Model Boat Mayhem

Please login or register.

Login with username, password and session length.
Pages: [1] 2   Go Down

Author Topic: Johnson 6-12v motor - Which speed controller?  (Read 13525 times)

buckfast

  • Guest
Johnson 6-12v motor - Which speed controller?
« on: February 01, 2011, 11:17:27 pm »

Hello everyone,

Please can I get some help?

I have just bought a brushed Johnson 6-12v motor and would like to know if this http://cgi.ebay.co.uk/ESC-30A-RC-Brushed-Motor-Speed-Controller-UK-/200566437028?pt=UK_ToysGames_RadioControlled_JN&hash=item2eb2b0f4a4#ht_2287wt_906 speed controller would be suitable to control it.

I've promised my son that by the summer time we'd have our model boat up and running.  I made a start on it over 2 years ago but work got the better of me!!

Hope someone can help.

Many thanks.

BF
Logged

buckfast

  • Guest
Re: Johnson 6-12v motor - Which speed controller?
« Reply #1 on: February 01, 2011, 11:19:11 pm »

I should have said . . .

The motor is rated as follows:

Approx 20,000 rpm drawing about 2.3 amps

Thanks again.

BF
Logged

Peter Fitness

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 7,376
  • Location: Wyrallah, near Lismore NSW Australia
Re: Johnson 6-12v motor - Which speed controller?
« Reply #2 on: February 02, 2011, 03:09:42 am »

The blurb on eBay doesn't mention if the ESC has a reverse function, which I would regard as necessary for a model boat. It seems to be intended for model aircraft.

Peter.
Logged

ACTion

  • Guest
Re: Johnson 6-12v motor - Which speed controller?
« Reply #3 on: February 02, 2011, 07:16:16 am »

http://www.modelboatmayhem.co.uk/Common/Electrics/How%20Fast.htm#Fast%20motors
See last section "Bad 540 motors".
The speed controller you have seen doesn't appear to have Reverse either. I'd suggest buying a proper British-made marine ESC and a motor which is matched to the model you have - both from a bona fide model boat supplier. There are plenty listed in the Traders section of this forum.
DM
Logged

john s 2

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,172
  • Location: Southend on Sea Essex
Re: Johnson 6-12v motor - Which speed controller?
« Reply #4 on: February 02, 2011, 09:00:23 am »

You could buy an Action Esc. Made in Britain. You speak to the maker who can advise if required. Are repairable in event of a mishap.
Im just one of his happy customers. John.
Logged

malcolmfrary

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 6,027
  • Location: Blackpool, Lancs, UK
Re: Johnson 6-12v motor - Which speed controller?
« Reply #5 on: February 02, 2011, 10:59:11 am »

If the 2.3A at 20000rpm is accurate, that implies a very small prop.  A large prop will drag the motor speed down and increase the current a LOT.  If you are totally sure that reverse (which is also your brakes) is not required, then the ESC will probably do the job, but getting the right gear in the first place will ensure a satisfactory result, and is usually cheaper in the long run.
Johnson make a vast range of motors - what size is yours?
It would also help to know the size/type of hull when guessing at the best combination of motor/battery/ESC/prop.
Logged
"With the right tool, you can break anything" - Garfield

unbuiltnautilus

  • Portsmouth Model Boat Display Team
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,154
  • Location: Portsmouth, England, third rock from the Sun....
Re: Johnson 6-12v motor - Which speed controller?
« Reply #6 on: February 02, 2011, 11:48:33 am »

http://www.modelboatmayhem.co.uk/Common/Electrics/How%20Fast.htm#Fast%20motors
See last section "Bad 540 motors".
The speed controller you have seen doesn't appear to have Reverse either. I'd suggest buying a proper British-made marine ESC and a motor which is matched to the model you have - both from a bona fide model boat supplier. There are plenty listed in the Traders section of this forum.
DM

I would agree with 50% of the above. Unless you know the reputation of these budget speed controls, I would avoid them like the plague.
I was surprised to see the big Johnson motor listed under 'bad motors', our club use these motors, running at 7.2v direct drive, with 35mm 2 blade props in 37" Perkasas and can squeeze 20 minute runs out of batteries of about 3600mAh, using mtroniks 20 amp marine speed controls, and I personally have run a pair at 14.4v through Robbe 3:1 reduction gearboxes on graupner 42.5mm handed 2 blade props, between them pulling about 15 amps (38" Vosper 71' MTB ). Its less 'Bad motors' and more 'Lack of knowledge'. I have seen so many examples of high revving motors over propped, to get the model to "go a bit faster". usually resulting in the speed control going pop.
Slower motors=more torque=bigger props
Faster motors=more amps=smaller props
Then you throw gearboxes into the mix.......... :-)
Logged
Listen politely, nod approvingly, then do what you want, works for me!

john s 2

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,172
  • Location: Southend on Sea Essex
Re: Johnson 6-12v motor - Which speed controller?
« Reply #7 on: February 02, 2011, 02:07:16 pm »

I agree that budget speed controllers can be dubious at times. The Chinese ones ive got come in with a burst and dont run slow
if they work at all. Theres no recause when they fail. John.
Logged

buckfast

  • Guest
Re: Johnson 6-12v motor - Which speed controller?
« Reply #8 on: February 03, 2011, 08:15:29 am »

Thank you for all your advice.  Am I right in thinking that you have to used a ESC for a brushed motor if you are using a brushed motor and vice versa?

I think I will give the Johnson motor the benefit of the doubt.  If it doesn't work then I'll have to use plan B.  Not that I have a plan B... {:-{

Cheers

BF
Logged

unbuiltnautilus

  • Portsmouth Model Boat Display Team
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,154
  • Location: Portsmouth, England, third rock from the Sun....
Re: Johnson 6-12v motor - Which speed controller?
« Reply #9 on: February 03, 2011, 08:54:05 am »

Thank you for all your advice.  Am I right in thinking that you have to used a ESC for a brushed motor if you are using a brushed motor and vice versa?

I think I will give the Johnson motor the benefit of the doubt.  If it doesn't work then I'll have to use plan B.  Not that I have a plan B... {:-{

Cheers

BF

Yes, that is correct.
Logged
Listen politely, nod approvingly, then do what you want, works for me!

buckfast

  • Guest
Re: Johnson 6-12v motor - Which speed controller?
« Reply #10 on: February 06, 2011, 11:20:28 am »

I have been looking at the Mtroniks Viper Marine 20 brushed speed controller.  Would this suit the Johnson motor?

What other types are available for brushed motors?  All the ones I have looked at are the brushless type - well at least I think they are {:-{

Thanks

BF
Logged

stallspeed

  • Guest
Re: Johnson 6-12v motor - Which speed controller?
« Reply #11 on: February 06, 2011, 11:27:33 am »

chuck the johnson motor away!
Logged

buckfast

  • Guest
Re: Johnson 6-12v motor - Which speed controller?
« Reply #12 on: February 06, 2011, 12:14:47 pm »

What motor would you suggest then?  The hull is 38" long.

I don't have an awful lot of money to spend on this at the minute and some of the motors are scary prices.

Thanks,

BF.
Logged

unbuiltnautilus

  • Portsmouth Model Boat Display Team
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,154
  • Location: Portsmouth, England, third rock from the Sun....
Re: Johnson 6-12v motor - Which speed controller?
« Reply #13 on: February 06, 2011, 12:20:09 pm »

I have been looking at the Mtroniks Viper Marine 20 brushed speed controller.  Would this suit the Johnson motor?

What other types are available for brushed motors?  All the ones I have looked at are the brushless type - well at least I think they are {:-{

Thanks

BF

The 20 amp mtronics marine control is fine with the big johnson at 7.2v with a prop no bigger than 35mm, bear in mind this motor is suitable for FAST scale models, not ferry boats etc, anyone who sells you one as such should be avoided at all costs, DO NOT chuck it away, if used properly, this motor is better than most of the Graupner 600 range of motors. Too often you get ill informed comment on the forum based on unhappy experiences brought about by poor advice from others. Ask our local club members, who use these motors in many different models. Worst case, if you feel the need to throw this motor away, please post it to Portsmouth, and that goes for anyone else out there. Thanks :-)
Logged
Listen politely, nod approvingly, then do what you want, works for me!

Timo2

  • Guest
Re: Johnson 6-12v motor - Which speed controller?
« Reply #14 on: February 06, 2011, 12:23:59 pm »

Hi Buckfast

               Contacts for ESC unit   ( 2 wire is brushed motor  / 3 wire is brushless motor )
          
            
              http://www.action-electronics.co.uk/home.html

              http://www.microgyros.com/index.html

              http://www.mtroniks.net/

            Contacts  for Motors  to suit most boats   :-

               http://www.action-electronics.co.uk/home.html
            
               http://www.graupner.de/en/products/dc7b05f1-7f41-4d3e-bbef-f2d8501398af/productcategory.aspx
        
              Contacts for retailers on line to many,   start with  ( 2 only to start )

              http://www.howesmodels.co.uk/RadioControl/index.php

              http://www.amodelworld.co.uk/
  Ok

   Timo2

   P.S.    Where in the world  are you  do tell  and some body locally may " Help You "

Logged

buckfast

  • Guest
Re: Johnson 6-12v motor - Which speed controller?
« Reply #15 on: February 06, 2011, 12:31:57 pm »

Thanks for the advice you two.

It looks like the motor will not suit my model anyway as it is for this hull - http://www.modelboatmayhem.co.uk/forum/index.php?topic=12499.0

I will keep the motor for a future project maybe.

What motor should I look at getting hold of?

My location is Redcar - North East.

Thanks again,

BF.
Logged

unbuiltnautilus

  • Portsmouth Model Boat Display Team
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,154
  • Location: Portsmouth, England, third rock from the Sun....
Re: Johnson 6-12v motor - Which speed controller?
« Reply #16 on: February 06, 2011, 01:23:59 pm »

Nice looking vintage project, my dad used to sail the Med as a deckhand on one of those during the 1950s,
Motors, your right, the Johnson is too big for this model, would suggest the following 500, 600 size motors;
Model Flight Accessories 457 RE540/1
Expo/Action Sun540
Expo/Action Sun555
Graupner 500E no1788
Electronize 545-12
These should all be ideal for your project, would suggest 6v to 7.2v and about a 35mm to 40mm prop.
I look forward to the pictures of the finished model :-))
Logged
Listen politely, nod approvingly, then do what you want, works for me!

buckfast

  • Guest
Re: Johnson 6-12v motor - Which speed controller?
« Reply #17 on: February 06, 2011, 04:27:50 pm »

Thank you for your advice.  I think I know what I'm looking for now. :-))

I'll let you know when I've made a purchase.


BF
Logged

buckfast

  • Guest
Re: Johnson 6-12v motor - Which speed controller?
« Reply #18 on: February 06, 2011, 04:50:30 pm »

I should have asked before.  Does this now mean I can get away with a smaller brushed ESC?

Thanks again

BF
Logged

DickyD

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 9,423
  • www.srcmbc.org.uk
  • Location: Southampton UK
    • SRCMBC
Re: Johnson 6-12v motor - Which speed controller?
« Reply #19 on: February 06, 2011, 04:55:15 pm »

Too often you get ill informed comment on the forum based on unhappy experiences brought about by poor advice from others. Ask our local club members, who use these motors in many different models. Worst case, if you feel the need to throw this motor away, please post it to Portsmouth, and that goes for anyone else out there. Thanks :-)
Novel idea, I like it, post your rubbish to Portsmouth, magic. :-))
Logged
Richard Solent Radio Controlled Model Boat Club http://www.srcmbc.org.uk

unbuiltnautilus

  • Portsmouth Model Boat Display Team
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,154
  • Location: Portsmouth, England, third rock from the Sun....
Re: Johnson 6-12v motor - Which speed controller?
« Reply #20 on: February 06, 2011, 05:09:37 pm »

Novel idea, I like it, post your rubbish to Portsmouth, magic. :-))

And we can slap a coat of grey paint on it and sail it around the local lake, we is nothing if not creative %%
Logged
Listen politely, nod approvingly, then do what you want, works for me!

Shipmate60

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 5,800
  • You bark - I will bite!!!
  • Location: Fareham
Re: Johnson 6-12v motor - Which speed controller?
« Reply #21 on: February 06, 2011, 05:32:12 pm »

Or, of course, we have the know how to us it, unlike some!!

Bob
Logged
Officially a GOG.

DickyD

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 9,423
  • www.srcmbc.org.uk
  • Location: Southampton UK
    • SRCMBC
Re: Johnson 6-12v motor - Which speed controller?
« Reply #22 on: February 06, 2011, 05:36:24 pm »

Or, of course, we have the know how to us it, unlike some!!

Bob
You was the one who told me to get rid of my Johnson motors Bob. ok2
Logged
Richard Solent Radio Controlled Model Boat Club http://www.srcmbc.org.uk

Shipmate60

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 5,800
  • You bark - I will bite!!!
  • Location: Fareham
Re: Johnson 6-12v motor - Which speed controller?
« Reply #23 on: February 06, 2011, 05:57:10 pm »

As stated in reply 21.

Bob
Logged
Officially a GOG.

buckfast

  • Guest
Re: Johnson 6-12v motor - Which speed controller?
« Reply #24 on: February 06, 2011, 07:10:25 pm »

This is what I've decided on thus far...

MFA RE-540/1 3 -Pole DC Motor with mount from CMB
Mtroniks Viper Marine 15 also from CMB

Gianitcod 2.4ghz 4-Channel Tx/Rx
Corona CS-928BB Analogue Servo from Giantcod.

Any criticism welcome before I type my card number in :}

BF
Logged
Pages: [1] 2   Go Up
 

Page created in 0.095 seconds with 21 queries.