[dinkyguitar]

Hi All,

I planning to build a cnc machine and I've been looking at different rail systems....whether to go with linear bearing or linear carriages or other types. And drive systems, ball screws, acme screws, rack & pinions, etc.

Since I'm new to all this can someone explain the different types of systems, thier costs, the best and worst etc. Or show me where I can go to get the information?

I originally wanted to build a budget machine but looking at those linear bearing systems and ball screws systems interests me...

Also frame construction...steel or aluminum extrude?

The purpose of my machine is to make guitar necks, bodies, and small aluminum brackets...

I really like the machine, it's the size I'm looking for.

Complete 2'x3' Router Kit : Fine Line Automation

I'm wondering if I can build it cheaper the price...

dinkyguitar

[jckstrthmghty]

One thing I know. The kit versions of the z axis will be a lot easier to assemble with good tolerances compared to someone without machining equipment and experience.

For me that's the whole point. Doing it the hard way and learning why things work the way they do. If production with lower costs is important then a kit is the way to go and there is a good selection of kits to choose from whatefver your needs are.

Cheaper usually (almost always) means less accuracy, more time, and much more aggrevation and more expensive in the long run.

Once again it depends on what your goal is.

[louieatienza]

Hi All,

I planning to build a cnc machine and I've been looking at different rail systems....whether to go with linear bearing or linear carriages or other types. And drive systems, ball screws, acme screws, rack & pinions, etc.

Since I'm new to all this can someone explain the different types of systems, thier costs, the best and worst etc. Or show me where I can go to get the information?

I originally wanted to build a budget machine but looking at those linear bearing systems and ball screws systems interests me...

Also frame construction...steel or aluminum extrude?

The purpose of my machine is to make guitar necks, bodies, and small aluminum brackets...

I really like the machine, it's the size I'm looking for.

Complete 2'x3' Router Kit : Fine Line Automation

I'm wondering if I can build it cheaper the price...

dinkyguitar

You could, but then you have the labor of fabbing all the parts; drilling all the holes. There is something good about hot having to 'enginner' stuff because someone has already done it!

There are so many different type of linear bearings! The determinung factors would be cost and what stiffness and accuracy you're looking for.

Similar with screws. There is no 'best' just what;s best for your application. Look for Swede's excellent writeup in the Mechanicals section.

[dinkyguitar]

That's kind of what I was thinking....not to try and invent the wheel..

I mean, how much cheaper will it be if I put something like that together as opposed to buying the kit? I'd rather buy the kit if it's going to cost me accuracy and a lot of precision labor...

Don't get me wrong I love building things and putting them together, but that's a pretty good price for a machine like that right?


Also, if I was building a machine that size, 2' x 3', what size supported linear shaft should I get? 16mm or 20mm, and if they were unsupported?

dinkyguitar

[louieatienza]

That's kind of what I was thinking....not to try and invent the wheel..

I mean, how much cheaper will it be if I put something like that together as opposed to buying the kit? I'd rather buy the kit if it's going to cost me accuracy and a lot of precision labor...

Don't get me wrong I love building things and putting them together, but that's a pretty good price for a machine like that right?


Also, if I was building a machine that size, 2' x 3', what size supported linear shaft should I get? 16mm or 20mm, and if they were unsupported?

dinkyguitar

I'd prefer NOT to use unsupported rail for cutting hardwood. It might be OK on the Z axis. It would be easy to retrofit a K2CNC Z axis, which comes pre-made. It uses unsupported rails.

20mm would be better for X and Y. I suppose you could use 16mm for the Z to keep it more compact.

You could also check out CNC Router Parts as well, for other ideas...

[dinkyguitar]

Thanks louieatienza,

But I'm not sure what you mean by, "I'd prefer NOT to use unsupported rail for cutting hardwood"

I'm as green as they come when talking about cnc...


dinkyguitar

[louieatienza]

Thanks louieatienza,

But I'm not sure what you mean by, "I'd prefer NOT to use unsupported rail for cutting hardwood"

I'm as green as they come when talking about cnc...


dinkyguitar

It means just that. Use supported rails whenever posssible...

[BanduraMaker]

The purpose of my machine is to make guitar necks, bodies, and small aluminum brackets...

Coincidentally, Louie just started a CNC primer thread on a luthier's forum....

I think the sentence above kind of choses your direction for you. If you want to build guitars, your best bet would be to either go with a proven design that has plans or, a proven kit.

Building machines is a lot of fun and for a lot of folks, it's an end in itself but, it can take ages if you're designing and building from scratch, especially if you're a total noob. Using a proven design knocks a lot of time off and a kit even more.

[louieatienza]

Coincidentally, Louie just started a CNC primer thread on a luthier's forum....

I think the sentence above kind of choses your direction for you. If you want to build guitars, your best bet would be to either go with a proven design that has plans or, a proven kit.

Building machines is a lot of fun and for a lot of folks, it's an end in itself but, it can take ages if you're designing and building from scratch, especially if you're a total noob. Using a proven design knocks a lot of time off and a kit even more.

I'm actually building a new machine right now, to offload most of the metal and composites work from my current machine. In fact I'm using my machine to build it!

I think you're on the right track with the FLA kit, or even the CNC Router Parts kit. The aluminum extrusion stuff is nice because they're modular, and you can grow your machine as your needs change. I decided to use a combination of extrusion and sluminum plate in my new build: http://www.cnczone.com/forums/diy-cn...ml#post1069252