How to make a simple device for cutting circles with a plasma torch

Although the effectiveness of cutting metal with a plasma torch is beyond doubt, cutting out a perfectly straight circle with it is not at all easy. This requires decent qualifications and time. But if you make a simple device based on a magnetic disk, then even a beginner can cope with such work.

Will need

Materials and tools:

steel plate;
magnetic disk with a single-sided hub and a threaded hole in the center;
screw, washers and nuts;
vice, hammer and core;
Bulgarian;
drilling machine;
emery wheel, etc.

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Manufacturing process of plasma torch wheel cutting fixture

We measure a distance from one end of the plate equal to the diameter of the magnetic disk and mark it with transverse marks. We retreat some more distance from them along the length and make a second pair of marks.

We fix the plate vertically in a vice at the level of the second marks and bend it with hammer blows 90 degrees.

We measure the height of the magnetic disk with a caliper and set it aside from the place where the plate bends towards the short side.

Using a grinder, we make a shallow cut along the intended transverse line and bend the plate again by 90 degrees so that the bent edge is parallel to the remaining part, but lies in a different plane.

Drill a hole in the center of the short bent part of the plate. We draw a longitudinal line in the center of the long side and mark points along the entire length at an equal distance from each other and make a system of holes.

We remove burrs and smooth out sharp edges after drilling the plate using an emery wheel.

We press the long part of the platinum to the surface of the workbench and insert a screw and washer into the hole of the short part from above. We put a washer on the back of the screw, screw on the nut, cover it with the washer and screw the magnetic disk hub onto the end of the screw.

After assembly, we make sure that the leash with holes rotates freely in both directions above the horizontal surface on which the magnetic disk is installed.

We attach the magnetic disk to a metal sheet, insert the plasma torch nozzle into one of the holes in the device, start the device and, by rotating it, cut out a perfectly round workpiece.