Model Boat Mayhem
Mess Deck: General Section => Model Boating => Topic started by: AlanP on December 04, 2008, 05:53:54 pm
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After parting with an arm and a leg to have two new window mechanisms fitted to the car, <:( I am left with the old ones that have good motors on them.
Has anyone used these motors in a boat
Alan
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These, plus seat motors, heater fan motors, wiper motors etc. are magic in a boat. The power produced is probably a tad excessive for the average model....but that is why you have a speed controller is it not? The advantage is that you can escape the unwanted attentions of a wayward model that appears to want to mate with you. Keep collecting them and use them whenever you can. BY.
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Hi Alan , i have fitted one of theose window motors in my barge . After a but of cutting away of the alloy around the motor shaft i simply fitted a piece of car fuel pipe over the worm gear shaft as a flexi joint .
High torque and low speed just right for powering my barge around with a 70mm prop and an all up weight of 6 12v 7ah batterys and a load of lead in the bilge,
it's heavy O0.
(http://i168.photobucket.com/albums/u176/darran77/barge/P1000595.jpg)
(http://i168.photobucket.com/albums/u176/darran77/barge/P1000912.jpg)
(http://i168.photobucket.com/albums/u176/darran77/barge/P1000914.jpg)
daz
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They're excellent and inexpensive. I use power seat motors. Lots of torque and cheap. Great for the tug I use in towing competitions.
John
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Got the motors out of the mechanism this afternoon and tried them on 12v with an ammeter, 3.75 amps with no load, didn't have a pair of stilstons (if thats how you spell it) handy to find out the stall current {-)
I now know why Portside has all those batteries in his barge.
Like the barge, might have to build one now I have a motor.
Regards Alan
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Alan, the batterys are just for ballast the barge needs all the weight just to bring her down to look about right .
On one 12v 7ah battery i can run her all day and for a few weekends without charging .
I will have to get an all up weight of it .
daz
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I tried my power seat motor for current draw. Its .26 Amps at 12v running free (no load). Under load ,holding the shaft with my hand, I can't stop the motor and the current draw at 15v is 1.1 Amps. I've pulled a 300lb person (not me) around in an aluminum row boat with no problem. On my competition tug I drive a 3 3/4" prop.
John
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I think I am going to have a visit to our local scrap merchant, nicknamed "Blair Sports" {-) and have a look at these here seat motors, perhaps I can swop a big cabbage from my allotment for one :}
Alan
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As a trainee engineer I stall tested motors the size of your living room but I never had to resort to using pipe grips or dislocated a shoulder in the process. :D
At the same time current reading was taken,stall torque was measured by a set of scales.
The longer the lever arm the smaller the scales.
You can reduce the chance of motor burn out by reducing the voltage and multiplying the result as if it was tested on 12v.
The locked rotor method is fine for a.c. motors but you only obtain a ball park stall figure with dc motors.
Regards
Sandy Calder
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Never tried a direct stall with these motors , but like John said the free running motor on 12v draws about .26 to .38A but under friction load (a towel wrapped around the motor shaft ,with the motor in the vice) i managed to draw nearly 2A , but i had to stop the experiment as the towel was starting to burn :embarrassed:
During these tests the rpm dropped only slightly , and if i had a rev counter i could tell you what it is /was (thoughts on a car rev counter would it work) .
daz
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... Hi Guys...
Some models of Vauxhall cars have Buhler Motors on their electric windows...
...Best Regards...Norry...
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Hi.... these 12 Volt automobile motors [ventilation fan....or windscreen wiper] are super low in current draw & are continuously rated....the only issue is they are designed for singular direction
The EMF draws the rotor inwards when exited [output shaft drawn inward] , & the thrust is taken up by a single ball....as in a ball bearing within the shell to the rotating armature shaft
Having said this, these motors are totally reversible.....however when the excitation is reversed....the EMF applies a directional force so the output shaft thrust is out-by & the armature shaft loading on the singular ball bearing is negative - the result here can be an irregularity in motor speed at low RPM - the armature shaft has approx 0.3 mm longitudinal float
From memory....& by design....thrust is taken up when looking on the output shaft that is turning closkwise............................ {:-{...Derek
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Hi.... these 12 Volt automobile motors [ventilation fan....or windscreen wiper] are super low in current draw & are continuously rated....the only issue is they are designed for singular direction
The EMF draws the rotor inwards when exited [output shaft drawn inward] , & the thrust is taken up by a single ball....as in a ball bearing within the shell to the rotating armature shaft
Having said this, these motors are totally reversible.....however when the excitation is reversed....the EMF applies a directional force so the output shaft thrust is out-by & the armature shaft loading on the singular ball bearing is negative - the result here can be an irregularity in motor speed at low RPM - the armature shaft has approx 0.3 mm longitudinal float
From memory....& by design....thrust is taken up when looking on the output shaft that is turning closkwise............................ {:-{...Derek
Interesting info. Would this apply to seat motors too? I figured they would have to reverse to move the seat back and forth so the thrust would be the same in either direction, or is my line of thought off?
John
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Hi,
I am looking for some low speed hi torque motors about 300rpm , anyone got any close up pics of these motors and the dimensions...also what make of vehicle are they fitted to ? :-))
Regards SUb.
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I think I am going to have a visit to our local scrap merchant, nicknamed "Blair Sports" {-) and have a look at these here seat motors, perhaps I can swop a big cabbage from my allotment for one :}
Alan
Please be carefulwhere you go. Some of these "scrap-merchants" will charge you an arm and a leg for something that they got for less than free.
If you have a choice, go to a yard that allows you to remove the motor yourself. I wouldn't like to pay more than £5 for a top quality and clean motor. A previous answer by "Chipchase" had a warning here. If you get a "Smiths" fan motor make sure it is from a car, the ones fitted to commercial vehicles may not provide enough power. BY.
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Hi,
I am looking for some low speed hi torque motors about 300rpm , anyone got any close up pics of these motors and the dimensions...also what make of vehicle are they fitted to ? :-))
Regards SUb.
I don't know what specific vehicle they come from, however I would expect seat motors on any vehicle would have similar specifications. They do have tons of torque, and run smoothly slowly and very quietly.
The dimensions of the units I use are:
diameter: 1.875"
length: 4.5"
square shaft female opening: .125" square
I purchase them at a local surplus outlet for $10 a peice.
John
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Hi.... these 12 Volt automobile motors [ventilation fan....or windscreen wiper] are super low in current draw & are continuously rated....the only issue is they are designed for singular direction
The EMF draws the rotor inwards when exited [output shaft drawn inward] , & the thrust is taken up by a single ball....as in a ball bearing within the shell to the rotating armature shaft
Having said this, these motors are totally reversible.....however when the excitation is reversed....the EMF applies a directional force so the output shaft thrust is out-by & the armature shaft loading on the singular ball bearing is negative - the result here can be an irregularity in motor speed at low RPM - the armature shaft has approx 0.3 mm longitudinal float
From memory....& by design....thrust is taken up when looking on the output shaft that is turning closkwise............................ {:-{...Derek
Interesting info. Would this apply to seat motors too? I figured they would have to reverse to move the seat back and forth so the thrust would be the same in either direction, or is my line of thought off?
John
The term "designed for singular rotation" has been misconstrued.It is not an issue and the motors are ideal for model boat use.
The motor has got an end bearing because the action of a worm gear or fan pushes the rotor inwards.
I really hate that term "low drain" when it is used as a sales pitch for motors.
Regards
Sandy Calder
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Fantastic.
They look just right for what I have in mind...what vehicle were they off please .
A question though do they come with a gear train or worm drive ?
Think I will be delving into my local scrappers .
Many thanks for the info.
Regards Sub.
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A quick heads up guys;
don't tell the scrap yard what the motors for they sometimes put
up the price when you tell them for model boats >>:-(
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Fantastic.
They look just right for what I have in mind...what vehicle were they off please .
A question though do they come with a gear train or worm drive ?
Think I will be delving into my local scrappers .
Many thanks for the info.
Regards Sub.
I don't know what car they are off, but I suspect they will be very similar among the various cars. After all there isn't much difference in seats and their relative weights. I haven't seen the power seat motors with gear drives on them, but the power window motors have them. Try your local body shop too. I know they can be had by talking the right body man.....provided he isn't a model boater too.
John
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If you go to the Mabuchi and Johnsonmotor website you will see things like "browse by application".
Their seat retract motors are all rated at 12 volts but they tend to use stronger magnets than the common model shop 500 and 600 size motors more suited to aircraft.That gives them the ability to direct drive larger props when used in model boats.
You can key in values here: http://www.specamotor.com/en/ (http://www.specamotor.com/en/)
Regards
Sandy Calder
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Another thing about seat motors with a square spring drive is that you don't need to buy any more couplings...just make up a home-made adaptor. Easy and cheap and very effective. BY.
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I was wondering about that, square drive to 4mm round, I don't suppose you would like to elaborate on that Bryan, I pic would be nice with a few simple words, just to give me a clue :}
Regards Alan
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Get the file out Alan :-))
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Yup, a file works well, or you could put some 1/8" square stock into the motor and the other end into a universal joint. If you use a brass universal joint you can solder the brass square section into it. The brass rod will slide back and forth inside the motor connection allow for any minor end movement in the prop shaft. :-))
John
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Hy Oldiron
Can you tell me where you got the lead shot that you are useing for ballast.
Many Thanks
Bosun
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Hy Oldiron
Can you tell me where you got the lead shot that you are useing for ballast.
Many Thanks
Bosun
It comes in 25 lb bags at the local sporting goods store. The " shelf loader" shot gun guys use it for shot.
John
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Hi Bosun,
As your in the UK your local gun shop will either stock lead shot or will be able to get it for you.
However you mind find this expensive compared with sheet lead from your local scrap yard.
Colin H.
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I was wondering about that, square drive to 4mm round, I don't suppose you would like to elaborate on that Bryan, I pic would be nice with a few simple words, just to give me a clue :}
Regards Alan
Point taken. Get a short length of aluminium rod about 3/8th" dia. Drill through about half its length to a size that fits your prop shaft. It's now up to you whether to drill and tap for a grub screw, or drill a hole all the way through the ally and the motor drive shaft to take a pin or something.
The other end of the rod ...drill a hole a bit smaller than the square spring....and then file the hole square to be a neat fit over the spring. The whole operation shouldn't take more than an hour. A bit tedious, but well worth the effort. BY.
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Great info. :-))
What RPM do they rev at on 12v any ideas, and are they seat motors or the window variety that are shown here please.
Regards Sub.
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the use of the seat motors with square socket looks a better idea than the wiper motors i use , although i fit a piece of fuel pipe onto the shaft for a tight fit and a flexable joint .
They have all had some cutting away of the casings to allow the shaft to be revealed .
(http://i168.photobucket.com/albums/u176/darran77/P1010157.jpg)
(http://i168.photobucket.com/albums/u176/darran77/P1010158.jpg)
(http://i168.photobucket.com/albums/u176/darran77/P1010159.jpg)
daz
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portside.
I note that these motors have what appears to be a worm drive shaft, is that the case ?? and if so does the shart go through 90 degrees to another output shaft, if so any pics of that 90 degree set up ??
Regards Sub.
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They did go through asort of 90deg drive but it was integral to the back and forwards thingy drive that wipped the rain from the windows %% :} if you can work that out , i know what i mean .
One day i will grind the shafts down and fit a flexable coupling on better but for the moment it works .
Oh the two big motors have three wires ,two for power but dont know what the third is for ,any ideas?? .
daz