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Old Jul 26, 2009, 11:18 AM
Retired for now
Bonita Springs,Fl.
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Decided to go with two MACK 5045 motors with single joint universals. These will give me a little more than 11,000 RPM's at 12 volts and if that won't do then I'll have to make the tunnels smaller. Be interesting to see how this all pans out. Fun working with it though. Wonder if four bladed props would move that much more water than three bladed props?
Pete
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Old Jul 26, 2009, 11:24 AM
no wings any more, just dust!
Ghost 2501's Avatar
stoke on trent
Joined Oct 2004
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Norgale, use silicone connection rather than those plastic uj's, they will run quieter and you will have less energy loss.

also, on the blades question, I noticed a SIGNIFICANT change in performance when going from 3 blades on Celestia to 5, something like 60% more thust. 4 blades will boost by 1/3rd
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Old Jul 26, 2009, 12:07 PM
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Plans?

Pete

Keep copious notes. I will borrow them. Is this boat a self design or did you draw it up youself?

Phil
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Old Jul 26, 2009, 12:30 PM
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No plans Phil and so far no notes. I'm just winging it off the top of my head so far. However you are welcome to come and take all the pictures you want and I will continue to post as I go aong. Maybe I could draw up something on it. I'll give it a try. Pete
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Old Jul 29, 2009, 09:39 PM
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Bonita Springs,Fl.
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Waiting for my motors but went ahead and made the motor mount platforms and put in rudder shaft blocks with the holes drilled and the shafts and tubes cut and in position. I'll cut the rudders out tomorrow and split the lower part of the shafts with a band saw. Then solder the rudders into the split. I want to have everything all set and in position for the motors and controls and batts and then I'll proceed to do the sides and the decks ect. Got some nice machinegun mounts from my old PT-109 that ought to look ok and maybe I can dig up some rockets or something too. Pete
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Old Jul 30, 2009, 07:41 AM
no wings any more, just dust!
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Joined Oct 2004
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cant see why it won't work
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Old Jul 30, 2009, 11:57 AM
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United States, LA, Moreauville
Joined Jan 2002
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I can't wait to see this one on the water!
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Old Aug 10, 2009, 07:59 PM
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Bonita Springs,Fl.
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Ok I'm back. Finally got my motors from MACK and they are awesome. At 11k rpm's they should push enough water forward and reverse to make this boat do some serious traveling. That of course remains to be seen.
Also found out that the props are 1" and in 1" tubes so they are a little smaller than I thought. It's hard to measure a prop with a ruler.
Here's a couple of pictures of the basic set up with the motors and props and shafts in place. I decided to double up on the shaft tubes to help keep vibration down. The shafts are epoxied into their respective tunnels and I'm thnking about an extra shaft brace across the floor boards between the motors and the tunnels. Rudders are a little smaller than I originally said but they do cover the whole tunnel opening and should work in forward and reverse equally well. Pete
PS; I do have to confess to buying two motors and the uni's because the small motors that I have and intended to use were just too small. I also hate robbing motors from other boats. Lot of extra work putting them back if I want to use that boat. Motors and uni's and freight was $138
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Last edited by norgale; Aug 11, 2009 at 09:48 AM.
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Old Aug 11, 2009, 03:01 AM
flying = good for my eyes
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Spokane, Washington
Joined Jan 2007
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I would like to see this boat in action. I have attempted to build a jetdrive using a electrical PVC pipe. It is not a 45 degree angle but a lot less sharp of an angle on the corner. It took 2 cuts. One was for the intake and the other was where the water comes out. However, the intake turned out to be an oval shape. The advantage of this is you don't need any sanding because the inside edge of the intake is already sharp. I did however plan to put an aluminum piece on the of the boat so, using autocad, I designed a perfect oval and laser cut it. Surprisingly enough the 2 fit together. Lack of time and money at the time brought the project to and end. I may continue it someday. I still have my jetdrive somewhere around here. Not sure where but if i find i will post a pic. I did have a problem with one thing and that was drilling the hole for the shaft. I first attempted this on a lathe but, since the drill bit is flexible, when it came in contact of the outside edge of the PVC housing it simply bent too far and the hole was not centered. I attempted to remove some PVC to create a 90 deg. where the bit was supposed to go through. The drill bit just went out of place and made a very non centered hole. Only way to fix this is to widen the hole and glue the shaft housing with epoxy and centering it by hand.
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Old Aug 11, 2009, 09:46 AM
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Hi russainred95 and I know the drilling problem. However on the 120 degree el's that I used there were mold lines that I followed all the way around the outside curve and then drew a line down the top middle. Where the two lines crossed I drilled a hole smaller that what was needed. Had to eyeball everything but the lines gave me a good starting point.Enlarged the holes a little at a time with frequent tests with the shaft tubes. Then with the shaft tubes in place and the shafts with the props on went in and then the epoxy. The props held the shaft and tube in place while the epoxy cured. If the prop rubs a little it will wear in with running. Even if the props arn't absolutly straight the tunnel behind the prop will straighten out the water flow so it shouldn't be a problem. The prop can't be too far off though,only a smidgen would be tolerable.
In your case maybe the drill bit wasn't real sharp and with a point at the very tip. Push hard at the point you want to drill and start the drill as slow as you can until a dimple is cut in the PVC. Then you can control the bit and it shouldn't wander on you. Start with a small bit and gradually use bigger bits once you have the hole drilled. So lets dig that old project out and get back working on it. Sounds like it should go ok. Pete
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Old Aug 12, 2009, 12:10 AM
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United States, ID, Rexburg
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Pete are you going to trim the tubes for the drives off flush with the transom or is that the way the tubes are going to be?
Foo
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Old Aug 12, 2009, 12:44 AM
flying = good for my eyes
russainred95's Avatar
Spokane, Washington
Joined Jan 2007
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Quote:
Originally Posted by norgale
Hi russainred95 and I know the drilling problem. However on the 120 degree el's that I used there were mold lines that I followed all the way around the outside curve and then drew a line down the top middle. Where the two lines crossed I drilled a hole smaller that what was needed. Had to eyeball everything but the lines gave me a good starting point.Enlarged the holes a little at a time with frequent tests with the shaft tubes. Then with the shaft tubes in place and the shafts with the props on went in and then the epoxy. The props held the shaft and tube in place while the epoxy cured. If the prop rubs a little it will wear in with running. Even if the props arn't absolutly straight the tunnel behind the prop will straighten out the water flow so it shouldn't be a problem. The prop can't be too far off though,only a smidgen would be tolerable.
In your case maybe the drill bit wasn't real sharp and with a point at the very tip. Push hard at the point you want to drill and start the drill as slow as you can until a dimple is cut in the PVC. Then you can control the bit and it shouldn't wander on you. Start with a small bit and gradually use bigger bits once you have the hole drilled. So lets dig that old project out and get back working on it. Sounds like it should go ok. Pete
Pete you are probably right. But, I was on a lathe so i am not that experienced. I never had the chance to mess around with the speeds. Lathe is way more accurate if the bit hadn't failed on me.

I don't know right now. I got my head up in another project (boat) and I take my time when building. Its the electric wild thing which has an outboard motor and a brushless system that I still need to buy...

Time will tell...

I will keep watching for the maiden and see how it goes.
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Old Aug 12, 2009, 02:08 AM
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United States, LA, Moreauville
Joined Jan 2002
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I can't wait to see this one finished! It's looking better and better!
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Old Aug 14, 2009, 08:13 PM
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Bonita Springs,Fl.
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Lot's of great compliments here and I thank you all for the kind words. For an experimental water craft she isn't looking too bad.
Here are a few more pictures of the motors in place and the rest of the equipment that has to go into the hold.
But here are two questions; How do you cut the SS shafts? I need to move the motors to the rear some more for balance so the shafts need to be shortened. My little brass saw won't touch this tough metal.
Also is there anything I can add to the shafts or something to make a proportional turbine sound without buying an expensive sound system? I'm thinking along the lines of the playing card I used to clamp to my bike wheel to make a motor noise but make a whining noise instead. Imagineers??????
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Last edited by norgale; Aug 14, 2009 at 08:19 PM.
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Old Aug 14, 2009, 08:27 PM
Grumpa Tom
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United States, CA, Los Angeles
Joined Sep 2003
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As the younger folk would say today: doood, that's sick!
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