prop

[gil sonsino]

OOOPS taking a close look to the first at left it is a 2160 that I use on my 67 rigger but consider the figures I mentioned (2170 diam 64 and cup 7.5)

Will greatly appreciate any of your advices Mark.

Gill

 

[shoboat]

Gill,

You do nice work. Try to stay between 64mm and 67mm,70mm is going to

be too big I think. I would try 65mm with 7.6" or 66mm with 7.1" of cup. You

could try to take a little more material off the propeller "around the corner". As

the leading edge turns away from the hub and starts to turn up towards the tip.

I call that the corner. Like anything else when you are looking for more speed,

it is trial and error and testing.

Thanks,

Mark Sholund

Props-4-U

 

[gil sonsino]

I'm sure that is a time consuming process that I really enjoy.A friend of mine with the same boat equipped with a CMB 90 is turning a 67mm cupped 7.1 and also is in the top club but I think the difference from my Mac 84 is the extra torque of his engine.

Anyway I will try the 65 or 66 mm that you've suggested and let you know the progress once we have another trial next week end.

Thanks for your input and best regards

Gill

 

[shoboat]

Gill,

Remember one thing about propellers,a bigger blade throws more water.

You have to balance the diameter with the engine setup though. I like smaller

propellers with more pitch,but sometimes a bigger blade is better.

Thanks,

Mark Sholund

 

[gil sonsino]

Hey Mark

In this meantime a new prop is born!

Let's see what's going on next weekend(65mm cup 7.1)

Thanks for your interest.

GILL

 

[ernest2]

hi! i have another questions. i know you guys are racers and are all out speedos.

i'm trying to make my own strut here, i will use a stainless steel nipple about 2" long (the one bought in hardware). i will then make someone weld a piece of stainless flat bar in it to make it a strut. may question now is the the inside diameter is almost 10mm (@ 3/8"). so my 5/16" and 1/4" brass tubes that make up the shaft tube will be a bit small. i was thinking of putting a 3/16" diameter collar in it to serve as a bushing. it fits perfectly in the inside diameter. now is it ok if the bushing of the strut don't rotate? because i'm planning to drill a hole in the stainless nipple so that i can fit the set screw of the collar there so the collar will not be lost.

thanks for any help.

ernest

 

[gil sonsino]

Ernest

If your flexshaft is 3/16 try to find a a smaller stainless steel nipple to make your strut. Stuffing boxes for this shaft size usually are 1/4 OD and 7/32 ID That way you can use your 3/8 nippel.

Coincidentally I'm making one strut for a friend ....see the pic.

Gill

 

[ernest2]

that's a nice strut. is it silver soldered brass parts? i am actually still looking for a 1/4" dia. nipple which will make life easier for me. thanks for that pic, helps a lot.

can stainless steel be also silver soldered?

 

[gil sonsino]

The strut is stainless steel silver soldered(45% silver).Need to remove the excess of soldering and then sandblast it to have a nice look like in the pic..

Hope this help you

Thanks

Gill

 

[Foolwitools]

Hi Guys!

Mark (Shoboat) mentioned an air filter mask in his post listing the stuff you'll need. I didn't see any other mention of this ............

Beryllium copper (some think it's brass), the gold colored metal that most props are cast from, is toxic! The dust from sanding and grinding can make you sick.

Invest $2.95 in a package of 3M paper dust masks..............And use them!!

Stay healthy,

Bob the Fool :blink:

 

[shoboat]

Hey Bob and Others,

Try a $45.00 toxic dust mask,the paper ones aren't worth anything. The dust

will get you later in life without a mask, believe me. I would buy the best mask

you can afford and change the filters often. Also,a great set of goggles will help

keep it out of your eyes. Stay healthy is right Bob.

Thanks,

Mark Sholund