For this step you should have a brand new armature spring that you keep crisp and straight-if you do not have that you can make something out of a striaght sheet of metal that is thick enough not to bend out of shape. The point of this is to attach the armature bar to the frame in the lowest possible position that the arm. bar is ever going to get-which is parallel horizontally to the armature post on the rear of your machine-and for it not to move. It should look like this.
Find the leaf that touches both the top of the front coil (on the left) and the base of the arm. bar perfectly-that is the thickness you need to shim THAT coil-for the rear coil (right) find the leaf that leaves a sheet-of-notebook-papers'-thickness smaller than perfect fit, and that is the proper thickness for the rear shim. Once you know what thickness is needed, you can either A: Find a supplier and order a washer to your specifications especially for this project B: find a pre-packaged assortment of shimming washers and hope they have enough to stack the correct combination OR (my favorite) C: make a shim out of the leaves of the feeler guage-sometimes it can be harder if you need to shim it more than less-you can pre-drill three or four holes in your "spare" feeler guage in the first few leaves together and use tin snips to round it off. Or, if you're lucky enough to know a machinist or have access to machine tools you can get them drilled and cut perfectly. Either way you do it, place the correct shims under the coils, re-attach the coils and tighten it up.
This is where you shim the coils-notice the washers on the coil-screws.
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