Hi all, new to the forum though I've heard a lot about it, I'm not a machinist but have a project with a relative who's an apprentice, and wanted to run this past you guys to see how feasible it would be before ordering more parts.
I'm working on making an admittedly overkill upgrade to the print surface of my 3d printer that will be carried forward to a full custom build someday. (unless I go for a larger size.)
The end goal is to be able to use removable flexible plates, but also have the precision surface to mount pei sheets, or use use on it's down, without any mounting holes or thick magnetic sheets that could affect flatness.
So, I'm hoping to mill out about 24 pockets into the 6.35mm tooling plate, leaving a 1.5mm gap between the high temp magnets themselves and the surface. These will be backed with some steel to increase the force they apply, then all capped off with a 500w heater. There's also going to be a few holes tapped for actually mounting. These will have threaded rods with some red loctite, so they're really only single use.
I wanted to check this over though, as it is removing a fair chunk of material from the sheet, and I'm not sure if milling that much out could cause some issues or warping. From what I understand there shouldn't really be any internal stress since it's a cast plate, but I wanted to be sure.
I know of other people who have milled shallower pockets in from the front, but that obviously means that the top surface isn't that ultra precise flatness that you pay for with tooling plate.
If it's of any help here are a couple pictures of more or less what the layout will be. I had been wanting to use round magnets, but with these bar ones there's a discount and I should be above 250lbs of force across the entire surface with said 1.5mm gap, stronger if I could get it down to 1mm, though that feels perhaps a little too close for comfort.
The first plate I ordered looked like Freddy Kruger handled it before shipping, so I do have a practice section we can use but I'd love to hear thoughts from you guys about this project.
edit: So with 24 of them backed with steel at a 1.5mm gap it should be 291lbs of force, assuming full strength on a fairly thin spring steel sheet, or 391lbs if I could actually get only a 1mm gap from the top surface. Perhaps 1.25mm and ~335lbs is a good compromise, again assuming that's not too thin of a section that might cause weird warping issues when being machined or heated.
I'm working on making an admittedly overkill upgrade to the print surface of my 3d printer that will be carried forward to a full custom build someday. (unless I go for a larger size.)
The end goal is to be able to use removable flexible plates, but also have the precision surface to mount pei sheets, or use use on it's down, without any mounting holes or thick magnetic sheets that could affect flatness.
So, I'm hoping to mill out about 24 pockets into the 6.35mm tooling plate, leaving a 1.5mm gap between the high temp magnets themselves and the surface. These will be backed with some steel to increase the force they apply, then all capped off with a 500w heater. There's also going to be a few holes tapped for actually mounting. These will have threaded rods with some red loctite, so they're really only single use.
I wanted to check this over though, as it is removing a fair chunk of material from the sheet, and I'm not sure if milling that much out could cause some issues or warping. From what I understand there shouldn't really be any internal stress since it's a cast plate, but I wanted to be sure.
I know of other people who have milled shallower pockets in from the front, but that obviously means that the top surface isn't that ultra precise flatness that you pay for with tooling plate.
If it's of any help here are a couple pictures of more or less what the layout will be. I had been wanting to use round magnets, but with these bar ones there's a discount and I should be above 250lbs of force across the entire surface with said 1.5mm gap, stronger if I could get it down to 1mm, though that feels perhaps a little too close for comfort.
The first plate I ordered looked like Freddy Kruger handled it before shipping, so I do have a practice section we can use but I'd love to hear thoughts from you guys about this project.
edit: So with 24 of them backed with steel at a 1.5mm gap it should be 291lbs of force, assuming full strength on a fairly thin spring steel sheet, or 391lbs if I could actually get only a 1mm gap from the top surface. Perhaps 1.25mm and ~335lbs is a good compromise, again assuming that's not too thin of a section that might cause weird warping issues when being machined or heated.