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Author Topic: Single screw motor  (Read 3041 times)

Stavros

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Single screw motor
« on: October 26, 2007, 07:42:58 PM »

HELP me got a problem as you have read me is building a TID TUG and have installed a Buller motor from Motors direct BIG MISTAKE for it to have any grunt it has to run on 24v the prop I am using is a Prop shop supplied 3in 4 blader which I am quite happy with and excellent piece of engineering.
Right what I want to know is ,is there anyone out there running a MFA 800 motor in their tug and secondly will it run a 3ins prop,reason I ask this is simple I need more POWER as Llanberis can be quite windy.
As the Buller only revs to 1200rpm on 12v so I would presume on 24 it would rev give or take to approx 3000 rpm I will stand corrected on that so me being me thinks that the MFA 800 will give me more revs and more pushing power.

Stavros
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Colin Bishop

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Re: Single screw motor
« Reply #1 on: October 26, 2007, 07:46:28 PM »

Could you use a couple of small 12v batteries in series or would that take too many amps Stavros?
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Stavros

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Re: Single screw motor
« Reply #2 on: October 26, 2007, 07:52:39 PM »

Need large 12 12 amps batts to weigh it down, the motor is just too slow revving. Colin I need around 5000rpm,yes of course it goes at scale speed on 24v but I feel 24v is not the answer

Stavros
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Colin Bishop

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Re: Single screw motor
« Reply #3 on: October 26, 2007, 07:59:58 PM »

You are probably right Stavros. Most associated kit is geared to work with either 6v or 12v. My unfinished Fishery Cruiser runs on 8v for various reasons which has caused a bit of headscratching  at times.
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boatmadman

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Re: Single screw motor
« Reply #4 on: October 26, 2007, 10:15:39 PM »

I used the same motor in my drifter. at 12v was grossly underpowered, so I upped to 24v, now its overpowered, but thats the way I like it!

On 12v the motor pulled 0.5a spinning a 65mm prop. I havent measured it on 24v, but I have run for nearly an hour without any sign of power drop.

Ian
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Shipmate60

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Re: Single screw motor
« Reply #5 on: October 26, 2007, 10:37:57 PM »

Stav,
In my Tid, I used a Deccaperm, then went to a 3:1 geared 550 on 6 volts, or you could use 6:1 on 12 volts, or you could use 1 of the graupner motors that run at no more  than 400 rpm.
My geared motor ran 1 amp in air and about 3 under load.
Hope this helps.

Bob
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Stavros

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Re: Single screw motor
« Reply #6 on: October 27, 2007, 08:40:53 AM »

Bob if at max rpm of the Buller motor the tug hardly moves suerly if I used a Graupener at 400 rpm it would not move or should thta read 4000rpm me confused

Stavros
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FullLeatherJacket

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Re: Single screw motor
« Reply #7 on: October 27, 2007, 08:57:07 AM »

Stavros
Check out the spec on the Graupner Speed 720 Torque (from Westbourne Models). It looks like a very tasty motor fpr such applications.
FLJ
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Stavros

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Re: Single screw motor
« Reply #8 on: October 27, 2007, 09:25:20 AM »

Thanks FLJ that's looking promising seems to have a good rev range etc

Stavros
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tolnedra

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Re: Single screw motor
« Reply #9 on: October 27, 2007, 09:56:44 AM »

Stavros,

For my Tyne Models "Alfred" I was recommended a Robbe Power 1000 by Westbourne Models. Having taken that advice, I am very pleased with the result. Just a slight touch on the stick, you can watch the prop rotate in the water, it's that slow. However, kick it on a bit and you can see the power available. Big motor, but seems to fit the bill.

Danny
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wombat

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Re: Single screw motor
« Reply #10 on: October 27, 2007, 09:58:12 AM »

Stavros,

I am running a Robbe 755/40 gotr from Pandan in Highlander - on 12V it swings a 4 blade 65mm prop fast enough to get the boat moving pretty sharpish - closer to actual speed than scale speed. It has plenty more go in it - it doesn't even get warm.

Wom
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cos918

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Re: Single screw motor
« Reply #11 on: October 27, 2007, 10:34:25 AM »

hi there stavros if you are thinking of the graupner 720. They are a great motor but bit price round 30 and second  they seam a bit hard to get hold of as my local shop has been trying and cant get them , he say graunper are out if stock. While i was talking about this on another thread a guy should another range that are identically and cheaper ,i am thinking of trying instead of the graupner motor. The thread was in the section of electrics under title of graunper , hope this is of some use to you
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corrado

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Re: Single screw motor
« Reply #12 on: November 05, 2007, 01:05:59 PM »

Hi Stavros,
I have also built the TID Tug & can offer some advice based on my experience.   Mine is 42 inches in length so it is very similar in size.   The motor I reccomend is a car electric motor which every modern car has these days.  It is a cooling fan motor for the car's Radiator.  I think Mobile Marine Models sells these in England, but you can get them at any Motor Wrecker.   These motors are 12 volts, spin at 3000-3500 RPM, have masive torque for large propellors and only draw 5 amps under full load (in the water) with direct connection.  I'll try to attach a couple of photos.
Cheers.........Corrado
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Stavros

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Re: Single screw motor
« Reply #13 on: November 05, 2007, 04:26:03 PM »

Thanks for all the replies have gone out and bought a Protech motor that revs to 4200rpm and draws only 3amp same size as the Graupener 900bb but only cost 1985 cheers

Stavros
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DickyD

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Re: Single screw motor
« Reply #14 on: November 05, 2007, 04:50:51 PM »

1985 sounds a bit pricey Stavros. :-\
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boatmadman

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Re: Single screw motor
« Reply #15 on: November 05, 2007, 05:08:36 PM »

Where do you get those motors from Stavros?

What voltage range do they cover and what size are they?

Ian
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Stavros

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Re: Single screw motor
« Reply #16 on: November 05, 2007, 10:34:39 PM »

12vsame size as the 900bb got it from Red Bank Models Blackpool visit this web site  http://www.protech.be/  download catalouge page 117 read all about it

Stavros
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