https://dengler-mechatronik.de/?p=560

The A-axis uses bearings described as 14x7x5mm, which in the US will get you a 14mm diameter bearing with a 7mm hole. The plans seem to assume that this size bearing will have a 5mm hole, so the described adapter bushing for M3 bolts doesn't work. I put together a quick alternative that fits a 7mm hole.

The nut holders for the stencil clamps, along with the "top counter" from the tensioning mechanism are meant to snap over 2 thicknesses of 2mm angle, however the vertical slot isn't nearly thick enough to allow this, so I modified these parts to allow the angle stack-up to fit.

 Until I have a chance to upload the corrected models, I've put them here:

https://bill.welliver.org/dist/4-axis-pcb/
 

There were a few confusing sections, so I took a few notes:

1. The sections of M8 threaded rod are 1.0mm (aka fine) pitch, which is less common than 1.25mm coarse pitch. I substituted coarse pitch parts at the expense of convenient tracking of z-axis changes.

2. The rear "eccenter" mechanism parts list includes 2 55mm sections of M8 threaded rod. This isn't necessary, and seems to be a copy-paste error. This mechanism mounts atop the top frame mounting studs.

3. It isn't mentioned, but a 9mm minimum ID spring needs to be mounted on each rear M8 stud between the lower and upper frames. If this isn't added, the rear eccenter mechanism won't function.

4. A drawing isn't included for the 5-bolt hole pattern of the upper portion of the A-axis turntable. I centered the part on the aluminum plate and mark the holes with transfer punches.  

5. The measured drawings for laying out the holes in the various aluminum components are extremely precise, and I simply wasn't able to replicate this successfully. It's probably easier achieve alignment by drilling somewhat oversized holes in the aluminum angle. Similarly, drill out the corresponding holes in the 3d-printed components that mate with the aluminum plates. You'll need to increase the number of perimeters in your slicer to have material to drill out. 

6. I printed these parts in PETG with 4 perimeters. Most parts should be obvious as to the proper alignment for printing, but the linear bearing holders and the parts that snap over the aluminum angle should probably be printed with the profile face on the bed, so that they have maximum strength in the directions they flex, respectively. You'll probably need to pay attention to getting them to stick to the bed, since they present a relatively small surface area in this orientation. 

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