Cutting holes

[bandphillips]

Hello. I am new to CNC. I have a project that requires cutting 22 holes 3"deep in a 4 1/2 x 6 5/8 block of wood. I am planning on buying a used Shop Bot. I have been looking at some of the tutorials but so far I haven't seen how to do the holes. Can I use a boring bit and plunge in and cut the hole in one plunge or do I have to plunge in with a router bit and then enlarge the hole with a circular motion. Will that be difficult to learn. Thankyou.

[steve_g]

Bill...
Do you know what software may be included with the Bot you are considering? Whether you make your holes by "peck" drilling or pocketing the software should handle either with ease... your biggest obstacle as I see it is the depth you're talking about... That's a lot of bit length you're talking about, too long for smaller diameter holes/ bits. I would not recommend a bit smaller than 1/2" for the job you're describing. The next issue is the amount of Z available to you... bit length is subtracted from your available Z height. then there's safe Z clearance, clamps and other Z eating factors.

Tell us more about your proposed ShopBot!

SG

[bandphillips]

Hi Steve. Thanks for the reply. The software is mach 3. Also they replaced the controller (Is that the right term?) with a component made by Custom CNC Inc. He told me they made the controller and the software and the software is 7 years old. The holes would be 13/16 diameter. I was able to do them on a drillpress with a boring bit. I would need one a little longer to do it on the cnc. I was thinking about mounting a platform between the crossmembers of the table and recessing it lower to make more clearance. Do you think a boring bit would do ok as high as 10000 rpm? That is as slow as the router will go.

[steve_g]

Any tool designed to be run in a drill press would be detrimental to your health!

Mach3 is your control software, I was more interested in your design software. The design software will have features and strategies for "drilling" holes and will vary by developer...

FYI Mach3 is a bit of a step child for ShopBots and your questions about it will be limited to the few users who are familiar with it!

It sounds like your plan is feasible... I'd use a 1/2" bit and a spiral tool path to cut a 13/16" hole. Depending on your chips ability to clear the hole, a clearing "withdraw" may be required... all easily programmed as max depth of cut.

SG

[bandphillips]

Thank you Steve. I have turbocad software that I use to make drawings now, but does it work for design software?

[gc3]

you need toolpathing software...artcam express $150 will do what you need for this

[steve_g]

Whoever you buy a used machine from will have a design software package to go with it unless they are just upgrading to a bigger and better machine...
Art cam, PartWizzard, PartWorks, V-carve pro and the premier design software in many peoples mind... Aspire by Vectric are some names to watch for. You can go to the Vectric web site watch tutorials and download trial software. Watching the tutorials will help you understand the workflow in CNC work. Don't be afraid to ask questions here... Seldom do members mock a newbie, we were all there at one point in our lives!

SG

[myxpykalix]

Bill,
Like Steve and Gene mention you should get some type of design program with your bot. In case you don't, to get you started you could certainly ask someone here to draw up some files and create toolpaths for you. Some may want a fee and some may be willing to do it for free. This is not a big job by any means but when you do get around to getting your machine and ready to cut if you do get someone to help you, make sure you explain in detail the type of machine you have so they can save your files with the proper post processor. They will know what i mean........good luck and let us know when you do get it so we can get you started off properly..:D

[bandphillips]

Thanks guys. Very helpful.

[srwtlc]

Bill,

I don't know what your hole layout is on these blocks, but there is a circular pocket wizard built into Mach3 that would do holes or I should say, one hole at one location. Rewind the code and run again to repeat.

[bobmoore]

This sounds like a production job to me, if you are willing to buy, modify, and program a machine to do it. Assuming that is the case I think you should look at getting a bit of the proper diameter and programming a peck drilling program for it. Your hole diameter will be more accurate and the program will be much faster. Bob

[bandphillips]

Hello guys. I got the machine and I downloaded the Artcam 20 trial version. I was able to get the toolpath generated with the help of a friend. We had to take the gantry off the machine to get it out of the shop. Is there any special process to get the gantry set up again. Remember I have the Mach 3 software.
Scott. This will show my ignorance I'm sure, but doesn't the Mach 3 only read the code generated by the design software. I am confused how the Mach 3 would have a wizard to do holes. Thanks guys.

Bill

[bandphillips]

I like that idea Bob. I didn't know if a boring bit would handle 10000 rpm. Is a 13/16 boring bit available that long. If it was I would do that.

Bill

[srwtlc]

Bill, there should be a button on your Mach3 main screen that is labeled 'Load Wizard' and in the list, there's a hole making wizard.