Prop Cup
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Yes, I've been pretty busy. I'll try to call tomorrow.Originally Posted by ezrizer
Yeah, I'm with you on most of that Frick, If I didn't have props that were already dialed in I would probably just have mine bent up and that would be that, still might do it anyway... I just wish I could get an answer on what the negative impacts of cup might be.
Brett
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Just considering the physics of it, seems that it will reduce overall prop slippage, and bring down your RPM due to the fact you are "grabbing" more water. Not sure if you would actually lose much top end, and the prop should be more efficient, proving more thrust, in turn requiring more hp to turn it to max or target RPM. IE: you may lose upper RPM, but gain back a little because you reduced the slippage. maybe?
You are correct on your physics.Originally Posted by frickstyle
Someone who knows alot more about it than me will chime in.Just considering the physics of it, seems that it will reduce overall prop slippage, and bring down your RPM due to the fact you are "grabbing" more water. Not sure if you would actually lose much top end, and the prop should be more efficient, proving more thrust, in turn requiring more hp to turn it to max or target RPM. IE: you may lose upper RPM, but gain back a little because you reduced the slippage. maybe?
Also, cup affect the prop differently depending on where you add it. Very important....the amount of cup used and where. Additionally, different prop designs respond differently to cup too.
Brett
Brett
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Brett, 2 props with the same amount of cup and pitch if one is an 3/4 to and inch smaller diameter would the smaller prop be worse at planing??
Most props I`ve tried just burn a hole in the water and will not get this heavy beast on plane until my current new Mercury labbed 17 3/4 X 27 . gets up no issues.
Ive run out of pitch and need to move up but planing is a huge concern. I`ve been finding some smaller props hence my question.
Most props I`ve tried just burn a hole in the water and will not get this heavy beast on plane until my current new Mercury labbed 17 3/4 X 27 . gets up no issues.
Ive run out of pitch and need to move up but planing is a huge concern. I`ve been finding some smaller props hence my question.
Quote:
Most props I`ve tried just burn a hole in the water and will not get this heavy beast on plane until my current new Mercury labbed 17 3/4 X 27 . gets up no issues.
Ive run out of pitch and need to move up but planing is a huge concern. I`ve been finding some smaller props hence my question.
Yes the smaller diameter would be worse at planning if indeed you had the power to pull the larger diameter. More blade area will create more thrust.Originally Posted by ICDEDPPL
Brett, 2 props with the same amount of cup and pitch if one is an 3/4 to and inch smaller diameter would the smaller prop be worse at planing??Most props I`ve tried just burn a hole in the water and will not get this heavy beast on plane until my current new Mercury labbed 17 3/4 X 27 . gets up no issues.
Ive run out of pitch and need to move up but planing is a huge concern. I`ve been finding some smaller props hence my question.
It is harder to find propellers at 17.5 and above diameters.
Brett
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It is harder to find 17.5" + 4 blades.
I would imagine if I did go down to a 17" prop but went to a 5 blade instead of 4 that should help things? ( more blade area)
I would imagine if I did go down to a 17" prop but went to a 5 blade instead of 4 that should help things? ( more blade area)
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I would imagine if I did go down to a 17" prop but went to a 5 blade instead of 4 that should help things? ( more blade area)
Yes, 5 blades are still being made and do offer better planning in most cases.Originally Posted by ICDEDPPL
It is harder to find 17.5" + 4 blades.I would imagine if I did go down to a 17" prop but went to a 5 blade instead of 4 that should help things? ( more blade area)
I am supposed to be getting a number of 4 blade prop sets in for CR sales. Should be on the web site soon.
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Frickstyle , sent you a PM
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Call me and we can talk about your issues.
Brett
Is that how you add cup to a #6 style cleaver prop? I was always under the impression the blades on them were too thick to try and bend to shape, and thats why they grind out material on those style props? At least thats what mercury racing says regarding those cleaver style props.Originally Posted by bbladesprops
Grinding in the cup is a complete no-no! I almost laugh and then cringe when I see that. The water can't flow correctly when you grind out a hollow for the water to run into it. We add cup via heat, dies hammers and many moons of experience.Call me and we can talk about your issues.
Brett
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Really, who at Mercury Racing told you that? Originally Posted by MILD THUNDER
Is that how you add cup to a #6 style cleaver prop? I was always under the impression the blades on them were too thick to try and bend to shape, and thats why they grind out material on those style props? At least thats what mercury racing says regarding those cleaver style props.
If Mercury Racing told you they grind out a hollow to add cup, Mercury Racing was mistaken in your question. I can promise you that unless something we developed over 2 decades ago has changed. And that is not the case.
You can bend and shape #3,4,5,6 drive propellers to some degree. It takes knowledge, background and talent. Some of that may have been lost or is being changed for easier production. But, it can be done.
Let's face it, the custom propeller ability is a fading art. Look at Mercury Racing, they don't offer custom propeller work anymore like when Dennis and I were managing the Laboratory. They offer one size fits all options now.
All the custom propellers we build at BBLADES come to you with 90 years of experience molding a handcrafted one off, if necessary, product.
Brett
