MHZ Mystic 1380mm build

[srislash]

. how many things have to be absolutely perfectly balanced at that rpm? Do they have unobtainium bearings? Who runs 80k rpm? I just want to here that.

Well I would imagine that would be them crazy German's that do 130 MPH with the MHZ and HPR's.I'm sure you've seen the vids.

[srislash]

I think .... like a car tire expands at speed so will the prop at 80k RPM LOL even if I used a 45mm prop it'll come back 50mm LOL LOL

I know they heat up from the water friction.It is an issue with the 1:1 drag boats.

[nata2run]

Well I would imagine that would be them crazy German's that do 130 MPH with the MHZ and HPR's.I'm sure you've seen the vids.

NO! they have a string attached that pulls the boat LOL, dont believe everything you see on video....

[Prop-a-Gator]

oh I've definitely seen the vids, but I must have missed the rpms or not calculated them. They're usually very good about listing the specs. I just can't imagine the details that come into play at those rpms. Not just prop balance but sharpness, and who knows what else.

[Prop-a-Gator]

an unobtainium string no doubt! LOL

[srislash]

oh I've definitely seen the vids, but I must have missed the rpms or not calculated them. They're usually very good about listing the specs. I just can't imagine the details that come into play at those rpms. Not just prop balance but sharpness, and who knows what else.

Well let me tell you,there must be a special store somewhere with very special props that I haven't found yet.Because I've been trying and buying.Kent would have fun with the collection.I am bound and determined to learn this prop thing proper.

[srislash]

an unobtainium string no doubt! LOL

Where can I get this substance you speak of.Maybe with this....

[nata2run]

Agree, the prop thing would be cool, I have quite a collection. Alot of the fast boats in Germany have props by "Jorn Oliver" by the looks of it. Maybe he holds the secret!

[srislash]

Agree, the prop thing would be cool, I have quite a collection. Alot of the fast boats in Germany have props by "Jorn Oliver" by the looks of it. Maybe he holds the secret!

Mmmm,Jorn Oliver,interesting.
I tried the thinning thing on a pair of ABC 2016/3's and oops,too thin.Hoping that I can rescue them for something else.I've got the good balance part down pat.There really is alot to it and it is just that much worse with twins.

[Chrisg81983]

Nooo dude, I cant do that!!! I have a set, S/B but you never know if you might need them. As your building that awsome boat you may run those props yourself. It's early days... "I lost shaft on the maiden" incl. the prop. would have been nice to have a spare set at that time.Hang on to them for a bit, you might need them, BUT THANK YOU for the offer!!!!

Ok then it's up to you even if you wanted to borrow them just tom try out I will send them just let me know ok

[nata2run]

Mmmm,Jorn Oliver,interesting.
I tried the thinning thing on a pair of ABC 2016/3's and oops,too thin.Hoping that I can rescue them for something else.I've got the good balance part down pat.There really is alot to it and it is just that much worse with twins.

I hear you!!! I dont thin any props, but I can sharpen & ballance ok. I do quite like my new CNC props though, feather light and tough

[Chrisg81983]

Kent with the cnc props how strong are they in comparison to a standard octura prop ? I heard from some that they are throwing blades at high rpm's , and twisting blades under hard acceleration. I have no experience with them, but sure would like to try them out.

[nata2run]

Kent with the cnc props how strong are they in comparison to a standard octura prop ? I heard from some that they are throwing blades at high rpm's , and twisting blades under hard acceleration. I have no experience with them, but sure would like to try them out.

Well, its hard to say as I'm no expert on those props. What I do know it that they break before they twist. You cant twist them (I think they are 7075 hardened aluminium) . I had a 445 CNC (same company) accedently hit the stand Reving up, and the prop snapped. clean off. Dont know about throwing blades?? are you going to do the famous 80K RPM??. I think they are safe at 40K Rpm and at that you will be going a 100mph in your HPR. I'm happy so far!! thats all I can say. If they snap at high RPM I'll be going back to the shop where I got them from!!

[Remmie81]

At 80K rpm the props will not be effictive anymore, they will cavitate. Good to make a milkshake, but not for getting youre boat faster :)
The high performance props are sharpened, thinned, and balanced. And then hardedend in an oven to prevent them from deforming(?) under load. (dont know how you guys call that process)

[srislash]

At 80K rpm the props will not be effictive anymore, they will cavitate. Good to make a milkshake, but not for getting youre boat faster :)
The high performance props are sharpened, thinned, and balanced. And then hardedend in an oven to prevent them from deforming(?) under load. (dont know how you guys call that process)

The process is called annealing.With copper berylium it takes 600 degrees F for 2 hours then good to go.Not sure about aluminum though yet.