1/4 scale Anzani Fan Engine

[creast]

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.
Cheers

 

[GreenTwin]

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.

.

 

[creast]

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.

 

[100model]

Both castings machined easily with no issues.

Nice looking iron castings and they look great after machining.

 

[GreenTwin]

That is fabulous !
Very nice castings.
Especially impressive as 1st iron casting attempt.

No going back to aluminum now.

.

 

[creast]

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.

 

[creast]

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.

 

[creast]

Having been distracted by other foundry projects and visiting relatives etc I found a little time to go back to the Anzani.
I have decided to try and cast the con-rods in Silicon Bronze. My thinking is this will give me enough strength combined with bearing properties to remove the need for bushings in the first instance.
Home brew Silicon bronze did raise some issues and these are covered in the foundry section of this forum.
The con-rods are quite small 70mm long x 20mm wide and after 3D printing a pattern I gave up trying to false cope the mould and re-printed the pattern as two halves and made a quick match plate setup.
It's been chilly here and my petrobond does not bind well when cold so I had another crazy idea and that was let's try molasses bonded sand like they do on those middle east Youtube videos.
Using normal foundry greensand I added a molasses (black treacle in my case) and warm water mix and mulled it by hand until resembled petrobond.
Mould strength was really good and the pour was less spectacular than petrobond with no flames and very little smoke.
I will definitely explore this method further.

 

[creast]

I just noticed that zooming well into the images shows weird textures and are obviously an artifact of my hdr setting of the camera.
I will turn this setting off and try again

 

[creast]

I should have been working on the crankshaft but I had to do some casting to do for my partners grandson so I decided to try my intended method for producing the finned cylinder/ heads.
These are quite elaborate and have a cavity that links across to the side valves and spark plug. I am hoping to shrink fit these to the steel liners in due course.
I hate printing with supports on a FDM printer as it invariably leaves a messy finish so after trials I found I could print the part with no supports on the internal cavities by standing it up vertically.
In truth I didn't hold much hope of the fins staying in place in the rather fragile investment plaster but it was worth a go.
First task was to make a perforated flask to improve vacuum filling of the melt and quickly make a vacuum chamber out of a baked bean tin!
It's all a bit makeshift but worth a try.
I was overwhelmed with the result as the fin details did hold and ok there are a few bubbles but this is very encouraging.

 

[GreenTwin]

Most impressive !

.

 

[Olli-Matti]

Super results! My compliments! You definately got the casting part going on exceptionally. It is always rewarding to not have to make dozens of casting attempts.

 

[vk7krj]

Excellent results Creast- what software are you using to create your stl files?

 

[creast]

Super results! My compliments! You definately got the casting part going on exceptionally. It is always rewarding to not have to make dozens of casting attempts.

Hi olli
Thanks for your comment.
Maybe I got lucky?
There are two more to make and it's a long process doing lost PLA castings.
I have yet to try the lost resin route which would give a better finish hopefully.
Rich

 

[creast]

Excellent results Creast- what software are you using to create your stl files?

Hi,
I am using an old version of SolidWorks. Ver 2017.
Rich

 

[GreenTwin]

Motorcycle cylinders can be cast in bound sand, but your method looks very promising, and you could cast any number of different types of cylinders easily without having to make a complex hand-made pattern for each.

https://www.homemodelenginemachinis...se-casting-motorcycle-racing-cylinders.35502/

.

 

[creast]

Motorcycle cylinders can be cast in bound sand, but your method looks very promising, and you could cast any number of different types of cylinders easily without having to make a complex hand-made pattern for each.

https://www.homemodelenginemachinis...se-casting-motorcycle-racing-cylinders.35502/

.

This method is the only way to produce this part as it only measures 62mm x 37mm x 26mm and the fins are only 0.8mm thick and parallel.
I wasn't even confident it would actually work as the refractory plaster is still quite fragile after burn out.
Jeff produces some fine castings!

 

[GreenTwin]

This method is the only way to produce this part as it only measures 62mm x 37mm x 26mm and the fins are only 0.8mm thick and parallel.
I wasn't even confident it would actually work as the refractory plaster is still quite fragile after burn out.
Jeff produces some fine castings!

Your method is much more versatile, and can be scaled up/down, modified in 3D, etc.
Not only good for rapid prototyping, but also good for making the final casting.

I really think lost PLA is the wave of the future.
.

 

[GreenTwin]

Makes me wonder if a product like "Velacoat" could be poured into the burned-out mold, drained, and then the mold re-heated to drive out moisture (carefully, since it is an alcohol-based product).

So like using an internal mold coat.

.

 

[100model]

I have decided to try and cast the con-rods in Silicon Bronze. My thinking is this will give me enough strength combined with bearing properties to remove the need for bushings in the first instance.

That is exactly why I used it for to replace my camera tripod parts that kept breaking. Looks like those parts came out great, silicon bronze seems to flow really well into sand molds.

I was thinking of making a three cylinder like you are making and I have seen a Anzani three cylinder in a local aircraft museum. It has the cylinder center line offset with the crankshaft center line. Why is that?