2021 POTD Thread Archive

Made a demagnetizer based on the suggestion from @woodchucker . Mine has 6 12mm diameter x 3mm thick rare earth magnets sunk into some 2" OD delrin. Used my dividing head vertically and nearly ran out of Z on my PM24. Used delrin rod as a plug for the magnets and made it a press fit to the holes. I then turned off the plugs. Installing the magnets was interesting. At first I tried installing one N up, then installing 2 holes away N up. This didn't work. By the time the magnet got to the bottom of the hole it had flipped over to S up. So the technique is to install the magnet the next hole over, the opposite pole. The fields will keep the magnet in the correct place.

I will make the "chuck" out of some aluminum tomorrow. Making the plugs took a lot longer than I thought it would. First couple took a while, but the last 3 took no time once I got the hang of it. Although totally unnecessary, I bought a brass washer and brass SHCS in 10-32.
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How does it work to demagnetize?
 
Started to look at how to machine down to size the backplate for the 4-jaw chuck... This one will be one dirty task... Just testing the setup and figuring out the speed and cutter to use, there was iron dust everywhere! I will need to use a respirator, face shield, cover everything around the area...

One project I wished I could just move the lathe outside to do it :D

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first protect the bed of your lathe with an old tshirt ... second use a shop vac to suck up the chips as they are occurring.

Third, you can turn the tool upside down and rotate the chuck the other way, forcing the chips down, instead of up...

it is a messy process, but that dust will ruin your bed /saddle.... if you don't clean it up fully. so put something over it to prevent it from getting there.
 
first protect the bed of your lathe with an old tshirt ... second use a shop vac to suck up the chips as they are occurring.

Third, you can turn the tool upside down and rotate the chuck the other way, forcing the chips down, instead of up...

it is a messy process, but that dust will ruin your bed /saddle.... if you don't clean it up fully. so put something over it to prevent it from getting there.
Thanks. Also got a few ideas/recommendations from Aaron_W in the other thread.
 
Spin the magnets in a chuck or a drill. Put object to be demagnetized next to flat face. Pull away slowly. The rotation causes an AC magnetic field, which demagnetizes your stuff.

Would that work to scramble old cassette tapes? I have several tapes that need to be destroyed but I don't want to burn them and don't want to throw them away recorded. Have work stuff on them. I was going to run them through a bandsaw and cut them to pieces. But erasing would be nicer to do.
 
Would that work to scramble old cassette tapes? I have several tapes that need to be destroyed but I don't want to burn them and don't want to throw them away recorded. Have work stuff on them. I was going to run them through a bandsaw and cut them to pieces. But erasing would be nicer to do.
I don't think it will get deep enough. but worth a try.
 
Today i spent few hours changing the lower torque mount on my father's peugeot. Its over 20 years old and needed a new one, i had to destroy it rest of the way to remove it but managed to install the new one.
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Started to look at how to machine down to size the backplate for the 4-jaw chuck... This one will be one dirty task... Just testing the setup and figuring out the speed and cutter to use, there was iron dust everywhere! I will need to use a respirator, face shield, cover everything around the area...

One project I wished I could just move the lathe outside to do it :D

View attachment 379941
Just a suggestion, but your toolbit is way too far out. Large overhangs reduce rigidity big time.
 
Just a suggestion, but your toolbit is way too far out. Large overhangs reduce rigidity big time.
I tried different approaches... anything else and I could not get the travel needed to cut across the thickness of the backplate...

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Trying to learn MIG welding, so my first real project was a welding cart. Have a bunch of lab table legs that I've been moving out of the way for years and slowly repurposing as the need arises (see the grinding table in the background of the first photo). A pair of them became the starting point for the sides of the cart. I suspect I created my own learning trial by fire using them, since the walls are rather thin and very easy to burn right thru, but it was a great learning experience.

Didn't come out too bad for a 'design as you go' project. The lower rack has room for a small plasma cutter if the day ever comes that I can't resist that siren's call any longer.

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