First time cupping

As the title says I took a m447 prop and cut it down to a 46mm, made some cupping pliers and cuped the prop and bent the tips just alittle, this with sharpening balance and thined the heck out of it,
well I feel my efforts paid off because with a stock m445 I hit may be 48.8 mph and with the modded m447 I hit 56.8 still need to do more testing w/ strut height it should go a bit faster. don't ask me what the pitch is or anything to technacal about the sizing because I have no clue what the pitch is know,I just know that it worked well and the ul-1 jumped on plane without hessation.
I will continue to try my hand in prop mods. test,test,test,

You will not get to much response to this thread, as nobody wants to give out secrets on how too's. But you will notice a big change in the size of rooster tail the prop makes when cupping...

Thats to bad that folks won't share info on what they did to there props, but I've read alots of articals and even on this forum there is some good info.
alot of folks out there are willing to do prop work for a $$ and even more money when cupping ect, hell, sharpening balancening detounging are a breeze once you know how and its not hard to learn, you just have to do it.
as far as cupping goes I just eyeball it like daren once said, I don't have a pitch gauge or dial indacator so I just wing it and see how it works and what changes.
oh yea it seems that roster tail was alot smaller because I changed the thrust cone.
thank for your reply though,
later G.

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Originally Posted by G-UNIT

Thats to bad that folks won't share info on what they did to there props, but I've read alots of articals and even on this forum there is some good info.
alot of folks out there are willing to do prop work for a $$ and even more money when cupping ect, hell, sharpening balancening detounging are a breeze once you know how and its not hard to learn, you just have to do it.
as far as cupping goes I just eyeball it like daren once said, I don't have a pitch gauge or dial indacator so I just wing it and see how it works and what changes.
oh yea it seems that roster tail was alot smaller because I changed the thrust cone.
thank for your reply though,
later G.

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I use a small hard chrome hobby anvil, a hobby hammer, brass on one end and teflon on the other, and hard chrome ball bearings ( different sizes ), to create what ever is needed.


http://www.modelgasboats.com/Voodoo_Cupping_Tool/

Thanks for the web site very interesting and use full.

If you look closely at the design of the pitch gauges that use a 0-1" dial indicator it's pretty easy to make one up for about 25 bucks using a plastic 360 degree protractor and some bits and pieces you have laying around.
All you need to know is that one blade matches the other.
You need to measure the amount of pitch over it's rotation from leading edge to trailing edge, the protractor allows you to measure the degrees of rotation it takes to go from LE to TE, then do the math to figure out what the pitch would be over an entire 360 rotation.
The protractor allows you to measure the same place in degrees on each blade.

If you can get a set of cupping balls it will help a lot. I have a Hughey pitch gauge but unless you have additional instructions it's very hard to use.

Attachment 59280

This thread has a good summary of the characteristics of stock Octura props and what various modifications do. Brian Buaas has posted the modifications he uses on his record setting props. You need to try different changes and run them against experienced racers to find the best combination.

Lohring Miller

good topic . i`d like to see some pics of some tooling . i just picked up some steel to make a cupping anvil . i am also going to tune up an old set of pliars , for cupping .

That tool looks like it need something to hold the prop while your working on it. how the heck do you get both or all three blades the same holding it by hand lol...the voodoo one looks much better