With all that in mind, we did a lot of reading and chose the Hypertherm Powermax 600. On steel plate it is capable of making:

1. A clean 5/8" cut at ten inches per minute.
2. A clean 3/8" cut at 24 inches per per minute.
3. A maximum cutting ability to make a rough cut 7/8" thick steel.

The Hypertherm Powermax 380 would have been suitable for us except that we were planning on doing some work on axle housings so the added power of the Powermax 600 was worth the extra cost to us.

Why did we choose Hypertherm? The easy answer would be because they're the biggest, most reputable name in industrial plasma cutters. But that's not how we make our buying decisions. We chose Hypertherm because they met all our requirements for what to look for when buying a plasma cutter.

First, they had a product that matched our power requirements.

Secondly, parts and service are easy to come by because there are so many Air Liquide stores servicing the product.

And finally, their extensive experience with designing industrial-grade plasma cutters has resulted in a lot of cutting-edge (pardon the pun) technology that they have rolled into their consumer- and small shop-grade systems.

Hypertherm's Technology

The Dragging Tip
Remember how I talked about how easy it was to make cuts by tracing templates? It was easy because of Hypertherm's "drag" cutting tip. It allows the operator to place it directly against the cutting surface so he doesn't have to worry about maintaining a stand-off distance between the torch and work material. For the plasma cutters that don't have this feature, you will need to practice using the cutter for a while to get the hang of maintaining that stand-off while following the template.
HyDefinition Plasma Cutting Technology
Hypertherm makes nothing but plasma cutters so all their R&D is focused on plasma cutters. This had led to the development of their HyDefinition plasma cutting technology. One of the benefits of this technology is increased electrode life, thanks to re-designed shields that prevent double-arcing and improve the electrode-to-nozzle alignment.

LongLife Technology
Another improvement comes from their patented LongLife technology. It uses computer control to manage electrical current and gas flow during cutting in order to minimize the shock load that occurs at the start of each cut. It also re-solidifies the electrode material at the end of each cut by automatically flowing cooling air through the torch after each cut is finished. The end result are torches that can make 600-1200 starts without any undue effect on the quality of the cut. Compare this to the other plasma cutters' torches, some of which are only rated at 400 starts.

Here are some of the features listed at Hypertherm's own website:

Power Supply: The Heart of the Machine
Advanced technology in the power supply enables the Powermax600 to cut with greater quality and efficiency.

• 40-amp, 5.6 kilowatt output cuts through steel up to 5/8 inch (16 mm) thick.
• Advanced digitally-controlled inverter design improves cut quality by delivering constant output regardless of variations in line voltages or torch-to-work distances.
• High duty cycle permits industrial cutting.
• Output current adjustable to 40 amps enables high-quality cutting over a wide range of thicknesses.
• An active electronic pilot-arc controller helps maintain uninterrupted operation when cutting expanded metal or grating.
• An architecture that tolerates power fluctuation and surges permits unrestricted operation on motor generators providing 8 kVA auxiliary power (see instructions).

The Torch: Intelligent Design for Easier Cutting and Lower Operating Cost

• Longer Consumable Life.
  • HyLife™ electrodes last longer than ordinary designs (113% longer, in some tests) by using the same patented hafnium-sizing technologies developed for advanced Hypertherm mechanized systems.
  • Dual-threshold pilot™ circuit significantly reduces nozzle wear by boosting pilot current precisely when needed for a strong arc transfer - and not before.
  • Patented nozzle shield technology protects the nozzle from molten metal spray and the double-arcing that destroys consumables.
  • Post-flow cooling reduces torch stress.
• Higher Speed. A patent-pending coaxial-assist™ jet design boosts cutting speed as much as 20% over conventional designs by stabilizing and shaping the cutting arc.
• Easier Operation. Torch shielding lets you drag the torch on the workpiece at full output without damaging consumables. Competitive stand-off devices can't match it for convenience and control.
• No Interference. Patented "blow-back" torch design provides a pilot arc without the excessive high-frequency interference that can damage sensitive electronics.
• Safe Starting. Hypertherm's patented PAC123T™ safety trigger torch protects against accidental starts.
• Rugged Operation. No breakable ceramics threaten the life of the torch. The durable, high-impact clamshell handle provides years of reliable service.
• Ready Access to Consumables. Built-in parts compartment keeps consumables close at hand.
• Easy Torch Change. A quick-disconnect feature helps keep service downtime to a minimum. (Not available on CE models.)
• Versatile Applications. Hypertherm offers consumables for gouging, extended nozzle cutting, pipe saddle cutting, and other applications.

Engineered for Superior Reliability
The Powermax600 anticipates heavy use under the harshest conditions.

• Mechanical and electrical design are validated through aggressive, accelerated life, stress, transportation, and field testing.
• Voltage input protection guards against damage from mis-wiring in the field.
• Wide voltage operating range of ±15% minimizes performance deterioration, shut-down, or potential damage due to fluctuating power line conditions.
• IP23 compliance means resistance to rain damage. The internally mounted air regulator is protected from impact damage.
• The Powermax600 is backed by Hypertherm's full two-year power supply warranty and one-year torch warranty. Unlike some competitive warranties, the Hypertherm warranty backs the entire system and torch.
• CE certifications comply with the highest safety standards.

Specifications

Input Voltages. .	208/240 V, 1 PH, 50/60 Hz, CSA 480 V, 3 PH, 50/60 Hz, CSA 400 V, 3 PH, 50/60 Hz, CE Certified 230 V, 3 PH, 50/60 Hz, CE Certified
Input Current @ 5.6 kW	208/240 V, 1 PH: 46/40 Amps    230/400/480 V, 3 PH: 17/9.7/12 Amps
Output Voltage	140 VDC
Output Current	Adjustable, 20-40 Amps
Duty Cycle	50% @ 5.6 kW, 40°C (104°F)
Maximum OCV	300 VDC
Dimensions	20" (510 mm) D; 9.5" (240 mm) W; 17" (430 mm) H
Weight with Torch	47 lbs (21 kg)
Gas Supply	Clean, dry, oil-free air or nitrogen
Flow Rate	360 scfh; 6 cfm (170 l/min)
Flow Pressure	72 psi (5.0 bar)

Operating Data

Material	Thickness		Current	Approximate Travel Speed*
	(inches)	(mm)	(amps)	(ipm)	(mm/min)
Mild Steel	26 GA. 16 GA. 1/8 1/4 3/8 5/8	.5 1.5 3 6 10 16	20 40 40 40 40 40	270 400 190 65 25 9	6,850 10,150 4,950 1,680 640 250
Aluminum	0.020 16 GA. 1/8 1/4 3/8 5/8	1 1.5 3 6 10 16	20 40 40 40 40 40	160 430 170 60 20 8	4,150 10,900 4,450 1,620 510 200
Stainless Steel	26 GA. 16 GA. 1/8 1/4 3/8 5/8	0.5 1.5 3 6 10 16	20 40 40 40 40 40	230 400 160 50 20 7	5,970 10,150 4,060 1,320 510 180

A:	Power On Indicator
B:	Pressure Gauge
C:	Low Air Pressure Warning
D:	Over-Temperature Warning
E:	Ready Indicator - Operating Conditions Met
F:	Cutting Current Output Control ­ 20 to 40 amps
G:	Low Line Voltage Warning
H:	Gas Test/Set Position
I:	Torch Cap Sensor Warning
J:	Pilot Arc Controller Switch (not on CE models)

Using the Hypertherm Powermax 600

If you've never used a plasma cutter before, I can tell you that it is an eye-opening experience. By that, I mean the fun kind that leaves a stupid grin on your face, not the kind that leaves you searching for a change of underwear. The first time I saw a plasma cutter in use was at Air Liquide's introductory welding course. A Hypertherm representative was on hand to introduce us to plasma cutting technology. After the presentation, we were shown a brief demonstration and then were allowed to try our hand at plasma cutting. Everyone that tried it came away with a goofy grin on their face. And that only involved making simple freehand cuts on small pieces of scrap aluminum and steel.

When I brought home my Powermax 600, I quickly read the instructions and set it up. Setting it up was quite simple. Plug it into the power outlet and then attach the compressor to it. To ensure a good quality cut and the longevity of the torch components, Hypertherm recommends installing a small air dryer (not included). I adjusted the Hypertherm's built-in pressure regulator according to the instructions and that's all that was required for the setup. After that, I began a maniacal quest to cut everything in half. This was more fun than welding! Wanton destruction ensued for the next hour as my scrap metal pile doubled in population, if not in weight. Aluminum sheet, expanded steel, tube steel, old skid plates, drum brakes, a 55 gallon barrel. Everything got cut. After that orgy of cutting, I started thinking about constructive uses for the plasma cutter (must...use...power for good...not evil).

The first project that came up was to make some spring perches for my sister-in-law's Cherokee which was getting an 8.8 axle swap. We found some 2.5" square tube, about 1/4" wall and cut it into two equal lengths. After that, we cut an appropriate template out of plywood and then used that to guide the plasma cutter's torch. There were two problems with this:

1. The template was a bit rough on the edges so it had a tendency to catch the torque tip.
2. I was using a 40 amp power supply which really wasn't up to the task of satisfying the Powermax 600.

We were able to cut the perches but it was a learning experience. The templates had to have smooth edges for best effect, and I really needed to upgrade the power circuit in the shop.

Another task required by the 8.8 project was that of cutting off the old spring perches and shock mounts. The Powermax 600 came with the dragging tip which was ideal for cutting out shapes but not so great for cutting out welds or cutting at any angle other than perpendicular. We were successful but there had to be a better way. And of course, there was. The solution was to use the right tip for the job! A few days later I dropped by Air Liquide and bought a gouging tip. With the gouging tip, it was dead easy to cut away old welds without doing any serious damage to the surrounding metal. Cutting control arms mounts off of one axle for transplanting onto another was now a viable option that didn't involve hours of painstaking grinding. The best way I can describe using the gouging tip is to liken it to using a MIG welding torch that has an eraser. It handles like a MIG torch but it removes welds instead of laying them down. By varying the power, the angle and the movement, you can achieve very fine control over how much metal you remove. So, if you're going to buy a plasma cutter, do yourself a favour and buy the gouging tip. It, and the dragging tip, are invaluable for 4x4 fabrication.

The other change I made was to install at 250V 50A outlet in my shop. Plasma cutters require a good power supply so don't try to get by with a substandard circuit. With the old circuit, the breaker would trip whenever I cut a continuous cut that took longer than about 20-30 seconds, even on thin steel. With the proper power circuit, that was no longer a problem and the cuts seemed cleaner.

The second 4x4-related project involved bobbing a Toyota pickup. First, we had to cut some sheet metal off the box so we could access some rusted bolts. That was a simple job even though the sheet metal was rusted and still had paint on it. As long as there was some bare metal where we started the cut, there wasn't a problem. After that, we used the Powermax to remove the old cross member and bob the frame rails. Cutting the frame rails was like cutting through butter with a warm knife. Yeah, I know it's a hackneyed phrase but it perfectly describes how fast and easy it was.

Speaking of "fast and easy," how many of you would associate that phrase with cutting and turning an axle yoke? No one? I thought as much. For those of you who don't know, adjusting the caster angle of an axle independent on the pinion angle requires grinding out the welds that hold the yoke to the axle tube and then hammering the yokes into the new position. It's a crappy job because the welds have a lot of penetration that goes deep into the yokes. Getting in there with an angle grinder requires using a small wheel and spending a long time getting intimate with the grinder. This fun job is also a requirement if you're trying to changes yokes or shorten (or lengthen) an axle's width without cutting/sleeving the tube. With a plasma cutter and a gouging tip, you need no longer cringe when this job rears its ugly head.

Pleasing the Spouse

This is probably the first metal fabrication tool that my wife likes. Why? Well, one day when she was surfing the Internet, she remarked on how much she liked a sheet metal heron that she had come across while searching for stained glass patterns. When I saw the USD$50 price tag, I scoffed that I could easily make the same thing for a fraction of the price with my plasma cutter. And so she called my bluff and before I knew it, I was committed (voluntarily or not) to make four of them for Christmas presents. As it turns out, it really was as easy and I thought it would be. We found a photograph on the Internet which I copied and turned into a silhouette using Paintshop Pro. Then I printed it onto an 8x10 sheet which my wife then took to Kinko's and had enlarged to about 3 feet in height. She then cut it out and we used it to trace the shape onto a sheet of particle board. Next, we clamped the board onto a large sheet of 16 gauge steel and I traced it with the plasma cutter. I made six heron silhouettes in about 40 minutes. Not bad for a first attempt! After that, I welded a steel rod to each heron so it could be staked into the ground. Very easy.

A Note About Safety

A plasma cutter requires the same safety precautions as using an arc welder. Always use the proper goggles (we used a number 5 shade) to protect your eyes from the arc rays. It is also advisable to wear a full-face shield to prevent getting an arc sunburn on your face. In some of the photos, you'll notice that I am wearing a respirator. I decided to use one in order to reduce the amount of vaporized metal particulates that got into my lungs.
By the way, a plasma cutter has about three times the open circuit voltage of your average stick welder. Although it seems like a very simple piece of equipment, you must be very respectful of how much damage that power can do. Be sure to keep the plasma cutter's cables out of harm's way (it's very easy to accidentally drop sharp, hot steel onto the cables!).

How to Maximize Your Enjoyment

Ok, so let's assume your "significant other" has for whatever reason (perhaps she has an insatiable hunger for metal garden art) agreed to let you spend your hard earned money on a plasma cutter. The plasma cutter and it's included tips are just the start of the package. You should also buy a small air dryer and make sure your power supply is up to the task of powering your plasma cutter.

But to get the most out of your plasma cutter, I strongly recommend these optional items:

1. Gouging Tip. You will use this just as much, if not more than, the drag cutting tip. I wish I bought mine sooner.
2. Extra Air Outlet. If you use your air compressor to power other tools while fabricating, add some kind of manifold so you can keep the plasma cutter and your other air tools hooked up to the compressor at the same time.
3. High Quality Respirator. These things are inexpensive so buy one and wear it! There's no point in ingesting tiny particles of vaporized metal.

The full line of Hypertherm products are available across Canada at all Air Liquide locations. Good luck and good cutting!

- Wil Girindra

Although small, the Powermax 600 packs a powerful punch.

We added this small water separator to dry out the incoming air. This will go a long ways toward extending the life of the consumables.

Hide anything of value when you bring home your plasma cutter. This poor rotor fell victims to our sick desire to play with the Powermax 600. This was a quick and easy cut.

The first real use of the plasma cutter came when I cut out some spring perches for a Ford 8.8 axle swap. Notice that I'm using a wood template to guide the torch.

Cutting the old shock mounts off the 8.8 axle.

Using a 2x4 as a guide, we're bobbing the end of this Toyota frame.

The plasma torch is easy to use in any position, but beware where the sparks and cut metal will fall!

Here's a photo of the crossmember we wanted to remove from the Toyota frame. Notice the welds on the layers of thin steel.

Using a gouging tip, it was remarkly easy to cut out those welds with very little collateral damage to the surrounding metal.

The results are just as good, if not better, than if I had used a grinder, plus it was much faster. Also, the torch can reach into nooks and crannies that would be impossible with an angle grinder.

Here's a hard to reach place.

But not too hard for the plasma torch.

Cutting through paint and rust was also possible, as long as you started the cut on bare metal.

Another use of a guide to ensure a straight cut.

The Hypertherm Powermax 600 is a dual purpose tool: it makes you AND your spouse happy. Once a template is made, you can cut out dozens of these heron silhouettes in one hour. The sunshine artwork was drawn free hand with a chalk marker and cut free hand.

Hypertherm www.hypertherm.com Email: info@hypertherm.com Phone: 603-643-3441   Hypertherm, Inc. Hanover, NH 03755 USA

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