Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Seaport Tugs => Topic started by: dhb141 on December 08, 2011, 07:53:13 am
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Hi,
I’ve just got myself a Seaport tug and inspired by the amazing rebuilds I’ve seen on the forum, I want to have a go myself but keep the costs as low as possible My question is about the electrics. I have an old 2 ch Sanwa Saber outfit which includes, servo, receiver, battery pack etc and I’m wondering if the batteries will give a reasonable running time - it’s a 6v nicad BEC pack - or do I really need to get something else? The receiver says power supply 4.8 v to 8.4 v so I’m assuming that the original batteries with the boat is too much. Another thought - could I use the original batteries to power the motor and the Sanwa pack for the receiver? Not being very well up on these things, any help would be gratefully received! Thanks in anticipation.
Don
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Hi Don,
your Sanwa Saber generally will do. You didn't mention anything about a speed controller which will certainly be needed. For the standard motor a little ESC for brushed rc car motors will be fine. But be careful: most of these ESC only allow 6-7 cell packs (7,2-8,4V) to be used. So I would also recommend a 6 or 7 cell racing pack with about 2000mAh. These ESCs mostly do have a BEC so that there is no need for a separate battery pack for your receiver.
Michael
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Hi Don
When getting a speed controller make sure it has reverse, not all car controllers have this.
The tug is a boat, why not use a marine ESC.
You will notice that most people use a 6v 5amp or 6v 4amp SLA battery. These give you a long run time and also the ballast you will need to get your tug low enough in the water.
My build if helpful. http://www.modelboatmayhem.co.uk/forum/index.php?topic=8411.0
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An old battery might be well into its retirement age by now, soa new one will be a good idea.
It is often cheaper to buy a "proper" ESC than a "bargain". The "bargain" often ends up being dead money, as an almost immediate replacement, by a "proper" one is needed.
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@DickyD
I like your build. I'm just converting my seaport tug to look like a Fairplay I/III/X tug.
Well, in fact I'ver never seen a brushed car controller without reverse during the last years but some marine controllers that don't have reverse. I'm using car ESCs in most of my boats without any problems.
I don't know if 6V are enough to get sufficent speed and pulling power.
By the way: Don likes to stay cheap so a dedicated marine controller and a SLA battery/charger might be too expensive.
Michael
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Hi All,
Many thanks for the replies which are really helpful. Sorry, I should have said that I intend to get Marine 15 ESC but was hoping that would have to be my only outlay. Does anyone have any idea what length of run time I could expect from the 6v nicads, bearing in mind that being a tug, I want to be running it at something like scale speed? And, will the 9v original battery pack not be suitable for the receiver I have? It's not that I'm tight - I just don't like spending money!
Don
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Hi Don,
doesn't your desired ESC have a BEC to power your receiver? If your receiver is rated up to 8,4 volts you shouldn't exceed this limit. Make sure that this voltage isn't forwarded to the servos because most servos are only rated up to 6V.
The length of the runtime can't be estimated without knowing the capacity of your battery.
Michael
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when you install the marine 15 amp esc. it will take a small voltage from your main motor pack to run the receiver in the boat. what size batteries in the 6v nicad?
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The marine 15 has a bec and is rated for 12v. Your high rated pack should be ok but if your motor was 6 v rated then may get a bit hot. But as long as you keep to scale speed all should be fine. Best try it and see. John.
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Thanks again to everyone for the replies. I haven't actually bought the Marine 15 ESC yet so don't know anything about it - as I said, I'm a novice at these things! Each of the 4 batteries in the Sanwa power pack is 1.2 v 700 mAh. Will that give enough power to run the boat at low speed for say 1/2 hr or am I being too optimistic?
Don
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depending on how old the nicad is if its been sat for a while you will probably find its had it. unless it charges and holds the charge of course. the run time depends on the amp draw of the motor. in order to run for half an hour the motor will need to draw a very little 1.4 amps and that is unlikely. you will have to see but i doubt it. The voltage from the original boat battery pack will be too high also.
what motor are you using?
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Hi Mike,
Thanks for your reply. I've been using the nicads on and off for about 3 years now to power the steering on a yacht and they still seem to be holding their charge pretty well. In the Seaport, I intended to use the original motor - at least for now.
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Mike,
I forgot to say that if changing to a different motor would make a difference with the batteries I have, that would be an option for me - just don't want to have to spend any more than is necessary!
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Thanks again to everyone for the replies. I haven't actually bought the Marine 15 ESC yet so don't know anything about it - as I said, I'm a novice at these things! Each of the 4 batteries in the Sanwa power pack is 1.2 v 700 mAh. Will that give enough power to run the boat at low speed for say 1/2 hr or am I being too optimistic?
Don
From what you say, you just have a receiver pack there? Is it a 4 cell pack of AA size batteries? If it is, that would only power a yacht for a short while, using the 2 servos. You will need a bigger pack to power a motor....preferably as Dickie says, a sealed lead acid battery of 6v...
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if the boat has the standard motor and prop in it then i wouldnt advise on downsizing the motor as this would overload it and draw more amps lol.
heres a pic of a 6v SLA, the esc and the receiver:
(http://s10.postimage.org/v8po5f8zp/IMG_20110609_191911.jpg) (http://postimage.org/image/v8po5f8zp/)
the main battery drives the motor. The BEC or battery elimination circuit in the speed controller drives the receiver thus eliminating the need for a seperate battery pack to run the receiver. If you get the marine 15 esc it will hve a BEC in it. I personally use car esc's in my boats as their cheaper. at 20 quid a go for a marine esc you could buy a second hand car esc and nimh battery pack for the same price.
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Very grateful for all the help and advise. Nige, the battery pack I have with the Sanwa is a 4 cell AA size and I only use it on the yacht to power one servo for the rudder - no sail control - which gives me as much sailing as I want in one go.
So from what you all say it looks as though I'm going to have to open my wallet and do some spending. Those £1 notes are still legal tender, aren't they!? :-). Thanks again.
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im a budget builder myself and try my best to do what i can on jelly beans. You will definatly need a new battery as those little 6v aa battery packs are only designed for the receiver, servos and other small load electricals.
i would personally use a car esc from ebay or something eg:
http://www.ebay.co.uk/itm/Mtroniks-20-Turn-Reversible-Car-ESC-Viper-/180771467071?pt=UK_ToysGames_RadioControlled_JN&hash=item2a16d1af3f
or this:
http://www.ebay.co.uk/itm/New-LRP-Ai-Car-Electronic-Speed-Control-/270868302836?pt=UK_ToysGames_RadioControlled_JN&hash=item3f11024bf4
tamiya one:
http://www.ebay.co.uk/itm/Tamiya-teu-101bk-speed-controller-brand-new-packet-/270867181805?pt=UK_ToysGames_RadioControlled_JN&hash=item3f10f130ed
if your willing to gamble and fancy some possible repair work this guy has all sorts of rc gear for sale:
http://www.ebay.co.uk/sch/i.html?_nkw=esc&_sacat=0&_dmpt=UK_ToysGames_RadioControlled_JN&_ssn=advan_gooch&_odkw=&_osacat=0&_trksid=p3286.c0.m270.l1313
if you bid dont bother going over ten pound including pnp for eg 7.50 bid pnp 2.50 etc.
you will also need a battery, nimh batteries can be found for nothing people practically give them away now. Dont bother with nicad there old news. if you go to wants and swaps or sales on this forum you might even be able to pick you a nimh battery for postage only. heres one on ebay:
http://www.ebay.co.uk/itm/GP-7-2v-3000Mah-NiMh-Battery-Pack-TC203-/320807209892?pt=UK_ToysGames_RadioControlled_JN&hash=item4ab1998ba4
that will work with the esc's, and the charger you have with the boat will charge it as long as the voltage of the charger is higher than the voltage of the battery.
for can get both parts for 20 quid.
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tamiya one:
http://www.ebay.co.uk/itm/Tamiya-teu-101bk-speed-controller-brand-new-packet-/270867181805?pt=UK_ToysGames_RadioControlled_JN&hash=item3f10f130ed
Be wary of these ESCs in boats they are very sensitive to damp. For the same money there are more suitable escs available
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of course these a car esc's and not marine ones. The difference is that although they are electrically the same, more waterproofing goes into marine ones and they have a higher tolerance for running high amps for long periods. Its normal waterproof to your radio gear anyway, car esc's rely on air flow cooling the heat sinks on top them. As long as you dont go daft like trying to run a 700 motor on them overheating is not as issue, especially with the small motor your using. so it wont hurt putting the esc is a balloon or something similar.
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Run a 6vSLA and get enough runtime to numb the brain.
I used above batt with an £8 Blue ESC O0 O0 and Grandson gets fed up after two hours.
BTW the SLA is 4.5AH and aforesaid Grandson runs it flat out most of the time (They do don't they <*<)
Ned
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if you not keen on bidding then you could buy these if your willing to wait for the post:
marine 1
http://www.ebay.co.uk/itm/130554115725?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2648
or car 1
http://www.ebay.co.uk/itm/380387245289?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2648
there hit and miss these esc's though, theres no QC on these chinese products so theres no guarantees they will work. its case of luck being on your side.
sla battery;
http://www.ebay.co.uk/itm/6V-4-5AH-RECHARGEABLE-SEALED-LEAD-ACID-BATTERY-SLA-NEW-/320698373781?pt=UK_ConsumerElectronics_Batteries_SM&hash=item4aab1cd695
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That's the blue marine one Mike
I know Dave No6 and others have had probs with them
but mine has performed ok.
I don't endorse the product though as mine could make smoke at any time.
The Dickie is more likely to be wrecked by the youngsters so the cheaper the better :-))
Ned
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i knew what you meant when you mentioned it. ive considered them myself. obviously ned your one of the lucky ones :-))
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Thanks again to everyone who's taken the trouble to answer my questions - and especially to Mike for the links to various items I might want to get. I'll do a bit of thinking, re-read all the threads again and then make up my mind which stuff to get. Who knows, I might even post a few pics of the rebuild if I can pluck up the courage :-)
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yeah some pics of your progress would be great :-))
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Just another quick question. Will the 'Blue 110 AMP ESC' that Mike put me on to work with a lead acid battery? It's just that reading the spec, it only mentions nicads, mimhs and lipos.
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yes it will but please bear in mind these esc's have a very bad habit of turning into smoke in a matter of minutes. Its better to get a second hand GOOD esc than a brand new rubbish one.
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heres a good one 5 mins to go though!!
http://www.ebay.co.uk/itm/150711214035?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2648
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Thanks for the advice Mike - a better quality one is the way to go, I think. Too late for the one on ebay though - shame!
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Hi dhb141, I am surprised nobody told you to check out ACTion electronics. You should have a look at what they make. They are local U/K & also sponsor this forum. Most of the Chinese stuff is very inferior with wild claims that the product will not live up to. Talk to Dave @ ACTion he will sort things out for you & no nonsense or false performance claims. Support your own local suppliers, especially when what they manufacture is far better quality than a lot of the FleaBay junk, no connection, just a satisfied customer speaking from experience. Mick B.
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Hi MickB - thanks for this information, I'll certainly look at what they have to offer.
Don
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what budget have you got in mind?
Ive sent you a private message don
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Budget? What budget!? I just want to end up with a nice reliable boat that isn't going to cost the earth.
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Hi again DHB141, just to let you know that Dave at ACTion will also plot a wiring diagram for you at no cost in full colour no less. Have a look at the diagrams he has done for lots of people on ACTion's web site , me included. Hope l am helping you get sorted & looking forward to your build. Mick B.
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Hi again DHB141, just to let you know that Dave at ACTion will also plot a wiring diagram for you at no cost in full colour no less. Have a look at the diagrams he has done for lots of people on ACTion's web site , me included. Hope l am helping you get sorted & looking forward to your build. Mick B.
Please would Mayhem members note that this service is only for ACTion customers? There is probably a diagram in there now to suit just about any model boat with a little modification, so have a look on the website here http://www.action-electronics.co.uk/wd.php (http://www.action-electronics.co.uk/wd.php) and here http://www.action-electronics.co.uk/ms.php (http://www.action-electronics.co.uk/ms.php). Much as I would like to, I simply don't have the time to draw wiring diagrams for anyone who asks, especially if they include equipment of which I have no experience.
DM
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Sorry about missing that point about who you will do them for Dave, I know you are a nice fellow, but NOT that nice LOL. Mick B.