discussion boatman's 1/72 HMS Tiger C20 build

[boatman]

So a 9.6v motor on a 12v battery..... Could that be the issue?
Looking at the motors you have given the info on I Would say that they are under rated for the system. As it says on the box you posted nominal 8.4v operating range 6 and 9.6v If you are feeding them 12v they are not going to play nice but you know that.
I would suggest a look at these from Krick. Max POWER 500.
https://www.krickshop.de/MAX-Power-...ick_e&SessionId=&a=article&ProdNr=42246&p=354
Pretty sure you can find them in the UK as well

I did not know that it was two motors per fuse and only two of the motors that are blowing fuses. (just guessing on the info given). Are the motors different form the ones that do not blow the fuse?

YES Ian the ones that dont blow the fuse are johnsons motors right up towards the rudder an the ones that blow the fuse are the graupner 600 motors but i think i will replace the johnsons as i dont think they are powerfull enough to power tigers wheight thats why im goin to get new 4 x new more powerfull motors if you get my meaning
chrisb

 

[boatman]

Gives me more questions than answers really Chris. You seem to be running 8.4 volt motors on a 12 volt system? They will therefore be able to draw much more current than they are designed for and quickly take damage. Are you sure that isn’t the root of your problems? What is the spec of the back ones that work successfully?

HI Tim the johnsons motors are the ones that dont blow the fuse an i cant tell you the specks as they come in a box with no intructions an ive used the grapner 600 ok in my nimtz an my norfolk so they should be ok but they are not direct drive as they are MFA mounting fitted in a cambelt drive so it 3 to 1 ratio an they go great only trouble is that ive only got one pair of cambeltdrive enough for 2 motors an not 4 as they are not made anymore
chrisb

 

[Tim Marlow]

Just did a fag packet calculation in my head…..do you know that each of those Groupners can stall at around a kilowatt each on their rated current…..added together that’s as much a draw as a two bar electric fire…..at best efficiency they each draw like a 100watt bulb.
If you are going to swap them out I would look for 12 V replacements. They should at least match your battery current then, and should simplify problem solving.

 

[Tim Marlow]

Don’t ya just love it when greenies talk dirty!!!

Er….what’s a greeny? Don’t mind being insulted, but it doesn’t really work if I don’t speak the lingo……

 

[Ian M]

If you are going to swap them out I would look for 12 V replacements.

Or at least a voltage regulator/limiter someplace between the power source and the motor.
What do you recon on the motors I linked to Tim? I read that they can handle a screw of upto 100mm so they should be able to handle the 33mm screws on Tiger in their sleep.

 

[wotan]

Congratulations Chris on a successful project launch.

John

 

[Tim Marlow]

Or at least a voltage regulator/limiter someplace between the power source and the motor.
What do you recon on the motors I linked to Tim? I read that they can handle a screw of upto 100mm so they should be able to handle the 33mm screws on Tiger in their sleep.

They look more suited to direct drive than the Groupners, revving much slower, so wouldn’t need the belt drive step down. They are half the power output….but if they are more efficient at converting that power into thrust than the Groupners (which are 75%), and are direct drive, which would also increase efficiency, then they could close that gap quite quickly. Trouble is, it’s poor old Chris’ wallet that has to play suck it and see…..

 

[Waspie]

Er….what’s a greeny? Don’t mind being insulted, but it doesn’t really work if I don’t speak the lingo……

Ok - ok, Sparky then!!!
Bloody civvies!!! :rolling: :smiling3: :smiling3: :smiling3: :smiling3: :smiling3: :smiling3: :smiling3:

 

[tr1ckey66]

Hi Chris
Tiger looks simply fantastic on the water - a magnificent and graceful looking model. Looks like you had a great day for it too.
It’s a shame about the fuse/motor issue cutting short the maiden voyage but I’m sure you’ll get it sorted.
Hope all is good with you and I’ve fingers crossed you’ll sort the motors in quick time.
All the best mate
Paul

 

[stillp]

HI Pete well 12v 12amp hr batt is the power an it goes through the fuse box an 40 amp fuse an then to a 320 AMP ESC then to the motors best i can exsplain it
chrisb

Chris, could you give me a part number for the ESC please, so I can find the full specification?
Pete

 

[Tim Marlow]

Ok - ok, Sparky then!!!
Bloody civvies!!! :rolling: :smiling3: :smiling3: :smiling3: :smiling3: :smiling3: :smiling3: :smiling3:

Me no sparky…..me biotechnology production specialist :tongue-out3:
….colloquially known as Plantlife by the others in my place of work……or as we ourselves called it….plantlife and bloody proud of it :thumb2:

 

[scottie3158]

Chris,
Wow, wow, wow she is an absolute beauty. Your hard work has been paid back in spades. It was a pleasure following the build and watching her come together and watching you problem solving. If we had one I would present the Golden dogs award. Fantastic seeing her on the water.

 

[davecov]

@boatman Congratulations on the maiden voyage of your HMS Tiger, Chris. It really looks at home on the water and I am sure that you will sort out the gremlins in no time.

It has been a pleasure following your build and am now eagerly awaiting your next one....

Dave

 

[tigersteve]

Beautiful Build ! and such technology is astounding........

 

[Waspie]

Me no sparky…..me biotechnology production specialist :tongue-out3:
….colloquially known as Plantlife by the others in my place of work……or as we ourselves called it….plantlife and bloody proud of it :thumb2:

Yer on yer own with that one!! "biotechnology production specialist" What on the planet Zod is that when it's earning a wage????

 

[Peter Gillson]

Lovely photos of her on the water. Its been great following the build and loveryl to see her in her natural environment!

Peter

 

[Tim Marlow]

Yer on yer own with that one!! "biotechnology production specialist" What on the planet Zod is that when it's earning a wage????

Basically, I grew bugs and turned them into a treatment for childhood leukaemia. I was the subject matter expert for the fermentation and recovery stages of the process, so when the FDA and the MHRA came calling I was wheeled out to answer the awkward questions. The product was called Erwinase.
This stuff….
https://portonbiopharma.com/products/erwinase/

 

[boatman]

Chris, could you give me a part number for the ESC please, so I can find the full specification?
Pete

HI Pete here it is the ESC on ebay AN my brother found out in a test that no. 4 motor is faultY so hopefully that was the problem pic below OF ESC

 

[Waspie]

Basically, I grew bugs and turned them into a treatment for childhood leukaemia. I was the subject matter expert for the fermentation and recovery stages of the process, so when the FDA and the MHRA came calling I was wheeled out to answer the awkward questions. The product was called Erwinase.
This stuff….
https://portonbiopharma.com/products/erwinase/

The mere mention of the word 'Proton' brought a shiver on!!!!
But wow -

 

[Tim Marlow]

The mere mention of the word 'Proton' brought a shiver on!!!!
But wow -

Porton is two sites…..the Health (HPA and Porton Biopharma) side and the MOD (QinetiQ) side. It was split in the late 1970s. Trouble is, nobody seems to know about our bit, only the MOD part…..even news stories like the Novichok incident talked about the MOD but showed stock pictures of our bit…..