Magnetic Trimming Chuck

[John Forstall]

The simple Magnetic Trimming Chuck can be a weekend project if you have a few hand tools and some experience cutting sheet metal.  The 11.5" diameter steel disc is cut from galvanized sheet stock bought at Home Depot for $4.  Although I didn't try it, you could probably get the same result without cutting metal by using the bottom of a 11" two-part steel (not aluminum) quiche baking dish bought from a kitchen shop, or on Amazon.

The steel disc is glued to any 12" bat that already fits your wheel.  I stuck mine together with strong double-sided sticky tape.  Four 1/4" Neodymium magnets are  epoxied to three 1.5" square pine blocks.  Dimensions are not critical, but it is a bit of a trick to keep the magnets from jumping together during assembly.  The blocks were faced with scrap foam Gripper Pad, but any medium stiff foam can be used.

So far the magnet trimming holder works well and is somewhat easier than using clay wads.  I have yet to make up a set of extension dowel rods for holding tall pieces.  Good luck and let us know how it goes, and if you have improvements.

11" Steel Quiche Pan:

http://www.amazon.com/Kaiser-Bakeware-Tinplate-11-Inch-Removable/dp...

Magnets:

http://www.amazon.com/Neodymium-Magnets-inch-Disc-N48/dp/B001KUWM3C...

Gripper Pads:

http://www.amazon.com/gp/product/B002LHVNTM/sr=1-65/qid=1361548645/...

Edit:#1 To Magnet Trimming Chuck

Hardest part of project is epoxying magnets because they want to spring together and make a mess.  So I've made a magnet assembly jig.

The photos show how to use the jig to make the three magnetic blocks.  First hammer then sand the tack heads flush then follow the photos. When chuck is finished first center your pot then slide the blocks to hold the pot. Any number of blocks can be used for any shape pot. 

John255

Edit #2

My attempts to build simple extensions for trimming tall pots were complicated.

Another approach I use successfully is to throw a double-ended trimming chuck and bisque  fire it. Then center the chuck on the mag-trim. (See photo below)  Dimensions are not critical.  I use a bulls-eye level to level the pot in the chuck. (This assumes your wheel is level.)  You could also buy a set of extensions from Bailey for about $16 and screw then to the mag-trim blocks if you like.

http://www.baileypottery.com/potterywheels/quicktrim2.htm

Good luck with your Mag-trim, and let us know how it goes.

John255

[John Forstall]

Brian,

Thank you for responding.

I was beginning to wonder if anyone was reading this.

Seeing some interest will help me to get busy making the extensions for tall pieces.

Total cost should be about 1/10 the price of Giffen Grip.

Regards,

John255

[Doug James]

Very cool idea! 

Thanks for sharing it.

[John Forstall]

OK Doug.

Glad you liked the post.

John255

[John Forstall]

Brian,

Your observation is true that you can add as many magnetic blocks as needed in any position.  If you wanted to add a thrown foot to a square slab pot that would be no problem.  All you would do is first center the piece and then add the holding blocks.

Thanks for your informative post.

John255

[Nadine Mercader]

Perhaps I am the only person here who does not understand how this tool works to keep the pot on the bat....Please clarify.

Thank you!

Nadine

[John Forstall]

If you are following this thread please note that I've modified the original post with EDIT#2 that includes an extension trimming chuck for trimming long-neck and domed pieces. 

Thanks,

John255