CNCRob's CNC Worklog

[CNCRob]

For awhile now, I have been wanting to make a CNC machine. Like probably alot of you out there, it was mainly to help make things for other hobbies. I thought that I was the only one that wanted to do this, but then I searched on the internet and it proved me wrong. I found that there were tons of people doing it, and producing some really nice machines. My job at work is programming parts and running a CNC router for a furniture company but that's along way from having the knowledge to actually build one. After my Internet search I quickly realized that CNC building and running was a hobby of its own. I have been doing research, saving money, and working on my plans to build one for myself. I have posted some pictures of my CAD rederings below to let you guys look at, and maybe give me some ideals and advice. I know you probably know alot more about them, then I do. I have been kinda nervous about posting them because I didn't know what you guys would think. I tried to keep everything as simple as possible since this is my first one. The over all footprint is about 22 by 33.5 inches, and the travel should be around 14 by 22 by 3.5 inches. Some of the details are missing because I'm still working out a few things. So feel free to let me know what you think and any ideals you may have, it will be a great help to me. I will try to keep you posted on the progress along the way.

[CNCRob]

I'm at a cross roads, Here is what's happened with my project so far. I got all the pieces cut out and I am ready to start drilling all the holes and then assembling it. I have done several test to try out different ideals that I have had. Things have gone really well all but one thing. Which is why I'm at a cross roads. I designed my machine to have linear bearings, So the other day I ordered one 1/2 and one 3/4 bearing from a local bearing distributor, so I could get the measurements and figure out a few things before I ordered them all. When I went to pick up the bearings the guy there said I couldn't just use any shaft I would need a hardened one and it couldn't be cold rolled. He gave me a quote on some for the sizes I need and they were like $25 and $40 a piece. The ones I had planed on using were only around $10 a piece. He said if I used the cheaper ones the bearing would rub groves in the rod and mess up the rod and the bearings. So now I'm in search of ideals. I'm starting to wonder if it would just be more economical to just buy a machine already built. I hate that I have already put so much work and effort in this and it would just all go to waste. Saving some money wasn't the only reason I wanted to do it, It was also the thrill of having created something that could do so much. I have seen allot of other people on here use rollorblade bearings but I have pretty much designed my machine around linear ones. I was wonder if any one has any suggestions? or has any one used the linear bearing with cheaper rods and had good results? Any help would be appreciated.

[ger21]

Check McMaster Carr, http://www.mcmaster.com page 958

36" 3/4 = $36
24" 3/4 = $25
12" 1/2 = $8.50

Around $140 for all six. Or try to find them on Ebay.
Buying a machine will cost probably at least $1500-$2000, I would think.