Need Help I AM IN WAY OVER MY HEAD

[DylanBJS]

So our business got a 4x8ft Industrial CNC (brand) machine. We have a few different lasers and use Lightburn for cutting our acrylic, coroplast, wood, ect. but we needed a CNC for our PVC, ACM, and wood preferably to keep the laser blades clean. That being said I haven't ran a CNC machine in 7 years and have completely forgotten everything not to mention we used all bootleg stuff at my previous job that we literally had to translate half the options on the software (it was a start up we did what we had to do lol). It came with BobCAD-CAM V36 and free version of Mach3.

I guess what I am asking is for some direction on how i can at least get it up and running to do what i thought would be these simple tasks, any links to reading material or youtube you have found particularly useful would be great!

The Goals:
1. Cut down these 4x8ft sheets of 3mm and 6mm ACM into various sized rectangles with rounded corners so we can hang up our panel saw.
2. Use customers vector line files to cut out these chickens that go in chain restaurants from this 1" thick expanded PVC material and have a tool change to add the key hole slots on the back (i assume ill just cut it mirrored so it would be the back side and do it all at once)

The Issues:
1. I am having the hardest time finding a starting point or how to find a starting point for anything like setting up a new material for BobCAD-CAM V36 software for ACM - is there a library somewhere that has the material info i could just import?
2. how to determine a feed/speed to start with - what information do i need to determine it? i assume the bit's width/length/flutes ect.?
3. i have made a rectangle in the software what the heck do i do next all the videos i have came across doesnt even touch on these simple noob questions


I know this is crazy and i am confidante i will figure it out eventually but i am hoping that you guys being smarter than me would be able to point me in a direction..

 

[Boudica]

get a tech out there to give you some training. Give the trainer a list of your goals and issues so they can walk you through it. I would think the cost of that would be equal or less of the time your wasting to figure it out, and the material wasted on fails.

 

[James Burke]

Tool and die guy here...

Speeds and feeds are dependent upon four main things: 1) The material you're cutting 2) The tool diameter 3) Number of cutting flutes 4) And the tool material (HSS, CBN, Carbide, High Carbon Steel, etc...). You can find that data in a copy of Machinery's Handbook, or look online. With that said, those values should always be considered "starting points" as other factors will also come into play (machine rigidity, workpiece rigidity, use of coolant, how far the cutter is extended from the tool holder, etc...)

As far as machine starting location points go, those are user-defined. For circles, it's always best to program an arc command going into your cut, and another coming out of your cut. The sweeping motion of an arc is better for the tool life of your cutter, and it's also least likely to a create divot in your part, especially if your machine has any amount of backlash in the ball screws.

The attached sketch shows your cut path if you were climb-cutting (traversing around your blank in a clockwise manner) around the sign blank.

In other cases where you have straight lines, you can use straight lead-ins and lead-outs if your part permits.

Another totally different, yet similar topic is "tabbing", leaving tabs of un-cut material along your cut path to support delicate areas or to prevent distortion due to material movement. Tabs should be added in your CAD program before your cut paths are posted to your CAM program.

Ultimately, there are a bunch of factors that dictate how you should set about cutting any given piece of geometry. CAM software is only as good as an operator's skill level. You might want to check around for a community college that offers a CNC programming course.

JB

 

[Vassago]

Probably the best program for you would be Millmage or carbide create.

Millmage is basically lightburn for Cnc machines - so if you already use lightburn, it's an easy step.

Carbide create is similar.

As for speeds and feeds, there are various calculators on the net - they'll give you a start.

Materials on cncs have to be built by the user as it's linked to your machines specs and how it works - so no real benefit to having a library - you build one as you're going along.

Single flute bits tend to be better with plastics though.

Alot of Cnc work is to get to know your machine and what it's capabl

 

[Vassago]

Capable of.

Get some scrap - start slow and play is the best way, then speed up with production.