Mike Larson
Well-Known Member
- Joined
- Apr 6, 2003
- Messages
- 927
Lets stimulate an otherwise boring day..... Why... is it that the cup ratio from 3.2 to 3.6 seems to be the magic numbers commonly run on current .21 props?.... Power to weight on the hull, motor to power to weight, all functions combined, what?...
reason asked is.... I've this box of props..... and while i've tested, retested, thrown, rowed, puked, needled, and otherwise ran my hulls, i'm always back stuck on the 3.4 prop for the best reliabilty... ie, throw it, and it goes, and fast......
While i'm not at all ignorant and constantly learning, a factory 1450, or 50x69, H5 or 7, will of course move something, and possibly well, with a range of props, stock, backcut, and prepared, what is it with the 3.2 to 3.6 46mm range that does it?.....
All else being equal, boat A pulled a 3.8 this spring in great air, with not much speed gained..... Boat A then degenerated through the test season, puking on 3.8, and pulling 3.4 all season long with ease, and consistent speed as always had recorded.....
having a small range of propellors, while nice, and a given pitch/cup doing well is nice, things ever changing is frustrating at best........
would you, do you..... cup them all around 3.2 to 4, and finite test from there, save up that massive 4.0 just for the spring, and fall, or work from around 3.2 to 6, and find THE magic one...... and copy it?......
question arising, that, as i'm sure we all have a little box of props that have little use ... ie; it wont pull that one, it wont pull that one, well it pulled that one this spring in great air, that one is junk, and wasting effort and time better spent trying to gain.......
winter's coming.... i'll be looking to fine tune a bunch of berylium junk..... searching for the magic, looking to gain.....
what is it, around that possibly being, most given .21 hydros weigh in around 4 lbs, and the given power output of a common .21 inboard motor that 3.2 to 4 or 6, are the norm.... how do you look for your pinnacle in any given prop/boat combination?...
Boat A ended the test season right back on 3.4 where I struggled all around it with little gain...... heat raced OK, but, as far as i was concerned it's a middle of the pack boat, ( great!)... but all i really accomplished was a little more wear on the motor, a lot of burned nitro, and some time and enjoyment invested.....
i'd like to come out in the spring with a positive jump in testing, a reworked box of little razor blades to spin, AND GAIN.......
otherwise.... i'm just burning nitro...... lotsa serious .21 guys around.... help me keep up..... mike
as a genera
reason asked is.... I've this box of props..... and while i've tested, retested, thrown, rowed, puked, needled, and otherwise ran my hulls, i'm always back stuck on the 3.4 prop for the best reliabilty... ie, throw it, and it goes, and fast......
While i'm not at all ignorant and constantly learning, a factory 1450, or 50x69, H5 or 7, will of course move something, and possibly well, with a range of props, stock, backcut, and prepared, what is it with the 3.2 to 3.6 46mm range that does it?.....
All else being equal, boat A pulled a 3.8 this spring in great air, with not much speed gained..... Boat A then degenerated through the test season, puking on 3.8, and pulling 3.4 all season long with ease, and consistent speed as always had recorded.....
having a small range of propellors, while nice, and a given pitch/cup doing well is nice, things ever changing is frustrating at best........
would you, do you..... cup them all around 3.2 to 4, and finite test from there, save up that massive 4.0 just for the spring, and fall, or work from around 3.2 to 6, and find THE magic one...... and copy it?......
question arising, that, as i'm sure we all have a little box of props that have little use ... ie; it wont pull that one, it wont pull that one, well it pulled that one this spring in great air, that one is junk, and wasting effort and time better spent trying to gain.......
winter's coming.... i'll be looking to fine tune a bunch of berylium junk..... searching for the magic, looking to gain.....
what is it, around that possibly being, most given .21 hydros weigh in around 4 lbs, and the given power output of a common .21 inboard motor that 3.2 to 4 or 6, are the norm.... how do you look for your pinnacle in any given prop/boat combination?...
Boat A ended the test season right back on 3.4 where I struggled all around it with little gain...... heat raced OK, but, as far as i was concerned it's a middle of the pack boat, ( great!)... but all i really accomplished was a little more wear on the motor, a lot of burned nitro, and some time and enjoyment invested.....
i'd like to come out in the spring with a positive jump in testing, a reworked box of little razor blades to spin, AND GAIN.......
otherwise.... i'm just burning nitro...... lotsa serious .21 guys around.... help me keep up..... mike
as a genera