Where can you get the ABC 1814-17-45 props? I didn't see them on OSE.
Where can you get the ABC 1814-17-45 props? I didn't see them on OSE.
Contact jim@abcprops.com and see who's carrying them. I'll email Steve and let him know to put them on his next order. Also contact Dasboata if you want to buy them already prepared, he may have some. I'll text him in a few hours to see. If he don't he can't get them from abc for you provided abc has some in stock.
32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was
I'm not convinced, after running the 2-Lap this weekend with Rafael, that the -17 rake props are the way to go. Have you tried the same pitch but with the -10 degree rake?
The reason I think this is that, with the -17 props, I had to run a LOT of strut angle downward in order to keep the nose down under the additional speeds. The lack of lift settled the transom more than with the stock prop, which, combined with the extra speed, resulted in some pretty spectacular wheelies down the straights.
I didn't have a pair of -10 props to try, but I suspect that the additional lift of these props would have allowed me to run less strut angle, and would have put more more of that thrust into pushing the boat forward, as opposed to hold the tail of the boat up.
Something to consider trying. I know that Rafael wasn't having to run as much strut angle as I did, and he was using the stock, X442 based props.
Darin E. Jordan - Renton, WA
"Self-proclaimed skill-less leader in the hobby."
I only ran 1mm of negative angle with the stock props. I saw the need to add .5 more negative angle with only 2 packs, and the props that Darin cut some rake in to. If I were just running around for fun, I would have run my struts neutral and dealt with the possibility of flipping backwards or letting off the throttle at the first sign of lift. But because this was a timed event, I didn't want to spend more time retrieving than running.
I think Darin is on to something. The energy used to lift the boat could be put to better use propelling the boat, forward. But, the fact that Travis reports back nearly 70 mph with 0-3* of timing is very impressive. Something is going right there. I guess it's up to the user to decide if the extra speed, at the advantages of less timing, is worth any potential propulsion loss due to running so much negative angle.
Last edited by Rafael_Lopez; 03-23-2016 at 03:07 PM.
Rafael Lopez
Product Developer-Pro Boat
My Facebook https://www.facebook.com/profile.php?id=100010183246751
I know the negative goes against traditional thinking but the negative is what these props like. I usually counteract that by having the nose a little heavier in the front of the boat by using epoxy in the tips etc. I want to leave this boat as stock as possible so I haven't done that yet. I have some negative in my even faster boats struts also. The only boat that doesn't require negative usually is a cheetah single. I've tried the 10 degree 1916 vs the 17 degree 1915 back to back and the 10 degree was about 10mph slower even with more pitch. I'm sold on the 17 degree props and my prop box shows it. I'm constantly replacing my octuras and 10 degree abcs with the 17's. To make them work you just have to put in a little work in tuning it. The octuras don't require as much tuning but if you want the edge and a little more speed, you'll put in the extra time in messing with the 17's. You can't argue the speed and how stable it was in the video. Stock boat. Stock motors. Just props, almost 75mph in 30+mph winds. The water may not look that rough in the video but trust me it wasn't ideal for going these speeds. If I wasn't leaving for Minnesota tomorrow, I'd be at the lake proving this boat will go 80 with these props. Don't be scared of the negative.....it's not hurting your propulsion.....
One thing I'd like to add. I've gone 70 and some change a few times in good conditions. With what I've been dealing with lately I'm only getting 64-65 and then the boat flips....with stock props and the struts level. So I swap the props, lower the angle to keep it on the water and its WAAAAY more stable so I can actually run it now.....and its 4mph faster than my best....and I did it in worse conditions. I see it as a 10mph gain because the boat is not running near as loose as it was to do 70. So I loosen it and it's going 80. No doubt in my mind. Darin if you were using the 1815's, they have more pitch....in my testing with these props, more pitch brought on more bow lift and more flipping. if it's easier than watching the video....
Last edited by kfxguy; 03-23-2016 at 03:10 PM.
32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was
OK... I'll just leave this to you. You clearly didn't read what I was saying, and hey, what do I know anyhow. It's not like I have anything that actually goes fast...
Darin E. Jordan - Renton, WA
"Self-proclaimed skill-less leader in the hobby."
I edited my post. I misunderstood (or didn't pay attention well enough lol) something you said, apologies. That's what I get when I'm trying to do two things at once lol. But I will admit that I automatically take defense to most of what your write because to me it seems to me like like to disagree with me a lot. So my fault for thinking that way. I'll try to read your posts in a more positive manner for now on. When you started of by saying you aren't convinced on the 17 degree props, I already had it in my mind you were disagreeing just to disagree.
32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was
Gotcha. I know these props can be a handful. I lost a very nice build to the depths of my lake because of an 1815-17 prop. I was too dang set on not wanting to give negative. Just seemed counter productive to me. But that's what they like. Still hard to get used to it.
Here's how yesterday went before the videos. At home on my setup board, I put the boat flat on it. Then lowered the strut angle to where the end of the struts were .020 from hitting the surface using a feeler gauge. That's a good bit of negative. Get to the lake and I'm popping wheelies as I'm getting into it. Not what I want especially since it's windy. I'm running out of time (wife texting me to come home) so I just put them full negative to see what happens. This time I was able to make nice full throttle passes. Maybe this will be my new method for now on. Major negative at first then loosen it up.
32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was
If the motors are truly a "D" wind, I would expect them to run hotter with more timing advance, regardless of the number of poles.
Hey, Travis, what else would you do to the 17 rake props beside S & B? Do you cup them? I do like them for monos.
32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was
I'm confirming the timing with both the ESC and motor vendor tonight. I'll have a better answer for you guys soon.
Motor temps seem to be around the same regardless of timing. What gets hotter as timing goes up is the wires and connectors being that the ESC is dumping power in to the motors at a tighter distance with higher timing.
Typically Delta wound motors do require less timing, but ESC programming also comes in to play. Since these are a combo and the timing was set rather high from the factory, 15*, I specified a lower timing on the ESC to be set at 7*.
I'll have confirmation from the vendors soon.
Rafael Lopez
Product Developer-Pro Boat
My Facebook https://www.facebook.com/profile.php?id=100010183246751
Good deal. Thanks!
32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was
Good Call. With these, it's really best to just get the next appropriate size. Looking at the latest list of what's available, it's a LARGE selection.
And, just to pass on something that I found at the 2-Lap... I was running 1815-17-45s with a bit of negative and the boat was doing OK, but as you can tell from the videos, was still getting lite in the nose (Wheelies down the front straight are fun to watch, but not fast! :) )... I had to modify them to get them to fit (hubs way too long for the stubs), but I put on a set of 1915-17-45s, which my Voracity motors will easily (EASILY) turn. The boat was clearly faster, BUT, more importantly, also keep the nose down MUCH better.
The reason is that, regardless of prop diameter, the setup is going to try to run on the last 40% to 30% or so of the prop diameter. Going larger in diameter is similar to lowering the strut on the back of the hull (something that isn't possible with this setup, only angle adjustments). Lowering the strut raises the transom, which pushes the nose down. All without any additional angle.
What I might suggest is that, if you find a props with the correct pitch (like in my case with the 1815-17-45 = 2.700" Nominal pitch), But you are having issues keeping the nose down OR would like to run with less angle in the strut, try finding the SAME pitch, but in a larger diameter prop. In the example case of the 1815, a 1914-17-45 (~2.66" Nominal Pitch) might be something interesting to try.
Darin E. Jordan - Renton, WA
"Self-proclaimed skill-less leader in the hobby."
Good info Darin. I need to try the 1715's. I was thinking the 1814's would be good because of the additional diameter because of the slippage upon takeoff with the stock props. Did seem to work much better but maybe the 1715's will be better. I'll find out in a few weeks.
32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was
Perfect.
ONCE you settle in on a diameter that let's the boat's attitude be "right", then, with these ABCs, you can go up or down in pitch to make the motors happy.
I'm actually thinking about designing my next SAW Hydro around this theory. Not worry about strut height. Just design it around a 35mm prop and work on pitch, rake, and pitch ratios from there. Could actually eliminate the strut that way if done correctly (some German boats already do this).
Darin E. Jordan - Renton, WA
"Self-proclaimed skill-less leader in the hobby."
I actually did this with my 32" cat. I settled on the diameter that worked well and then went up in pitch as I checked logs and temps to see if the motor and esc could handle it. I'm at 98 with it and I have one more step in pitch I can go up. So that theory does work well. I was doing that and didn't realize it till you just said something. Lol
32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was
Got lucky today and got my Zelos cleared from customs! Having a hard time getting my flex shaft loose to grease them. Tight space!
Rafael Lopez
Product Developer-Pro Boat
My Facebook https://www.facebook.com/profile.php?id=100010183246751
This is what I have been doing, it just changes the attitude too much going up in dia. Kind of came upon it accidentally. Sorry to come in here halfway Darin/Travis but I've been meaning to subscribe.
No Zelos here yet but this is what's been working on the Fantasm.
I haven't had any difficulty getting the couplers loose although they are located in a more confined space than say the Voracity. It's just the nature of the beast. The cooling lines and water pickups are somewhat in the way when I wipe the grease off the tip of the flexes. On my boat the stuffing tube liner was longer than the brass tube. I cut the liner off flush so I have a little more room to get my rag in there to wipe the tip of the flex off before inserting it into the coupler. It takes more time to do the maintenance on this boat and that's just natural since it has twins.
What size wrenches are you guys using? I won't be able to get the flex shaft greased until Monday evening. I used 7/16 and a wrench on the voracity but can't on the Zelos.
One thing I found on real boats that sounds like is working here as well is that high rake props (bow lifting at neutral trim) with the right amount of negative trim actually generate tail lift because the narrow cone is being thrust into the water. We found that to work best at 1/2 to 1.5 degrees of negative, if we needed more negative we then would decrease the rake until we got into that range. Difference to this is we also had the ability to change prop shaft height. Darin is correct most of the work that the prop does is the outer 40 percent, when we broke props 90 percent of the time it would be in the same place.
Rafael Lopez
Product Developer-Pro Boat
My Facebook https://www.facebook.com/profile.php?id=100010183246751
Damn it! Don't think I have a 10mm wrench.
That's one of those silly details I put in the manual, lol
Rafael Lopez
Product Developer-Pro Boat
My Facebook https://www.facebook.com/profile.php?id=100010183246751
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