Suggestions for a 3 blade prop?

[d.a.v.e]

Some of the fast guys I run with I see are running 3 blade props on their SV27's. Wondering if I should be doing the same on this boat and what might be a good fit?

Got my Impulse out for the first time today. I'm not sure my GPS is working so I did not bother with it but based on the speeds I get from my Geico (43mph) this boat felt pretty slow. Maybe because the water was like glass & the boat does not bounce like the Gecio? I'm not sure why the my Impulse came with a X642, I also got a X445 with the boat but have yet to try it. The 642 seemed to push the stock electronics pretty well. I forgot my temp gun but things felt pretty good and my Eagle Tree showed it was pulling in the range of 60amps most the time bouncing up to 70 or so in the turns?

[SFC K]

I running the M445 prop on mine and it is pretty fast. Not sure what the actual speed is but fast enough for me. I would be curious too on a three blade prop for the Impulse. I have not found anything here yet or online.

[d.a.v.e]

I just bought a M445, I'll give it a try today. Wish my GPS was working..

[Stephavee]

Mine is running a m445 with 5000mAh 30c lipo @ 37mph on a garmin Etrex gps "kinda heavy"! not fast but man can it cut a turn!!!!

[dana]

The obvious choice would be x440/3 or grim 40/52/3 which are close in comparison

[roadrashracing]

when I ran three blade on my proboats it seemed like it took a lot more to get them onto plane

[dana]

when I ran three blade on my proboats it seemed like it took a lot more to get them onto plane
Yes that's sounds rite. 3 blades are faster overall but slow to get up. They also draw more amps, but doesn't a v style hull handle much nicer with a 3 blade? Less torque effect and a smoother ride. IMO

[Stephavee]

Yes that's sounds rite. 3 blades are faster overall but slow to get up. They also draw more amps, but doesn't a v style hull handle much nicer with a 3 blade? Less torque effect and a smoother ride. IMO The IM31 has that offset prop shaft so torque roll is at a min. If you ran a three blade on a stock IM31 V1 with 4s would it be too much for the esc? For you guys that have deeper pockets than i do get some 3blade props and gps your speed...You all got me thinking about a new prop now!

[dana]

You'll be ok. Even tho it's 3 blades and will draw more amps than its 2 blade equivalent, it is most likely still less amps than an m445.

[dana]

Most people say that 3 blades are slower top end and faster out of the hole, I've found the opposite.

[Stephavee]

Mine is running a m445 with 5000mAh 30c lipo @ 37mph on a garmin Etrex gps "kinda heavy"! not fast but man can it cut a turn!!!! I take that back she did 38.6mph. I looked at the video again and saw i was shorting myself. Also would those 3blade props give me a higher top speed than what im running? I will say i dont race, and kinda like how fast it takes off with the m445. I also tryed a m545 but it just alittle to much for my stock setup.

[d.a.v.e]

I'll try the 440 if Kentec has it in stock as I'm ordering some stuff today.

I tried out the M445 this weekend and it got the boat more toward the speeds I was expecting. Still don't have a working GPS but Eagle Tree tells me its pulling pretty consistently in the 70amp+ range and my connectors (EC5's) were coming back pretty warm.

[nickB722]

I'll try the 440 if Kentec has it in stock as I'm ordering some stuff today.

I tried out the M445 this weekend and it got the boat more toward the speeds I was expecting. Still don't have a working GPS but Eagle Tree tells me its pulling pretty consistently in the 70amp+ range and my connectors (EC5's) were coming back pretty warm.

Let us know how it works Dave, I'd love to give it a shot at some point in the future if you have decent results!

[SFC K]

I ran mine last weekend and it ran pretty well with the M445. Motor and ESC temps were just over 100 degrees once I got the hatch off. I'm still running the stock conncetors though and they were pretty warm.

I was running with my friend and he had his custom hand made Air boats running side by side with mine. he has GPSed his at 33-34 MPH consistently and my impulse would pass it rather quickly. I'm estimating mine was doing 40 and I have the dual rudder sytem on mine.

Here is the video.

http://youtu.be/5NkYbFVraZQ

[Stephavee]

Cool video! looks like from the video your faster than mine at 38.5mph...i know looks can be deceiving but i would bet money on it! Is that a three blade prop?:beerchug:

[SFC K]

Thanks! I know it looks fast and my friend thought it was faster than 40 as well. I think it is perfect for me. It is the M445 prop. I think we are waiting on Dave to try out the Kentec...

[Stephavee]

This is my M445 video. What are you running for batterys?
http://youtu.be/NxHXrsEIjoQ

[SFC K]

Wow! She was flying. Some close calls. Mine seems to be a bit more stable than yours. How do you have your trim tabs set up on yours and were do you place your batts'?

I'm running 2- 2s Turnigy Nano-Tech 5.8mAh 60C batts in mine.

[Stephavee]

I was running her kinda hard! Just tring to get comfortable with how well this boat handles! I made a small ajustment to my strut, moving it up some and the tips of my trim tabs are flush with the bottom of the hull. My batterys were all the way back with my garmin Etreks gps fwd of them. She handles great when im not driving like a p!ssed off teenager but whats the fun with that? I have a nice rescue boat and a raft! so i dont mind getting alittle loose.

5800mAh 60c nano-teck.....How do you like them? im in the mood for new cells soon.

[d.a.v.e]

I had a chance to try the 440x3 today and it felt like the boat was running in the mid to high 30's? Wish my GPS worked but I can say the prop was pulling consistently in the 65-70amp range which is less then the M445 which is in the 70-80+amp range. I also tried a carbon 447 today that felt really fast & was running in the 70-80+ amp range as well. Both of these props felt like they ran in the low 40's? I would give the edge to the 447 but have nothing to quantify that.

FYI: I'm running all stock electronics, have an upgraded shaft, 5.5 bullets on the motor and EC5's on the battery's. The batteries were 40c 2x2c softpack zippy's that have about 5 runs on them. Trim tabs are set level with the boat & the prop is set pretty deep. I did not play with strut adjustments all three were run in the same spot.

[nickB722]

Thanks for getting back with us Dave, I was going to pick up a 440-3 or Grim 3 blader today at the LHS but they were out of stock, now I'm really hoping to get my hands on one. Was there any chine walking or torque issues with the 440-3? Keep us in the loop if you do any more testing!

[Stephavee]

I have a bumb question...I know that some esc's are under rated as far as amps but how is it ok to run a prop that is in the 70-80a range on a 60a esc? am i missing something? Im running a m445 on 4s with all stock motor esc. Am i pushing it or not?

[d.a.v.e]

Yes with the 3 blade the boat was pulling quite a bit more to one side. I'm assuming that's the direction the prop was turning? I think if I had more time out there today I could have easily dialed it out with the steering trim or ideally adjusting the trim tab on that side a bit. Unfortunately it started to rain and my 4yr old was with me so I had to keep an eye on him and his boat (reef racer) as well.

I would guess yes you are running it at the edge of what it can handle with the m445 as I have seen spikes in the 100+ amp range with that prop. The connectors come out very warm after I run mine with that prop. Generally when the water temps are cooler the boat runs cooler but as the summer progresses you will want to watch your temps as the lake/ponds heats up.

Last year when I got my Geico I did a fair amount of prop testing and pushed the 40amp esc the same why I'm running this one. By about the middle of the summer it started having some issues (it never went up in smoke) so I replaced it with a 180amp esc and things seem to run a bit cooler in that boat now. Surprisingly the motor never gave out though despite running it 4 days a week with at least 3 times a day (usually back to back).

[nickB722]

It would stand to reason that it would be walking more to the side with a blade already in the water, but I'm sure it's just a matter of adjustment to get it tracking straight and true.

How were the speeds compared to stock and the M445 (I've run both of them but GPS'd neither)? And how about handling in the turns?

[Stephavee]

I have made some cooling mods like esc 1st inline with high flow tubing and 5.5 connecters on the bats. but i only run once a day and less than once a week:sad: i have an 9munth old that takes up alot of my time i think i will savethe stock 60a esc for my next boat build ( A Dumas Racing runabout kit ) and i will use the old motor out of my BJ26. On 2s it should run well i think. as for my IM31...A seaking 180a is going in. that way i shouldnt have to worry about too big of props and if i wanted i could run 6s...:beerchug:

[d.a.v.e]

So I tried out the 3 blade 447 (not sharpened or balanced) on the stock electronics today. It seemed to pull an average of about 93amps over a 2.5min run and spiked at 109amps. Everything was hot! When I temped it the 5.5 bullet connectors on the motor temped just above 300 degrees, the motor was around 170, ESC was about 165, lipo pack was 125, and the EC5's were over 200 on the battery leads. I was running a 4 cell 5000 Turnegy 40-50C pack.

The strut should have been lowered a bit and I'm sure I could have got more out of it but as is the GPS recorded a top speed of 34mph. I would have guessed it would have been faster then that the way the boat was running. Its a new GPS and I need to do some trials in a known configuration to see if its reading correctly. Anyway the boat handled well and I would have guessed it was in the high 30's looking at it. Unfortunately in the current configuration run times suck.. Maybe 3 min on a 4 cell 5000mah pack. Hopefully the 1500 motor will help here?

I also got a 3 blade 450 & a new m445. I'll try testing the 445 tomorrow on the stock electronics but I don't think I want to push it with the 450.

[stadiumyamaha]

I have a feeling that the 450 prop may have you buying some new gear. I blew the caps right off that esc with a less aggressive set up.

[Heaving Earth]

450 on an sv27?!?! Lmao def a gOod idea. The 447 did worse than the smaller props so go bigger "rolls eyes"

[d.a.v.e]

450 on an sv27?!?! Lmao def a gOod idea. The 447 did worse than the smaller props so go bigger "rolls eyes"

I'm going to assume you did not read the thread or this history & ignore this comment. You may want to pay more attention to what your really commenting on next time and think of something helpful.

[Heaving Earth]

I read it, I was just being a smart ass. Sorry.... Try ul1 motor in that thing

[nickB722]

I'm off to the LHS now, hopefully they've got a few three bladers in stock to try out. Looking at the Grim 40x52/3 and/or a 440/3 this time around, hoping to add a x642 and getting a new m445 to replace the one I dinged up in transport a few weeks ago. I'll post results if/when I get a few good runs in.

[nickB722]

Got a Grim 40x52/3 last Thursday. Got her sharpened and balanced but didn't have a chance to run this weekend. My summer is pretty much over next weekend, so I'll have one last shot to get some real world running in. After that, the only chance of runs will be an occasional straight run in a ship model testing tank too narrow to turn in and too short to reach top speed (but data, high speed camera footage, and telemetry will make up for the lack of turning... I hope).

[nickB722]

Tonight I had a chance to run the Grim 40x52/3. I didn't have very good results as she wouldn't plane off without a huge push at the start (and fell off plane in all turns). My initial guess was that the strut was a bit too high (not enough bite on takeoff), but I'm not sure. When I was able to get the prop to hook up with a big push, it seemed to take off much faster than the stock one and threw a decent looking (low and long) roostertail. I wasn't able to adjust the strut as it was getting DARK way too fast to even bother with anything but quick CG adjustments. I'm probably out of luck till next season, but I'll do what I can to tweak when I get the chance to run.

I did get a few runs in with the stock prop for initial baseline setup/tuning/testing purposes. I was able to commandeer a laser temp gun for the night and got a good bit of data as far as heat goes. I'll have to find my notes to get the exact numbers, but I took readings on the batteries, deans plugs, motor bullets, ESC caps, and the motor itself as well as the water and air. It is my hope to get this data up here as well as adding info to it as I test different props/setups.

I was able to pick up a new M445 to replace the one lost in the sinking incident, I'll sharpen and balance it when time permits and get good temp reading samples once I get her dialed in.

Also, if anyone has had luck with the 40x52/3 I'd like to hear about strut position/angle and CG if at all possible.

[gtrcguru]

i tried a 40x52/3 and had the same results as you. the further down i moved it the better it got though.
dont really know what the angle was but i go on how high strut is in relation to strut mount.
the best run was when strut top was level to just below top strut mount. batts were center middle of batt tray. thats as far as i went with it.
ive also run a x452/3 and it seemed to plane out alot better without as much top speed but that was before it was sent to be sharpend.
im sure it will be a bit faster after its trim down

[nickB722]

Well I figure with the NiMH batteries I run I won't have to go quite that low on the prop, but I'll definitely be lowering the strut.

Were you able to eventually get her on plane and running well with the Grim prop? How were speeds compared to some other props you had on her?

Glad to hear it's more than just a few of us Michigan types screwing around with the three bladers!

[gtrcguru]

it planed out alot better with it low. it still had some run up issues but once it was on plane it flat got with the program.
i would say it was one of the fastest props ive tried but i only put a couple runs on it so i never really found its sweet spot. its out being s&b
if you do the math i think it comes out to the boat moving 3.2" per revo of the shaft. thats pretty fast as far as props go.
i like the 3 bladers because its more scale. i even ran it on my mystic. i could tell big difference on it.
still had plane issues but again once on plane you better hold on!!!
i think the 42x55/3 would be a better prop. more prop in the water which = higher strut angle & more speed.

[nickB722]

Thanks for the details/updates. I'll definitely give the adjustment a shot when I get the chance, hopefully turning it into a project for prop/powerplant matching later this semester.