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The first in a multi-part series on comparing preventive maintenance to run to failure in the CNC plasma Industry

So, you just finished your one day of free OEM training on your new CNC plasma system and now you’re expected to know everything. You’ve learned in one day what some people spend their entire career trying to learn.

The problem is that most companies will continue running with this thought and never know that they’re costing themselves hundreds or thousands of dollars annually just because they’re not doing something correctly or just not doing it at all.

Most CNC plasma manufacturers only supply one or two days of training after the system is operational, mostly because trying to teach your operators and programmers everything they need to know for you to be the most profitable would take days or even weeks. Training includes more than just the ‘how’, it includes the ‘why’ and ‘when’ as well.

Do you know when to schedule the two most common part failures to be replaced, before they fail?

The OEM does.

Do you know what accessories you can add to your machine that can cut your consumable cost?

The OEM does.

Do you know how to properly nest your parts to get the absolute best plate utilization?

The OEM does!

An OEM partnership should be an essential part of your overall strategy.
While YouTube, Facebook, and many other social media outlets supply a great deal of knowledge, we find most of that information is geared to the hobbyist. No one talks about big things on big system like: input gas pressures; the effect of condensation in your airline; whether to run F5 or water secondary; intervals for filter, contactor, or relay replacement; and if your CAM software is configured to give you the highest rate of return on your investment? These are just a few of the many unknowns that can cost you money in the long term if you’re not monitoring them properly.

So how do you balance the OJT and the OEM partnership?
The best way is the easiest way: sign up for a preventive maintenance program that offers service by an OEM certified technician that fits your schedule. Typically, these programs allow you to schedule two or more annual visits, where the technician visits you onsite, mitigate any issues with training and assess the operational state of your equipment.

Preventive maintenance (PM) visits: what does it cost and what do I get?
Let’s assume you’re within a 300-mile radius of the OEM’s technician coverage area and that you have a Hypertherm high-definition or X-Definition high-end plasma system. The cost of a one day visit to complete a full system PM and supply 3 to 4 hours of training to operators would cost around $4,000. That price includes the technician’s travel time, onsite time, hotels, and OEM recommended maintenance parts for the cutting system. During this visit you can expect the following services:

On the Plasma
  • Test all gas inlet pressures
  • Examine and replace air filters on the plasma
  • Flush and replace coolant
  • Examine and lubricate O-rings on the torch
  • Examine hoses, cables, and leads
  • Check for gas leaks
  • Check coolant system for proper flow
  • Open plasma power supply and clean it
  • Replace contactors
  • Replace pilot arc relays
  • Check plasma grounding
  • Check for firmware updates
    On the machine  
  • Examine and replace bearings as needed
  • Examine and replace drive pinions as needed
  • Check system for square
  • Check system’s CNC for software updates
  • Clean linear rail and drive rack
  • Check lifters
  • Check motion accuracy
  • Check all homing/limit switches for proper operation
  For the operator  
  • Refresher + advanced training on CNC
  • Ensure proper consumable use
  • Update safety training
  • Discuss any annoyance issues operators are experiencing

Additional training during these visits is a staple of most OEM PM programs. Preventive maintenance is something you’re doing anyway, aren’t you?

What can it cost me if I don’t do preventive maintenance?
That’s a really big question with a very wide range of answers. In a future blog, we will break down a four-year study completed by a national plasma service provider that looked at the cost of run to failure versus preventive maintenance. The results will blow your mind! For now, let’s make a few assumptions and do some simple math.

We’ll assume you’re running a Hypertherm high-definition or X-Definition plasma on a large format cutting system. We’ll also assume that you’ve entered Year Three of owning your machine. Year Three is typically the first year of not having a warranty and, according to Murphy’s Law, it will be the first year something big breaks.

The machine goes down on Thursday and you contact the OEM for help. You spend an hour on the phone with tech support and the OEM decides a technician should be dispatched. The OEM says they can have a tech on site the following Wednesday. The tech arrives on Wednesday morning, does a full evaluation and determines that the main contactor on your system has burned out. He orders the part for next day deliver, then goes and sits in the hotel until the part arrives at 10 am Thursday. UPS arrived on time, the tech installs the parts and (assuming nothing else was damaged during the failure) you’re back up and running seven days after your initial phone call.

What did that one run to failure decision cost you? Let’s do the math!

Technician Travel, onsite time, per diem and hotels$3,220
Parts$1,750
UPS overnight w/early AM delivery$110
TOTAL$5,080

Now, let’s add five business days or 40 hours of lost production on your system. Let’s be generous and say that you didn’t have a full schedule, so you only had 30 hours of burn time scheduled that week. Our numbers show an average hourly cost of downtime to be about $200 per hour, so 30 hours gets you $6,000 in lost production.

Add the technician’s time, travel, parts and overnight shipping and your total just went over $11,000!

Did you know the part that stopped you is included in the standard PM kit?

That $4,000 you could have spent at the same time being able to schedule the 6 to 8 hours of downtime around your production schedule isn’t looking so bad now.

I ask customers all the time: Do you change the oil in your car’s engine? Do you ever replace the tires? Would you fly in a plane with no maintenance record?

If you follow preventive maintenance in your daily life, why would you gamble your productivity on a run to failure strategy? Systems will break but, if you’re smart, you can stay ahead of a lot of the damage and downtime and lower your overall cost of ownership by thousands of dollars..  

So, what’s your plan?



Author: Walt Lewis

Walt Lewis is a 30-year veteran of the service industry with 15 years of focus in CNC plasma and oxy-fuel cutting. He is the current operations manager at Victory CNC Plasma Systems in Owensboro, Kentucky. He can be reached at walt@victorycnc.com, Walt Lewis (@plasmawalt)