building a router...im my head

[.xXACEXx.]

been working on this for about a year and a half,in my head,...so may choices so little money i want one machine to do it all...needs to be able to cut a any thing i want.. wood, plastic,alum.,(steel..maybe) the way i see it there are several ways to build a "way" roller bearings on round or square tubing (or gas pipe)plate steel with bronze sliders,drill rod with bronze bushings,ball bushings ond thompson hardened rod then there are the controllers for stepper motors ,or servo controlers and servos it boils down to how much ya want a cnc machine and how much ya want to (or are able ) to spend on the machine,everyone wants the best "bang for the buck"
i guess the machine i want to build is cheap above all..i got alot of want to do's..so it will need to be cheap to build ,but i am in a odd situation..ive been machining for about 11 years now,have access to any machine i want,so cheap can work for me if i can force it to..by machining with other machines...milling blocks to .001 tol.or turning gas pipe to assure it is round smooth and strait. (i know some are asking why does he even want a machine)
so...having said ALL that(i tend to ramble alot ...sorry)...my idea machine i want to build and work really well... will probably be about a 24 x 12 x 6 ..a 1inch drill rod guide and bronze bushings...for the "x" and 3/4 inch for the "y" and "z" ...i love the ideas about using gas pipe and roller bearings...but i keep thinking about a production machine at work with rollers bearings on the door guides..if a chip gets stuck to the track...the thing wants to stop solid...but this is a "production machine" might not be so bad on a one part every two weeks machine...(PLEASE dont take that as a critisism,to all yall that have that type guide way im just here looking for input )the table will probable be mdf i just looked at home depo today at the price of that stuff...man it is WAY cheaper than same size alum plate...like 5 bux vs.like 200 bux...any way....was wanting to build my own spindle...with skate bearings...but if i dont build my spindle i want to get a variable speed router (or try one of those speed controler things )i think i will go with the xylotex kit for motion controls,if i knew more about electronics i would no doubt build my own,,but moving on.....
so if your still reading all this...and have built a clone on this idea...what would you do diffrently.again i have been drawing this up at work and in my head for about a year and a half..but i havent made a single part of the machine...i dont have anything i am wanting to build on the machine ..that is why it will need to be a do it all type machine...i know...i know...jack of all trades...master of none...so thanks for the input guys..i need the incouragement to get this thing going...(well i win the award for longest post...yeah!!)...thanks guys!!

[.xXACEXx.]

over 200 veiws..no replys...hmmm

iv re-read my post, i check it about every day,and it may seem to some,a little harsh ..especialy from some one with no machine building experience... so let me be a little more clear.i am here looking for suggestions.not to critisize.some one told me my post was to critical ,,so i thought that may be why no-one has posted a reply..in my previous post i mention several ways to build..i was actually wanting in put from people who have built a machine based on those diffrent ways..roller bearings on steel seems like a very smooth guide way, bronze bushings seems good too,as well as ball bushings ,
But i simply dont know if they work wel as i havent actually made any thing...the machines where i work all rely on a film of oil ,but have steel on steel guides .and my questions are relating to easy motion ,and reliable positioning ,i dont know much about stepper motors...in my own head (again no experience) bronze bushings seem like they would work fine..
anyway.. if you have built a machine with any of the designs .what would you do diffrently next time??... what didn't work as well as you had hoped??
again i dont want to step on any toes..just looking for some advice on building a "play" machine

((i guess now i have won the longest reply to my own post,with no reply's))

thanx guys

[ger21]

Unless everything is nearly perfect, bronze bushings can bind fairly easily. Most that have tried using them find out th hard way.

[.xXACEXx.]

thanx for the reply...thought i was posting wrong or something lol..im fairly new to cnc zone (a couple of months) ger21 do you have a home built machine?what type ways do you have? and do you have any problems with it? i hate to ask so many questions.but im prolly only gonna build one machine..and cant afford to spend alot of money

[txcowdog]

I don't think you will find a less expensive way to build a machine other than skate bearings and gas pipe. The jgro build is about the cheapest build I
have seen. I have tried the oil impregnated bronze bushings and as ger21 said, I found that it is nearly impossible to keep the bushings from binding due to the extremely tight tolerances necessary. Those perfect fits are not practical in a home built machine. My best suggestions for you would be as follows:

Download the jgro plans and print them out. Spend some time looking them over and gain an understanding of the machine. Then look at joe2000che's first machine which makes a few improvements on the original jgro design. His first post is chronicled here http://www.cnczone.com/forums/showthread.php?t=8432. Joe then went on to a second build that was a larger machine with many improvements and was capable of light production. That build can be found here http://www.cnczone.com/forums/showthread.php?t=10067. After reading about these two builds you should have enough info to get you started with your own machine and have good expectations about cost and abilities of each machine. I encourage your exploring the possibilities of CNC and this board has a wealth of info toward that endeavor. Best of luck to you.