First, I have begun to build a cnc router using 80/20 and still haven't determined what I should use for the linear rails and guides. While I managed to find a pretty nice deal on 80/20 at $3/lb, I began with a very limited budget and right now I'm trying to find a solution for less than $75, a temporary solution I guess. I've determined that the cost for 4 supported shafts + carriages, even at a tiny 12mm diameter, is not affordable at this time ($200-300 for 4 supported shafts & 8 carriages).
One option has been discussed in only a few threads (that I could find), 80/20 Unibearing. The 80/20 Unibearing pads have slight play in how they fit in the slides but can be shimmed to remove that play but the consensus of these bearings seems to be friction and wear on the bearing pads. I have some scrap metal around to make my own plates so the cost of pads are in my budget.
The other option, cnc router parts carriages are still a little more for my budget + the cost of buying steel flat for the bearings to ride on so I designed a carriage that is similar to this but made it taller and spaced the bearings out one 1/4" so the bearings ride comfortably on the 80/20 (1530). I made a carriage out of wood and I was able to remove all play in the bearings to allow the 80/20 to glide 1/8" off the surface. With some spare time on my hands, I ran the carriage back and forth for about a half hour with varying pressure to see if the bearings would show any signs of wear on the 80/20. While there wasn't a single mark from wear, 30 minutes is not nearly enough time to conclusively say that this could be a reliable solution for the time being. Ideally this would be the best option since my only cost would have to be about $20 for enough bearings. If nothing else, I can make the carriages with what I have and then the cost of steel flat should keep me within my budget.
The carriages I made are 4.75" tall x 6" wide x 1" thick and holds 4 bearings on top and 4 bearings on bottom that ride about 1/4" in from the end of the extrusion and then I put 4 bearings in horizontally which was also 1/4" from the top and bottom of the 1530. The bearings used are 608-RS.
So does this option seem viable for maybe 50 hours until a more permanent option is afforded? The image should, hopefully, show what I explained.
One option has been discussed in only a few threads (that I could find), 80/20 Unibearing. The 80/20 Unibearing pads have slight play in how they fit in the slides but can be shimmed to remove that play but the consensus of these bearings seems to be friction and wear on the bearing pads. I have some scrap metal around to make my own plates so the cost of pads are in my budget.
The other option, cnc router parts carriages are still a little more for my budget + the cost of buying steel flat for the bearings to ride on so I designed a carriage that is similar to this but made it taller and spaced the bearings out one 1/4" so the bearings ride comfortably on the 80/20 (1530). I made a carriage out of wood and I was able to remove all play in the bearings to allow the 80/20 to glide 1/8" off the surface. With some spare time on my hands, I ran the carriage back and forth for about a half hour with varying pressure to see if the bearings would show any signs of wear on the 80/20. While there wasn't a single mark from wear, 30 minutes is not nearly enough time to conclusively say that this could be a reliable solution for the time being. Ideally this would be the best option since my only cost would have to be about $20 for enough bearings. If nothing else, I can make the carriages with what I have and then the cost of steel flat should keep me within my budget.
The carriages I made are 4.75" tall x 6" wide x 1" thick and holds 4 bearings on top and 4 bearings on bottom that ride about 1/4" in from the end of the extrusion and then I put 4 bearings in horizontally which was also 1/4" from the top and bottom of the 1530. The bearings used are 608-RS.
So does this option seem viable for maybe 50 hours until a more permanent option is afforded? The image should, hopefully, show what I explained.