Learning my new shark

[Joeshark]

Well I am going to say it up front. I don't know what I am doing. I under stand how the CNC works with the program. I worked with CNC machines for about 15 years at Chrysler. The machines I worked with would touch off on the parts to be machined on all four corners. I guess my question is how does this CNC know where the part is on the table by just touching off on one corner. How does it know it is straight on the table? I learned to think a long time before pushing the go button. Thanks for any help. Joe

[ger21]

I guess my question is how does this CNC know where the part is on the table by just touching off on one corner. How does it know it is straight on the table?

It doesn't.

[martin54]

As ger21 says it doesn't, to elaborate a bit the material set up when you start designing will define your material but the CNC will never know it's true size, you are 100% responsible for placing it on the machine table correctly how you do that may vary depending on its overall size & shape

[Joeshark]

Ok that makes sence. Just trying to get everything right in my mind before I hit go. Thanks for all your help.

[wmgeorge]

Ok that makes sence. Just trying to get everything right in my mind before I hit go. Thanks for all your help.

Do not have a clue about your Shark but most CNC machines have a ALL HOME or similar. It returns the spindle or whatever to a preset location. I then load in my CNC gcode file and on Mach3 it shows the file on the preview screen. I then Jog my spindle over to the work piece, in my case a board, and then Jog the Z down slowly so it just touches the corner, some use a sheet of paper to check or I have a really thin sheet of stainless steel so I can insure its just touching. Then I Zero the Z and push GO or Start, the Z will go up to its Safe Z setting and move to the Origin you have set in your file.

Danger, warning...... Yours might be entirely different from my machine. To really get used to your machine, Create a very simple design in VCarve, SAVE TOOLPath and when you do the above, just pretend you have a board on the table and set that Z zero about 2 inches above the actual pretend work and run the file, in the air above the table.
PS In the Download section on this website there is a CNC Basics or something like, download and read and read all the documentation that came with your Shark.

[Joeshark]

Thanks wmgeorge. I'll check it out.

[DHDeitrick]

If you have a touch plate for your Shark, you can use Virtual Zero, which touches the plate at each corner and the center fo the material & sets a "virtual zero" that can vary from one spot to the next on your material.

[FixitMike]

About the Sharks. These do not have the capability of automatic setting of the X0 and Y0. One locates the material on the table and then manually locates the bit to the 0,0 location. The table has T slots parallel to the Y axis, which help. Myself, I have set wood stops parallel to the X and Y axes and set the material against them to locate. I use the laser edge finder to set my zeros to the edges of the material or to locate them at the center, depending upon which I have set. http://lasercenteredgefinder.com/

This picture shows my arrangement with the laser edge finder aimed at approximately the center of the material. Or you can use the end of a V bit for locating.
The Shark touch plate is good only for setting Z0.

[Joeshark]

I guess if you have a over size peace to start with, and your project is inside that over size peace, then you don't have to be to accurate with your positioning of the peace. Does that make any scence.

[wmgeorge]

As long as you have a way to trim your work piece to what you really wanted. You might try the suggestion that just Zero it all out on the Origin and be done with it. Practice on some scrap pieces until you get the hang of it all.

[joeporter]

Joe, most of the information you need to run your project is set up when you open your Vectric software. The first thing it asks for is material size in X and Y and thickness and where you want to start from (one of four corners or the center) and this must correspond to the X and Y direction of your machine. You then set your Z to zero by some method the machine understands. And, yes, If your material is over size, all will be Ok, as long as you figure on cutting to finished size with a cut out toolpath. Usually I go outside and actually measure my material and then put that into the software so all matches. I hope this is of some help...joe

[Joeshark]

Yes all the information is very helpful. We just ran our first project. Made a ovel sign of about 10 by 10. Everything went well, need to learn about spindle speed and feed rate. Some chatter with the 60 degree v-cutter. Do we need to slow down the feed rate? We ran at 100%. But all and all, not bad for first project. Baby steps!

[Steve Misher]

Joeshark: you say your cutting at 100%.
When you select the cutter you want to use, you also select the actual feed rate in that same box. What is your feed rate you are actually using?
If you are trying to cut at 200 ipm, you need to slow it way down to cut properly. There is simply too much flex in the gantry to cut that fast!

[Joeshark]

Steve, I am not sure what the feed rate on the program is. I'll have to check it out. Can I slow the feed rate down with the pendent? Is there a feed rate that you run on the average? Or should I try to add more passes and take less material off. Sorry about all the questions. Thanks

[Steve Misher]

Joeshark: When you go to your tool pats selection, and choose a cutter all that information is all there for you. There is a default setting for your cutter that is only a suggestion, but because every machine is different, you can start out by slowing the speed, feed rate, plunge rate all in that selection box and then just click ok. With a Shark, I suggest you start with a feed rate of about 100 ipm and a rpm of 14,000- 18,000 rpm.
I would also suggest you watch as many youtube videos you can stand. There are several really good ones on basic setup.
Vectric has some really good ones you should watch. Setting up your project is the most important element in your learning process.
Try just typing CNC for beginners on Youtube and you will find many videos. You will be able to weed out the good ones from the bad very quickly.