Motor Query

[Powder Monkey]

Hey all

I've just bought the Caldercraft Marie Felling Tug.

This is my very first build and I apologise for the noob questions.
The instructions recomend a 'Decoperm Geared Motor', I have sourced two Decoperm motors 6v and 12v.
What is the difference and which would be more suitable, also are there different models elsewhere with different gear ratios?
The instucitons also recomend useing a 65mm, 3 blade, medium pitch propeller.

I've tried to do as much research as possible, any info would be well apreciated.

thanks

Gary

[CaptLee]

Gary Use the 12 volt one, my 6 volt ones like a 2.5" 3 blade Prop Shop one ok but more power is always more enjoyable. talk to Simon at Prop Shop about your needs and he will get you right what you need. Remember it is a tug so use the lower pitch one in your size. Put as much battery in as possible so run times are long and boat floats at the waterline. keep the weight as low as possible in the bopat so it does not get too tender.

[pompebled]

Hi Gary,

Did you buy the single or the twin screw version?

Gears are not my first choice due to the noisy nature, direct drive is much quieter.
On a single prop, a 900 motor would work, also a fan motor from the scrap yard, gobs of torque and low amperage, cheap (and some weight low in the hull).

Regards, Jan.

[Powder Monkey]

Thanks CaptLee and Jan

It's a single prop, I'll try 'Prop Shop' - Just got the site and will email Simon.

Good point - the instructions say weight is needed low down, but adapting the fan might be a little too complex for me! Is the 900 a range of motors? (sorry your talking to a complete noob)

again thanks both

Gary :)

ps. just thinking - why would Caldercraft recommend a "geared motor"

[nick_75au]

ps. just thinking - why would Caldercraft recommend a "geared motor"

So the motor can spin a large prop efficiently,

I looked at the Westbourne site and they recommend a 6:1 ratio set-up. Generally the motors for hobby use such as the 550 to 700 series motors are high rpm motors(20,000 -30,000 rpm) they are most efficient at that rpm. If you put a large propeller on them they do slow down but will draw large current and generate lots of heat. The gearbox allows the motor to spin at an efficient rpm and also gives the torque to spin the large prop without the heat and excessive current draw.

The other option pompebled mentioned is a car heater fan motor or similarly a small scooter motor both available very cheaply, don't need a gearbox, direct drive to the shaft, larger and heavier (not a problem for your case) much quieter. No more current draw than an efficient geared setup.

You don't need to adapt the fan you remove it completely then couple the shaft of the motor to the shaft of the boat.

900 is a series of motors not that common in my part of the world.

Hope this helps
Regards
Nick

[pompebled]

Good point - the instructions say weight is needed low down, but adapting the fan might be a little too complex for me! Is the 900 a range of motors? (sorry your talking to a complete noob)


Noob or not, there's really not much to adapt on a car fan motor for use in a tug.
I know things may look daunting, but there's nothing to it, if in doubt, ask us silly...

I've added a few pics of industrial motors which are original from a Xerox copier, I found them in a surplus shop.
The fan motor in the picture has been slightly modified, in the way that I've made cooling slots in the housing, to improve airflow and to gain access to the brushholders in order to add brushtab cooling, hence the mess of clear pvc tubing...
I added the cooling and slots, because this motor is going to drive a 110cm MTB model, running on 24 cells, which is twice the Voltage it ran on in it's previous life in a car.

For a tug, my guess is, a simple cooling coil around the can will be sufficient to keep the motor cool, running on 12V for hours on end.

One of the copier motors is going to power this tug in future, with just a cooling coil.
http://shop.strato.de/epages/61433551.sf/de_DE/?ObjectPath=/Shops/61433551/Products/11101011

The closed can motor in the pics (the 'small' one) is a 900 series motor.

Regards, Jan.

[pompebled]

900 is a series of motors not that common in my part of the world.
Regards
Nick

Check out the replacement motors for powertools, these are often in the 800-900 size range.

Regards, Jan.

[pompebled]

For props, check out:
http://www.raboesch.com/

Catalog 2

Distributed world wide, should be availble to you in the UK.
Nice props, nicely priced.

Regards, Jan.

[Powder Monkey]

Thanks guys
I'll take myself down to Taronis and have a look around. (some nice pictures - I'll know what I'm looking for.)
The Raboesch site looks good.
As soon as I get it fitted I'll post some pics.

again Thanks

Gary