Continued Questions

Where is the procedure for re-doing the truck on the Y axis on the gantry? I can move this axis a little while everything is turned on. The mag mount does not move. So this is my next step I believe to alleviate some wavy corners. Also, if this does not fix my corners, should I try lowering my Accel and/or Velocity numbers?

Will 1 or 2 edges always have a slight bevel? ie never get 4 perfectly square edges on a square piece?

Best way to figure out kerf width is just straight lines, at varying cut speeds, until I get the smallest cut size? Using feeler guages? Top or bottom of cut, or should it be relatively the same on both sides?

Also, should I be checking Kerf Width on all material I cut? As in, 1/8, 3/16, 1/4 may actually all be different kerf widths for my setup?

Thanks for the continued support.

Before you do anything lets do some checking

1. Best cut will be on the right side of the toolpath. This means outsides must be cut clockwise and insides counterclockwise. You will always get some degree of taper with a plasma torch but the cut direction must be ideal for the best quality. To change direction you can do this in sheetcam by clicking "reverse direction" when your doing an operation (either clicking the magic wand or clicking operation/plasma cut). The cut path directional arrows in sheetcam dictate the direction of the cut path...direction can easily be changed in sheetcam.

2. Any play in an axis is a direct result of a gear into meshed fully into the rack.

3. A rock in the Z axis can happen at high velocities and speed changes. This machine is not a laser. Cutting thin material must be done at lower amperages and lower speeds. There is a system that CandCNC offers that uses the Hypertherm serial port to control air psi and amperage in mach for better corners but the interface is pretty clunky yet and needs refinement. You can drop your accel and deccel to 35 and that should help in the corners. The lower amperage will help with dross as well. Fine tip consumables are what you want for thinner materials for a Hypertherm 65/85/105 and for a Hypertherm 45 the powermax 30 (30 amp consumables) are what you want to go with for your best cut quality on thinner materials. Hypertherms book will list 250-450ipm cut speed for different materials. To get a crisp geometry (corners and sharp points) at 250+ ipm you need an accel and deccel rate of at least 60 without changing your amperage or air pressure on your machine. There are less than 1% of CNC plasma machines on the market that will achieve this. Most CNC plasma machines sold have less than 15 accel deccel rates. That is why Hypertherm put out a lower speed cut chart.

4. Bevel has everything to do with thicker material and the cut path. When your cutting thicker material it is best to loop sharp corners to setup the air flow through the material. This is done in sheetcam when your processing a drawing. If your bevel is pretty bad a quick checklist should be used

a. Cut direction
b. Amperage
c. Consumable condition
d. Tip volt (distance of cut height...NOT to be confused with initial cut height set in sheetcam)

5. Kerf width is very consistant between materials. We find the book is off a few thousanths and almost all materials cut between a 45 and a 105 are cut at a .080 kerf width. Kerf width can be changed to .001 to obtain a tapered hole like a 3/8 hole in 3/8 material where the top of the hole will be 7/16 and the bottom will allow a 3/8 bolt to go through. There are alot of ways to use these settings for different jobs.

6. Lastly the Y axis truck. This truck is setup behind the Z axis. To adjust it (typically doesnt ever need adjustment twice) you need to remove the Y axis belt reduction assembly by taking off the 2 fine threaded 3/8-16 stainless steel nuts from the stainless steel studs using a 9/16 socket and remove the Y axis asssembly. The Z axis has 4 bolts behind it (socket head capscrews) that use a 1/4 ball end hex wrench to loosen. Once they are out the Z axis will come off. Be carefull as not to stretch the wiring too much. Then you can slide the Y axis truck off the end of the gantry after taking the little bolt stop off. The Y axis truck is adjusted by first loosening the setscrews on the cam journal. Depending on the truck it may have up to two cams. The can can be turned after loosening the main bolt shaft on the other side. The truck should take a decent amount of force to put on we call this preload. The Z axis will lessen the preload by its weight so the truck must start with preload. Once your preload is tight the two setscrews must be tightened and the assembly put back together.

There is a path for all this stuff and is usually why we like to build and assemble the entire table instead of a gantry kit.