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[Seaspray]

Hi 
Got a new electric motor and thought I would do some testing.

Its a 540, 5 pole with a current max efficiency 5.75amps. no load 1.24amps 6v-12v useage.

 I ran it on 6v 10 amp gel cell.

On a 35mm 3 and 4 blade props.  I got reading of 10amps full throttle.  7.5amps /1/2 throttle in the bath operated by a electronize EC.settling to 5.5 amps in 10 seconds on 1/2 throttle

Out of the bath direct battery to motor wired I got 10amps settling to 7.5amps and in the bath directly wired I got 15amps Then removing the prop returning the model to the bath the reading dropped to 10amps.

I think I'll need to find another motor to power this boat as it is a 35 inches displacement hull or is this the normal for a low drain 540 motor ?

Previously a had a Johnstone 600 fitted, say no more as it was a National Grid power supply job.

Feel free to offer suggestions of any kind except the rude ones ,which I know.


Seaspray

[Ghost in the shell]

you did say low drain didnt you, that motor certainly does not sound low drain.  get yourself a Graupner 500E, I have one of those in my Sydney Star and she'll sail all day long on a 12ah battery

[HS93 (RIP)]

You say you removed the prop , was that the prop or prop shaft joint as it seems a lot of drain for a prop in air, as a 5 amp drop is a lot

peter

[Seaspray]

Hi Peter
I alter the post should have said back into the bath no propeller on and it dropped to the voltage on post. Is the graupner 500e the size of a 540 motor and fit the MFA motor mounting ?

Hi Ghost
It said it was low drain but the setup might just upset the performance see below.Its a 2 pulley belt driven setup with the pulleys in the north and south configuration

[malcolmfrary]

Certainly doesn't sound low drain.  How free is the propshaft?

[Seaspray]

Hi Malcolm
Checked it out, there is backlash so its not binding can turn it by rolling your finger over it es easy

[malcolmfrary]

Sounds like a chat with model motors direct would do no harm at all.

[HS93 (RIP)]

Remove the belt and see what the belt and shaft is drawring.

Peter

[Seaspray]

Hi HS93
I've already u coupled the motor from shaft and the readings are to spec regards a "no load"

Wonder if it being belt driven is what is using up the amps or does it take less to drive a shaft if motor/shaft are in line of each other ?

[HS93 (RIP)]

So if you are saying the belt takes nearly 5 amp, that is a lot. Is it a smooth belt or a toothed belt?  it seems a lot I use belt drives on a few of mine and its only about 0.25 to 0.50 amps draw for the belt but they are toothed and ballraced.

Peter

[Seaspray]

Hi HS93
Its a toothed belt of 50mm circumference and is a nice fit.

Any chance of a picture of one of your belt drive and the spec of pulleys and belt used ?

[FullLeatherJacket]

Seaspray

It does sound an awful lot of juice disappearing into that belt-drive. From my experience of the MFA units, the belt should be just  tight enough to avoid skipping onto the next tooth, and you should check that the edges of the belt aren't chaffing the flanges each side of the pulley teeth. This will happen if the two pulleys aren't aligned exactly one above the other fore-and-aft, and it don't 'arf lower the speed and turn up the current!

I'm also wondering if you actually need a reduction drive at all. A tame 3-pole motor should turn a 35mm 3-blade scale prop on direct drive in a displacement hull that size without too much trouble. It's a myth that all 545s are nice and tame; some of mine spit fire at you, whereas I also have some silky smooth 3-pole jobbies that would run all day on 6v without even getting warm. I've not personally used a Graupner 500E, but the 600E is a super little job and this range is not too expensive. Check out the Gliders website for the full tech specs on Graupner motors, and I think that Electronize have a "motor/prop suitability" chart on-line.

Suit yourself.

FLJ

[Seaspray]

Hi FLJ
I've had to use a pulley system because I can't get the motor in line with the propshaft as there is no room in the hull . Just barely got the pulley of about 55mm dia. in. Not using the pulley system as a reduction unit.

Have looked at Electronize and their charts and motors especially the 545-12.

Anybody got first hand experience of this motor ?

[Telstar]

Hi Seaspray
In your thread you say that the motor meets spec. with the belt unhooked ( spec being 1.24A)
But with belt on and no prop (just belt & propshaft) you measure 7.5A .
That seems an awfully high reading, it would suggest to me that the propshaft is excessively tight, and?or the belt drive is adjusted too tight(putting too much side pull on the motor & shaft bearings. 
If this is so it won't be corrected by buying and fitting a new motor.
The remark in your observations (current settled after 10s ) would suggest to me that the prop shaft is grease filled, possibly over filled (too much grease in bearings etc can be worse than too little)
I know this from my own experience in industry, when a over enthusiastic helper caused two fan motors to overload & trip out after using a high pressure grease gun on the fan bearings and pumping ‘till grease came out the sides
However back to your problems
I would suggest you check the belt tension carefully (as FLJ says, it should be tight enough to prevent slipping only) and also the pulley alignment both vertically and horizontally.
I personally prefer to fit oil lubrication to my propshafts it causes less ‘drag’ and with a ‘head’ of oil pressure I don't appear to get any problem with water up the tube (that sounds painful) 

[HS93 (RIP)]

as req a few pictures of the way I do belt drives, this was built a long time ago , and I got half way through a re ferb and lost interest as another project came along.my latest boat has a very similar set up but as the belts are not on I thought this may be better, there are about half a dozen boats running with this,and none draw anythink like 5amps for just the belt.

Peter

[Seaspray]

Hi Telstar
Yes the tube is greased and it was put in with some pressure.Thinking a long time ago I done this with an I.C. engine and it made a difference in its performance. So I am going to degrease it and fit an oil pipe as per your drawing.

Hi HS93
Very nice set up engine over shaft.Unfortunately I don't have the room in the hull for that setup and have the motor facing the shaft with the pulleys north and south as previously mentioned. I do like your quality of the pulleys and belts on your setup. Could you let me know where they were bought ?

Somebody mentioned (Malcolm) Model Motors Direct which remained me that I have a 777 motor in the shed.  Having run this motor up on 6 and 12 volts I was impressed as it had enough speed for the model and only draws 1amp (no load) and I couldn't stall it with my finger on the shaft (lots of torque)  Unfortunately the shaft is larger and shorter than the current motor used.A redesign of the whole setup my be needed,unless the removal of the grease in the shaft cures the problem. If not, hopefully I can find a way of fitting the 777 up to the propeller shaft

[HS93 (RIP)]

I have NEVER been a fan of grease with electric motors and I only use vegetable based oil castrol R mine is quite thin but I use ball bearings and tufnoll that don't need oil , the oil is to stop rust with the BB . the gearboxes I have been making them like this for about 10 or twelve years hear is a picture of my latest,they can be made very simply its just a flange solder on the end of the shaft that holds a bearing and the motor plate is bolted on ,, when you have removed all the grease lets have another test to see what the grease is doing..Peter

[anmo]

I have NEVER been a fan of grease with electric motors and I only use vegetable based oil castrol R.

And I bet your boats smell just wonderful as they sail past.

I expect that Peter's post will attract a few appreciative responses from some of the more mature bikers on Mayhem.

[HS93 (RIP)]

I got it when I was playing with one of my cars I had a few drums of it , the problem is since Cats have been on cars I cannot put it in petrol any more, its not the best for prop shafts because it emulsifies in water but it is non harmful to the environment  (or less than others) before the forum jumps on me and I use very little of it..
Peter

[HS93 (RIP)]

As req, I hope you can understand it sorry its a bit dusty in the boat

.Peter

[Captain Povey]

There is some super looking work there Peter. I thought you might like to see the sort of 'Cat' they have tried to fit on my car. Cheers Graham

[Seaspray]

HI Peter
Excellent picture of the setup now I can see what the construction looks like,cheers

[HS93 (RIP)]

Captain Povey   Ok so your cat can work on engines but can it do this. Peter

[Seaspray]

Hi   

New motor setup pulleys and belt arrangement soon to be fitted.

Will give the new amps reading when I've done the test.

Special thanks to a certain forum member for their patience and assistance.