OutdoorKing Repair Forum Forums The History Forum The Old Soap Box Early Mowers with Fan Cooling

Hi all,

From what I had seen on this subject ,had me convinced the early Villiers motors with the alloy cake tin top
used leather fan blades and not rubber.

1 Patents from the time mention rubber blades or rubber like blades.

2 I just cant imagine the rubber blades back in 1954 would be very durable.

3 when looking at an original black and white image it shows the light coloured alloy flywheel cover with light
coloured fan blades ,if assuming the blades were rubber they would be black and the fan blades in the black
and white image are not black.

4 The narrow slits on the flywheel cover suggest that if thin rubber was inserted here it would not hold its shape.

So if anyone has any thoughts on whether the fan blades are rubber or leather ,it would be good to get other people's
opinions here, as I hadn't considered rubber blades could work.

Villager had this type of cooling system. https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/79231/VILLAGER_MOWERS_-_Twin_Cooling.html

Champion was another that used this cooling system. https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/112665/champion-first-model-c1954.html

I'd thought some old mowers still had some leather blades fitted but don't recall seeing rubber blades.

Cheers
Max

Hi Max
Many thanks for the research and thoughtful commentary.

I can only speculate.

We know the Villager patent specifically mentions rubber vanes
or like material. So, I have an open mind about this.

I have done some research on India Rubber and it certainly
could be moulded into all sorts of shapes and colours, including tyres
boots, and garden hose.These require durability.

A second point would go to the demise of the system and the
availability of spare parts. I would have thought rubber moulding
required specialised industrial techniques.

Maybe leather was the most available option for replacement;
given that rubber requires special moulding techniques.

It would appear that many of these 'cake tin' coolers
were simply removed and discarded.

I mean, Many Champions I have seen seem to favour beautifully
polished brass flywheels. I guess that's over restoration.

Certainly an interesting point you raise.

Cheers Max!
------------------------------
Jack

G'day Jack,

Thanks for the reply Jack ,I just thought the thin rubber blades would distort when the mower was cutting
grass but obviously they were made to bend if anything came into contact with the spinning rubber blades .

It sounds like the original blades would be lucky to last 10 years as some manufacturers of garden hose at the time only
guarantied rubber hose to last 10 years.

The great disappearing mystery of rubber fan blades makes sense now ,this reminds me
of the weird phenomenon of disappearing garden hoses from the fifties where Garden hoses started to
spontaneously burrow their way into the dirt and would never be seen again ,many were cut loose
at the tap.

https://www.weirduniverse.net/blog/comments/the_great_hose_mystery_of_1955

I guess the rubber fan blades were not strengthened by using a ply material like
when manufacturing car tyres.



Cheers Jack !

Hi Max

Yes, a decade or so for general natural rubber products seems right.
I have seen how old rubber blisters and congeals over time.

When I started researching Pope Products I would always find
complimentary rubber garden hose advertising. It was the miracle
product of the day.

I guess the synthetic rubbers [Turner used Dupont rubber tyres] and
modern plastics offered much better stability and durability.

The 'Great Hose Mystery of 1955' must be sure fodder for
conspiracy theorists. I suspect communism as the root cause ...

It would be wonderful if a set of NOS fan blades would appear
for Champion or Villager mowers. That would solve the mystery -
rubber or leather. Maybe one day ...

Cheers and thanks Max!
-----------------------------------------
Jack

G'day Jack,


Yep we should have know communism would fail ,there were a lot of red flags.

Pic below of an old Villager but not sure how original the fan is, yes one day
we may see new old stock blades.

Cheers
Max.

I don't usually LOL ... I did on that one.

G'day Max
Kye has generously sent me through a couple of images
that are very interesting. He says ...

" I recently picked up an original cake tin with 2 original fans,
one is in poor condition but the other is quite nice.

They are indeed rubber! They are in safe storage for now,
I hope to make reproductions in the not too far future.

I have attached 2 others of the best fan.
Feel free to use these images and ask if you need any more.

Max, the blades do seem to have a moulded T section
at the base to locate and position the blades.

I don't know if the covers are Champion or Villager.
Any ideas?

Cheers
--------------------------
Jack

G'day Jack,

Thanks Jack and Kye for this info.

I did wonder about the black and white image of the new Villager mower as the colour of the fan blades and cake tin looked the
same but I had seen traces of gold paint on the cake tins on old mowers.

The original images of the new Villager Mower suggest the rubber blades were painted gold to match the cake tin .


The images from Kye I would say are from a Villager Mower as the fan blades are on a roughly 45 degree angle
and the Champion cake top has the fan blades vertical so I would say the idea of the Champion blades
is to have a radial blade fan. Blades are perpendicular to the axis of rotation. Radial Blade design is used for high pressure application. Although low in efficiency the design is excellent for a dusty environment as the dust can't stick on the blades because of geometry.

The Champion mower with its radial fan, the air hits the fan wheel, turns at the right angle, and is accelerated by radial flat blades on the flywheel. The accelerated air is discharged radially, thus, the name. The airflow is induced by the centrifugal force, which is produced in a rotating column

In other words this fan would remove the heat at the top of the motor pushing the heat away radially .

The Villager with its pitched or angled blades, these blades not only push air, but create a downdraft so as to move air efficiently through a space, the downdraft is directed down past the cylinder for cooling
purposes.


Great to finally see a good image of exactly how the original blades were.

Cheers
Max.

Hi Max
Many thanks for the detailed and technical explanation of the cooling styles.

I think the Villager patent for 'Twin Cooling' had a much better
grasp of heat flow and transfer than the Champion one.

I guess the Villager system had twin cooling blades - on the
blade holder and on the flywheel.

Max, I collected a small image from VM some time ago.
I can't say whether it is original or a backyard mod.



It was a clear move to a shrouded fan but I have found
no evidence that it was a Champion production part.

Someone went to a lot of trouble ...

Cheers and thanks
--------------------------------
Jack

Hi Max and all fan fans.

I guess we should discuss the other important fan cooled mower from the period ...

Max, what is your feeling about the Victa 'Fan Mowers'.
Was it closer to the Champion system?

The Victa fan spun anti-clockwise and the images suggest the
air flow was downward - to wards the engine cylinder.

Given the fan was un-shrouded, would it have been better
to have drawn the hot air upward as per basic physics?

Cheers
----------------------
Jack

G'day Jack,


The Champion fan shroud looks well made ,it kind of looks factory made as it has no welding distortion in the sheet metal.

I think the back of the shroud with the flat section is open for the fan blades to stick out as the Champion
mower wasn't designed to push the air flow downward past the cylinder.

I don't think the Villager and the Victa fan mower were good designs as pushing air flow downward past the cylinder
with unshrouded engines and no way of having a leaf guard would result in leaves and grass accumulating in the
cylinders cooling fins causing the motor to run hotter.

The Champion Patent mentions - " Positioning of the fan relative to the motor as shown in Fig. 1 suffices to send a stream
of air about the motor which keeps it cool and keeps it cleared of grass clippings ".

The Champion fan blows away the rising heat from the cylinder just like the model 1 and 2 Rotomo because
these too are unshrouded engines ,the 1 and 2 Rotomo have a small fan shroud on the flywheel but nothing
to direct airflow down past the cylinder.


The 2a Victa with the full shroud directs air flow downward past the cylinder and when fitted with the first
style of recoil starter that is a close fit to the shroud this would act as a leaf guard but when Victa
changed the starter design to a higher mounted starter (ie bigger gap between the cowl and starter,
the only way to restrict leaves and grass entering the fan was to install a leaf guard .

Jack has written about the twin cooling Villager here https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/79433/VILLAGER_MOWERS_-_Twin_Cooling.html


Cheers
Max.

G'day Max

Brilliant!
Your explanations make logical sense to me and you have
the technical understanding whereas I fall short.

The Champion shrouded fan mower remains an enigma.
It seems to be on the cusp of mainstream engine makers offering
affordable small air cooled rotaries for AUS rotary makers ...
Local mower makers 'made do' in the interim.

For the record, the idea of small rotary engine fan forced cooling is
much older. Reel mower maker fan-forced cooling is older again.

I know the British Rotoscythe was offering fan forced cooling
on their rotaries in the interwar years.

These were sold here!
None have been recorded here!



Max, I do want to thank you for raising this topic.
No one here has done that!

My most general view is that AUS rotary makers were aware
of small fan-forced engines made overseas, but they had no access
to them in a constrained post-war environment.

Aussies came up with cheaper and novel solutions:
the Victa Fan Mowers; the Champion 'Cake Tin' coolers; and the
Villager 'Twin Coolers' all were novel approaches.

All of this changed when overseas engine maker came on board
and offered us cheaper and available fan-forced air cooled engines.
We're talking late 1950s.

By this time, Victa got the knowledge to do it here.

The rest is history.

Cheers Max
----------------------
Jack