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Instruction Manual
Thick metal cutting techniques
For HPR400XD™ and HPR800XD plasma cutting systems
White paper
Introduction
Using plasma to successfully cut thick metal requires more
skill and technique than using plasma on thinner metal. The
thick metal cutting techniques described in this document
may be needed from the beginning of the cut with an edge
start all the way to finishing the cut with a completely
severed part.
Note: Unless otherwise specified, for the purposes of this document,
thick metal consists of stainless steel and aluminum from 5 inches to
6.25 inches (125 mm to 160 mm) thick. The techniques detailed in this
document were developed using 304L stainless steel. Materials used for the
development of this white paper were based on U.S. customary units
(inches). Metric conversions are provided for reference.
This document describes thick metal cutting techniques
developed for the HPR800XD that can help manage the
large plasma lag angles associated with thick metal cutting.
It also describes the timing and sequencing needed to be
successful in piercing up to 4 inches (100 mm) stainless
steel and 3 inches (75 mm) aluminum. This document is
broken into four sections:
• Thick metal cutting techniques overview on page 2 is an
overview of different lag angle management techniques for
thick metal cutting that covers a plasma cut from the
beginning to completion.
• Dogleg lead-out details for thick stainless steel on page 4
covers the details of a special lead-out technique (known as
the dogleg or acute angle lead-out) that can allow you to
completely sever a stainless steel part up to 6.25 inches
(160 mm) thick.
• Stationary piercing (up to 3-inch stainless steel and
aluminum) on page 8 describes the timing and sequence to
be followed to perform stationary piercing on 3 inch
(75 mm) stainless steel and aluminum.
• Moving pierce technique (up to 4-inch stainless steel) on
page 10 describes a moving pierce technique for thick
stainless steel that can be used with both the HPR800XD
and the HPR400XD. This technique, combined with
PowerPierce
technology, extends the pierce capacity for
®
the HPR800XD to 4 inches (100 mm) and for the
HPR400XD to 3 inches (75 mm).
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Table of Contents
Related Manuals for Hypertherm HPR400XD
Summary of Contents for Hypertherm HPR400XD
- Page 1 Thick metal cutting techniques For HPR400XD™ and HPR800XD plasma cutting systems White paper Introduction Using plasma to successfully cut thick metal requires more • Thick metal cutting techniques overview on page 2 is an skill and technique than using plasma on thinner metal. The...
- Page 2 Thick metal cutting techniques overview Edge start Initial cut speed (lead-in speed) A reduced cut speed should be used for at least the first Positioning 1 inch (25 mm) of the cut before traveling at the full cut speed. The recommended initial cut speed should be 75% Proper positioning of the torch is important to allow the of the full cut speed.
- Page 3 Completing the cut External contour part cut (dogleg or acute angle lead-out) The dogleg (or acute angle) lead-out technique can be used One of the following techniques may be necessary on metal to redirect the tail of the arc and the molten metal flow into 5 inches (125 mm) thick or greater to fully complete the cut.
- Page 4 Dogleg lead-out details for thick stainless steel Proper lead-out for thick material is critical to completely This tab is due to the extreme lagging tail of the arc, the lack sever a part; otherwise, a small tab may keep the part of molten material flowing through the kerf, and the attached to the skeleton at the point where the lead-out insufficient voltage to maintain the arc attachment at this...
- Page 5 Overshoot In order for the leading kerf edge to enter the lead-in edge (with kerf compensation active), the programmed path must overshoot by some distance (see Figure 6). Figure 6 – Overshoot definition Programmed path Kerf width (K) Overshoot distance Leading kerf edge α...
- Page 6 First segment and geometry limitation Assuming 60 degrees, the minimum length of the first segment would have to be: A geometric limitation was found during the development of the dogleg method that resulted in a “Kerf Too Large” CNC • 0.459 inches (11.66 mm) for 5 inches (125 mm) stainless error message.
- Page 7 Table 2 – Dogleg parameters for 5 inch (125 mm), 6 inch (150 mm), and 6.25 inch (160 mm) stainless steel Calculated first Second segment Third segment segment Thickness Lead-in length Kerf Angle Overshoot length length at 400% length at 115% minimum length cut speed cut speed...
- Page 8 Stationary piercing (up to 3-inch stainless steel and aluminum) Piercing thicknesses over 2 inches (50 mm) has been Move to transfer height challenging in the past. As a result of the PowerPierce Position the torch to the transfer height as listed in the cut technology incorporated into the HPR800XD, piercing up chart (by process and metal thickness).
- Page 9 Figure 8 – Stationary pierce timing diagram Torch height Time Pierce height Arc penetrates plate Move to pierce height Transfer height Motion begins Lead-in Cut height Torch drops to cut height prior to beginning contour cut Move to cut height Initial height sense Move to transfer height Arc transfer, shield flow switches from preflow to cutflow...
- Page 10 HPR800XD to 4 inches (100 mm) sensitive equipment. and for the HPR400XD to 3 inches (75 mm). Note: The moving pierce parameters in this document were developed The torch lifter must have the capability to use transfer using linear motion only.
- Page 11 Figure 9 – Moving pierce torch height timing diagram Torch height 14 14 Time Pierce height AVC begins as MP AVC delay expires prior to starting cut Pierce end height Move to transfer height Transfer height Pierce delay Cut height Moving delay Initial height sense Move to pierce height...
- Page 12 Table motion sequence Refer to Figure 10 for an illustration of the following sequence. After transfer, the table motion begins for the first segment at a fast gouge speed (the first “F” code) for the required segment length necessary to establish the evacuation channel (or trough).
- Page 13 Embedded part program parameters If you are using the EDGE Pro controller, use the following list of parameters to control the moving pierce (MP) sequence. Table 3 – Moving pierce (MP) embedded part program parameters Parameter name Embedded program code Description MP feed #1 - fast gouge Speed = 45 ipm (1143 mm/m)
- Page 14 Thick stainless steel moving pierce parameters The following tables contain the moving pierce parameters (both English and metric) that have been developed for piercing up to 4 inches (100 mm) of stainless steel. Table 4 – Thick stainless steel moving pierce (MP) parameters – English 800 A H35/N2 400 A...
- Page 15 Sample EDGE Pro code for 400 A – 3-inch (75-mm) stainless steel The following sample code from a Hypertherm EDGE Pro CNC assumes the use of U.S. customary units (inches) and is intended to provide an example of the codes that may be used to perform a moving pierce on a 3-inch (75-mm) stainless steel plate at 400 A.
- Page 16 HPRXD, PowerPierce, EDGE Pro, Phoenix, Sensor THC, ArcGlide THC, ProNest, and Hypertherm are trademarks of Hypertherm Inc. and may be registered in the United States and/or other countries. All other trademarks are the property of their respective holders. One of Hypertherm’s long-standing core values is a focus on minimizing our impact on the environment.
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