Making a round disk from flat plate.

[Darren]

I saw this elsewhere and thought it was a neat idea ..


"Another idea - if you insist on to it from flat plate - first, lay out the part - center hole, use a caliper to mark out the OD, and just as importantly, the bolt circle. Working carefully, you can then use the calipers to lay out the bolt circle. center punch the location of the 1st hole, and by trial and error, walk the calipers around the now marked circle, when you get that right (sorry typing errors - in a lot of pain this AM - health issues). Once they are laid out, center punch and mark them too. NOW drill out the center hole (you don't need to tap it yet) and at least one of the bolts for the bolt circle

Mount the work to a sacrificial faceplate - wood is OK, so is Al, heck, whatever. The center hole is for the center (duh) and the hole on the bolt circle is for a driver pin!

Now, mount the faceplate and work in your lathe, center the work, and turn down the outer edge - one way that I've not seen anyone mention is trepanning the work - aka you cut in from the face till the work parts off

I'm gonna guess you can figure the rest out from there"

[Bernd]

Darren,

I read that also but can't remember where I had found it. Almost sounds something like Bogs would do. 

Bernd

[John Hill]

Thats pretty much how I made the rotor for my gyroscope project where I found it was essential to secure the outer piece being cut off during trepanning.  If it is not secured it will fall off and get tangled around the tool,  OK I suppose if you really wanted a metal pretzel!

[RipSlider]

In the MIT video's ( link has been posted lots of times ) the chap just uses double sided tape to hold the flat plate onto a face plate - I seem to remember with a brace piece in the tail stock. Seems to take only a few seconds to set up, and looks like it works well.


Steve

[John Rudd]

I took a long bolt, inserted it into the chuck head first, attached my ally plate that had a hole drill for the bolt and just trepanned it with a shaped parting tool and a bit of WD40 for lube,and made this................Its the tacho disc for my lathe ( an ongoing project)