Frankinpump he go buggerup.

[Jamesrl]

if you were really clever you could profile the blades to a NACA profile based on the speed of the motor. that way it would be running at maximum efficiency resulting in greater airflow thus increasing the available power to the pump by using autodesk virtual wind tunnel.

Dam, I didn't think of that either.

Mind you the original fan was pretty NACAd in the first place.

I never thought of that either but then I ain't got a clue what you're talking about.

[Julian]

My one area of excellence being heroic failures, the fan pictured earlier in the post was too tight for the shaft (printer may need a re-calibration me thinks!) and split whilst I was gently encouraging it to fit with a hammer.

So, while I was changing the size of the central hole I thought I'd revert to the original blade design as the straight blades seemed extremely strong.










It was quite a snug fit on the shaft as can be seen by the light coloured swarf.

A quick run on the bench shows that it shifts a reasonable amount of air over the motor cooling fins, so all's well with the world.

[Jamesrl]

Very nice young man, very nice but I'd have still gone at least 8 blades.

[Julian]

Very nice young man, very nice but I'd have still gone at least 8 blades.

But, but, think of all that extra plastic ... it's all right for you wealthy pensioners with your final salary schemes, state pensions, disability allowances, free nurses, meals on wheels, winter fuel payments, reduced Council tax, free prescriptions and your bus passes!

Us tax payers have to watch the pennies!

[Jamesrl]

We don't get reduced council tax and meals on wheels ain't free.

And to top it all the barstewards tax me.