Introduction and a couple of questions.

[Mike OMelia]

Hi Andy... had no idea you were into CNC. I'm getting there but have decided to go with Joe's 4x4 hybrid. I actually enjoy the process of building this stuff.

Mike

[Andy Birko]

Hey Mike,

This is a recent development - I had an epiphany that CNC would answer some of the major obstacles I'm having manufacturing a re-tune mechanism for my banduras and I could use it to speed up a lot of other steps in the process as well (once I figure out what I'm doing).

I think if I had more time on my hands I would have built one from scratch but I simply haven't got the time. The Xzero went through 2 or 3 minor iterations to get where he is now so I'm able to skip a lot of the headaches that way.

What kind of stuff you plan to do with yours?

[Michael Simpson Virgina]

I would really stop and think about things some more as you waffleing all over the place in your decision on a CNC. The Xzero is no comparioson to the WD-1 and I would deffinitly put it in the DIY catagory.

I would not even look at a CNC with a center drive on the X-axis for CNC router work.

I think what you need to do is to hookup with someone with a CNC and see how you can utilize it in your projects. This may give you better insite into how a CNC will help you. It will also help set you expectations as to what A CNC can deliver.

There are three pieces of software that are needed for CNC.
CAD
CAM
Controller.

From what I can tell Solidworks will get you your 3D CAD but you will still need a decent CAM product to convert the CAD Geometry into Gcode that your controller software can use. One of the cheapest CAD products is Vectric Cut-2D ($149) But its extremly limmited and you should look at Vectric Cut-3D or Vcarve Pro. While all of these CAM products have some level of CAD built into them its not the same as a real piece of CAM software like SolidWorks, AutoCade, ect.

Even though I have Autocad I tend to do all my part design in Corel Draw (2D). I then use Cut-2D to gen the Gcode and Mach3 to control the CNC.

[Andy Birko]

I would really stop and think about things some more as you waffleing all over the place in your decision on a CNC. The Xzero is no comparioson to the WD-1 and I would deffinitly put it in the DIY catagory.

Thanks for the feedback, Mike. Could you elaborate a bit on this aspect? I understand that the Romaxx is definitely more polished than the Xzero but, the Xzero guy is essentially putting a turn key package together for me. I'll be seeing it work in person before the $$ is exchanged. I do understand that there will be some more work to be done on the Xzero but I think I can handle it.

I would not even look at a CNC with a center drive on the X-axis for CNC router work.

Why? There seem to be a lot of industrial machines with center drive that seem to work fine? Perhaps it's the quality of the linear bearings that dictate whether it will work well? The WD-1 has twin ballscrews but, they're timed with a belt which could pose its own problems. I'm actually going to hook up with a WD-1 owner on Saturday to check it out - No one's ever 100% committed until the check is cut!

From what I can tell Solidworks will get you your 3D CAD but you will still need a decent CAM product to convert the CAD Geometry into Gcode that your controller software can use. One of the cheapest CAD products is Vectric Cut-2D ($149) But its extremly limmited and you should look at Vectric Cut-3D or Vcarve Pro. While all of these CAM products have some level of CAD built into them its not the same as a real piece of CAM software like SolidWorks, AutoCade, ect.

Because I'll be milling many 3D parts, I definitely need a 3D cad package like Solidworks or Rhino for that aspect of the design work. I'm currently evaluating Alibre as another option for parametric CAD. There are also a number of interactive parts so a full parametric system is pretty essential for that aspect of it.

For my CAM software, I'm currently evaluating VisualMill - it seems quite a bit more powerful than Cut 3D & 2D but it's also twice the price of those two combined and, it seems pretty complicated so far (I'm running all the tutorials). Vcarve pro will not do what I need, for sure. I'm currently leaning toward going for VisualMill as it covers both 3D and 2-1/2D carving and even V carving and apparently their tech support is outstanding. My fear is that I'll buy Cut 3D&2D and end up buying VisualMill 6 months later because the Vectric stuff won't do what I need it to. As a side benefit, if I ever decide to go to a contemporary version of solid works, there is a native plugin for VisualMill (costs $500 though!) too.

Mach 3 will be my controller irrespective of my choice of machine (unless someone has a good reason to go with EMC2)

It may seem like I'm waffling but that's not really true. I've been researching this stuff for around 2 months now and it's steadily been progressing toward the Xzero. The WD-1 was the leader until the Xzero guy proposed a turn key package. The specs on the Xzero just blow everything else in its price range out of the water. Yes the WD-1 has twin ballscrews on the Y-axis but it also doesn't have a 3/4" gantry with 25mm high end linear bearings. The WD-1 has shop made bearings and very thin gantry uprights. I'm sure it's a good machine, but from what I've heard from other sources is that the Xzero is in another league.

Thanks for the feedback though - this is a huge purchase from me and I want to get it right the first time. Keep it coming!

[Michael Simpson Virgina]

I looked into the Xzero myself a while back. There was quite a bit of interest when he first started his design. He listned and made changes, so it has gotten better. A few things that turned me off.
1. He does not have a real web site. Its a Forum with pictures. He is such a small operation It looks like he would have problems supporting his products. What is his warrenty?
2. In looking at the threads on his products on cnc zone it looked like at the time there were individuals waiting a long time for deliver. This may still not be the case but I would look into it.
3. Single drive X axis.

A fixed gantry that has a moveing table (normaly used for metal work can have a single drive. But a single drive X axis is going to rack under load when cutting off axis. This will affect accuarcy As for indiustrial machines using only a single drive down the center. Well I would not purchase one industrial or not. Another down side to this type of design is that you have to use a wrap around gantry. This means you can not support the table the whole length. This means flex, which will also affect accuracy.

You might ask how will this effect on accuracy show its self. For one a cnc makes many of its cuts in several passes. Any flex will show itsself here. You will see small lines.

The bottom line is the main reason for a single drive X axis on a moving gantry design is to lower costs. Personaly I would pay the extra $ for the added rigidity.

[Andy Birko]

The bottom line is the main reason for a single drive X axis on a moving gantry design is to lower costs. Personaly I would pay the extra $ for the added rigidity.

And there lies the dilemma: Xzero uses a single ballscrew for the long axis to save money, Romaxx uses house made linear bearings to save money. most of the people I've spoken to say the nod goes to the upgraded bearings over the double ballscrew. K2 is known as a pretty good outfit and their "frame only" for a similar machine to the Xzero is $6100 - with a single ballscrew for the long axis!

Unfortunately, these things are too expensive to buy multiples and bench mark them!

[james mcgrew]

i go with 90+ percent of what mike is saying with an exception or two, watching the xzero is kinda amusing (i do this daily) the fellow has some good ideas but there is something that just isn't right about the whole thing. on the issue of the single "Y" drive in the cartesian rule (cannot figure out why some call this x but that is another thread) the fellows at camaster have designed a R&P that is of an industrial nature, they gain stability with the width between the bearings on the "y" gantry under plate, this leads to excellent speeds and accuracy, that said i am no fan of the single ballscrew for a y axis, escpecially over 36" in length.

[Michael Simpson Virgina]

Yes it allways seemd to me that the X should be called the Y. With my current CNC I originaly worked from the side so the long axis became my X. It also lined up how my laser was setup so it made sense. Now I access the CNC from the front and I am constantly messing up as it should now be the side. It really doesnt matter cause with MAch3 its easy to change. Im just too lazy to do it now.

There is another advantage to a double drive axis. I can square up my gantry by just adjusting the screw that hits the limmit switch.

[Andy Birko]

watching the xzero is kinda amusing (i do this daily) the fellow has some good ideas but there is something that just isn't right about the whole thing.

Please elaborate - This is a big deal for me and I really want to know what I'm getting in to. I spoke with a guy who makes and sells jeweler's CNC machines and he said that bang for the buck, Xzero is going to win every time, it's that customer service is where he falls short. He recommended I go there and check out the machine in person before I bought. I spoke with the Xzero guy a couple times on the phone and he's willing to let me do just that before I buy. I'm not sure what more I could ask for.

I understand I'm giving up the customer service thing but, I'm also saving about $3 to $5k depending on who's counting.

[Gary Hair]

on the issue of the single "Y" drive in the cartesian rule (cannot figure out why some call this x but that is another thread) the fellows at camaster have designed a R&P that is of an industrial nature, they gain stability with the width between the bearings on the "y" gantry under plate, this leads to excellent speeds and accuracy, that said i am no fan of the single ballscrew for a y axis, escpecially over 36" in length.

I'm curious about your statment regarding X and Y axes. I thought X went left and right and Y went to and from (I'd call it up and back but don't want to confuse Z). The way I was taught is that you look at the direction that the "arrow" in the letter "Y" points, if you are confused. The "arrow" in the "Y" points down, or toward you, that's the direction of the y axis. The "X" could get confusing because you could say the arrow points both up and down and left and right, but that's why the "Y" is the reference. The mnemonic that I have heard is "y points to the sky"

Here is a wiki reference to cartesian coordinates:
http://softimage.wiki.softimage.com/...oordinates.htm

So, if you are talking about a "single y drive" then I think you are possibly confused? maybe I'm confused...

Gary

[Gerry Grzadzinski]

Just go to CNC Zone and read his threads.

[Ross Moshinsky]

There is no right way to label the X and Y axis. Its a matter of industry standard and personal choice.

I've been looking at CNCs for months now on and off. I've looked at XZero CNC many times. I have similar opinions as many of the others posted here. Considering the price, a single screw is about what you'd expect although I'm not sure why they don't want to go R&P on most of those machines. The design feature I really don't care for on the XZero CNC are the round bar frame rails. The frame should really have a more substantial frame. The fact the whole frame is held together with 4 bolts doesn't sit well with me.

Frankly, I've read the 90+page XZero thread on CNCzone and there is something completely odd about XZero. They seem to produce a new machine daily. The way owner posts and represents his product comes off as amateurish. The company seems based on the idea the owner built one CNC and decided he could build and sell his own so he is. Doesn't actually seem like he has a business plan or any chance of lasting.

[Andy Birko]

The design feature I really don't care for on the XZero CNC are the round bar frame rails.

I think you're looking at the wrong machine. I'm looking at the square rail version.

http://www.xzerocnc.com/forum/viewtopic.php?f=4&t=3

True, only 8 bolts holding it square but with the table on it should be much sturdier.

[Andy Birko]

There is another advantage to a double drive axis. I can square up my gantry by just adjusting the screw that hits the limmit switch.

Sorry to bring up an old thread but this came up in conversation the other day. If you can square up your gantry by adjusting a screw, what does that say about your gantry's rigidity?

[Michael Simpson Virgina]

Does not matter what material you cnc is made from. (Wood, Steel, Aluminum) When you start spanning 4' or more if you remove your drive method the gantry can be racked one way or the other by a small amount. This why larger better cnc routers use two drive mechanizams (One on each side) instead of one down the middle. The design will dictate how much it can be racked.

When I say squaring up the gantry Im talking about fine tuning .005 or so one side or the other.

Now keep in mind I am talking about CNC Routers. When you start getting into mills they use different techniques such as a moving platform so you will use other methods to fine tune or adjust. But they generaly do not span just distances for good reason.