Model Boat Mayhem
Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: RCGazguzzler on April 09, 2012, 07:40:34 am
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Hi, I’m new to the electric boat scene and I’m struggling with my set up. I bought a second hand Fireboat (1 metre long) “Feuerloshboot 2” that was in good condition but needed a complete rewire. I wanted something with a good turn of speed when pushed…..however I’m really struggling, it’s been in the water 3 times, all with problems.
I am using a 12volt battery, a Fusion Aquapower 280A water cooler ESC and two traxxis 20 turn stinger motors, all this was advised by local model shop (who aren’t boat specialist) but as I say I’m a novice so I was happy to take their advice. I’m using the standard plastic 3 winged props, about 45mm dia.
However, I ran a 30A fuse, and at half power this would pop and leave the boat stranded. I changed a few fuses before going to a 50A lorry fuse and holder (this seems completely OTT for a model boat?) however this is untested. Any one use massive fuses or have I got more problems?
Now the ESC seems to be shorting out? I am getting continuity between the + and – feed and also between the ‘outlet’ to the motors, basically everything seems connected to everything!
I have spent a lot of money and getting very little entertainment at the moment so would really appreciate some help.
Thanks in advance,
Phil
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firstly where abouts are you phill , im sure if theres a member nearby they would be only too happy to meet up and look at what set up you have ?
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Wrong setup, that's for sure, the motors are too fast with not enough torque, they are designed for 7.2 volts in a buggy. I think the ESC is now toast despite the 280 amp rating.
You could fix the amp draw problem with a gear reduction like this
http://www.maxxprod.com/mpi/mpi-10a.html
near the bottom of the page, part: ACC365
or replace the motors with motors more suitable for direct drive such as a 12V Speed 700 BB Turbo , either option will reduce the amp draw EDIT :Should have been Turbo
Are you running 2 motors with the one speed control?, I would seriously consider 1 ESC per motor ( less work for each ESC and gives you some options for manoeuvring)
Nick
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If you have been sold a 12v Lead-Acid battery then save it for a displacement boat like a tug or puffer. The weight of these makes them unsuitable for planing models. Better off with either NiMH or LiPo packs; same capacity but much lighter. Slight correction to Nick's note; the 12v 700BB motor Graupner part #6317 is called a Turbo, while the much-slower 720BB (#6372) is called Torque. It's the Turbo motors you want.
Can only agree with Nick otherwise. Stick to a specialist model boat retailer in future. They will sell you what you need whereas the rest will just sell you what they have on the shelf.
If you omit the centre motor and speed controller then this is perhaps more like what you need http://www.action-electronics.co.uk/pdfs/S-Boot%20-%20Peter%20Bruce%27s%20Mate.pdf (http://www.action-electronics.co.uk/pdfs/S-Boot%20-%20Peter%20Bruce%27s%20Mate.pdf)
Dave M
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Guys, I cant thank you enough for your prompt replies, I'm in Aberdeen by the way
I will buy the gruapner motors you advise (turbo ones), however the ESC needs a little more investigation for me. I have already 'wasted' about £90 at the model shop on unsuitable motors, ESC and batteries, so you can see why I'm keen to purchase correctly this time!
I have seen an Action advert (in Model Boat Magazine, I think) a gizmo that controls 2 ESCs automatically with just a few clicks! I presume I need one of these? What ESCs are known to good strong units, do any match this unit well? Obviously I already have water cooling, but if new ESCs dont need it, I'll just water cool the motors instead.
Can I keep with my batteries as a stop gap? I had one 12v battery and the local club members said it was bobbing too high and advised me to fit the 2nd one (a spare) as ballast. I did this on the day, which did help, but for sake of room, I have removed the second battery and used some lead weight to give me "adjustable" ballast. However if I need new batteries I will purchase them.
As they say a little knowledge is dangerous, but thats where I am at the moment!
Luckily the boat I bought is nice, so I'm keen to get back in the water and spraying water with the fire monitors!
Finally what current draw should I expect with 2 new motors, so I can select the correct fuse.
Thanks
Phil
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Sorry Dave, I just looked at your link, ignore the ESC question, I looks like I'll be calling you for a matched set up, that just works!
Thanks
Phil Birt
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The shop should not have advised you on a matter they obviously have no clue about. They were making guesses and sold you any old **** they had lying about just to make a bit of money. It just goes to show how irresponsible and reckless some retailers are >>:-(. Im afraid to say Phil theyve wasted your money.
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At the risk of sounding like a creep...go for ACTion stuff everytime. I use it, and I've abused it far more than others do and it all still works perfectly. On the odd occasion that I've popped something, Dave has advised me on what I've done wrong, and repaired it with a very rapid turnround. (Ok, he's called me a bl**dy idiot and relieved me of more of my pension) but it's good to know that he's only a phone call away.
Rich
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Thanks Guys, Action is shut today but I'll try again tomorrow
Heres some pics of the boat in question;
(http://i1069.photobucket.com/albums/u478/RCGuzzler/100_2177.jpg)
(http://i1069.photobucket.com/albums/u478/RCGuzzler/040.jpg)
Hopefully that'll work!!!
Phil
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hi ya that's the Robbie Graupner Dusseldorf - I built this model a while ago for my son. The motors for this model are supposed to be the Navy Compact Motor - part number M-RB4105 and these were motor gearboxes with a 3.3 to 1 gearbox ratio driving a 2 bladed 45mm prop and I believe the actual motor was equivalent to a Graupner 600 running on 7.2's. No doubt there will be an equivalent for today; but I think you may pay more than £28 a piece - but you never know - check ebay.
If you want to go direct drive; I would say between a 600 and 700 Graupner motor running at about 10-15 thousand rpm. Also, I would go for one of ACTion's speed controllers - one of their P98 thingamygig. The motors you were supplied by the shop, I would keep for a rainy day - cos no good for this model.
Sounds as though your speed controller might have been fried - hope not - but it sounds like it might have been.
aye
john e
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Thanks, for all the feedback. I have purchased ACTion P94 ESC, fuse board, Power DB. I ordered Graupner 700BB with cooling coils from Cornwall Model Boats, but as a stop gap I will remain with my original lead 12v batteries. I want to see the model working before I spend anymore money on it!
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And if you need any Batts then there is only one place you should think about, Component shop simply the best place to get them from
Dave
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I have a metre long cabin cruiser, using two 550 motors, and I'm happy with the speed, so a couple of 700;s will make it fly.
I'm using a 7 year old fire alarm gel battery, 12 volts 7 amps, (salvaged from a battery dump) and so far have no complaints. havent done any endurance runs on it yet though. 10 -15 minutes is good.
i have the P94, and apart from a minor adjustment problem (I hope) it works very well.