Carbon shocker build

[PROP]

If you were using a Teflon liner would there be any point in polishing the flex shaft?

[kfxguy]

I have not done this as of yet, I imagine my Fantasm ones have done themselves by now. But maybe I'll give it a shot after my first go out this year. You know I'll also be looking for anything more.

Yes it does do it after some run in on its own. This boat has hardly any time on it. You know how a boat gets faster the more you run it even without messing with anything? I think this is part of the reason why along with the motor bearings loosening up. I've had boats with many runs and pull the flex and inspect it and there's polished areas. Now that I think of it, I changed the flex in one of my boats one time and it slowed down from the worn in flex.

[kfxguy]

If you were using a Teflon liner would there be any point in polishing the flex shaft?

Well I had the stuff to do a Teflon liner. And it may/may not be better. That's a big controversy, but I'll tell you why I didn't go with it.

1) to do it right and last (in my opinion) you need a thicker liner than the little cheesy thin stuff. So what that does is make the tube that the flex goes through a bigger diameter. More drag. That I think would offset the benefits. Having it in a twin because the tube doesn't drag in the water may be more beneficial.
2) turning the flex by hand in the liner feels like more drag to me that without it. I may be wrong or it may change when water gets in there or the Rpms are much higher, but I didn't want to chance it.


Don't want to start a controversy but those are just my opinions and I could be wrong. I will test it one day.

[PROP]

I've noticed the different opinions on liner vs no liner.
Have you considered changing your hatch thumbscrews for countersunk? I realize it's marginal but wind resistance at the speeds you're going may be worth another mph or two.

[kfxguy]

I've noticed the different opinions on liner vs no liner.
Have you considered changing your hatch thumbscrews for countersunk? I realize it's marginal but wind resistance at the speeds you're going may be worth another mph or two.

Actually I was looking at the boat last night and that stuck out to me, however, it would be a pain in the rear to have to use tools to unscrew the hatch every time. Something I'm not willing to do even it it is worth a mph or two. Might check into some lower profile thumb screws tho.

[dmitry100]

kfxguy: Where did you buy the black pool noodle... is it real pool noodle, or is it the stuff from like Home Depot for tubing insulation?

Have you ever tested the difference between regular strut bearing vs actual ball bearings? I'm sort of wondering if I should drill out some stingers I have... unloaded it'd be spinning about 68k rpm or so, so I figured with enough rpm it could be a big difference.

By the way, you might want to just switch out your 6 bearings for just 2 good (sealed?) boca ones... and use a spacer tube exactly the diameter of your bearing/strut inner diameter and tight enough so that it can hold the rear strut bearing (or you can maybe use thread locker). That way your prop shaft doesn't wobble around in the strut with those loose bearings and less overall resistance.

[kfxguy]

kfxguy: Have you ever tested the difference between regular strut bearing vs actual ball bearings? I'm sort of wondering if I should drill out some stingers I have... unloaded it'd be spinning about 68k rpm or so, so I figured with enough rpm it could be a big difference.

By the way, you might want to just switch out your 6 bearings for just 2 good (sealed?) boca ones... and use a spacer tube exactly the diameter of your bearing/strut inner diameter and tight enough so that it can hold the rear strut bearing (or you can maybe use thread locker). That way your prop shaft doesn't wobble around in the strut with those loose bearings and less resistance.

I haven't done back to back testing between a bushing or bearing. I mainly do it to keep water from going up the flex when using thin or minimal oil. It works well for that.

I have 4 good sealed (boca) bearing in there now. A piece of brass separated the two front and two rear. I'm doing that many for support. It's machined tight enough that there is no slack. No thread locker needed. A snap ring holds them in place. There's no wobble. Much more accurate than a bushing that has a little wear on it.

[dmitry100]

I'd imagine some good ball bearings would keep things at alot better tolerances than a typical strut teflon lead would... which I'd imagine would mean less vibration, etc? especially at higher rpm...

How did you manage to drill out your struts for the bearings anyway?

I have some drives that I want to drill out with my new drill press, but after drilling some tube I found that it can be trickier than it looks to make the hole straight because then the shaft and bearings would be spinning the prop at a different angle lol, and probably end up ruining the bearings if anything.

Where'd you get your black pool noodle, man? Secret store? :P

[kfxguy]

I'd imagine some good ball bearings would keep things at alot better tolerances than a typical strut teflon lead would... which I'd imagine would mean less vibration, etc? especially at higher rpm...

How did you manage to drill out your struts for the bearings anyway?

I have some drives that I want to drill out with my new drill press, but after drilling some tube I found that it can be trickier than it looks to make the hole straight because then the shaft and bearings would be spinning the prop at a different angle lol, and probably end up ruining the bearings if anything.

Where'd you get your black pool noodle, man? Secret store? :P

I have a mill and a lathe. I used the lathe for perfect alignment. I don't think I'd try it with a drill press.

[kfxguy]

I'd imagine some good ball bearings would keep things at alot better tolerances than a typical strut teflon lead would... which I'd imagine would mean less vibration, etc? especially at higher rpm...

How did you manage to drill out your struts for the bearings anyway?

I have some drives that I want to drill out with my new drill press, but after drilling some tube I found that it can be trickier than it looks to make the hole straight because then the shaft and bearings would be spinning the prop at a different angle lol, and probably end up ruining the bearings if anything.

Where'd you get your black pool noodle, man? Secret store? :P

I have a mill and a lathe. I used the lathe for perfect alignment. I don't think I'd try it with a drill press.

[Turbo Dan-O]

Where'd you get your black pool noodle, man? Secret store? :P

[kfxguy]

http://workoutz.bmobilized.com/?task=get&url=http%3A%2F%2Fworkoutz.com%2Fshopping%2Fproduct%2FPool-Noodles

If the link doesn't work it's workoutz.com in the aquatics section.


Also if you do two part foam you can mix epoxy dye in it.

[dmitry100]

The dye thing with marine foam is a good idea -- might be a good idea to make custom shapes out of.
I wonder if its possible to dye pool noodle though... Perhaps something like a permanent marker-- but more permanent lol.

Is 2 part marine foam as light as the pool noodle? seems as though it could be a lot more heavier...

Btw, with your shocker-- I don't know if you're having major blow overs just yet but have you ever tried blocking a bit of the tunnel with perhaps say... a pencil or something bigger?

[kfxguy]

Well I'm not having blow overs. I did just crash it badly just now. At 98mph it unsettled and bounced a little bit. Not sure why. It did the same thing a while back. And so did my mono. I'll post videos of those too. I don't think I'm hitting anything. There's never any prop damage or under boat damage. This lake does get a weird current or roll to it sometimes. It's not shallow where I'm running it either. It's 20ft to 40ft deep and the water was high today. I'm disgusted to be honest. It bent the rudder, rudder bracket, broke my hatch at one of the bolt holes, and broke the motor mount. Plus the esc doesn't work anymore. Now that I say that I'm wondering if it's the esc at fault because my mono did the same thing with this esc. I must mention that neu originally sent me a 2900kv 1530 by mistake and I ran that on 6s several times. I've noticed that it likes 6s, barely picks up (maybe 5mph) on 7s and screams on 8s (picks up 19mph over 6s or 14mph over 7s) which makes no sense to me. Here's the video and a couple of pics

O and it went from 79 to 81 on 6s from previous runs with the things I did to it.








And the video. Tell me what it looks like happened

[dmitry100]

After playing it a few times in slow motion and it appears to have done a barrell roll and then a hard nose dive. Maybe the rudder hit a fish, stick, or something like that?

Thats some pretty bad damage there... that sucks. So the Esc is done? No smoke, nothing? Just stopped working out of the blue afterwards?