Introduction and a couple of questions.

[Andy Birko]

Howdy all,

My name is Andy Birko and I'm currently knee deep in learning about CNC and so forth. My main focus right now is building an instrument called the Bandura. I've got a blog documenting some builds.

At present, I can manage to make about one instrument a year and have decided to go to CNC to help manufacture some of the more tedious parts like the neck and scroll and also to push the boundaries of this instrument by adding a key change mechanism. This has been done in the past with limited success mostly I believe, because a brute force method to achieve it was used. In a former life I was an engineer (and even have the piece of paper) and I think that armed with a good CAD package and some time, I can come up with something that's actually going to work. The CNC router will hopefully have the accuracy I need to realize the design.

So now on to the questions - I'm not interested in going the home made rout for the machine - I'm interested in pretty much turn key (the one exception is the Xzero which looks almost turn key). I've narrowed it down to the Romaxx WD-1 or some variant of the K2 3925 (edit: I'm still open to suggestions though). The price range of the K2 varies from just a little more than the WD-1 to a lot more if you go with the THK ballscrew & rail model. Does anyone on this board have either of these machines? If I go with the K2, I'd like to go with the 8" Z as well, is that machine rigid enough to handle it? Is the 3925 with just the 8" Z upgrade good enough for fine instrument work or does one have to with the THK version to do good work?

Next, One of the things that's kind of critical to make this worth while is that parts need to be "glue ready" right out of the machine. Having never seen parts right out of a CNC router, is it possible to cut mating 2D curves that are a tight fit? i.e. less than .001" gap?

I know it's a lot of questions but hopefully you guys will be able to help.

Thanks so much!

[Andy Birko]

Tap tap tap....this thing on? Anyone with any experiences here?

My search has broadened out and my list of potential candidates gets longer. Candidates now are:

Romaxx WD-1
K2 3925
Camaster Stinger
With the Xzero at the bottom of the list since it is not a turn key system. Reading about the amount of tuning that needs to be done with a non-turnkey system is really turining me off to that idea.

At the moment, the Romaxx is probably in the lead because of cost and reputation. It worries me a bit that the rails are made in house but....maybe that's how he's able to make such a good machine at that price.

Any input would be much appreciated!

[Brandon MacDougall]

Roger, Roger, come in Redbird..

I not sure where your located but the Carvewright would be a good tool for this.. Nice work on your instruments...

[Michael Simpson Virgina]

You have to remember that a number of factors will determine accurace. Many CNCrouters will give specs to .001. This is theoretical. First most routers with bits installed are hard pressed to get you that kind of accuracy. I have several high end routers and can tell you will be doing good if you can get .005. Also Just one day after cuttint the wood will move more than .001. For fine woodworking .005 is very acceptable.

The more tuned the CNC machine the less you will have to work the wood after you cut the part. But some types of wood when cut by a router will have to be cleaned up a bit. I think any of the three machines (looking at the specs) would do the job. I prefer machines with two seperate motors on the main axis of the machine to move the gantry. I dont like timing belts used to keep them moving together. By using two motors that are in sync you can make small tiny adjustments using your controller to the square of the machine.

Also keep in mind that to set up a cnc machine there are other costs. Router, dust collection, Stand, Holddowns, software.

The cnc machine will not magicly create a part for you. You will have to spend a great bit of time designing and tooling the part. Once done you should be able to spit out that part with the proper fixtures.

Look at the K2 cnc videos cutting out the guitar. This is the kind of cuts you will get. Notice the slight splintering and the multiple passes. I can guarantee that body will need some light sanding cleanup. Good Cam software will allow the CNC to cut the part at about .05 or so off size then do a complete full depth finish pass to clean up. This I have found will get you the best finish on the cut.

[John McClanahan]

Not to argue with other members recommendations, but I would skip over a Carvewright. It uses proprietary software that has low, to no compatibly with other CAD-CAM software. Your ability exceeds Carvewright's capability, and it won't grow,IMHO. Nice work!

John

[Michael Simpson Virgina]

I would have to agree with jhon on the carvewrite but not just becase of the software. While I am sure it could probably help you make an instrument. Its not or can nver bee a production tool.

[Andy Birko]

Thanks guys. The carvewrite is definitely not on the list for a number of reasons. I had a long phone conversation with a long time CNC owner/maker last night and I'm coming to the conclusion that the Romaxx may just be what the doctor ordered - which is nice as that will give me more $$ for software & tooling.

My volume will be light so I probably don't need high end bearings (i.e. this machine will not be putting in 8 hour days day in and day out), They're local so I can camp out on their front porch if something goes wrong. It's got the capacity I'm looking for. I've got testimonials from other users that it will do what I want.

For my next step, I'm going to contact him and see if he can make a few test parts on his machine for me to examine to determine if it's going to do what I want. I'll draw up the test parts to be representative of what I'm worried about (e.g. curved mating surfaces) and basically try and "break" the machine. If all goes well, I may be getting a machine sooner rather than later!

P.s. - I'm currently using and old copy of Solidworks99 for CAD. Does anyone have any experience with Alibre? Seems that even the Pro version is very economically priced for a parametric package. Does it have surfacing capabilities or is that only with the moi 3d add on?

[Brandon MacDougall]

I build a variety of custom instruments with the CW and do not have a issue with the system. But I not talking about the high tollerence large HASS machines as a option for my setup at this time..

[Mick A Martin]

Tap tap tap....this thing on? Anyone with any experiences here?

My search has broadened out and my list of potential candidates gets longer. Candidates now are:

Romaxx WD-1
K2 3925
Camaster Stinger
With the Xzero at the bottom of the list since it is not a turn key system. Reading about the amount of tuning that needs to be done with a non-turnkey system is really turining me off to that idea.

So any new on what machine you are going to buy?

Mick

[GVJeeper]

I just ordered the WD-1 - hands down when I compared it to other machines.

[Andy Birko]

So any new on what machine you are going to buy?

Mick

Well, the WD-1 is still the front runner. I'm trying to hook up with an owner in SouthEast Michigan to see one and run a couple of test parts. If anyone on this board lives in SE Mi, please contact me - I'll pay for a demo.

The XZero is starting to look more interesting though because the specs are just fantastic. I could get a machine that's a little larger than the WD-1 with THK rails etc..for a little less than the WD-1. The rub is that some assembly is required. An E-stop button is really important to me. The K2 is still on the list but mainly as a plan B

BTW, I stopped at a rockler to check out the CNC Shark and I wasn't impressed. The gantry is very floppy and the samples they had weren't very impressive at all. You could easily see where the gantry was deflecting and vibrating during the cuts. Perhaps the Pro is better but still, plastic gantry = rough cuts.

[Andy Birko]

News Flash: I just spoke with George from Xzero - because I'm willing to pick it up in person (Toronto is about a 4 hour drive and I have business there anyway) he's willing to put the whole shmeal together for me at a very affordable price: about $4500 OTD, just add a computer and Mach 3. That includes the following

Square Railed (NSK) Frame
8" Square rail Z axis
425oz steppers and gecko drive
power supply
Cable tracks
E-stop
Wiring
PC router mount
Setup
Table

This just got interesting!

[GVJeeper]

What design software are you going to use?

[Andy Birko]

I've got a really old copy of SolidWorks 99 that I have installed on my computer as well as the beta version of Rhino for OS-X. As much as I'd love to get SW2011 to use as my design software, I just don't think I can afford to spend the $5k on a seat. My current plan is to use SW99 until I hit some kind of brick wall with it. The surfacing features of SW99 aren't up to current standards but it's still a very powerful piece of software.

The other software I'm looking at is Alibre which also is a parametric CAD package that uses MOI 3D for 3D surfacing (apparently its native 3D is lacking). I've downloaded a trial version but haven't had a chance to play with it.

I guess the good news is that I have enough "free tools", SW99 and Rhino for OS-X, that I can buy a machine and get making parts and evaluate which one's going to be the best bang for my buck. Who knows - maybe I'll be able to afford SW2011 if I can get some side projects for the machine that will make a few bucks!

[Andy Birko]

So, I've decided that I'm going to go with the Xzero - just looks like too good of a machine. I also spoke with a guy who's a long time home CNC-er and he reassured me that it's the way to go.

I'll post some reviews once I get everything running.