New to any CNC...Few question with current users/ experts

Hello everyone,

I am planing to buy Longmill to start some small projects. I have never used any CNC and I have a lot of questions in my mind.

I would like to ask a few questions here:

  1. How do we know what type of bit is required for what type of design/ project?

  2. How do we change bit(s) if required to change within a design?

  3. Does software suggest the bit type for a design type?

  4. Could we pause the design and continue where it was stopped?

  5. If power outage or similar during a complex design, will it start it from where it was stopped?



First of all Welcome! Boy you picked some heavy questions to start with. 1 - Bit selection is based on material used. Hard and soft woods, plastics, foam, aluminum. Too much detail to explain here. 2 - Unless you have a cnc and software that will let you stop a job midstream we usually set up multiple tool paths and change in between, re-home position and start next tool path. 3 - Some may but I persoanly don’t trust their recommendations. 4 - Yes you can pause but you can’t turn anything off. Controller loses position. 5 - There are some gcode senders that will track where you are and let you restart in case of crash or power failure. Most of the info you are asking for is available in more detail on a superb amount of youtube videos. A lot of searching though. We all learned through video or job training or just trial and error and have had our share of crashes, failures and DOH! moments. Don’t be afraid to make the plunge. It’s sometimes frustrating but in the end it’s fun and enjoyable.

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Thank you for your reply!

@Hamdan Welcome,Hamdan. Heyward has pretty much covered anything that I could in reply to your questions. In terms of bit selection, it is largely influenced by the project you are working on and the degree of detail any carving requires. There is an excellent discussion on here about feeds and speeds and those two parameters will influence your bit selection, too. As Heyward said, much of this for most of us is trial and error - lots of error in my case.

I found that I learned a lot about bit selection, feeds and speeds and software foibles while cutting foam. It’s inexpensive, easy on bits and gives you a good idea about bit size and the associated level of detail.

Thanks for the reply. Could you please see my another post. I asked about carving on Laminated floor wood.