1/4 scale Anzani Fan Engine

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It will be interesting to see if 30 minutes is ok, or if that is too short a time period.

Perhaps 30 minutes is enough.
I err on the side of caution with an overnight cool, but that my not really be necessary.

I have a few appointments tomorrow but hopefully will get some time to try machining one.
Phosphorus is used as an additive to greatly increase fluidity of gray iron, and the art-iron folks that I know use old radiators exclusively for scrap.

The old books mention that iron with phosphorus should be avoided for engine work, but I read about someone casting a V-8 model engine block using radiator iron (if I remember correctly), and I have not heard of him having problems with the metal being brittle and cracking.

There are levels of phosphorus too.
It may be that the scrap you used had phosphorus in it, and so could have excellent fluidity, even on the lower end of acceptable pour temperatures.

I am pondering using radiator iron for the proposed ball hopper castings, since they are very thin, such as the water hopper.
The water hopper is a non-structural element anyway.

And it may be possible to alloy radiator iron with Class 40 scrap, and get improved fluidity without getting too high a percentage of phosphorus.

There is a spiral test that I think 100model has tried, and you can measure the fluidity of the iron by how many times it travels around a long spiral in the mold.

It will be interesting to see what sort of results you get.
Keep us posted.

I managed a couple of hours in the shop and did the turning part of the cast iron flywheels.
Breaking off the sprue revealed a nice even grey structure with no chill skin.
Both castings machined easily with no issues.


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Not much progress to date as I am waiting a delivery of fresh bar stock so in the meantime I machined the flywheels to accept the crankpin and drilled the 70 holes, 2mm dia, in each flywheel half. This is when you guys with CNC have the edge!! Took me hours!
While doing that, the 3D printer churned out another pattern for casting which is the rear cover for the timing gears.
With hindsight I could have used this for lost PLA as it is quite small but I will try sand casting first.


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Today was taken up mainly with the weekly food shop but I did get a couple of hours in the workshop so I knocked up a mould in Petrobond to cast the rear cover.
Its so small I hardly detected the aluminium flowing in and I was certain it was a no fill situation.
However, it did fill and has come out pretty good. The pattern had dimples to mark the hole centres so I could pick them up for drilling and will later be used as a guide for drilling the rear crankcase hole positions.
The other bores will be line bored from the crankcase to ensure alignment.
You can see how Petrobond really picks up the detail of the layer lines from 3D printing.


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