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Foundry

02/17/2008 10:44 PM

Hi all. I am restoring an old electric motor and must make a cast for the cooling fan made of foundry molded aluminum. I believe using wet sand comtained in a metal box will hold the desired shape for molten aluminum to be poured into it. I have a can do aditude and welcome any help. Thank you!

Any feedback or ccomment is welcome!

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#1

Re: Foundry

02/17/2008 11:59 PM

Wet Sand will Not do!!! and would be very dangerous...I will reply later with a link on DIY foundry works....Molten Metal and Wet\damp sand, unless done properly is an exposive reaction.

Super Hot Steam and dangerous expansion + moten metal + Hot sand.

There is also spattering molten metal.

Regards,

Stuart.

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#2
In reply to #1

Re: Foundry

02/18/2008 6:58 AM

As promissed...Have a look at the link below.

http://www.backyardmetalcasting.com/

This site is gold for DIY foundry info...But...Be VERY VERY CAREFULL!!!

Foundry mistakes can be lethal and\or burn your home\workshop down.

Regards,
Sapper

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#3
In reply to #1

Re: Foundry

02/18/2008 10:46 PM

Snapper,

Thanks so much for the heads up on wet sand! To let you know I thoughly research a subject like this before attempting it. Thanks again.

candoitall. (I can do all things through Christ who strengthens me Phil. 4:13)

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#4
In reply to #3

Re: Foundry

02/19/2008 1:19 AM

What state are you building this foundry,candoitall.Depending on your location there is a wealth of info and help that is available free of charge.

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#5

Re: Foundry

02/19/2008 7:06 AM

What are you using for a pattern? The old fan? Also, be careful with "wet sand" - water & molten metal are not friendly materials. When you say "wet sand", do you mean "green sand"? that is, round to subangular silica bonded with western bentonite, and mulled with around 3.5% water? If you don't have a muller, you will never activate the bonding strength of the bentonite. Consider a plaster molding material, or a chemically bonded sand - such as a sodium silicate, mixed in almost any kind of mixer, then rammed around the pattern, and gassed with CO2. Or, an air setting chemically bonded material - several kinds. If you are not real familiar with these materials, suggest you get a good book & read up. American Foundrymen's Society in Des Plaines, IL - excellent source.

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#6

Re: Foundry

02/19/2008 8:10 AM

If you're looking for a casting larger than a couple pounds, I don't recommend doing it all yourself. You need a pattern with appropriate provisions for pouring in metal and for excess metal to rise into (to allow shrinkage as it cools). You need a means of handling the molten metal (HOT). You need protection from spills and/or splatter. You also need to know how to avoid excessive porosity in the final casting.

Make the pattern, then have a foundry make the casting. You can then do all the machining yourself.

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#7

Re: Foundry

02/19/2008 8:52 AM

A model for casting and ease of use is to make model from styro-foam rammed in to the cope and drag with minimum problems of model making. Pour the molten aluminum into the forms for a completed casting replacing the styro-foam.

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#8

Re: Foundry

02/19/2008 9:03 AM

After you make your part it will need balanced. Static balancing may be sufficient if done very carefully.

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#9
In reply to #6

Re: Foundry

02/19/2008 9:03 AM

HarryBurt, and all,

Let me specify the scale of this fan I am seeking info on. This is a 3.5 in diameter disk with raised fins on one side 3/8 inch high. The area where the arbor passes through is 3/8 in above the disk face.

Thus far, my description of wet sand was corrected with the term "green sand".

This is all very helpful and please be aware I will NOT do something this dangerous without seeking knowledge from those "in the know". Having said that, HarryBurt, I personally thank you for your comments of concern.

candoitall

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#10

Re: Foundry

02/19/2008 9:31 AM

There are foundry suppliers that will sale small amounts of air set silica (sand) that you can use or they offer plastics (repro) that you can reverse you part(s) and make your own mold. Look for the foundry suppliers they supply to prototype shops also one that comes to mind is Porter Warner Southwest. But with todays method create a 3D model have it printed with a 3D wax printer and have a foundry pour it using the wax (investment casting).

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#11

Re: Foundry

02/19/2008 9:37 AM

Casting Aluminum may be a bit dicey since you'll need a shielding gas to keep the aluminum from oxidizing. You might do better using zinc or brass.

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#12

Re: Foundry

02/19/2008 11:04 AM

Dear Candoitall,

Although already commented on by others, please be advised that casting this yourself can be very dangerous.

There are some high tech means out there to help you along, however it will cost some - but might be a little price to pay vs. getting burned by molten metal, when not equiped with proper safety equipment. Molten metal can react unexpectedly violent, particularly when water is involved and moulds can crack and spit out molten material.

3D rapid prototyping printers are able to print patterns and even moulds in 3D, Z-Corp(R) is partnered with various competant foundry partners and resellers in the US and Canada.

The manufacturing process would be:

Create a 3D CAD model of your component as a pattern for sand casting, or of the entire 2 pc mould(!), into which you could pour metal directly.

Upload CAD to someone with a 3D Z corp(R) printer,

Go to the partnered foundry and have them pour into your mould with your material specifications.

Alternatively:

It seems you like to use a cast process here, but since you only need one part, it may be advisable to look at possibilities of having a competant CNC metal shop machine a fan from a solid block.

Perhaps you could also consider an alternate design of using a metal ceter hub and welded on crafted steel blades.

Just some more ideas... regardless take a look at the Z-corp(R) website to see how this could help your casting application!

I hope this helps you, I have some more info on this if you wan`t to contact me directly - mircog@canstampconsulting.com.

Regards, Mirco.

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#13
In reply to #12

Re: Foundry

02/19/2008 12:38 PM

Foundry Sand moulds are mostly baked.

Sometimes CO2- hardened after Water Glass bonding

For Aluminium mass production better will be Injection Moulding in Split- cooled die.

For 1 piece never waste time trying any Casting.

mirco advised correctly--'Go fabricate it of steel'. You might make it even lighter'n Al.

You won't notice any difference in Cooling the windings.

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#14
In reply to #11

Re: Foundry

02/19/2008 2:27 PM

Rorschach, Thanks for the heads up!

Candoitall

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#15

Re: Foundry

02/20/2008 12:35 AM

candoitall: you can get all the info you need to do it your self from http://www.lindsaybks.com/index.html more specifically https://openlibrary.org/works/OL7586567W/Elementary_Forge_Practice

Just use some common sense. Then again if you don't understand the dynamics of the situation get help from someone who does.

Just remember things can and will go wrong and plan for it. Or as I like to say act don't react.

Brad

CR4 Admin: Lindsay Books ceased operation in 2012. Open library has a few titles available online at no cost to the user; the active link above goes to one of them. Print copies are probably available at many libraries.

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#16
In reply to #15

Re: Foundry

02/20/2008 3:44 AM

Excellent Links...I'm going shopping for books

Sapper

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#17

Re: Foundry

02/22/2008 6:50 AM

Why to bother casting new fan.We get here (in India) similar fans as spares with blind holes. We drill hole and make keyways to fit exsisting motor. Here is joke for all, I worked with a company mfg. Hoists and Cranes.We used to buy motors from Siemens or Crompton, whenever customer would ask for motor fan as spare we used to get from O.E.Ms. Now these MNC used to sell at higher price as spare, then we used to add up our margins, so finaly the price of the motor fan used to workout higher than Ceiling fan which has motor and blades etc. One wise customer questioned the price of motor fan as spare and said he would rather buy a ceiling fan and fix above the motor.

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#18
In reply to #17

Re: Foundry

02/22/2008 9:05 AM

02-22-2008

Dear suresh sharma,

The replacement of this motor or the vacuum it is for would cast more then this indevour to recast this fan. Thus far the replacement bearings were under $5.00 dollars and a new vacuum would not posess the honor of belonging to my father.

Therefore, this discussion for casting an aluminum fan carries deeper meaning and challenges my abilities to accomplish this endevour. Then, I could pass this vacuum to one of my sons, yes it isnt a pocket watch but you understand. finally, casting this repairable vacuum motor away would make my name false! You see, "I can do all things through Christ Jesus who strengthens me." (Phil. 4:13 KJV).

Sincerely,

Candoitall

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#19

Re: Foundry

02/28/2008 5:28 AM

Keep molten aluminium and the water in the wet sand well away from each other!

This is the sort of thing that a local foundry would be happy to make given a suitable wooden pattern. Talk to them!

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#20
In reply to #4

Re: Foundry

02/29/2008 1:25 PM

Dear Soya123,

I reside in Ohio. Any info on this topic will be very appreciated.

I am currently building my furnace fron an old 12 inch dia. compressor

air tank. I had to use a hacksaw but the top is off.

Candoitall

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#21
In reply to #19

Re: Foundry

02/29/2008 1:28 PM

Dear PWSlack,

Warning taken and duley noted.

Thanks!

Candoitall

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#22
In reply to #18

Re: Foundry

02/29/2008 2:08 PM

If I were you and determined to do this yourself and save money while learning the process the first place to aquire information would be

http://www.lindsaybks.com/

I have used some of these methods and improved on them until some of the projects that started out as a hobby actually returned the investment several times over.

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#23
In reply to #22

Re: Foundry

03/01/2008 7:02 PM

Thanks Guest,

I just received their catolog and haven't had a chance to look it over yet.

Candoitall Phil. 4:13

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Anonymous Poster (3); candoitall (6); DaveB (1); HarryBurt (1); majordud (1); mircoconsultant (1); MUKULMAHANT (1); PWSlack (1); Rorschach (1); Sapper (3); soya123 (1); Stirling Stan (1); suresh sharma (1); U V (1)

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