Zinc based alloy?

Advert

New Replies

Report Bug

Help/FAQs

Zinc based alloy?

This topic has 35 replies, 17 voices, and was last updated 14 February 2021 at 15:02 by Bo’sun.

Viewing 25 posts - 1 through 25 (of 36 total)

1 2 →

Author

Posts
30 April 2020 at 09:15 #30013
Bo’sun
Participant
@bosun58570
Advert

30 April 2020 at 09:15 #468029
Bo’sun
Participant
@bosun58570
Good morning,

I'm in the process of making a Stirling Hot Air Engine. The construction requires a cast flywheel made from "zinc based alloy". Casting for me is out of the question, so I wondered if I might be able to get a billet of said, or similar, material, 90mm dia x 25mm thick. Mild steel is an option, with a bit more machining to bring the mass down, but I'd like to keep the finished engine as true to the plans as I can.

Thank you.
30 April 2020 at 09:20 #468031
Brian Wood
Participant
@brianwood45127
You could substitute Aluminium instead
30 April 2020 at 09:27 #468033
Michael Gilligan
Participant
@michaelgilligan61133
‘Zinc based alloy’ would typically refer to MAZAK or ZAMAK which is used for mass-production die castings.

My guess therefore, is that the words may be an oblique reference to a commercial item.

MichaelG.
30 April 2020 at 09:33 #468034
old Al
Participant
@oldal
Standard zinc ingots are smaller than the size you want. Time to think again
30 April 2020 at 09:46 #468038
AdrianR
Participant
@adrianr18614
Myfordboy on youtube uses ZL12 to cast his flywheels. Its casting temp is about 500C so is not so hard to do casting. Artisan Foundry sell 1KG ingots for £7.99. Maybe near you could cast you a blank.
30 April 2020 at 09:47 #468039
Bo’sun
Participant
@bosun58570
Posted by Brian Wood on 30/04/2020 09:20:55:

You could substitute Aluminium instead

I guess they suggest a zinc based alloy because it's a little heavier than Aluminium for a flywheel.
30 April 2020 at 09:49 #468042
Bo’sun
Participant
@bosun58570
Posted by Michael Gilligan on 30/04/2020 09:27:34:

‘Zinc based alloy’ would typically refer to MAZAK or ZAMAK which is used for mass-production die castings.

My guess therefore, is that the words may be an oblique reference to a commercial item.

MichaelG.

They clearly expect you to be able to cast the zinc based alloy, because there's a drawing for the required pattern.
30 April 2020 at 09:50 #468043
Bo’sun
Participant
@bosun58570
Posted by old Al on 30/04/2020 09:33:05:

Standard zinc ingots are smaller than the size you want. Time to think again

That's why I am considering steel and reducing the mass.
30 April 2020 at 10:06 #468051
JasonB
Moderator
@jasonb
Many old designs expected you to cast your own parts and I'm with Adrian that something like ZL12 would be ideal, think it is only 10% lighter than cast iron. Myfordboy does do one off castings for people so you could contact him for a casting or just a simple cast disc.

Steel would be OK and probably a lot less hassle.
30 April 2020 at 10:14 #468055
Circlip
Participant
@circlip
"They clearly expect you to be able to cast the zinc based alloy, because there's a drawing for the required pattern."

Stuart turner show flywheels but they don't expect you to cast your own?

What engine are we referring to?

Regards Ian.
30 April 2020 at 10:16 #468057
Michael Gilligan
Participant
@michaelgilligan61133
Posted by Bo'sun on 30/04/2020 09:49:31:

They clearly expect you to be able to cast the zinc based alloy, because there's a drawing for the required pattern.

.

Are you psychic … or did I miss an important detail in the opening post ?

MichaelG.

.

Edit : That was posted before I realised that you were the originator of this thread.

My question should therefore have read:

Do we need to be psychic … or did I miss an important detail in the opening post ?

Edited By Michael Gilligan on 30/04/2020 10:30:55
30 April 2020 at 10:17 #468058
JasonB
Moderator
@jasonb
Ian, you want to take a look at some of the old mags plenty have pattern details in them as I said, That 1936 midget engine I made a few months back had details of all the patterns and you were expecte dto cast your own, even some of Westbury's designs in ME expect you to make your own patterns.
30 April 2020 at 10:19 #468059
JasonB
Moderator
@jasonb
Michael, you missed the words "construction requires a cast flywheel made from "zinc based alloy"

As the OP says he can't do the casting he wants to cut from solid in a similar material hency the search for a billet of same.

Edited By JasonB on 30/04/2020 10:21:15
30 April 2020 at 10:24 #468062
Michael Gilligan
Participant
@michaelgilligan61133
Posted by JasonB on 30/04/2020 10:19:43:

Michael, you missed the words "construction requires a cast flywheel made from "zinc based alloy"

.

< with Pantomime voice > Oh no I didn’t !!

Those words include nothing about patterns, or home foundry work

a cast flywheel is a cast flywheel, whoever makes it.

MichaelG.

.

Edit: ___ see edit of my previous post

I will shut up now … it’s turning into a bad day.

Edited By Michael Gilligan on 30/04/2020 10:32:26
30 April 2020 at 10:35 #468065
Circlip
Participant
@circlip
Easy to shoot posters down when you're looking at something no one else is. Give us ALL the information available if you want a reasonable answer.

Think the original question has been answered, if you don't like the answer, do your own thing.

And yes JasonB seen lots of drawings giving pattern details but these assume the person reading has the ability to be able to either cast the bits themselves OR has access to a local (not nowadays) foundry and didn't have access to t'internet.

Regards Ian.

Edited By Circlip on 30/04/2020 10:39:45
30 April 2020 at 10:37 #468066
JasonB
Moderator
@jasonb
"Casting for me is out of the question" that suggests to me that the OP can't do home foundry work
30 April 2020 at 11:14 #468078
Bo’sun
Participant
@bosun58570
Posted by Circlip on 30/04/2020 10:14:41:

"They clearly expect you to be able to cast the zinc based alloy, because there's a drawing for the required pattern."

Stuart turner show flywheels but they don't expect you to cast your own?

What engine are we referring to?

Regards Ian.

The engine is one I made at secondary school around 1972. A school "Hot Air Engine" project by T. E. Haynes. However, it's been lost (I'm sure it's somewhere, we just can't find it). My Father was so proud of it, I want to make another for him now I've sourced the plans.
30 April 2020 at 11:14 #468079
Dave Halford
Participant
@davehalford22513
My school used to do alloy casting back in the 60's. Lots of cast garden hand forks full of gas bubbles.
30 April 2020 at 11:20 #468082
Bo’sun
Participant
@bosun58570
Thanks for the suggestions, but please keep it civil.
30 April 2020 at 12:09 #468096
not done it yet
Participant
@notdoneityet
Question: Is brass considered as a Zinc based alloy? Some are 50%, or more, Zinc.
30 April 2020 at 12:26 #468104
Roderick Jenkins
Participant
@roderickjenkins93242
That'll be this one then:

Haynes hot air engine for schools

Rod
30 April 2020 at 13:10 #468117
JasonB
Moderator
@jasonb
Posted by not done it yet on 30/04/2020 12:09:09:

Question: Is brass considered as a Zinc based alloy? Some are 50%, or more, Zinc.

Probably not in this case, the low melting point of alloys such as ZL12 made them easy to cast with the smaller school furnaces or even in a ladle with a big brazing torch and as teh OP wants to keep it looking as close to the one he previously made the colour of brass would also be wrong on the usually unpainted rim.

Should look like this

Edited By JasonB on 30/04/2020 13:12:59
30 April 2020 at 13:22 #468119
Bo’sun
Participant
@bosun58570
Posted by Roderick Jenkins on 30/04/2020 12:26:04:

That'll be this one then:

Haynes hot air engine for schools

Rod

The very same one. The original books are going for silly money (if you can find them).
30 April 2020 at 13:42 #468124
SillyOldDuffer
Moderator
@sillyoldduffer
I suppose the point of specifying Zinc Alloy like Zamak, or as my Dad called it 'Sh1t Metal', is its easy to melt and cast – no problem at all in a school metalwork class and very educational. Car door handles used to be made of it, and an ordinary blowlamp could melt them in a steel saucepan.

For a flywheel, almost anything roughly the right size and weight will do. My few examples were machined from a 150mm dia Aluminium rod or turned from a Cast-iron block cut to an octagon with an angle-grinder.

Trust me, I'm a doctor. Angle grinding cast-iron is only a teensy-weensy bit messy. Hack a lump of it in your living room and wifey will think fondly of you forever…

Dave
Author

Posts