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4th boat build. Mini-Kaze Stepboat

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Old 04-05-2012, 07:54 AM
  #101
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Default RE: 4th boat build. Mini-Kaze Stepboat

I disassembled mine last night and am preparing to move my motor back 1" - remount/seal my radiotuperware, I looked at my rudders again and think I make have sheared a tooth or two in my servo - can't really come up with a better design without COMPLETELY re-building the rudders and if I do I will probably go back to a single - so for now - I did a little tweaking free d up the control rods a little added a bigger screw to hold the control arm down tighter and well see.

Ok 1 picture - latest project - a motorized bike trailer - attach to any bike and see hopefully 30 mph - some bikes may not be ready for 30 - mine are. Keep in mind this is a mock up and the spring clamps will be replaced by bolts
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Old 04-05-2012, 04:22 PM
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Default RE: 4th boat build. Mini-Kaze Stepboat


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ORIGINAL: dadkins

I disassembled mine last night and am preparing to move my motor back 1'' - remount/seal my radiotuperware, I looked at my rudders again and think I make have sheared a tooth or two in my servo - can't really come up with a better design without COMPLETELY re-building the rudders and if I do I will probably go back to a single - so for now - I did a little tweaking free d up the control rods a little added a bigger screw to hold the control arm down tighter and well see.

Ok 1 picture - latest project - a motorized bike trailer - attach to any bike and see hopefully 30 mph - some bikes may not be ready for 30 - mine are. Keep in mind this is a mock up and the spring clamps will be replaced by bolts
I think it may be in your best interest to rebuild your rudders. Ideally, you dont want any slop in it so you can actually go straight. You could simplify your linkage at the same time. Tie your rudder blades together with some small control horns and a threaded rod, and then use a single control rod from the servo to another control horn on the bottom of one of the rudder blades. I used this method on my big Kami's air rudders and it worked really well. I had to turn the servo travel down in the "right" direction because it would bottom out the rudder linkage and it would get stuck in full-right turn mode. Hard to catch this way, lol...

The goped thing looks neat. I had a 43cc Goped for awhile.. I think it topped out at about 40. Fun toy.

Here's a couple pictures of the servo tray comparo. Saved some weight, and I might be able to save a little more to get it down closer to 3oz even. The new servos are very very fast. Hitec 82MG, 47.22oz in. of torque at 6v, and a transit time of .12sec (60°). Thats almost twice as fast as the big 645MG's.

Hoping for a decent day coming up to test the mods..

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Old 04-06-2012, 06:04 AM
  #103
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Default RE: 4th boat build. Mini-Kaze Stepboat

Sullivan cables- who sells the BTW. My electric airboats use stranded brass but in shorter lenghts and work fine but want to do exactly like you did when you sent a picture of your work, thanks for your time and patience.
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Old 04-06-2012, 07:31 AM
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Default RE: 4th boat build. Mini-Kaze Stepboat

I get Sullivan cables from my LHS, in 4' length kits. I would assume tower or the Airrage store should have them. The cables I use are brass plated .056" thickness I think. I use 4-40 rod ends and clevises.
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Old 04-07-2012, 06:05 PM
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Default RE: 4th boat build. Mini-Kaze Stepboat

Just thinking about buckled braided wire. The present wooden bracket looks deep enough to have a spring on the underside. That way it will have a straight draw back toward the airboat instead of sideways.Now it would look like a channel or trought. The same thing on top but start cable alot sooner to get a more direct line to rudder. Just a suggestion!
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Old 04-07-2012, 07:36 PM
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Default RE: 4th boat build. Mini-Kaze Stepboat


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ORIGINAL: Mikeup

Just thinking about buckled braided wire. The present wooden bracket looks deep enough to have a spring on the underside. That way it will have a straight draw back toward the airboat instead of sideways.Now it would look like a channel or trought. The same thing on top but start cable alot sooner to get a more direct line to rudder. Just a suggestion!
The exact reason I use Sullivan cables is they are much more rigid than the Dubro equivalents. These cables are semi-flexible, but do not buckle. The rudder cable is attached to the engine stand and used some thin aluminum sheet metal to make a clamp and cable stabilizer. If the boat weighed 12 pounds, I'd worry about that cable flexing. Its only 5, so it should be fine. I've ran a half gallon through it on the water so far and all of the rigging is working surprisingly well. The only beef I have with the throttle cable is the minute amount of play between the cable and the sheath.

When I get around to it, I'm going to put a ball and cup rod end on the rudder cable to make the break-away a little more linkage friendly when it activates. So far the break-away hasnt kicked in yet, and even if it did, at the most it may bend the clevis a little. I have spares. I've also thought about re-doing the break-away using a spring, but I dont think I'll need to bother. Who knows though.. I'm making a lot of modifications to it.

I made a new engine mount plate to add in an additional 1/2" of plate travel and 1/4" of engine travel, allowing me to move the engine back a total of 3/4" from where it is now (1/4" back from original build). I did some messing around with balance of the hull and I think, maybe, with the engine moved back some, and the lighter bow area... It might just work. I still have a few things to test, but some decent weather needs to happen first.

I'll post some better pictures of my linkages tomorrow so you can see how the cables really dont have the chance of buckling.

The biggest problem is overcoming drag and getting the weight transfer just right at WOT. Up to 3/4 throttle, the boat runs and handles fantastic. Turns like its on rails, and gets out of the hole nice and quick. Only at WOT the bow would dig in a little and plow. I got a lower pitch prop to try out than what I have been using, that may help some too. I'd like to see at least 30mph from it before I'll be "happy".
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Old 04-08-2012, 07:05 AM
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Default RE: 4th boat build. Mini-Kaze Stepboat

Now if it digs in at 3/4speed, how about adding washers underthe rear part of mont. This would draw air from the tip of airboat. You say yourCG isclose so raising the rearmight be the answer. Thenagain, moving CG back a 1/4" might be the answer. Ihad a Sef-Inflicted foam airboats and was taking it out of car and accidently hitthe tx trigger and had 9 ststches in wrist andhandand drove 5 miles to a doctor holding wrist up wrappedin roll towel. The unit is history. Nowit ran great with no rudder but a wing in back. I thought i had safety switch on, never learn. Ouch.
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Old 04-08-2012, 09:21 AM
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Default RE: 4th boat build. Mini-Kaze Stepboat


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ORIGINAL: Mikeup

Now if it digs in at 3/4 speed, how about adding washers under the rear part of mont. This would draw air from the tip of airboat. You say your CG is close so raising the rear might be the answer. Then again, moving CG back a 1/4'' might be the answer. I had a Sef-Inflicted foam airboats and was taking it out of car and accidently hit the tx trigger and had 9 ststches in wrist and hand and drove 5 miles to a doctor holding wrist up wrapped in roll towel. The unit is history. Now it ran great with no rudder but a wing in back. I thought i had safety switch on, never learn. Ouch.
I have shims installed that have the AoA set at 1° below centerline, but I have a shim to set it at 0° or perpendicular to the water's surface. The AoA was originally 2.5° above centerline, but was designed to be at 0°. Something went weird when I skinned the center section that changed the angle I think. My fastest speed was with the engine at the original as-built location, but I get better running characteristics with the AoA down lower.

My radio box was rather heavy, so I swapped to micro servos and lithium batteries which saved me almost 3oz, so hopefully with that and the engine stand mods I'll get rid of the plowing at WOT. I got a lower pitch prop to try also.

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Old 04-09-2012, 06:10 AM
  #109
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Default RE: 4th boat build. Mini-Kaze Stepboat

Ok You have made a lot more progress than I - I finally pried open the cracked stern and dripped some glue in there to seal er up.
ground my mounts back an inck or so and will try the motor a half inch further back first back first. STRUGGLED with the video cam trying to upload our vids - finally when the kids would'nt help I gave up. They Are still on the camera and I WILL give ity another try.
Now if the wind would die down for a day or two we can give em another try.
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Old 04-09-2012, 09:58 AM
  #110
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Default RE: 4th boat build. Mini-Kaze Stepboat

Yeah, I've been busy. I am almost finished with my new rudder for the big kami. I have a few more holes to drill in the new Engine mount on the minikaze and then they will both be ready to run again. I'll get some pics soon. I'm in the process of changing the heater core in my truck so it'll be a couple days.

I got a couple more props to mess with too. This Saturday is car bashing day so maybe Sunday if the weather is nice.
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Old 05-13-2012, 06:17 PM
  #111
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Default RE: 4th boat build. Mini-Kaze Stepboat

The minikaze got a facelift. I'm not done tweaking the .29 yet but wanted to see if she would handle a .46. She did so quite well. So well, it might handle a .61 without sinking. Maybe. Lol.

She is almost a handful now. http://youtu.be/-VWdVetOiO4
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