New ShockWave 26 Brushless

[J.W. Pepper]

...im still trying to figure out why they went with a lower kv motor instead of the original 2900...
2 reasons...
1. The 2900Kv motor was disco'ed a long time ago. They only used it in two models... The original Shockwave 26 and the Widow Maker... http://www.proboatmodels.com/Product...ProdID=PRB3900 - Goes back to what YellowBird said... "The 2900kv motor is designed for about 7.4 volts (2 cell lipo or 6 cell NiMh) battery and gives good power [2900kv x 7.4 volts = 21,460rpm nominal]..." that's what PB wanted for those two boats. The WM was never that popular and faded into obscurity rather quickly. Interesting to note that both boats used the same 1.34" x 2.06" prop now found on the MG24.

2. Check the end of my last post - I said "bottom line is: PB took a discontinued model, updated the graphics, added a BL option & gave it a new name = practically zero $$ on development costs." The original PB 1500Kv motor has been reborn as the Dynamite 1500Kv motor, so it's still a current production motor that's also used in the MG29v2.

...is there really that much a difference between the 2,or is the lower kv motor basically more efficient causing the increase in torque?...
YellowBird came up with as good an answer as any... "I think it has different internals in terms of the magnet design", sounds like a good answer to me. It was probably PB's first BLM, they learned from what-ever mistakes were made and came out with the 1500Kv & 1800Kv motors they use today. Like I said before, they're torque mysters, I have both of them. It is because of the 1500's greater torque that they can spin the larger prop. The 1800 spins that same size prop in the IM31 V1 & V2.

I covered the subject of props in post #100, so I will refer you back to this website... http://rcraceboats.webnode.gr/news/gas-prop-essentials/

Ok, bin feelin kinda crappy today, feel better now, so time to get to work...

Happy Boating to all

thanks for the reply J.W.i already figured out the Impulse 26 and the Shockwave V3 were basically the same boat,just done up a bit.(I compare it to a base 69 Camaro to a Z28 lol).as far as the difference between the 2 motors,im still trying to figure out why they went with a lower kv motor instead of the original 2900.i have been doing a lot of reading,and I don't really see a difference between a higher rpm motor using a smaller prop,and a lower rpm motor that uses a larger prop(if the said voltage is the same).is there really that much a difference between the 2,or is the lower kv motor basically more efficient causing the increase in torque? it sounds to me like its a crapshoot really,unless there is a big difference between the 2.im guessing the higher kv with the same voltage and smaller prop would be a faster boat than vice a versa.i apologize for the questions,and keeping you away from your projects,just very curious.thanks again for your responses.

[yellowbird]

Hi all

To clarify, the 2900kv motor is actually a 2-pole design while the 1500kv is a 6-pole design. The higher pole motors have higher torque.

I suspect the design change to 1500kv was done to simplify the number of motors to be carried in the factory/ spare parts business - by using the more powerful motor with a single 3S battery it keeps the costs of the charger, battery and speed controllers down for first-time shoppers. The bigger 1.6" x 2.5" prop simply suits the high-torque motor better than the old 1.34" x 2.06" of the original boat so that came out of the "parts bin" as well.

Also, the original 30A brushless speed controllers had a habit of catching fire if overloaded with bigger props or even stock, whereas the 45A ESC seems to be much more reliable.

- yellowbird

[bigcam406]

thanks for the replies and your time guys.

[J.W. Pepper]

@YellowBird - Thank you!! - I knew there had to be some reason for the high KV rating, the 2-pole design answered my question. There was no torque, so they made up for it with RPM's.

I already knew the PB 1500Kv & 1800Kv motors are 6-pole as are they're Dynamite replacements; as well as both AQ's boat motors - 1800Kv MC, SVR, Revolt and 2030Kv for the UL-1.

Post #50 in this thread.... http://forums.offshoreelectrics.com/...ng-boats/page2 - Cheif stated the new Dynamite motors are the same as the old PB motors and quoted a very knowledgable source.


@Bigcam406 - I have a SW26 brushed on the way, due next Tues. If this oppressive heat wave will ever let up (me & the porcelain god were talking into the wee hours this morning cuz of it), I'll try to get the maiden run in by the weekend. First run is going to be stock out of the box except for the normal pre-run maintenance & a replacement motor coupler. I'm not expecting anything really exciting, just want to make sure all the stock parts work correctly before I dive in and start modding stuff.

After that, Im going with the 1800Kv IM31 motor with a SK90A ESC; will try several different props and see what happens. While I was still trying to decide between the MG24 & SW26, I was trying to figure out what prop size I would use with the MG24 upgraded to BL. And finally found the picture that tells a 1000 words... http://www.ebay.com/itm/VXP-FAST-M43...item4854e472f7 - side-by-side comparison of the Octura "M" and "X" style props.

Lenny's been telling me to run a 3-blade prop on my Rio to solve the torque roll issue. Every time I do, torque roll goes away and so does top end speed. After seeing that pic, I'm whacking the ears off one of my x436/3's in case I have torque roll issues with SW26 after upgrading to BL. I don't care, it's a $5 Venom plastic prop I bought for testing purposes, so fine I'll test with it.

If the 1800Kv still proves to be to much for it; fine I'll go back to my original plan of running the 1500Kv motor I got out of the swap shop recently. Jan doesn't CNC'ed x640's anymore and I recently read some rather discouraging info on the subject of pre-done S&B props, so not sure what I'll do bout a prop. Cross that bridge when I get to it.

Hi all

To clarify, the 2900kv motor is actually a 2-pole design while the 1500kv is a 6-pole design. The higher pole motors have higher torque.

I suspect the design change to 1500kv was done to simplify the number of motors to be carried in the factory/ spare parts business - by using the more powerful motor with a single 3S battery it keeps the costs of the charger, battery and speed controllers down for first-time shoppers. The bigger 1.6" x 2.5" prop simply suits the high-torque motor better than the old 1.34" x 2.06" of the original boat so that came out of the "parts bin" as well.

Also, the original 30A brushless speed controllers had a habit of catching fire if overloaded with bigger props or even stock, whereas the 45A ESC seems to be much more reliable.

- yellowbird

[bigcam406]

sorry your not feeling well,J.W. hope your feeling better soon.keep us posted on your results.

[J.W. Pepper]

So long as I stay inside I'm fine. I was checking out Accuweather.com the other day... normal temps for this area at this time of year are mid to high 80's.

This year it's been very high 90's with real-feel's in the 100's, some days temps are just south of 110°. WAAAYYYY too much for this just shy of 60-year old man.

I don't think I'm going to get much boating done this year. Got a new body for my Slash, need to get the RPM front bumper so it will fit correctly. I can run it around my apartments after the sun goes down till dark, around 9-ish.

Also finally got my Blade Tandem rescue heli re-assembled, crashed it bad last summer. Had the parts, just needed to get off my a$$ and work on getting everything put back together. Still have some fine tuning to do to make it fly better. Got a new body & light harness, just have to figure out which lights go where so I can put it on.

sorry your not feeling well,J.W. hope your feeling better soon.keep us posted on your results.

[Boat_guy]

The 1.6" x 2.5" prop looks like this... 1.60"(40.64mm) x 1.5625"(39.6875mm) pitch - for a total pitch of: 1.6 x 1.5625"= 2.50"(63.5mm). It's very close in size to the Octura x640 - 1.5748"(40mm) diameter x 1.6"(40.64mm) pitch - for a total of 1.5748" x 1.6" = 2.51968"(63.9999mm).

Sup guys! I'm actually waiting for my Pro Boat Shockwave 26 BL to arrive sometime next week. I have been reading about props and noticed that a lot of Pro Boat Shockwave 26 BL owners run the x435 prop.

Based on the quote above, has anyone actually tried the Octura x640 prop on their Pro Boat Shockwave 26 BL? I have not read or seen videos of anybody with a Pro Boat Shockwave 26 BL that runs the Octura x640 prop. Would there be heat issues? ESC getting toasted?

Thanks in advance!

[bigcam406]

the x435 prop mentioned previous is suitable for the shockwave v2 which comes equipped with a 2900kv motor.the v3 comes with a 1500kv motor,which has been explained to me as having much more torque,which can spin a larger prop with no issues.the 640 you mentioned has similar specs as the stock prop which comes with the v3.i don't think there would be a problem using it,though,maybe others could chime in,as im no expert on props,but the specs look similar to stock.

[Boat_guy]

the x435 prop mentioned previous is suitable for the shockwave v2 which comes equipped with a 2900kv motor.the v3 comes with a 1500kv motor,which has been explained to me as having much more torque,which can spin a larger prop with no issues.the 640 you mentioned has similar specs as the stock prop which comes with the v3.i don't think there would be a problem using it,though,maybe others could chime in,as im no expert on props,but the specs look similar to stock.

The V3 has more torque and it definitely could spin a larger prop. Although the x640 has similar specs to the the stock prop, the V3 it may not be able handle that prop due to it's weight (Being metal) and this may cause issues. That's the reason why I asked if anyone has any experience with that particular prop. I just want to make sure that the $39.99 for the x640 prop is worth the investment.

Thanks for the input btw.

[ray schrauwen]

With the PB using the 1500kv geico motor, there is no problem turning a x640 prop or an x642 for that matter but, start small.

[lenny]

What amp is the stock esc 45a ?
If it was me I would try and find a good used x440/3 prop and see how it runs.

The V3 has more torque and it definitely could spin a larger prop. Although the x640 has similar specs to the the stock prop, the V3 it may not be able handle that prop due to it's weight (Being metal) and this may cause issues. That's the reason why I asked if anyone has any experience with that particular prop. I just want to make sure that the $39.99 for the x640 prop is worth the investment.

Thanks for the input btw.

[yellowbird]

The stock prop is a plastic 1.6" x 2.5". ProBoat make a stainless steel upgrade/ replacement for this prop for $12 - part number PRB4019. I's suggest this as a budget upgrade before spending lots of cash on something from Octura - it will give better performance and be less likely to break a blade than the original plastic prop.

-yellowbird

[Boat_guy]

With the PB using the 1500kv geico motor, there is no problem turning a x640 prop or an x642 for that matter but, start small.

With what you said, I might try the x640.

Thanks!

What amp is the stock esc 45a ?
If it was me I would try and find a good used x440/3 prop and see how it runs.

The stock esc = 45 amps. Will that help in spinning a heavier prop? Or does the motor determine this ability to spin props?

You made my choice harder man. Lol! Now, i have to look into the prop that you just mentioned.

The stock prop is a plastic 1.6" x 2.5". ProBoat make a stainless steel upgrade/ replacement for this prop for $12 - part number PRB4019. I's suggest this as a budget upgrade before spending lots of cash on something from Octura - it will give better performance and be less likely to break a blade than the original plastic prop.

-yellowbird

I actually saw that prop on pro boats website. Your right btw. I may have to try this prop first before going for the octura. Being $12, and as stated on the website, this prop still needs to be balanced, shaved, and polished.

[bigcam406]

also remember,a balanced and sharpened prop will produce less stress on the running gear than an unbalanced/non sharpened one.it will be lighter as well.the easier it cuts through the water,the better.i'd go with the b/s 640.