Bending cast magnesium

Joined
Sep 12, 2008
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behind enemy lines FEMA sector IV
Hi all
I have a bandsaw I am refurbishing and it appears one of the 10" cast magnesium wheels is slightly bent. The wheels have 4 spokes about as thick as a toothbrush and twice as wide.
From what I am reading, magnesium does not have to be heated to bend it.
Any suggestions?
 
Joined
May 2, 2009
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salt lake city
sounds risky to me...you can whack at it with a rubber mallet but more than likely you'll do more harm than good. it stands a good chance of developing stress cracks and getting it trued up will be a pain.

magnesium ehh? it must be old. i thought they phased that stuff out a while ago. i'm not sure but if my memory of highschool chemistry is correct magnesium is flamable / explosive. might wanna be careful heating it.

i guess it can be done but i think your better off finding a new pulley / roller for the bandsaw. i betcha you could find one in an Industrial Supply/Granger/Northern Tool kinda place.
 
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bay area, ca
magnesium is flammable, but you have to get the entire mass hot enough. so, VW engine blocks used to catch on fire, but i wouldn't expect a band saw wheel to get anywhere close. motorcycle engine case covers are commonly made of magnesium, get hotter than your bandsaw wheel will, and i'm not aware of any spontaneous motorcycle engine case cover fires

HOWEVER

shavings/dust can be extremely dangerous. if you ever have to machine/drill magnesium it should be drenched in coolant of some kind while chips are being generated.

pillguy: if it's bent enough to be useless now, you have nothing to lose trying to bend it back. personally i don't think it'll work that well, and i'd ask around at greasy old machine shops to see if someone with more experience is willing to help. perhaps look for someone that straightens motorcycle wheels and frames
 
Joined
Sep 12, 2008
Messages
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behind enemy lines FEMA sector IV
Guys,

Thanks for thoughts and suggestions. I spoke to the machinist who did some work on it already and he suggested boring out the center straight and putting a larger set of needle bearings in the top wheel.That is doable, but I actually found some spare parts on fleabay and bought them. I am waiting to get home to take a look at them and see what I got. Hoping not to have to buy more needle bearings.
I have to post some pics when I am done, as this is a nice small band saw that can also be used to cut steel if I resize the pulleys.
As a side note, anyone know where I can get an inexpensive used 1/2-3/4 hp electric motor?

Thanks,
magnesium is flammable, but you have to get the entire mass hot enough. so, VW engine blocks used to catch on fire, but i wouldn't expect a band saw wheel to get anywhere close. motorcycle engine case covers are commonly made of magnesium, get hotter than your bandsaw wheel will, and i'm not aware of any spontaneous motorcycle engine case cover fires

HOWEVER

shavings/dust can be extremely dangerous. if you ever have to machine/drill magnesium it should be drenched in coolant of some kind while chips are being generated.

pillguy: if it's bent enough to be useless now, you have nothing to lose trying to bend it back. personally i don't think it'll work that well, and i'd ask around at greasy old machine shops to see if someone with more experience is willing to help. perhaps look for someone that straightens motorcycle wheels and frames
 

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