Would it be a good choice as first milling machine?

[Nghia Hoang]

I have some experience in cad but no experience in cam software. Sould I buy something else first before getting this machine?
Is it possible to made an auto tool changer for it (first thing any of my friends who worked with cnc machine before asked me when they heard about this machine)?

[Joel Wismer]

Would this be a good machine to start on?

Yes. It is going to be small; going to sell at a great price; and going to be easy to attach a vice, fixture, or clamp right to the table. Plus, since it is 5-axis, you can learn on 3-axis (just do not code for 4 or 5) and add axes as you learn. These are all thing to look for when looking for your first CNC. I am likely missing some though; anyone else have more key traits to look for?

Here is an excellent resource for different CNC and milling machine terms:
http://www.americanmachinetools.com/how_to_use_a_milling_machine.htm

Is it possible to make an auto tool changer?

This is just speculation but based on the current design, I bet you could. It would, however, add a lot of complication if the code for it does not exist (Duane, will the custom post processor support it?). You would also have to create the change mechanism which, because the spindle was built for hand tool changes with the lever, would require an elaborate attachment and detachment mechanism. If you watch the video (here: http://www.youtube.com/watch?v=0Y9Bg1gJXi4&sns=em) you can see hand change of tools is super quick. If you could do all of your projects with a 1/8in tool (the most common tool size) or don't mind manually changing the tools if you have to, life would be a lot easier. The function of the automatic tool changer is to increase speed of production CNC's, making 1000's of the same part (what is a tool auto tool changer video found here [the tool changing for the Pocket NC would likely be more complicated]: https://www.youtube.com/watch?v=Hgyq3JYlBmw). Often when they change the tool, a new collet is needed. To change the collet on this spindle requires a little extra work and to automate that would be even more difficult. If you do plan on this degree of production, a tool changer would certainly be worth investing some time into making.

Here is the product information spec for the NSK NRR-2651 spindle used on the PocketNC:
http://www.artcotools.com/nsk-nakanishi-nrr2651-lever-type-spindle.html

Here is a list of their compatible collet groups:
http://www.nsk-nakanishi.co.jp/industrial-eng/hpms/dw_pdf/e3000.pdf

Here is a list of the compatible collets within the CHB Goup (2mm, 3mm, 3.175mm, or 4mm):
http://www.nskamericacorp.com/pdf/parts_collet_chuck.pdf

I hope this helps. As I am not an expert in the design, I would be interested to hear from Matt, Michelle, Gary, or Duane.

[mat...@pocketnc.com]

Thanks Joel,

I don't think I could have said it better myself! Currently, the best software solution for the Pocket NC mill is Fusion 360, it is free for Hobbyists and start-ups making less than $100k USD/ year. With the Fusion software, a tool change happens like this.

1. Machine rapids to Z max.
2. Spindle turns off.
3. Machine rapids to Y/X Max.
4. Machine rapids to A 0.
5. Flip lever and change tool.
6. press cycle start.

-Matthew

[Nghia Hoang]

Thanks, that is a lots of information.

I'm not worry about speed of tool changing, more about accuracy when changing tool.
Maybe all I want is a touch plate.

[Nghia Hoang]

Thank you,
What I concern is difference length of the tool.
Could I cooperate something like a touch plate for this machine?

[mat...@pocketnc.com]

While a tool probe would be nice, we do not have anything in the works. I have found that using a shaft collar on the tool allows me to set the tool length within the tool table without issue.

Thanks,
Matthew

[Duane Bishop]

Hi Joel, the post processor does support tool-changing. Currently, the way this works involves that a selected tool is chosen in the CAD/CAM software for a given cut and that tool's path (and tool selection) is rolled into the g-code at compile time. From there, the machine needs to have been previously setup with a 'tool-changer' script (g-code) to automate the mechanical action. However, out-of-the-box default the CNC control software just runs a generic g-code script to present the chuck to the user for manual tool changing. However, the functionality of a full-on, industrial-grade, auto-changer is there already.

As far as the collect goes, that's Matt's area of expertise.

Best regards,

Duane