Tinner
Well-known member
This is not that hard to do. Grind the edge of the plate smooth. Set your combination square at 1/4" and scribe a line the length of the plate. With a 36 grit sanding disc, tip your grinder about 11 degrees and pull the grinder the length of the sheet. Do that 3 more times, so you have four equal flats that hit your center line.
Flip the sheet over and do the same from the other side. The object is to get eight fairly equal flats that are slightly larger than your finished size.
Now switch to a 60 grit and try to knock the corners off those flats, so you turn 8 into 16 and come closer to your finished size. The lines will become less distinct. Now go back with a 60 or 80 grit flap disc and blend it all together. If you use a radius gage you can get it to look very nice to the eye, if not perfect.
The trick is to pull the grinder not push it. Lay the wheel flat, don't dig with the edge. I like to turn sideways to the edge and walk backwards. Some like to face the edge and sidestep. On your first attempt you may want to do each step twice removing less material. This gives you a chance to even things up if you wander.
If you have some scrap to practice on, so much the better. This is how it's done every day in fab shops. It isn't hard to learn, it's more a matter of confidence and learning to see the proportions.
Flip the sheet over and do the same from the other side. The object is to get eight fairly equal flats that are slightly larger than your finished size.
Now switch to a 60 grit and try to knock the corners off those flats, so you turn 8 into 16 and come closer to your finished size. The lines will become less distinct. Now go back with a 60 or 80 grit flap disc and blend it all together. If you use a radius gage you can get it to look very nice to the eye, if not perfect.
The trick is to pull the grinder not push it. Lay the wheel flat, don't dig with the edge. I like to turn sideways to the edge and walk backwards. Some like to face the edge and sidestep. On your first attempt you may want to do each step twice removing less material. This gives you a chance to even things up if you wander.
If you have some scrap to practice on, so much the better. This is how it's done every day in fab shops. It isn't hard to learn, it's more a matter of confidence and learning to see the proportions.
