Maiden Runs - Insane FE30 & Insane Mono 34

[srislash]

Mine are all 1-2mm up Rick. I do believe it is better to have a space to enable the hull to break loose rather than have the tabs get 'glued down' to the water. That analogy make sense?

[rickwess]

Mine are all 1-2mm up Rick. I do believe it is better to have a space to enable the hull to break loose rather than have the tabs get 'glued down' to the water. That analogy make sense?

It does. The Speedmaster CNC billet tabs are a strange beast though. For the tab to be 1-2mm above the bottom, the bracket needs to be flush with the bottom of the hull. I'm going to raise the bracket up 1-2mm and give the hull a bit more room on the water.

Also, the tabs are much longer than a "normal" tab so I can see how any misalignment would have a greater influence on the boat. In hindsight, probably not the best choice for a first build, but they do look so cool.

[rickwess]

OK. I'm almost ready to try it again. Thinking it might have been the trim tabs that were causing the instability, I have moved them up on the transom a little and will adjust them all the way up for the next run. The stinger is back to neutral.

It's so crammed at the inside stern area that need to remove the motor and ESC to work on the transom. Just need to put it all back together before I can test.

Neutral stinger:

IMG_20140515_102026.jpg


Trim tab when neutral and adjusted all the way up:

IMG_20140515_102432.jpg IMG_20140515_102702.jpg

[rickwess]

Well, just ran the mono with the stinger neutral and tabs pulled all the way up. Running a x447/s prop that's been detongued. The CoG was at around 10"

I'll have to rename it the Insane Porpoise.

Thoughts on how to tame this?

[tlandauer]

When you said "tabs pulled all the way up"-----do you mean like in you picture all the way "positive"? I agree with not mounting them flush with the bottom, but the tabs should not angle with such drastic attitude, if anything, the tabs can be ever so slightly in a "negative trim", but at least in neutral to begin.
Just my opinion.

[rickwess]

I thought a previous suggestion was to take them out of the equation and see what happens. With this I'm pretty much where I was on the first run. I'll try again with neutral then start adjusting them negative.

One small other problem. One of my 4s packs looks to have a problem. I nursed it into shape to get this run in, but it definitely has a bad cell. Not going to risk it damaging the other 4s. Have one on order and hope it comes in by the end of the week.

Just as well, the waiting that is. The black flies are the worst I've seen them in a long time. You can only stand still for a minute before you attract a swarm. A two minute test is all I could do before they were going after my eyes. After 31 years at the cottage, I may have to invest in a bug hat.

[tlandauer]

To take them out of equation you have to take them off, I am sure pulling them up all the way will only complicate things. I am glad you don't see any rocker, nonetheless, as I told you on another occasion mine acted similarly and I had to sand the bottom, which means I was willing to let go of the beautiful gel coat. Hopefully you will have the hull dialed in w/o this procedure.
Them flies could be annoying, but your location is beautiful!

[srislash]

I thought a previous suggestion was to take them out of the equation and see what happens. With this I'm pretty much where I was on the first run. I'll try again with neutral then start adjusting them negative.

One small other problem. One of my 4s packs looks to have a problem. I nursed it into shape to get this run in, but it definitely has a bad cell. Not going to risk it damaging the other 4s. Have one on order and hope it comes in by the end of the week.

Just as well, the waiting that is. The black flies are the worst I've seen them in a long time. You can only stand still for a minute before you attract a swarm. A two minute test is all I could do before they were going after my eyes. After 31 years at the cottage, I may have to invest in a bug hat.

It did not take much negative to fix mine. Make very fine adjustments. I'll try to get a pic later for you Rick.

[rickwess]

I wish I could try it before I head home. It'll have to wait until next weekend though........ need to travel this week.

Even though the runs have been disappointing overall, the bright side has been the TP4060 2040kv motor. This is a fairly heavy boat with the two 4s packs, but I can tell it will be fast once it's dialed in. I've only been able to run 1/4 throttle and I'm still using the smallest of my x series three blade props. Still have an x450/3 and x452/3 that Dasboata worked his magic on.

[rearwheelin]

Curious to see a inside lay out pic. I have a feeling this could be drive line related .

[rickwess]

Sorry, travelling. The build thread is here on OSE.

The motor is in the rear with batteries farther up front. The CoG can be adjusted from about 8.5" to about 10.25". Supposedly, 9.75" is the sweet spot for this hull.

[rearwheelin]

Sorry, travelling. The build thread is here on OSE.

The motor is in the rear with batteries farther up front. The CoG can be adjusted from about 8.5" to about 10.25". Supposedly, 9.75" is the sweet spot for this hull.

No pic necessary now.... I have seen this on another build a couple years back . My advise to you is to either shorten the gap between your drive dog and strut wich may ( depending on the gap or lack of) place the boats thrusting point at the strut, this would eliminate any lift or decrease the thrust at your collet. If you run a big gap then all your thrust is placed on your cable wich will push your boat in the direction your motor is angled at, it's also ( IMHO ) harder on your cable. The bunny hoping is probably due to the back and forth transfer between the two thrusting points. Build a boat with this idea in mind. Boats that need the rear lift like hydros , riggers and some cats like a bigger gap between the drive dog and strut. I prefer to use a stack of thrust washers on monos with a very minimal gap( not bigger than 1 mm , this keeps the thrust at the transom and not the motor. Some will argue this for days with me but I have never busted a cable or had a mono do anything quirky like that. Depending on how you like your boats to handle motor placement plays a huge role not just you cg. The motor is also a gyro of sorts and the farther forward in the boat the more stable it will be but you will loose some turning ability. Hope this helps !


Also I'm not a fan of those stepped struts . I think they cause the prop to dig in if they aren't adjusted right.

[Rumdog]

^what?!

[rearwheelin]

^ Ducking for cover now ! lol

[rickwess]

Good news on the Mono. I tried a few different negative angles on the trim tabs.

I first tried a negative angel that put the trailing edge of the tab level with the bottom of the hull. That didn't seem to have much affect. I then increased the negative angle so that the spot of the trim tab that was level with the bottom of the hull was 22mm off the transom. This time all the porpoising was gone.

In fact the hull was running wet. Wet enough that the ESC/motor wire were warm enough to start to loosen the heat shrink. Now that I have my end points, I can back off the negative angle until it runs how I want it.

My videographer was still sleeping so nothing to show yet. Hopefully tomorrow.

Thanks for bearing with me on this learning experience.