Ok... had some time this weekend amidst the travel I had to do for work. I got a "sample" of the RSR40-800 and also did more thinking about how to get greater accuracy for less money. I surfed Misumi's website for very inexpensive, high accuracy components. Here's what I found:
Round Rail system for the Y-axis:
PSFJ8-500.0-LKC
- This is an 8 mm diameter, precision ground rod, 500mm long, made of hardened shaft steel with a hard chrome plating
- Price = $18.60
- Qty = 2, Total = $37.20
LHBB8
- This is an 8 mm diameter, precision pillow block made from aluminum with a high precision linear slide bearing inside
- Price: $10.30
- Qty = 2, Total = $20.60
SCTN8
- This is a 2 hole, 8mm diameter shaft collar
- Price: $2.80
- Qty = 4, Total = $11.60
Total for Y axis guides: $59.40
X Axis:
RSR40-800
- This is a "C" rail car, all metal, 40mm track width. It is preloaded and supposed to have zero slop.
- Price: $53.50
- Qty = 1, Total = $53.50
This gives a linear guide solution for the XY axis of $112.90. This is pretty good and should be VERY high accuracy. Since, I was able to arrange a "sample" of the RSR40-800, I got a linear rail solution for $59.40, before discount. That's really good and will be VERY high accuracy.
Here is a picture of the xy assebly. The best part: everything is bolt together and can be cut on the laser (the only thing that needs to be done is countersink 8 holes after cutting, but that is a no brainer with a countersink bit.
- XY assembly
I have to design motor mounts, put the motors, shafts, belts, pulleys, frame, laser, and mirrors together yet. I am going to use a significant amount of "box" joints to make plates and such from acrylic parts. This joint is easy to cut, provides a lot of glue surface, great strength and high accuracy alignment. I hope to not use any parts that require drilling the side of the acrylic parts so we only need a laser to replicate. I'll probably buy some of barts laser mounts though.