What designs are most economical while still maintaining accuracy?

[pinjas]

Hello,

I've been lurking about these forums for some time, I have seen a lot of designs but I have trouble telling which is the 'best'. I think that anyone could agree that the best is whatever is cheapest while not throwing away the desired effect.
I really liked what I saw when I looked at designs with V rails, but I always come back to asking myself if there is any reason not to go with angle beams either on it's edge or flat and using several bearings for motion.
I work with a lot of sheet aluminum, all of the cuts I've made have been with wood working tools. I have gotten to a point where I feel it would be stupid not to make a CNC plasma table. However, I have a small budget. Luckily, I have plenty of will and a little bit of skill. I can TIG weld just fine, I can operate a drill press, a miter saw, circular saw and I plan to get a plasma cutter for this operation in the new future. Unfortunately, with my small budget I am stuck with getting something made by slaves, my budget is probably around 1500 which pretty well has to include the plasma cutter.
I am going with an xy design and a manual z. I got that idea from some forum thread I found googling about, I think it's genius considering there is no need for depth variation for what I do, I guess that idea alone should shave off a hundred or two.
I have some great local sources around me for steels and aluminum. I've imagined that basically the entire table can be made out of angle, sheet, and bar steel. Any input would be greatly appreciated.

https://www.midweststeelsupply.com/store/ These guys are my primary source of materials, there are a few others in my area (St. paul and Minneapolis Minnesota) that I may compare prices to but I buy from these guys most of the time.

[curlyweld]

I have two side rails with rack and drive gears that came off from a ez router 5 by 5 table. I converted my table to a 5 by 10 and have these left over. I've been meaning to put them on ebay but don't want to mess with shipping. I live in RED WING,MN about a hours drive from the TWIN CITIES. You could even look my table over to see if that helps with any ideas. I do have the router for mine but have never hooked it up. Email me or call 6513886032, I run a small welding shop(CURLY'S WELDING) here in RED WING. Call if you'd like to talk. CURLY

[jcc3inc]

Sir,

Before retirement, I had done quite a bit of work designing commercial plasma cutters. After retiring I built a small prototype router using many of the ideas we had used earlier.
I'd be pleased to send you pix of the machine. Later, if you'd like to discuss you needs and ideas, I'd be happy to talk with you.

Regards,
Jack C.
jccinc-at-owc-dot-net

[WSS]

pinjas,

Take Jack up on his offer to send info, His stuff will make you think, He has provided lots of useful info here on the zone.

WSS

[AustinT]

I agree , Jack C helped me a few years ago when I build my machine. He is extremely knowledgeable

[pinjas]

I sent jack an e-mail. I tried a private message at first, but it didn't go through, it seems this message board has an extremely small limit concerning private messages.

Thanks.

[pinjas]

I guess I've come to a fair number of conclusions but I still have just as many questions or uncertainty about the design of the table. I've upped my budget a fair bit, I could be fine with spending 1500 on the table, this includes the drivers, steppers, and metal needed to fabricate the table.
I suppose that is all pretty irrelevant. I have some questions I am hoping someone could give their perspective towards.

1. Why is it I don't see any, if not very few, tables that have the X axis running on regular bearings across a flat surface? Is there some advantage to running the X axis on some of the other designs?

2. Why do some table designs seem to have an upper and lower set of bears on the X axis?

3. A lot of people seem to have different opinions on what way to drive a table is best. Rack and pinion, belts, chains, really long bolts. Any input on what determines the ideal choice in these options?