| Author |
Message |
Graham John Davies (Mtb488)
Member
Username: Mtb488
Post Number: 1
Registered: 8-2006
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| Posted on Sunday, November 19, 2006 - 12:58 pm: |
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Dear Sir. My name is Graham J Davies I Make very large model boats with twin motors and the question I have. Which speed controllers should I use, I was looking at your 4QD VTX 24V 35A type will these do. The system I have at the moment is powered from 2 x 24 volt - 24amp Gel batteries the cyclic type. I think the motors only pull 6 amps as they only last two hours flat out doing some 7 1/2 mph at 4000 rpm approx. The motors are pavalux and are 60 watt. Would I need to use the 3401-004 4QD rc Interface Mixer Boxed with these controllers. Or do I need more powerfull controllers. So please advise me. Regards Graham |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 324
Registered: 10-2004
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| Posted on Sunday, November 19, 2006 - 6:47 pm: |
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Hello Graham,
We need to make sure of the motor rating. You say they are 60W which would mean a current drain of under 3A so your combined current drain would be under 6A. So, with 24Ah batteries, your current drain would be 0.25C giving a very typical running time of just over 3 hours. So the figures do come close to balancing, maybe your batteries are not delivery as much energy as they should or maybe the motors are taking a bit more current.
As for a controller, the 4QD VTX 24V 35A will be fine but you would need a pair of these and an interface like you suggest our 3401-004 or 005. There are other options though, you could use a pair of Electronize controllers 1 off 1500-014 and a 1500-015 (if you need the BEC else a pair of 1500-014) with a mixer (unless you are happy to use tank steer) 3401-012.
You could also use a pair of 1502-010 again with a mixer 3401-012.
So 3 options, I would suggest the Electronize solution. |
Graham John Davies (Mtb488)
Member
Username: Mtb488
Post Number: 2
Registered: 8-2006
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| Posted on Wednesday, November 22, 2006 - 8:12 pm: |
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I have used electronize types before and have blown them up as my batteries are charged up too over 26 volts and they cannot take this voltage. What do you mean tank steerage I am using a Robbe / Futaba TX FC-16 The information that you require on the motors are as follows = PM10c Permanent Magnet Motors Variable Speed - DC, Totally Enclosed IP 54, cont 60 watts , 1 hour 75 watts, 15 mins 100 watts. Starting current Approximately 3 times full load I have tried to up load a data sheet the pavalux motor. Regards Graham |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 327
Registered: 10-2004
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| Posted on Wednesday, November 22, 2006 - 8:55 pm: |
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Graham,
The majority of our customers use the Electronize on 24V without problem, I suggest you may have a different problem with your installation.
See here for an explanation of mixing.
Thank you for the motor data, I am quite happy to recommend the Electronize set-up but the 4QD will easily suffice if that is your preference. |
Graham John Davies (Mtb488)
Member
Username: Mtb488
Post Number: 3
Registered: 8-2006
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| Posted on Thursday, November 23, 2006 - 8:39 pm: |
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Thanks for the help and I will be going down the 4QD VTX way with the Interface 3401-004. What I do need to know is can I mount the speed controlers in the same housing and provide a fan on top of the box. Regards Graham |
Admin (Admin)
Board Administrator
Username: Admin
Post Number: 329
Registered: 10-2004
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| Posted on Thursday, November 23, 2006 - 9:50 pm: |
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Hello Graham,
You certainly can mount the controllers in the same enclosure and you should not need a fan. Use a diecast aluminium box making sure the controllers aluminium heatsink is securely bolted to the diecast box. Also use a heatsink compound between the aluminium block and the box to help heat transfer. A fan will not do any harm, maybe try it without first and see how you get on. Do let us know as feedback always welcome. |
