Maximus throws blade at my SCX
 

This is what happens when you throw a blade. Water was smooth as glass I was running about 6300 RPMs. Then all of a sudden vibration out of the wazu.

Scx

luckily it only got the cavitation plate, this is why i hate labbed props you never know when they will give up

Blade was 3months old from merc racing

I stopped running labbed props in 2004. I had a set of 4 blade 26p labbed bravos behind a set of HP500's. We were at the LCM Poker Run and the water was rough. I had it on the rug, we got some good air (I felt like I throttled it perfectly) and when we landed on the next roller I broke a blade clean off right at the hub. The vibration was unreal. I only had regular bravo 1's at the time and it bent the shaft. It did a lot of damage to my boat. I was assured by the person that did them that it was an anomaly. I tried one more set and they were always folding blades. They always seemed.to kill the midrange and holeshot as well. I finally got away from labbed props and made the decision that if I wanted to go faster, I would build more HP. That has saved a lot of time and disappointment over the years.for me.

I have #6's now and they seem to have enough meat on them that labs work well up to about 1200hp. Now they make even thicker wheels for 1200hp and up but they will slow you down. I guess the new forged wheels are the ticket, but I have other things that I need to be spending $23K on other than a set of props right now.

Dude, I have four of those. Two labbed and two non. It doesn't matter. I think mine are from the high X dim....oh and 3 prop shafts as well, one of them I was looking at the prop while on the trailer, spun in by hand gave it a wiggle and a pull. Off came the prop with a big chunk of shaft with it. After you throw a blade take a really good look at the shaft.

Sorry to see that. Hope you find something that works for you.

This is one of the reasons why I like the Arneson #7M conversion over the Imco, Bmax, Max works ect. stuff. You don't run the Bravo style props.

I have a couple of them as well. Surfacing these props kills them.

Your dead on.

X dim having surged up in the search for speed with hardware made to be lower. Their is a reason why #6 props are so much more expensive and shafts beefier.

Here on the lake guys are throwing blades and breaking shafts on a lot of these Bravo set ups. Mostly Fountains.

My X is 2.5 below but it still pierce the water. My P5X doesn't pierce the water but 4 MPH slower. Lesson Learn

Whose tag line is: "Fast. Cheap. Reliable. - pick two."?

Perfect...

It can happen to any of them. I had a blade "tear" off of a stock 4-blade B1 prop. It didn't come off right away, and made a couple rotations as it was separating. I ended up with 2.5 slices through my cavitation plate.

Miami Boat Show Poker Run this past February, just left Gilberts and heading back to Lauderdale in my buddies Nor-Tech and threw a blade, was just cruising and it let go.... Violent Vibration in the boat...

I have a pair of Hydro H-6s for SCXs...32p if you are interested...

Mercury prop?

Is this prop Aluminum???

That is a Merc prop and no it's not aluminum.

Mercury Racing Labbed Maximus

I assume the props throwing blades must be only on boats with semi-surfacing props/high x-dimensions? I have a 7.5" prop c/l and have been running labbed props for 10 years behind as much as 1100 hp in my boat and have never had a blade fail, Smitty

He was asking about the cleaver off the Nor-tech.

Got that right Smitty. When Bravo props are semi or fully surfaced, they flex like crazy. They don't when they are run as they are supposed to. A Bravo drive is not a surface drive. If you want a surface drive, buy one that was build as one, that spins real surface props.

Being I am on learning curve like everyone else is or was at one time or another I made a mistake not knowing the out come. I just kept adjusting my SCX till I got great results and it does haul a$$ like it sits but at a cost. Now I know ill have to loose some MPH to keep a blade on it. Thanks to you guys… I know why it did it. (AS I SAID LESSON LEARN)

Hering does cast thicker eared props for this reason just in case you wanted to ck them out . good luck

And they break blades too.

And have a massive price tag.

at least they have a year warranty if you buy them new .

I hope it's a typo. But if you were spinning that prop at 6300RPM's what do you think was going to happen??

Mercury started using higher strength alloys a few years ago. They even had to re-tool because of the hardness of the metals.

When was the last time you inspected your prop? If there was any kind of ding or scratch caused by hitting the prop with a tool, rock, wood, etc., it could have caused a stress point on a blade. Centrifugal force at 6300RPM and it came apart.

There shouldn't be anything wrong with your props as long as they are worked properly (were they repaired?).

Include a visual inspection of the props prior to splashing the boat and check for loose nuts and proper torques on the drives on a regular interval. You would be amazed at what starts to come loose when we run the hell out of these things.

That's funny:lolhit:

What are you on about? These props are not meant to be surfaced, stress risers or not. Do you really think the prop was spinning @ 6300? The motor was. The words gear ratio comes to mind. Let's crunch a number for fun. 32" pitch @ 6300 rpm's with 10% slip. 172 mph!!!
The Herings will hold up better, but as with big hp Bravo style drives, it's on limited time.

Geez, I don't know you, and you don't know me. Your complaining about what I'm on about? I'm trying to help a fellow boater out. Put the bottle down and quit feeling sorry about yourself because I have a bigger boat then you. And it's a FOUNTAIN!


www.mercuryracing.com/propellers/maximus.php Here is a link for maximus propellers. Maximus are designed for high x dimensions, re: surface piercing props. No the prop wasn't spinning at 6300rpm, but if he has a 1.5 gear ratio then the prop was spinning about 4,200 rpm compared to 3,500 rpm if the engine was turning 5300 rpm. If he has a 1.35 ratio the numbers would be 4,600rpm vs. 3,900 at 5,300rpm. Don't know his drive gear ratio.

Point is centrifugal force exponentially increases with increased rotation. Look at his picture close up. On the leading edge of the prop you can see where the separation is at an angle then goes straight across the blade. That looks like where a crack started and the forces ripped the rest of the blade off.

Doesn't matter if it's a boat propeller, an airplane propeller, or a turbine blade. If there is a dent or ding thats not properly dressed out it becomes a stress point and will eventually fail with catastrophic results.

It's not the propeller thats to blame. Just include inspecting your prop just like you check your engine oil prior to starting up.

Cheers

:angry-smiley-038:

I'm not attacking your person, and no, I don't know you. You state in your post, that he's spinning 6300 and therefore he's prop is comming apart. The rpms has nothing to do with it, it's because of blade flex. That is why I wondering what you are talking about. Wether or not he needs to check more often for cracks, I know nothing about.

Oh and my boat is 42 feet, and I don't drink.

Happy boating.

Just my opinion but the labbed props also have a limited life span. I know a few people that after a few years of running them had to 1) send them back to re-pitched or 2) throw them in the garbage all together.

I have two prop the Max and a P5X hydo. I just put the max on that day so yes I looked at and it sill look like new.

Which prop runs the best ?

what gear a 1.50 =6300rpms =10%= a 32p prop = 114mph. did you mean 1 to 1 gears? I'll look that up. arh ha thats the ticket 1 to 1 = 172 that would be some fast biotch!!!

which gives you more bow lift?? thanks or rides better

Max is 4MPH faster the boat rides tall.

The max with 5/8" cut off the tube bow rides very hi = short tube
The max with long tube bow hight is = to the P5X the boat rides a little flatter and the transom is higher. I had to settle the transom down(china) so I cut the tube now it ride great at WOT.
The P5X is a great prop... better low and mid performance by 8MPH.

thanks, I just started testing the saber and its all over the place. I have a konrad ace with a shortie. started at 3'' and it porpoised so bad. even with tabs all the way down the boat rode bow high. with a 1'' spacer its its a little better I think, we didn't run it much. I hope to try a full size lower to see if its better. other wise its balance. it was a hard porpoise.