Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Navy - Military - Battleships: => Topic started by: watupbrudda on August 05, 2009, 06:28:15 pm
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Hey guys,
I'm new to model boating, and in fact this forum. I've done some previous work on remote control trucks and cars, but never anything to do with boats yet, and the Robbe PT-15 is my first build.
First off - the instruction manual is appauling, but I'm struggling my way through it. Finished the hull and installed motor, rudder and servo, and also got the batteries sorted and a sound generator and speaker. The one part I'm missing is a speed controller, as I was stumped as to what amp speed controller I would need. If anyone could let me know how to work it out it would be really appreciated. I also have to parallel wire the batteries with the sound generator, and the ESC with the sound generator, and all of my previous projects have been series wired, so does anyone have any advice on parallel wiring, how to attach the two loops etc? It would help a lot.
So basically - if anyone could help me with the following two questions it would help a lot:
1) How do I know what amp ESC I need,
and
2) What connectors/harnesses etc. do you need to parallel wire?
Thanks in advance to anyone that answers this, and if anyone wants to ask me any questions about the model feel free.
I have found this forum helpful many a times in the past, and hope to be putting something back into it sooner or later.
Cheers
~Watupbrudda
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What motor are you using ?
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I think the PT-15 takes a standard 540/550/Speed600 so you need an electronic speed controller (ESC) about 20Amps.
Wiring? Have a look at: http://www.action-electronics.co.uk/pdfs/ESCs.pdf
A few Mayhemers have built the venerable PT - 15 :
http://www.modelboatmayhem.co.uk/forum/index.php?topic=4447.msg43376#msg43376
http://www.modelboatmayhem.co.uk/forum/index.php?topic=195.0
http://www.modelboatmayhem.co.uk/forum/index.php?topic=841.0
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You missed one Martin
http://www.modelboatmayhem.co.uk/forum/index.php?topic=4789.0
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Sorry Richard, that was the first one I was looking for! :embarrassed:
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I would always and do, install an ESC that has 10amp rating higher than the stall speed of the motor. I also install an in line fuse of about 10amp less than the stall speed. This way I never have to worry about burning ESC's out. The reason for 10amp more on the ESC. If I'm at the water and I have to remove the in line fuse for any reason (normally because I don't have any on me or have burned my supply out). I can still sail that day. For me going for a sale takes a little bit of effort and planning.
As for your other question, I'll leave that for some more qualified. O0
Mark
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Thanks all for your replies. I'm using Robbe's geared reccomended motor set since it was my first one and I wasn't clued up enough to pick a direct drive unit. I think it's a speed 600, and I've gone for a 40amp Speed Controller. Will this be okay? Thanks to all for your help on this.
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The 40amp speed controller will be fine.
I suggest you put an inline fuse in your +ve cable between the battery and the speed controller, say 30amp.
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Ooh Dear - What Have I done?
All was well and good, got everything in place and ready to test the electrics, plugged in servos and turned on transmitter - worked fine, needed some trim adjustment, but worked fine.
Time to test the motor, set transmitter to neutral, plugged in the battery, connected up all the wires, and switched it all on. Upon doing this all was fine, the motor wasn't spinning - it shouldn't have been at neutral - but as I ramped up the transmitter stick to test the motor speed/connection, there were sparks, and smoke, and a really bad smell coming from the connection on the motor end, along with a constant "beep" all the time it was connected. Is it time for me to order a new motor?
Please help!
Thanks
Watupbrudda
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Does the motor still work if you connect it direct to the battery?
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Nope :(. Just Lots of sparks.
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... new motor required. If it's new and nothing fell in it, ask the supplier to replace it.
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Kk thanks - I'll contact robbe or just order a new one depending on what effort I want to go to.
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Mark47,
Nice in theory, but as some standard 540 motors can stall at 90 plus amps I have 2 questions.
How do you measure the stall current as none of my gear will go anywhere near 100 amps.
Do you really suggest a 100 amp plus ESC for a standard 540?
Bob
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Mark47,
Nice in theory, but as some standard 540 motors can stall at 90 plus amps I have 2 questions.
How do you measure the stall current as none of my gear will go anywhere near 100 amps.
Do you really suggest a 100 amp plus ESC for a standard 540?
Bob
What I usually do is put a small strip of rag around my prop run at full pelt (without esc) and put an amp meter on the motor. Power comes from a 12v DC plug (similar to a sealed lead acid battery charger). If I get a reading of 90amp, which I have never had yet, then yes I would put a 100amp speed controller on it. I have burnt out speed controllers just because I've had a little bit of duck weed wrapped around the prop. Spend the money first time around and it will save replacing esc after esc. By the time your on your second esc you've just about spent more than the 100amp would cost.
Mark
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anyone know where I can get a 30A fuse?
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Dave at ACTion RC Electronics sells the in line fuse holder and Halfords sell the fuses.
http://www.action-electronics.co.uk/stuff2.php
http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_210613_langId_-1_categoryId_165562