Agree with John Tracy above, you can build a copy of Wally Malewicz's 'ladder' for less than a dollar. All you need is a cheap 50c plastic ruler and a plastic bolt/nuts. Can be made in 15 minutes with very basic tools.
Here's Wally's original.
Here's my copy
Use a fairly stiff plastic ruler, not the really thin bendy ones. The lower platform on my jig has the flat side of the ruler (ie reverse side of ruler) pointing up for a nice flat cartridge platform.
Here's Wally's original.
Here's my copy
Use a fairly stiff plastic ruler, not the really thin bendy ones. The lower platform on my jig has the flat side of the ruler (ie reverse side of ruler) pointing up for a nice flat cartridge platform.