MHZ Mystic 1380mm build

[srislash]

I just got my 5017's from PropShop.6s is coming.Perhaps I'll work them tomorrow morning and run after.

[nata2run]

What props seem to be the best so far?

[Chrisg81983]

Any twin setup sounds cool but twin lehners sound great, and wait until you hear them spinning on a higher cell count. I am glad the cooling is working how it's supposed to. Keep it coming !!!!

[srislash]

What props seem to be the best so far?

So far I am fond of the 5018/3's on 5s.I am hoping that I can go to 6s with the 5017/2's.I have been running 6s with 648 two blades.Everything has been cool temp wise except for that last run where a cooling line got changed and one side of the ESC didn't get water.All is well though.

I may have more water to run in here as the Fraser River is threatening to flood some areas.

[Chrisg81983]

Srislash what are you running those props on do you have YouTube videos of it going

[srislash]

Hey Chris,I am running my CF Fightercat Shocker.TP 1820 kv 4082's. Here is a couple of the latest vids

http://www.youtube.com/watch?v=xcE546NbC4k&feature=plcp

This one is a little more entertaining:

http://www.youtube.com/watch?v=IO93aXMlmWk&feature=relmfu

[Chrisg81983]

Cool thanks I will watch them now

[keithbradley]

Mhh, a little strange and maybe even dangerous recommendations. I mean I know applications for LMT's with 100k rpm stable but thats a completely different world than our boats.
One of the guys running the highest rpms here is a friend of mine named Hennes, he runs several boats with up to 65K rpm loaded. And thats what it sounds like:

But that takes YEARS of experience and a lot of knowledge. These speeds are also possible with less than 40K rpm. So be aware, high rpm setups may sound great and can achieve very high speeds but also demand knowledge and accept hardly any mistakes at all!!

For the TP issue: Mhh 1600kv on 8S is not so much, I can hardly imagine a rotor will disintegrate due to temperature/high current. I see the problem more in too high rpms and bad armouring. I've already seen a few 4-pole motors from other manufacturers with bad armouring of the rotor and when these fail the rotor almost explodes. But we'll see, when everything gets right next week I'll build a HPR C5009 with 2x TP 2350kv on 6S each. Should be fine for ~100mph.

regards,
Manuel

I didn't see where anyone in that thread reccomended 80k on a motor...maybe I missed it?

I commented on the 8s/1600kv setup in that thread by stating that you can't expect high RPM setups to last like lower RPM setups. 8s on 1600kv can work if the load is kept low enough, but 95% of the people that try these type of setups don't prop accordingly. They take a setup that runs good on 6s, and up the votage to 8s to go faster without changing props. If they had a setup that pulled 180A on 6s, that's going to be a problem on 8s.

I run higher RPMs than that in some of my boats, so I know it can be done. You just have to be intelligent about it. 8s/1600kv is going to require very small props to stay within a safe range of current draw. If you're pulling 5-6000W through a 2500W motor, it's not going to last long.

Manuel, do you have any experience with TP motors? I'm building a large cat, the size of the c5008 and I'm thinking of powering it with 5892 TP power inrunners...I don't know of anyone who has run these yet though...

[srislash]

I didn't see where anyone in that thread reccomended 80k on a motor...maybe I missed it?

I commented on the 8s/1600kv setup in that thread by stating that you can't expect high RPM setups to last like lower RPM setups. 8s on 1600kv can work if the load is kept low enough, but 95% of the people that try these type of setups don't prop accordingly. They take a setup that runs good on 6s, and up the votage to 8s to go faster without changing props. If they had a setup that pulled 180A on 6s, that's going to be a problem on 8s.

I run higher RPMs than that in some of my boats, so I know it can be done. You just have to be intelligent about it. 8s/1600kv is going to require very small props to stay within a safe range of current draw. If you're pulling 5-6000W through a 2500W motor, it's not going to last long.

Manuel, do you have any experience with TP motors? I'm building a large cat, the size of the c5008 and I'm thinking of powering it with 5892 TP power inrunners...I don't know of anyone who has run these yet though...

I don't think anyone was recommending 80,000 rpm Keith.Just saying there were rated for it(or claim to be).Like the TP 1820's being rated for 58,000 rpm and 50 volts(That would be a brave run). I think I will pick this time to state that I am quite careful about testing new bigger props and check specs with an ET data logger.I'm just trying to learn and get acquainted with props myself here so as to do a bigger/better build in the future.
My goal is to stay under the 40,000 loaded rpm mark.

If you play with the speed calc you will find just how much of a smaller prop will get you more speed by increasing voltage.

Shawn

[Chrisg81983]

Shawn your fc hull runs real nice you did a good job with it thanks for posting the link for me

[srislash]

Shawn your fc hull runs real nice you did a good job with it thanks for posting the link for me

You're welcome Chris.Can't believe you missed it so far.There will be more to come.Here's the build http://forums.offshoreelectrics.com/...hawn-s-Shocker
At some point I'll step up to a 1150 hull

[keithbradley]

I don't think anyone was recommending 80,000 rpm Keith.Just saying there were rated for it(or claim to be).Like the TP 1820's being rated for 58,000 rpm and 50 volts(That would be a brave run). I think I will pick this time to state that I am quite careful about testing new bigger props and check specs with an ET data logger.I'm just trying to learn and get acquainted with props myself here so as to do a bigger/better build in the future.
My goal is to stay under the 40,000 loaded rpm mark.

If you play with the speed calc you will find just how much of a smaller prop will get you more speed by increasing voltage.

Shawn

Oh...I guess a lot of motors are rated high...some manufacturers are probably more accurate than others.

I think you've done quite well with your Shocker Shawn. It runs great. I think if you do decided to lose the 5018s and run a smaller 2 blade prop at higher RPMs you're going to love it. I'm not suggesting anything is wrong with the 5018s, just that they're a large prop for that hull and I think you will be impressed at how it handles with something like x447s. I'm running 442s on my Explorer hull by the way, and it's similar in size.

I don't use the speed calc much anymore. It works for some stuff, but there is a point of diminishing returns in real life situations that the calculator doesn't apply. It will always tell you that a bigger prop and higher voltage will add lots of speed, but it doesn't always translate. Often a bigger prop can actually slow a boat down.

I love that video Manuel posted. High RPM twins sound so beautiful...

[bruiser77]

Hi kieth, here is a link to a video of a Hpr ct04 running tp 5850's.http://www.hydroworld.de/vb/showthre...CT04-Erstfahrt

[srislash]

Oh...I guess a lot of motors are rated high...some manufacturers are probably more accurate than others.

I think you've done quite well with your Shocker Shawn. It runs great. I think if you do decided to lose the 5018s and run a smaller 2 blade prop at higher RPMs you're going to love it. I'm not suggesting anything is wrong with the 5018s, just that they're a large prop for that hull and I think you will be impressed at how it handles with something like x447s. I'm running 442s on my Explorer hull by the way, and it's similar in size.

I don't use the speed calc much anymore. It works for some stuff, but there is a point of diminishing returns in real life situations that the calculator doesn't apply. It will always tell you that a bigger prop and higher voltage will add lots of speed, but it doesn't always translate. Often a bigger prop can actually slow a boat down.

I love that video Manuel posted. High RPM twins sound so beautiful...

Keith,I do have a pair of PropShop 4518/2's and a pair of 447's not to mention everything Ben sells up to the 5018's that has been played with.I am really tempted to cut down the 1.7's or even the 5018's to bring the diameter down and pitch up.Not sure yet.Just getting ready to get serious about 6s.

My apologies to Kent for this blatent thread hijacking.

[nata2run]

That's right!! This is a productive thread LOL