What does cycle time mean in fabrication?

Cycle time is how long a job actually ties up the machine. Cut time only counts the moments the beam is cutting. Cycle time adds everything the head does in between:

• piercing each contour before it can be cut, from a fraction of a second in thin sheet to several seconds in thick plate
• rapid travel between features and between parts
• slowing down for corners, small holes and fine detail

Some shops include loading and unloading the sheet in cycle time. Others track sheet change time separately. Either works, as long as the quote and the shop floor use the same definition.

How is cycle time used?

Cycle time multiplied by the machine's hourly rate gives the machine cost of a job, which is the core of most laser cutting prices. A worked example with round numbers, for 100 parts:

• 72.6 m (238 ft) of cut length at 3 m/min: about 24 minutes
• 500 pierces at 0.5 seconds each: about 4 minutes
• Travel and slowdowns: a couple more minutes, depending on the nest

That's roughly 30 minutes of cycle time. At a machine rate of $150 an hour, the cutting costs about $75, before material, setup and margin.

Cycle time also drives scheduling. It tells you how long the machine is booked and how many jobs fit in a shift.

Why does cycle time matter?

An error in cycle time lands directly in the price. Underestimate it and the job runs at a loss. Overestimate it and the quote loses to a shop with a sharper number.

The usual misses are parts with lots of small features. Each hole means another pierce, more travel and a slower fine feed rate, so a part covered in small holes takes much longer than its cut length suggests. Checking holes against the minimum hole size at quote time catches the worst of these.

Quoted vs actual cycle time

Every job has three cycle times: the one in the quote, the CAM software's estimate when the job is programmed, and what the machine actually takes. Comparing them is the simplest way to keep quotes accurate.

If actual times keep running over the quote, the usual causes are feed rates set too high, pierce times too short, or small-feature work priced at full speed. If they come in well under, the feed rates may be out of date, often after a machine upgrade. Checking a few jobs a month against the machine's own timer is enough to spot the trend.

Cycle time and quoting

Cycle time is where a drawing turns into a machine cost. Tempus Tools works out the full cycle time from each part's geometry, including cutting, piercing and travel between features, using the feed rates and pierce times you set for each thickness, then applies your hourly rate.

Further reading: Laser cutting hourly rate: what should be included?