Stumble blocks ???

[Tim leyde]

Wondering how deep to make a set of stumble blocks on my tunnel. What should the distance be between the bottom of the stumble block to the bottom of the sponson?

Thanks

TL

 

[Mike Luszcz]

What hull Tim?

 

[Tim leyde]

It's on a one of a kind Vision.

 

[Mike Luszcz]

Oh Ok, you better ask a Vision expert! I didn't know if this was for your 300 sponsons as I only have them 1/8" shallower than the sponsons on all my hulls. Anything more seems like it would allow to much settling at the bow and possibly allow hooking...Just my take on it! Mike

 

[Tim leyde]

Thanks Mike! I was thinking 1/8 aswell. They are around 1/4. My thoughts were to keep with Shawn's original built in design of them. However just add some sealed balsa to bring them down a bit, in the 1/8 area.

TL

 

[Tim leyde]

I would like to make something clear here. I by all means am NOT saying anything negative about Shawn his craftsmanship, design or any other. I believe this hull was a one up carbon fiber prototype build. This hull is outstanding! As with all hulls, I'm simply dialing it in. I also know Mike feels the same way and is helping me along. THANKS FOR ALL THE HARD WORK YOU TWO DO FOR THIS HOBBY!!!

TL

 

[Mike Luszcz]

That is probably a good thing to do, clarifying I mean! I was only giving my opinion and wanting to make sure it was not an info request for a 300 tunnel. Shawn definitely makes a very impressive hull, with some of the best glass work in the business!

 

[Andy Greene]

I'm curious Tim , have you made this mod to any other Vision boats, and if so, what gains did you see ?

Andy

 

[Tim leyde]

I'm curious Tim , have you made this mod to any other Vision boats, and if so, what gains did you see ?

Andy

This is my first Vision, so no. I just had some stuffing problems in the turns. I believe the setup was off since I had a tad negative in it and the COG at 8.25. Water conditions were perfect. I'll keep ya posted.

TL

 

[HTV Boats]

Tim, You might want to try a little motor setback. Say 3/4-1". Will move your CG back and hold front weight up better. Easy to change back if it doesn't help. Mic

 

[Grimracer]

Tim is it stuffing past the apex?

Grim

 

[Mike Luszcz]

Also, raising the lower unit straight up a little will let the stern settle, and in turn will let the bow sit up a little more in the straights. Mike

 

[Tim leyde]

Thanks guys, sealing the stumble pads tonight. Also set up to Shawns instruction. I'll let you know how the testing goes.

 

[Tim leyde]

Tim is it stuffing past the apex?

Grim

Yes, after the apex.

 

[Tim leyde]

Update, I tested yesterday. There was a 5mph wind. The boat was very flighty at the setup stated. I ended up adding 2 oz behind the radio box. This brought my COG to 8 1/8". The motor is at natural, bottom of the bullet is 1/8" above bottom of sponsons. I did not add any stumble pads yet. While testing I really turned the water up by going in circles. Then I came back and turned as sharp as I could through it. Guess what, no stuffing! Down the straights it was recording 41-44mph. This weekend will be the real test at our clubs second race of the year.

TL

 

[Tim leyde]

Took the boat out today for some practice. Wind at 5mph with a 15mph gusts. Well, same old stuffing issue.... This time it is happen before the apex.

 

[Kris Flynn]

Usually they are fine in calm water. But in race water you cab see water coming over the top of the center section which pulls the boat down in the front?

I had hooking issues with a normal vision which turned out to be a stripped spline on a servo horn or a dodgy/weak servo

 

[Hayden Bright]

Just out of curiosity how much steering end point travel is programmed In your setup. I fine you don't need much more than 50% to 60% steering servo travel and that's on a tight course.

 

[moparbarn]

OS lower, tim? is the hinge pin set to stay nuetral in the turns? hinge pin angle can cause this. at least the OS lower allows separate trim & hinge pin adjustments.

 

[Hayden Bright]

Another thing I had been thinking about is the scale speed we're asking these tiny boats to corner at. I would imagine a 3.5 tunnel would be closest to 1/10 scale and clocking 50 mph + speeds so that's a scale speed of 500 mph. Not to many full size boats cornering at 500 mph me thinks