Zip's CNC Router

[ZipSnipe]

Well I,m pretty close to having my design for a cnc router finished. I plan to take the Widgitmaster's advice by purchasing the spindle motor and spindle(X2 R8 spindle) and building around that. The cnc router will be used to cut sheets of stainless steel, steel for punches and dies. I also wanted to be able to route wood with it. Being that I had planned to cut stainless and steel, using a off the shelf router would not cut it. My preferred work envolope would be 24x48 ", however economics will really decide how large I can build it. The base will use 1/8 angle and 1/4" steel plate while the outside frame of the router itself will use 1/2 steel plates. The Y and Z axis will use 1/2 aluminum plates. The table itself is still in decision. I,ll either go with 3/4 steel or aluminum, however I,ve also given thought to laminated MDF or even some Delrin. Keepin it as rigid as I can is a main focus. Anyway I,ll keep posting pics of the progress as it developes which will be slowly as I am also moving my shop into a little bit bigger and cheaper place. http://www.cnczone.com/forums/attach...1&d=1166127794
CNC Router.jpg

[project5k]

half inch steel plates to mdf seems like a large reange of materials... my personal suggestion is that if you can afford the steel to go that way... well that and can work the material.... (speaking with no experience) i would say that being able to cut steel and wood on the same machine may be dissapointing, from what i've heard and to the best of my knowledge your feed rates are going to be very slow when cutting steel, and your feed rates for wood should be much faster... I'm not sure how your going to be able to make a machine do both.. i would think that you would want a high tpi screw for steel and a mid to low tpi for wood... just a couple things that came to mind.. if you think that you can honestly do it, then i say got for it, and take lots of pics and vids if you can...

[digits]

An interesting looking design ZipSnipe

Have you thought about using angle for the top of the gantry frame as well - I would have thought that it'd be a lot stiffer than 1/2" flat plate?

[ZipSnipe]

Well most angle I,ve seen comes either 1/8 or 1/4' thick however if you find me a source for 1/2 thick angle , I,ll look into getting some. But what is available locally is 1/2 plate. I really wish I knew how to weld as I would replace all that drilling for brackets and such with welding. And really the only steel I,ll be cutting is some punch dies every once in awhile and some prototype flat shapes in stainless steel. For wood , i,ll be cutting recess for inlays and whatever else I conjure up.. I also go my manual mill if heavier cutting is needed. I also have access to a Bridgeport and a Sharpe mill( my fav of the two)at work. The design is inspired by another member of this forum(forgot his name and the pics of his mill are no longer on this site) but I always liked his idea of keeping everything above the cutting area, just makes sense. As for feed, I,m in no hurry and one of the things thats nice about cnc is the ability to get it goin and let it run while you do other things.

[digits]

Hi ZipSnipe - my guess is that if you used angle, you might not need 1/2" thickness to get the same or better stiffness as a 1/2" flat plate. It's the whole I-beam vs solid bar thing - you can get the same strength or stiffness with less material or much more strength and stiffness with the same quantity material if you use a non-flat shape. My worry is that the flat plate on the top of the gantry won't offer much resistance to sideways forces.

I am currently looking for some data to back this assertion up - I'll let you know what I find!

[ZipSnipe]

Well after screwing up and buying this motor http://cgi.ebay.com/ws/eBayISAPI.dll...7207&rd=1&rd=1
Its HUGE!!!. Anyway I decided to just use the mill head from my manual mill http://www.cnczone.com/forums/attach...2&d=1163376569
, I figured I would just make a dovetail mount for it. That way I can just unscrew it from the z axis on the manual mill and move it over to the cnc machine when needed. I will also make a dovetail mount setup for a router. I figured I,ll just use that motor above for my cnc lathe project that I plan to do after the first cnc machine is complete.

[vger]

I am very concerned about the upper frame stiffness. Being in the vibration analysis and balancing business I run into a lot of stuff that vibrates, resonates, and otherwise moves in an undesirable manner. I noted in your design the THK rails against the sides, those will add a little stiffness. I absolutely agree that a non flat shape with the same quantity of material will be stiffer. 3 X 3 X 1/4 angle will be far stiffer than a 3 X 1/2 plate. There would be a big smile right here if you used some C channel to support those THK's. The only other area that concerns me is the distance up to the ball screw across the top. Once you get it together, try pushing or pulling against the side of the carriage near the bottom with about 5 Lb of force with a dial indicator attached near the THK's to measure the deflection. You may be suurprised to see how much deflection there will be. Cross bracing from near the ball screw nuts down to the other sides would be a fix, even if the bracing were removable.

I'll be looking forward to seeing pics and learning of your progress.

[ZipSnipe]

Yeah I,ve listened to you guys and reconsidered my design call for the half inch plates and instead will use 1/4 angle 4x4 for the vertical posts and 5/8 plate for the horizontal support. I also decided not use THK rails(too expensive) and instead will incorporate the DIY rails and trucks like Jayson,s design http://www.cnczone.com/forums/showthread.php?t=29075
Jayson's #2 Machine - CNCzone.com-The Ultimate Machinist Community

looks like a good economy way to go. I,ll be starting the z axis assembly this week and will post pics soon.

[ZipSnipe]

Well with recent success in learning cad with the Spectralight(Sherline) I,m fired up again on building a larger cnc machine. I also redesigned from my original which would have cost extra( dual ball screws and servo motors on the x) I,ve come up with a stout traditional design. Let me know what ya think. I,m still working on the z axis and plan to go with servo,s.
http://www.cnczone.com/forums/attach...1&d=1198303153
CNC Router2.jpg

http://www.cnczone.com/forums/attach...1&d=1198303153
CNC Router2r.jpg

[ZipSnipe]

Here's the backside shot and the zip file is the actual model in Sketchup. This is all done in Sketchup by the way which I suggest to all newbie cnc hopefuls. As its easy to learn and great for seeing how it,s actually going together. My plan is to build it out of steel(black and dark gray areas) and aluminum(light gray), hopefully find deal on thk rails if not build rails out of steel(like in the pic) and get servo,s with a good quality drive(haven't decided which one). I choose servo's over steppers because my little cnc machine has steppers and I see what missed steps can do to your work piece aka scrap!! I,m still trying to figure out the z axis set-up. I,ll start the actual build hopefully in Feb. if my business picks up. I,m slowly crawling out of a hole I've been in for two years. http://www.cnczone.com/forums/attach...1&d=1198337695
CNC Router3.jpg

http://www.cnczone.com/forums/attach...1&d=1198337695
CNC Router.zip

[ZipSnipe]

Bump!