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[stevieg]

Hi ... I have stumbled into model boats having found this model in a junk shop in Brighton (see picture)
It appears to be be hand built ie not a kit and someone has obviously spent a lot of time making it so I couldn't resist it.
It has a fibreglass hull and all the superstructure pieces have been hand made.
It came with a dc motor installed with prop & working rudder.
I have since picked up an old remote control unit from a boot fair for £20 its a digi-fleet XP/FM unit with 8 channels & 4 servo's.
It was a bit of a risk buying it but the guy seemed genuine and sure enough it works really well.
I have installed one of the servos onto the rudder which works perfectly & I was wondering how to control the motor when I found your
excellent website and  an article on Speed controllers in your Technical section.
To this end I have just bought a second hand  40A firmtronics unit on ebay to hopefully finish the job and try her out on the water.
( already tested for leaks in the bath)

I have some questions and sorry if I'm being a bit thick as I am learning as I go along:-

1. The motor is German made and the only info on it is:- 12volt, J leer ca 0.3A, J max 4.0A.
    I did check that the firmtronics speed controller is for a brush motor and the 40A rating should be ok but the battery I was going to use was
    from my son's old electric quad bike which is a small sealed 6V lead battery ( see pic)
    The battery runs the motor ok when I hook it up but I have concerns using this with the controller as it only mentions rechargeable Li-PO,Ni-cd,Ni-mh.

    see link:-

http://www.firmtronics.com/documents/SpeedMax-40.pdf

   Are ESC speedcontrollers not capable of charging lead battery's?

2. The speed controller has BEC  .. is there a downside to using this in place of the receiver battery that came with the Digi- Fleet unit?

3. Does anyone know what my boat is? It looks like a tug boat and has KON on the front.

Thanks for your time & if anyone has any other advice or tips they would be appreciated.

Cheers Steve

[mattycoops43]

Hi. I can answer some of your q's, but I am a boat newbie so will kleave some to others with more knowledge.

The esc will run fine off a sealed lead acid, however, a 6v will not allow a huge current draw. But the type of boat does not warrant shooting round on the plane, so will be fine for scale speeds. it might be worth trying a 12v lead acid with a nice high capacity (7Ah or so) as it will give a bit more oomph and a massive run time. I don't know what run time you will get form a single 6v cell.

Nihm and nicad and Lipo are designed for very high discharge so are better in high speed boats.

One important question. What frequency is the radio gear. If it is 35Meg it is for aircraft use only and cannot be used on a pond, it will interfere with aircraft within a pretty large radius. it is hopefully 27, or 40 meg, which is fine for land use.

Don't worry if you have picked up an aircraft set, you will be able to sell iton and you can get a 27 or 40 2 channel set for very little money these days. If your radio set is not 35meg, then you did ok there as 8 channels will give you all sorts of options for the future, it's just that it tends to be aircraft sets with that many channels!

Hope that helps. There's plenty of people on here who have loads of knowledge about tug boats!

Matt

[stevieg]

I have just checked and it is a 35Mhz unit so it's for planes only it seems which is a shame.
I'll have to get another one for boats but thanks for that.

Steve

[mersey dave]

hi steve if the speed controller has bec do not use the receiver battery. with bec your receiver is powerd through the speed controller.

regards dave.

[mersey dave]

Steve, you can get the new transmitter & receiver on 2.4 now for around £35, with 2.4 no worries about frequencies.

Regards Dave.

[Shipmate60]

Steve,
The motor is called a Deccaperm.
These run about 3750 rpm on 12 volts so would suggest a 12 volt battery used as this should power her well.
The ESC will be fine as the operating voltage is 5-12 volts.

Bob

[Shipmate60]

Try here for a cheap 2.4 Ghz system, but only transmitter and receiver.

http://www.giantcod.co.uk/gianitcod-24ghz-4channel-mode2-transmitter-p-403779.html

Bob

[dodgy geezer]

Only a minor point, but if you have already tested the boat in the bath, did you check where the waterline came?

Ideally, it should probably be at that white band between the red and black. To get it there you will probably need to add some weight to the hull - if you do this in the bath and then work out what weight you needed, you will then know the maximum weight of batteries you can carry.

Oh, and make sure everything is well tied down inside before her maiden voyage...

[stevieg]

Thanks for all your advice and links gear

 With regard to batteries I do have another 6V of the same type so I can put these in series for 12 V.

 When I put it in the bath the bow was high as I had no batteries installed so I will need to arrange these to get it even and
 add ballast as necessary  which is another good point.

 Cheers Steve
 

[mattycoops43]

Yes you can run two together, what capacity are they?

[barriew]

You can retain the rudder servo from the Digifleet set - it will work with any RC set, as will the Speed Controller. I would certainly advise getting the new 2.4Ghz set from Giant Cod. With this you do not have any problem with needing crystals, and can just turn up at any water and sail without having to check what anyone else is using.

If you need to buy batteries, Component Shop sell sealed lead acid batteries in 6v and 12v and various capacities - very quick service and cheap postage.

Barrie

[stevieg]

Hi The batteries are 6V 12AH so with them in series if my school physics is correct will give me 12V 12AH.

I have looked at the Giant Cod and it seems ideal , Barrie has just answered my next question .. can I use my existing servo.

I will install an inline fuse to the battery .. I was thinking a car blade 5A fuse as the motor is rated as max 4A or is this too low?
Also I have read it is a good idea to put a 47UF ceramic capacitor between each terminal of the motor and the motor casing for suppression,

Thanks Steve

[dodgy geezer]

Well, you seem to be pretty well set up!

A couple of little points: Do you have a box or something to carry the boat in? It's a good idea to protect it while it's being hauled around..

And the cheap Giant Cod Radiolink T4U radio is amazing value - I have two myself - but you need to be aware that it is very much built down to a price. It comes with no instructions (you don't really need them..) and you will find that the trim is very cheap. The radio works fine - but if you want a somewhat prettier cheap one there is the Planet T5 set which a lot of places are selling for £40-£50.

I would certainly stay with the new 2.4Ghz sets. If you use the systems with the older 27, 35(aircraft only) or 40 Mhz frequencies you will need to know what the rules are for using them without interfering with anyone, and you will probably have to buy another set of crystals to give you flexibility in changing frequencies. You don't need to worry about any of this with 2.4Ghz - just turn up and go.

You might also get confused with the electronic speed controllers (ESCs). There are two kinds of motor, 'brushed' and the modern 'brushless' motors, and you can't use a brushless ESC with a brushed motor (or vice versa!). You have a brushed motor (rather a nice one) but the Giant Cod site specialises in brushless motors, so you won't be able to use any of their cheap ESCs.....

[Master Cheif]

6v LA battery's in parallel will work, but you can pick up a new 12v 3ah LA for £20 from MFA  which will do the same job with less wiring.

you can't use a 35mhz tx and rx unit with a boat there for aircraft usage only, you have to use 27fm, 40fm and 40am or the newer 2.4ghz which is preferable as no crystals needed so no fear of crossing signals with anyone else.

'Are ESC speedcontrollers not capable of charging lead battery's?'  nope. you have a charger for that! im not sure but at a guess i think that the 40A esc is actully to small for the motors and a 50A may be better suited, re-check the motors draw though i didn't bother looking  

' The speed controller has BEC  .. is there a downside to using this in place of the receiver battery that came with the Digi- Fleet unit?' bec are ok... but you should beware of the draw from the battery that system can draw at any one time up to 1A of power for the servo alone if its being asked to work harder then it should ' recent article from MMI mag October 2010 page 38-39 will explain all....

your tug also looks like mountfleets new Lowgarth or there about not to sure that's a rough guess, might put you in the right area to finding out.
.

[mattycoops43]

Allt this talk of giant cod is great, but don't forget the other option of looking for a model shop near you and going to see what they have! CML (distributors) are now selling a 2.4G set, very similar to the planet 5 set, for the £40 mark and you can support your local shop too!

"master chief"- Why would he go and buy a 3Ah battery when he has a pair of 12Ah ones? and the extra wiring is only 1 link wire from one battery to the other??

Matt

[Shipmate60]

Steve,
Although the motor states 4 amps this is just a rough running guide.
The motor will be on a higher load when maneuvering eg going from full ahead to full astern.
I usually fit a 10 amp fuse for these as this will protect your ESC, but if something like weed around your propshaft stalls the motor these motors can pull 20 plus amps.

Bob

[Circlip]

And if you want to retain the solid feel of the Fleet Transmitter case, you can buy a 2.4 Giggly conversion set to save Txs lying about.

  Regards  Ian.

[malcolmfrary]

To help master cheif, having read the question, the idea was not to put the batteries in parallel, but in series.  The two 6V 12AH batteries will give 12 volts which should give very adequate.  Its always a good idea to ensure that they are always charged to a similar level to prevent one of them over-discharging, but if you always make sure that they are fully charged before sailing, and they are in good condition anyway, the chances are that you will get tired and hungry before they run down with batteries that size.
The 4 amp draw might be a bit notional, and the real draw could exceed this, usually for short periods during sudden starting and doing a panic stop, but long enough to blow a closely matched fuse.  10A is the next normal step up, and should be fine.  Insert it in the battery - ESC lead and you are protected against internal ESC problems.
I've never heard of that make of ESC, so I will assume an oriental origin.  It has been noted that oriental amps are often much smaller than ours, so the rating may be suspect.  Does it have reverse?  If it has a "brake" feature, can it be disabled?
It is widely thought that with 2.4GHz's greater immunity to airborne interference, that suppression is not needed, but this is a view held by people who think that the aerial is the only way for interference to get in.  Spare suppression might not be needed, but equally, it can prevent future problems.  Its usually easier to fit at an early stage, and costs pennies.

[hollowhornbear]

can you post a picture of the plug on the servo you have, as if it is a fleet plug + and - are reversed and will need modifying as will the plug housing which is unlike any modern ones.

[dodgy geezer]

can you post a picture of the plug on the servo you have, as if it is a fleet plug + and - are reversed and will need modifying as will the plug housing which is unlike any modern ones.

Very good point! The fleet servos will work, but if they need a different plug it will probably be cheaper and easier to buy one new servo - they are only a few quid. It would be a shame to cut off the fleet servo plugs and then have a non-working fleet set because the old fleet plugs can no longer be obtained...


Giant Cod do small servos starting at £2 - here is a nice big one for £4: http://www.giantcod.co.uk/sg5010-towerpro-servo-torque-p-205.html

[John Mk2]

Thanks for all your advice and links gear

 With regard to batteries I do have another 6V of the same type so I can put these in series for 12 V.

 When I put it in the bath the bow was high as I had no batteries installed so I will need to arrange these to get it even and
 add ballast as necessary  which is another good point.

 Cheers Steve
 

A little tip for trimming her.   Get a small spirit level when your bath testing & ballast till true  Saves a lot of hassle at the lakeside

[stevieg]

Hi Above is a picture of the connector to the servo  but I think I will just buy a new one if they are only £4 as mentioned to keep the fleet stuff intact.

Yes it was a typo in my initial post I meant did the ESC support lead batteries not charge them ... that would be a pretty incredible feat!

I just checked out the spec of the firmtronix again ( made in South Africa ) you can turn the break feature off but there is no mention of reverse so it
must be for a plane ( again! )  .. so I've just bought a digi pro 200 Marine off ebay which should be OK .. the clue is in the name.
This goes up to 12V input so will work with my batteries has forward/stop/reverse, BEC and 40A rating (30A continuous).
I don't intend to hammer the boat just potter about .. I'm already being asked daily by my kids when we can use it on the pond so hopefully maiden voyage will be next weekend.

Thanks for all the other advise re testing/carrying etc. also I went to Mountfleet's web page but couldn't find a picture of the Lowgarth mentioned by Master Cheif.

Cheers Steve

[dodgy geezer]

Hollowhornbear is quite correct - the standard for current servos is:  Black or Brown (negative),  Red (positive),  a light colour (White or Yellow - signal). So the Red should be in the middle fro modern use.

You will find that modern plugs aren't handed, either - so you have to look carefully to put the plug in the right way round....

Do you have instructions for your ESC? You will probably find that the ESC has to be 'set up' when you get it. I don't know the Digi-Pro series, but some ESCs are set up by plugging them in, turning the R/C system on, and then moving the throttle stick up and down in response to beeps from the ESC. If you have any problems, I'm sure an experienced Mayhemer will be here to help....

[malcolmfrary]

To swap pins around, usually it is possible to free the terminal in the socket by poking the catch and withdrawing that terminal, pushing them back into the new correct holes as required.  If required, they can always be returned to the original placement.
Having decided amongst themselves that a common size and layout for the plugs was a good idea, most manufacturers then decided to key them to ensure that only "their" servos could work with "their" radios.  Fortunately, we are modellers, and have access to such things as files and sandpaper, and are prepared to use them.  The plugs still work with the offending bits scraped off, and with the modern wire layout, plugging in reversed just results in the servo not working until it is unplugged and then plugged in the right way round, since the pos remains in the same location, but the ground line is connected to a pin that DC cannot get through.