• Can I use my PlazPak for other types of CNC cutting besides Plasma?
    • YES!  You can switch to router cutting by simply starting MACH3 with a router Profile.  We include a router profile and load it during the automated setup we provide.  All Plazpaks come with two auxiliary power relays (one 20A and one 10A that can be used to turn your spindle/router on/off from code
  • Can I add a plate marker or scriber to my table for marking metal?
    • YES!  You can use the aux relays to trigger a pheumatic scriber and leave it perminately mounted to the Z.  With a special POST in SheetCAM you can run a job with mixed plasma and scriber operations just by selecting a scriber tool in SHEETCAM when you build the file.
  • How About Rotary Plasma Cutting and Rotary Indexing?
    • CandCNC is the only vendor that includes a FREE rotary cutting Wizard for cutting round and rectangular/square stock.  You can order a package with 5 axis of drives and motors so switching to your rotary setup is as simple as loading a new profile in MACH
  • What is the difference between the Plazpak Systems and the less expensive BladeRunner Dragon-Cut system?
    • Short Answer: SIZE.  The BladeRunner Dragon-Cut shares all of the interface logic and electronics with the Plazpak (DTHCII included) but the power section and motor drivers are twice the size and rating. The BladeRunner series peaks out with the 620 oz-in 23 frame motors whereas the Plazpaks START with 740's 34 frame motors and go all the way to large servo motors and 1.5KW power supplies.
  • How do I know what size system I need?
    • Ask yourself two questions: a.) how heavy is my gantry?  b.) am I going to do just non-contact (plasma/oxy-fuel/marking) or also contact type cutting (routing)?  If your gantry weight (total) is below 100 lbs and the table use is non-contact cutting (or light rotary cutting like engraving and light router cuts) then you need to look at the BladeRunner Dragon-Cut.  If your ganty is closer to 150lbs or you intend to mount a full sized router and make deep cuts in wood or you plan on routing aluminum then the BladeRunner Dragon-Cut Servo series is the place to start.  The heavier the gantry, the bigger you need to make the drive motors.  With plasma cutting, it is as much about acceleration as it is speed.  If you want sharp corners you need good acceleration. The heavier the gantry the more torque you need to get good acceleration  If you want the optimum performance for both contact and non-contact cutting the larger servo Plazpaks are the place to shop.  Still confused?  Call us at 903-364-2740
  • What are the PROS AND CONS of Stepper VS Servo systems. 

 STEPPER

FACTS

PRO
Less complex easier to setup and troubleshoot. Fewer parts
Less expensive
Fixed resolution of 1.8 deg + final gearing to load
No position feedback.  Can lose steps if operated outside their torque-rpm curve.
Can have mechanical resonance problems with some motor drivers (not Geckos)
Stalls on overload (non destructive)
Better low end torque/size ratio
Motors lose torque with RPM
Limited RPM (approx 600 - 800)
Requires small or no final drive gearing
No possibility of RUNAWAY
Very Low RPM not as smooth
Power requirements are moderate

 

SERVO

FACTS

PRO
More Complex.  Harder to setup and tune.  More moving parts.  Requires encoders .
More expensive
Resolution is defined by the encoder count + final gearing to load
Position feedback.  Will correct for minor position errors.  Fault on large errors.
No mechanical resonance problems
Will not stall  on overload - burns motor out  (unless externally protected ).
Better high end torque/size ratio
Motors maintain torque with increasing RPM
Typical RPM of 2500 to 4000 RPM
Requires high ratio gearing (can be 10:1 or higher)
Prone to possible RUNAWAY
Smooth operation at all speeds
Power requirements can be high

SIX MYTHS ABOUT SERVO's VS STEPPERS:
  • Servos are  "better" than Steppers   FALSE  Depends on the application and the design of the machine
  • Steppers are "better:' than Servos.  FALSE  There are applications where servos are needed.
  • Servos are more accurate than Steppers FALSE  Accuracy is defined by lots of factors beside raw resolution.
  • Steppers lose position (lost steps) TRUE(Partially) Steppers operated within their torque-RPM curve DO NOT
  • Servos run smoother  TRUE (partially) Modern stepper drivers with microstepping and anti-resonance run very smooth at medium to higher RPM.
  • Steppers are "old" technology.  FALSE  Servos are DC motors invented BEFORE steppers  Technology has improved on both types of motors.  Modern steppers have higher torque to size/weight ratios and are more efficient than motors even a few years older.  New stepper drive technology has made them more less prone to resonance problems and rough motion

Bottom line:  It's better to match the motor type to the application and load requirements.  Each motor and control type has both Pro's and Con's.  There is no black & white answer.   If you need high torque AND high speed from the same machine then servos are the solution. If you have a light load or a narrow speed range steppers can be a cost effective way to get quality cuts. 

  • What software do I need to do plasma cutting?
    • You need three pieces.  It's the CNC "Triad".  It consists of CAD(Drawing); CAM(toolpathing) and Control.  The CONTROL part consists of taking motion code (G-Code) and moving the motors and providing feedback to t he operator via a screen or console.  CAM is the process of taking a drawing and defining HOW you want it to be cut:  What tools to use, what type of cuts, kerf offsets, lead-ins/outs, pierce moves, etc.  CAD is the drawing tool you use to get the design from your head to "paper".
    • There are numerous variations of the three types of software and a lot of packages that combine two or all three of the operations in one.  We think the flexibility to select which three you want is the best approach.
      • CAD (Drawing) for mechanical shapes like brackets and plates: AutoCad or a clone.  For decorative drawing including clipart import and good Font handling CORELDRAW or INKSCAPE
      • CAM for all 2D and 2.5D cutting (especially plasma) we recommend SheetCAM.
      • CONTROL MACH3!

We sell bundles of plasma software for the Control and CAM. that are made to work together and with our plasma software.  You can find older versions of CorelDraw on the web cheap.  Any version back to Ver 12 will work fine.  Inkscape is FREE and included in our Software Bundle CD's. 

  • What is "Smart Power" I keep seeing in your descriptions.  Why do I need it?
    • Smart Power is a CandCNC trademark for our processor based power systems.  We have found over the years that as long as you operate power electronics in their safe zone they will last a very long time.  Subject them to out-of-spec conditions and they tend to fail. Simple fusing is just not enough. The ESPII Smart Power System used in ALL of our Plazpak and BladeRunner products controls all the aspects of providing safe power to the drivers and motors.  The front panel "brain" measures the motor voltage, each motors load, the temperature inside the enclosure and the temperature at the motor drives.  It will instantly shut down if it detects any abnormal condition and do so fast enough to save the electronics.  On the larger systems it controls the power on sequence (called Soft Start) to reduce damaging in-rush current to safe levels.  Overvolage can come from AC line surges or back EMF from rapidly de-accelrating motors.  Any time the ESPII shuts down (normally or from a fault) it does a Dynamic discharge (load dump) of the DC bus. Overload can come from a wiring short or from a servo being stalled.  Conditions that can take out expensive electronics..Over temp comes from a fan being defective or the filter being clogged.. If the Smart Power system shuts down from a fault it will display the cause on the front panel.  As an option you can connect the ESPII unit via serial cable to the Control/Interface and display the operational parameters and even fault messages on the screen.
    • Do you need smart power?  Not if you never have a condition that could cause a failure or you don't mind having down time while you are waiting for replacements.
  • What is a "Floating Head" (aka Floating Torch Holder).  Why do I need one?  Do you sell them?
    • The floating head is a device to allow the end (tip) or your torch to be a surface probe to sense the top of the material.  In most cutting Z zero is the top of the material.  You moves are all relative to Z zero.  In conventional cutting (milling routing) the top of material remains the same and is set at the beginning of the job and does not change.  In plasma cutting because of warping and the fact the cutting head has to hover above the material the Z zero can change.  The procedure is called IHS (Initial Height Sensing) and typically consists of a touch off BEFORE each pierce point to re-establish where the top of material is so you get an accurate pierce height and accurate beginning of cut height prior to the THC taking over and holding a constant cut gap as it cuts.
    • You need one because piercing too low or two high results in ruined consumables or a bad pierce.  The beginning cut height needs to be correct before the THC takes over or it can result in a head crash (and ruined consumables)  Consider that most pierceing is done from .125 to .187 aboive the material and beginning cut height is from .063 to .120 above the material and you don't have a lot of margin of error.
    • We don't sell the Floating Torch Holders.  We do not sell table mechanical parts or torch holders.  You can find Floating Torch Holders in our Links section of the website.
  • What other things should I look for in a plasma CNC vendor?
    • Support.  Can I get support direct from the vendor?  Are there ways to get answers after hours and weekends?  Is there more than one support method?  Is the support free and unlimited?  Does the support person know the product well enough to not have to "research" a problem before you get an answer?  Does the vendor support ALL of the products they sell (hardware and software).  Will they support their equipment if I am not the primary (first) owner?  Is there more than one source for common items like motors, motor drivers etc?
    • Installation.  Does the vendor supply detailed install and setup instructions and automatic installs for their specific drivers and custom interface?
    • Manuals.  There are a lot of good products with bad manuals but few if any bad product with good manuals.  Never buy a product uless you can get a copy of the manuals first. Good vendors have their manuals available on-line for download BEFORE you spend your money. The qualtiy of the manual will predict the possible hassle level you will face making it work.
    • Reputation.  Find other users of the product on the web forums and get their feedback as to the company.  Did they get everything they paid for?  Was the support there so they could get it setup and running?  Is the quality of the product consummerate with the price?  Does the vendor make promises they don't keep.  Do they treat you different as a paying customer that a potential buyer?
    • Experience.  Does the vendor REALLY understand the actual type cutting I am going to be doing?  Do they use the products they sell.  Have they actually spent time cutting with plasma or using the software they are selling?
    • Features.  Does the equipment have features that will improve the cutting process. Is the vendor working to add features and improve their product?  Is it versatile enough to use for other types of cutting.