Aligning camera on the MPM AP25| 25 September, 2011
We recently aquired an old MPM-AP25 stencil printer that printed paste with a large error (about .060 inches). I concluded camera alignment to be the cause but was surprised by the magnitude. I found the camera beam splitter prism misaligned and loose. Having no experience stencil printers of any kind I restored what I thought the configuration should be and pondered what the alignment fixture looked like and what the procedure might be.
I was able to achieve a precise calibration with a pencil and a post-it note.
I picked a stencil with some geometry near the edge so the camera could be positioned conveniently close to the front of the machine. I put the post-it on the front vacuum rail underneath the geometry. I jogged Z up to touch the stencil. I attempted to mark the geometry on the post_it with various pens but couldn't get a clear image until I tried a pencil. The pencil outline traced through the stencil was of course in perfect alignment. I lowered Z and brought the camera forward to view both stencil and post-it. I carefully tuned the camera adjustments to get the images to overlap.
The machine now prints with perfect alignment. You could use this trick perform or just check your camera alignment in just a minute or two.