Motor

kollegeknight

Hi,
I have a design problem. I have designed a snow mobile for the leaving cert project and space is tight,

I have made it to hold a work gear and spur gear to transfer power.

the problem is I am 12-14 mm out from the spur gear I have to use.

Anyone know can I get a motor like the one below, but with an approx dia of 27mm rather than the 54mm shown with the offset shaft on it.


Is there a larger dia wormgear people know of or maybe a simple set of gears.

Here is a photo of the design area. I have alot of parts made so starting again would be difficult.

Any help would be greatly appreciated.

coolwings

You've got a geared 500 or 600 size motor. Diameter 35mm. Output shaft 3.2mm.
You need a geared 400 size which has diameter 28.5m as far as I remember.

You wll find when you get it that the output chaft is 2.3mm, so that's the reason you're looking for the smaller motor with the gearbox. The one off the larger motor won't transfer/fit.

Model airplane shops should have these sizes.

kollegeknight

Thanks cowlings, you're great can you recommend an online shop?

coolwings

A 400 geared will do 65 watts on 6 volts source continuous for an rpm of approx 18000.
Geared 3:1 that gives you 6 thou per minute top throttle.
Your worm gear and pinion/spur gear will reduce it more.
A speed controller will bring it down to workable rpm. The one you used with the gearbox shown in your photos will work a smaller motor fine.
Don't try to get a 9V square cell to power it, they can't, you need 4 x AA cells at minimum, C's or sub Cs are better still.
Most 400 size geared motor/gearboxes have 3mm or 4mm output shafts which is what you will have to get your worm gear to go onto. Thicker = easier!

Suggestions:
greenhobby dublin
sussex uk
slough uk
stevewebb uk
maybe noelbarrett Cork
maybe helimodels Ennis near your location too.
alshobby uk possibly
But loads of others would have them too.
The low cost "inline" gearboxes have more friction (three gears inside+ extra shaft to turn) than the ones where the motor shaft and output shaft are offset by 5-10mm or so (only 2 gears inside doing the same job=more efficient).

kollegeknight

and will that fill the gap between the spur gear and the worm gear. i have about 12mm gap to close.

\thanks again coolwings for all your advice

coolwings

kollegeknight wrote: »

and will that fill the gap between the spur gear and the worm gear. i have about 12mm gap to close.

\thanks again coolwings for all your advice

Well here are pictures:


Now a drawing. Don't look at the side views as they are a different type.
Look at the second diagram from left.
Your motor shaft would be centre hole hidden inside the gearbox, and output shaft the smaller lower hole.

I guess maybe 10mm offset?
You might have to make slots in model structure instead of holes, so you can slide the motor mounting bolts over a bit more before tightening.
Would that take up the gap you have?
Those are Aeronaut gearboxes, google would locate some.
There is another make called Graupner which is not too different.

If you need more offset, there were belt driven gearboxes that had a mighty offset. THE US in particular made them, but there was a UK maker called MFA Como. Not sure if they did a 400 size though. UK model shops might have those, particularly the model boat oriented places.

Hope you get sorted.
Cheers

kollegeknight

Coolwings, Thank you so much.