So just had a wee play with your numbers suggested above, with the 30 mph…5700rpm. Came out at 22% slip for me…assuming it’s the 1.83 gear ratio and 13” prop. Defo worth another run out to double check the data.
So just had a wee play with your numbers suggested above, with the 30 mph…5700rpm. Came out at 22% slip for me…assuming it’s the 1.83 gear ratio and 13” prop. Defo worth another run out to double check the data.
Here is what I got for the 15”. This and the above at 20% ish slip…might even be the norm for a pontoon perhaps. Either way…there is definitely a fair bit of variation or uncertainty around the numbers perhaps.
Likely correct…especially with the rpm range and peak power being as it is…but be great to get the details and numbers verified first off, I think. Huge gaps and discrepancies currently. The mention of 0% slip and 1% slip tells the story. Further confused me, after I ran the numbers, getting hugely different results. Defo needs to start again, to get any progress.
You run out of torque... I'd say blade design is a bit different on the 13 as well. 200-250 is per inch but when at the top of the torque curve, it can dump rpm in a hurry.
Blade design is exactly the same between the 13 and 15 pitch 3 blade Hustler props.
Run the numbers with the correct big foot gear ratio please.
No it is not, unless one of them is incorrectly labeled.
Think you may have left that out ! Regardless. The slip of 1% is still not in the realms of reality. The vessel view won’t be wrong either. You also just wont get 6200 from that engine. Best of luck next year, when you get a chance to get some better data.
The normal gear case hub will not fit the bigfoot. The spline count is different. I used the same hub (Turning Point 501) for both three blade props, literally removed it and installed from the 13 to the 15 before sending the 13 back on trade.
Yes I apologize for that, I guess it was critical for double checking my numbers.
Just suggesting you try again. That’s all. It’s not me that has an issue with it. It’s the physics that does
The weight is evenly distributed using 50lb bags of salt to mimick how it will be setup in the spring. All have been stationary in the same places for all testing.
Trust me I am dumbfounded as well. I am a Validation Engineer by trade so this really pisses me off. I will be sending all data to Turningpoint this afternoon. I already confirmed vesselview can't really be wrong.
I hear you. Things like this annoy the life out me too. 10 years as a professional marine engineer at sea…16 years after as an engineer in renewables. Frustrating eh. Only reason to be mentioned the previous is that I’m not totally convinced that engine should see 6200 without a limiter before it. Just this afternoon l, tried my mercury outboard flat out there. It’s range is 5000-6000 rpm. She limited time and time again at 6120-6150 on smart craft and VesselView. Both of them couldn’t get to 6200. Mine is from 2016
Then you certainly know that you're not going to figure out what is going on from a single data point.
I have a thousand engineer jokes.
