you can make up your own mind about whether the effort is worth it.

I use only square drives. 1/4" square ended cables from wrecked whipper snippers. Ensure the flex is wound the right way. I use teflon lined stuffing tubes, the teflon from Octura is actually teflon, as opposed to what many people buy thinking they are getting teflon. The flex is soldered to an Octura or similar ferrule. The OD of the ferrule should be 1/2" to 13mm

I make my own struts from stainless steel. These have an OD of 13mm. It would be possible to use the Octura brass strut that is about 14mm OD, the ferrule should suit this diameter.

The needle bearings are INA brand SCE 47, which are 1/4" ID, 7/16" OD, 7/16 long. I tried another brand, but it had about half the needles, so I recommend the INA. Ring up CBC bearings, Gardner Bearings etc and find out who has INA. The strut should be reamed through with a 7/16" reamer to ensure the correct bearing fit and alignment.

The thrust bearings I use are from Minature Bearings Australia in QLD. They have a 7mm ID and 13mm OD and have grooved washers and a brass cage. I dont remmember the part number. These are infintely superior to the type that Octura sell and should last over a year with regular greasing.

Because both the hard thrust bearings and hard needle rollers will wear into soft stainless shafts I use 1/4" ejector pins. These are precision ground industrial items used in plastic injection mould manufacture and are available from companies like DME, STM and Hales (in Australia) in 18" lengths for quite reasonable prices. The ejector pins cannot be cut with a hacksaw or filed. I cut them using the edge of a grinding wheel on a bench grinder. All the flats for the grub screws will need to be ground on using the bench grinder or using a mounted stone in a Dremel.

The strut should be packed with grease regularly to ensure the survival of the needle bearings.

Good luck! ;D

Ian.