Prop pitch verses diameter

[FloatDaBoat]

one other question how does the grim props numbers work eg, 42 x 55
i understand its 42mm dia but whats its pitch it cant be 55mm unless that overall pitch,but that would then mean its pitch is 1.3"
no wonder props are called a black art, its like voodoo

the formula for converting mm to inches is: millimeters X 0.03937 = inches

that equates to 2.1654 inches pitch (overall total) for the GrimRacer 42 X 55

[ozzie-crawl]

the formula for converting mm to inches is: millimeters X 0.03937 = inches

that equates to 2.1654 inches pitch (overall total) for the GrimRacer 42 X 55

thats what i mean the 55 is total pitch.
but to get total pitch we multiply pitch by dia EG x440 1.4 x 40 =56 (2.204")
so if we do a grim 42x55 dia is 42 mm 1.4 x 42 = 58.8 mm not 55mm
if we multiply 42 by a 1.3" pitch 1.3 x 42 = 54.6 mm
see what i meen or am i looking at this wrong or does the grim prop only have 1.3 pitch

[FloatDaBoat]

thats what i mean the 55 is total pitch.
but to get total pitch we multiply pitch by dia EG x440 1.4 x 40 =56 (2.204")
so if we do a grim 42x55 dia is 42 mm 1.4 x 42 = 58.8 mm not 55mm
if we multiply 42 by a 1.3" pitch 1.3 x 42 = 54.6 mm
see what i meen or am i looking at this wrong or does the grim prop only have 1.3 pitch

You're thinking correctly, the actual pitch ratio would be (1.3095238) X 42 = 55 - - but that's a mite awkward to calculate. Either way you look at it, a calculation must be made to compare each method to the other. I use a spreadsheet, as it gives me a direct comparison.

[ozzie-crawl]

think i have a spread sheet some were on props mite save doing my head in with all the numbers floating around in there
so the grim only has a 1.3" pitch,may explain why the guys are adding some cup

[ozzie-crawl]

Hold off Oz, the stage10R-GT supercharged comes out next month Apparently, its so fast, with the right pitch and diameter prop, You only get to see it once. You hit the throttle and it rockets its way into another time w/ Doc and Marty McFly... Stupid fast man.. stupid fast

hey i helped test that stage 10r-gt super charger, i ran it about 6 months ago
on the 16 of july 2023 i have to go back to the lake at precisely 4.42 pm the boat will reappear

[electric]

All, there is a huge prop chart under the (tips) section on this website. It has all the calcuations done. It also has a link to all kinds of tools to calculate amp draw, speed, battery life etc using different props. I never go look and that area anymore, but was surprised what I found when I did. Hope this helps someone out.
http://www.offshoreelectrics.com/propeller-chart.php