Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Submarines => Topic started by: silent running556 on May 15, 2011, 08:39:55 pm

Title: u boat probs
Post by: silent running556 on May 15, 2011, 08:39:55 pm
I've been trying to get the electrics going on my u boat recently and the first time the speed controller lit up and the servos gave a slight judder and that was it. The second time there was a red and white light on the speed controller then a puff of smoke and a burning smell coming from the relay. There's a scorch mark on the underside where it was in contact with the base plate. I've not seen the motors running yet either, What am i doing wrong? Ta.
Title: Re: u boat probs
Post by: essex2visuvesi on May 16, 2011, 06:23:43 am
Whats the make and model of the speed controller and motor?
Title: Re: u boat probs
Post by: Mankster on May 16, 2011, 07:26:12 am
I think we are going to need more information.
Exactly what boat to you have?
Did you just wired it up you self for the first time, or was it built and running correctly before.
How is it wired up? Using a BEC or separe batteries? Any chance of a shoted contacts somewhere?
Batteries and Voltage? What ESC are you using (you say relays? So its not a modern ESC?)
And finally a few pictures will help.

But by the sounds of it, it seems you have a blown ESC.
Title: Re: u boat probs
Post by: silent running556 on May 17, 2011, 07:04:47 pm
It's a Robbe U-47 with a Rokraft 120 speed controller, the relay's also the recommended model by Robbe. I think what's happened is the polarity has been somehow switched and black and red wires have been mixed up. Looks like i'll need replacements i suppose.
Title: Re: u boat probs
Post by: silent running556 on May 17, 2011, 07:07:10 pm
It's not a BEC so separate 4.8 batteries. The power batteries are the 5ah brick like ones recommended by Robbe too.
Title: Re: u boat probs
Post by: silent running556 on May 17, 2011, 07:10:49 pm
I think i'll try to get it into a local shop and see what they think, they don't do Submarines but the basic electrics are the same as planes etc so they should offer some sort of replacement parts, they use JP and another one but i can't remember its name at the moment. Thanks for the responses much appreciated btw.
Title: Re: u boat probs
Post by: Subculture on May 17, 2011, 07:50:01 pm
I believe that controller has a BEC. Might be your problem.
Title: Re: u boat probs
Post by: essex2visuvesi on May 18, 2011, 06:20:32 am
I believe that controller has a BEC. Might be your problem.

Yes it does

See here
http://www.hobbydirekt.de/Robbe/Regler/ROKRAFT-120-%B5P-Robbe-1-8367-8367::79508.html?language=en

Specification:
Operating voltage: 5 - 10 NC Volts    Weight: 50 g
Momentary: 25.00 A    connector system: JST / TAM
Dimensions: 55 x 41 x 13 mm    BEC: 5 V, 1.2 A
Title: Re: u boat probs
Post by: Mankster on May 19, 2011, 10:18:25 am
If you radio is powered by a separate battery then you should still be able to get the servos to work even if you have disconnected/removed the ESC. If this is not happening then you'll be want to sort that out first before looking at the ESC.
Title: Re: u boat probs
Post by: silent running556 on May 23, 2011, 08:53:23 pm
I've taken it into the shop and they'll have a look at it and see what parts need replacing if any. It went in on friday.
Title: Re: u boat probs
Post by: silent running556 on May 27, 2011, 02:44:28 pm
I phoned them up this morning to ask how things were and they said it was on the bench but they were struggling to get it going. PANTS!
Title: Re: u boat probs
Post by: john s 2 on May 27, 2011, 06:12:45 pm
Doesnt sound to good to me. Do they really know what their doing or poking and hoping? Or worse still
talking your bill up? Time will tell. John. 
Title: Re: u boat probs
Post by: Subculture on May 27, 2011, 07:16:39 pm
It sounds to me like you've fried something in the ESC, and it's not worth repairing unless you do it yourself to be honest.

I'd recommend one of the Microgyros ESC's, much cheaper than a Robbe ESC and better specced. These controllers also come with good instructions so you shouldn't have too much difficulty wiring them up.
Title: Re: u boat probs
Post by: silent running556 on May 27, 2011, 09:33:14 pm
Sounds like a DIY jobbie then. I only got that eSC because it was recommended in the kit.
Title: Re: u boat probs
Post by: silent running556 on May 27, 2011, 09:34:08 pm
Doesnt sound to good to me. Do they really know what their doing or poking and hoping? Or worse still
talking your bill up? Time will tell. John. 
As far as subs are concerned anyway NO.
Title: Re: u boat probs
Post by: Davy1 on May 28, 2011, 11:17:50 am
Have a look at Mtroniks speed controllers too.
Very widely available and very good in my experience.
Title: Re: u boat probs
Post by: john s 2 on May 28, 2011, 08:23:11 pm
Motronics have on there website brand new ESCs taken off the production line to test witch then are sold
as used at discounted prices. John.
Title: Re: u boat probs
Post by: hmsantrim on May 29, 2011, 12:17:28 am
Hi silent running556.
                            did you find out what current the motors are drawing or are you just taking pot luck and hope you have fitted a
                             speed controller with a high enough amperage to do the job.??? me thinks the latter. 

                              point in Question in my first boat I fitted a 12v hectoperm, it said 3amps on the casing I fitted a 3amp board the
                              boat sailed 3ft and stopped as the board was fried.  There are too many variables to guess what current your
                               motor is drawing or is everybody now buying 50-100amps speed controllers. 

                                Is the skill of how to amp your motor not being passed on in clubs,    maybe its time the Mods placed a how to
                                tutorial on the subject on the forum which can be referred to when required. 

                                               ................Frank 

Title: Re: u boat probs
Post by: silent running556 on May 30, 2011, 08:48:42 pm
Have a look at Mtroniks speed controllers too.
Very widely available and very good in my experience.
I'm quite happy to look at other makes etc, i just thought as a beginner i'd be safe  sticking to what the info in the kit said.
Title: Re: u boat probs
Post by: Subculture on May 30, 2011, 10:14:29 pm
A decent 20-25A ESC is suitable for U47. FWIW I much prefer microgyro ESC's to Mtroniks, and I have used both, but either will work for your boat. I would recommend fitting a fuse on the main power line to your ESC.
Title: Re: u boat probs
Post by: silent running556 on May 31, 2011, 02:48:19 pm
Thanks mate.(http://[IMG]http://i852.photobucket.com/albums/ab90/brindle-girl/DSCF0194.jpg)[/img]
Title: Re: u boat probs
Post by: silent running556 on May 31, 2011, 02:51:05 pm
I'm trying to upload some picture of my u-boat so that you can see the parts and wiring. I just collectd it this morning, looks the same as when i left it 10 days ago tbh. {:-{
Title: Re: u boat probs
Post by: silent running556 on May 31, 2011, 02:52:44 pm
I've got about 11 pictures on photobucket at the moment and trying to get them on here.Bare with the electrical great one.
Title: Re: u boat probs
Post by: silent running556 on May 31, 2011, 03:14:53 pm

(http://s3.postimage.org/2dq06k0as/DSCF0187.jpg) (http://postimage.org/image/2dq06k0as/)

(http://s3.postimage.org/2dq8g8qro/DSCF0196.jpg) (http://postimage.org/image/2dq8g8qro/)

(http://s3.postimage.org/2dr27wzno/DSCF0195.jpg) (http://postimage.org/image/2dr27wzno/)

(http://s3.postimage.org/2dsrestxg/DSCF0193.jpg) (http://postimage.org/image/2dsrestxg/)

(http://s3.postimage.org/2dtyeruro/DSCF0194.jpg) (http://postimage.org/image/2dtyeruro/)

(http://s3.postimage.org/2duovdeo4/DSCF0192.jpg) (http://postimage.org/image/2duovdeo4/)

(http://s3.postimage.org/2dwfpslfo/DSCF0191.jpg) (http://postimage.org/image/2dwfpslfo/)

(http://s3.postimage.org/2dwxwpev8/DSCF0190.jpg) (http://postimage.org/image/2dwxwpev8/)

(http://s3.postimage.org/2dxmprm9w/DSCF0189.jpg) (http://postimage.org/image/2dxmprm9w/)

(http://s3.postimage.org/2dyjsik5g/DSCF0188.jpg) (http://postimage.org/image/2dyjsik5g/)
Title: Re: u boat probs
Post by: Subculture on May 31, 2011, 04:13:47 pm
Difficult to see where you've gone wrong from those pictures I'm afraid. If you bring it down to the Dive-in at St Albans, I'll go through it with you.

What is the relay for, BTW?
Title: Re: u boat probs
Post by: silent running556 on May 31, 2011, 08:16:16 pm
Funny you should say that coz the bloke in the shop said the same thing. The red wire from the main batteries go into it and then a red wire from the ESC connects up to it too. i assume it was to prevent components from being fried, hence the scorch mark on the underside. Do you think the wires for the motors look correct?
Title: Re: u boat probs
Post by: Mankster on May 31, 2011, 08:58:22 pm
Is the relay for switching on the main power supply from the transmitter? If so, its not needed. You can wire the ESC to the main battery with a simple switch/plug to make and break the connection manually.
Cant really tell anything about the wiring from those photos really. However is pretty should be pretty straight forward to diagnose.
Title: Re: u boat probs
Post by: Subculture on June 01, 2011, 09:41:45 am
The motors look okay from what I can see there. But many of the shots are poorly focused or lack sufficient coverage. I agree the relay seems to be superfluous. I'd rather have the boat in front of me to check over the whole installation than try and diagnose this by proxy.
Title: Re: u boat probs
Post by: silent running556 on June 01, 2011, 01:05:03 pm
I try to pop it along on the 11th anyway.
Title: Re: u boat probs
Post by: silent running556 on June 02, 2011, 03:24:27 pm
Some very good news, i tried the system without the relay and it all started up, even the ESC lit up with a red light, the servos moved and the motors even started and revved to the transmitter, i could have hit my head on the ceiling when the servos jumped. I think i'll get a replacement relay to be on the safe side and try to finish off the rest of the u-boat, thanks everyone for your support and knowledge on the subject. I loathe this remote keyboard it makes me sound like Rainman. %) :} :-))
Title: Re: u boat probs
Post by: Mankster on June 02, 2011, 07:06:22 pm
You dont need a Tx controlled relay, a simple plug like a Deans connector will do.
Title: Re: u boat probs
Post by: silent running556 on June 03, 2011, 03:56:47 pm
Oh pants, now my rear end doesn't line up properly, the I beam bits push the mid section slightly out of shape and so doesn't like the back section very much at the moment. I've found some old car paint from my old Clio too and some primer, could be half tungsten met grey and Subaru silver after all. {-)
Title: Re: u boat probs
Post by: silent running556 on June 04, 2011, 07:15:13 pm
Is there a better way to join the rear to the mid section by any chance and keep it shaped correctly?
Title: Re: u boat probs
Post by: silent running556 on June 06, 2011, 03:40:23 pm
Has anyone got a piccy of how the tubes on the stern tube fix up please? I've got a nice hole through my book etc thanks to my pup and so can't see how the silicone tubes etc connect on to the stern tubes. A bit of soldering i think think. BTW Can you shrink the shrink wrap without a heat gun at all?
Title: Re: u boat probs
Post by: Mankster on June 06, 2011, 04:12:33 pm
Most hairdryers will do it, or slide the metal shank of a soldering iron on the heatshrink tubing.
Title: Re: u boat probs
Post by: Subculture on June 06, 2011, 05:16:00 pm
You can heatshrink with just about any heat source, even the soldering iron you use to solder the wires together with. However I find I get the most consistent results with a heat gun. You can get them very cheaply these days, think I only paid a tenner for mine.

Andy
Title: Re: u boat probs
Post by: silent running556 on June 06, 2011, 09:44:49 pm
thanks guys, my motors are going the wrong way too.
Title: Re: u boat probs
Post by: trevor v on June 06, 2011, 09:54:19 pm
all you have to do is swop the leads over on the motors(black & red on the motors not motor to motor)