To begin, let's examine production capacity as a factor in equipment selection and in your daily life as an embroiderer. Production capacity is important because of the direct impact it has on how much embroidery you can produce, and therefore, on how much money you can make - or in how many hours per day you will need to work.
The formula for calculating production capacity begins with how many stitches per minute a machine will embroider. Quoted as sewing speed or stitches-per-minute, this number can be compared to the potential speed of a car. If your car's speedometer has a maximum speed of one hundred and twenty miles per hour, that does not, as we all know, mean you can travel a one hundred and twenty-mile distance in one hour.
What it does mean is that one hundred and twenty miles per hour is the top speed for your automobile - it is as fast as it can possibly travel, but not as fast as is practical or likely to travel. When a commercial embroidery machine lists 1,200 stitches-per-minute as top speed in it's specifications, that value represents the number of revolutions the machine is capable of performing in a minute, and, technically, it also indicates how many stitches-per-minute the machine will embroider. However, just as in our example of a car's top speed, there are practical limitations to using this value in a formula to calculate production capacity.
To begin with, in general, commercial embroidery thread will not function properly at 1,200 stitches per minute. At this operating speed, the operator will experience an unacceptable level of thread breaks or thread frays. The increase in thread breaks defeats the purpose of embroidering at top speed due to the time it takes the operator to re-thread the needle and restart the machine.
It is the equivalent of driving down the highway at 120 miles per hour and pulling over to a complete stop periodically to check your oil. A car traveling at a steady 65 miles per hour will reach the destination first, without the hassle and distraction that consistently pulling over presents. The same is true when operating an embroidery machine. By operating the machine at a more moderate rate, a design will typically be completed sooner than if the machine were being operated at top speed.
Also, the quality of an embroidered design can greatly diminish at higher speed levels, especially on hats and other difficult applications, and on more common projects, such as golf shirts, as well. By selecting a moderate speed setting, both quality and productivity tend to go up. In equipment selection and during productivity calculations, do not be overly swayed by the top speed of a certain model or brand, but instead plan on using a more realistic value for stitches-per-minute.
The stitches-per-minute value is the primary unit of measure for determining production capacity. As an example, let's assume that we are using a single-head, single-needle home embroidery machine and that we are embroidering a one color, five thousand-stitch design on a knit golf shirt. To determine the time that this design will take to embroider, and therefore how many items we can embroider in an hour, we will divide the total number of stitches in the design by the number of stitches we anticipate embroidering per minute. For this example, we will use five hundred stitches per minute as our sewing speed.
5000 (stitches) 500 (stitches-per-minute) = 10 minutes (embroidery time)
In this example, the calculation is five thousand stitches in the design divided by five hundred stitches per minute for an approximate production time of ten minutes per shirt or six shirts per average production hour. This anticipated production time per shirt is an important figure in the equipment selection process, calculating production capacity, and in determining what direction you want your business to take. Production information is the key factor used in calculating the price that you will charge for your work.
In our example, we used a single color design and determined that each shirt would take approximately ten minutes to embroider. This is assuming that there were no thread breaks, frays or other related problems, and that our actual stitches-per- minute sewing speed used for calculations had already factored in thread breaks and other embroidery related issues that would cause the machine to stop. If we had used a multi-color design in our example, we would have added time for color changes and the resulting time per shirt would be directly impacted by the time it took the operator to cut, tie and pull through the required number of colors.
These extra steps could add two to three additional minutes, or more, to our per shirt time resulting in a total time of thirteen minutes to embroider a multi-color, five thousand stitch design on a knit golf shirt. This results in a productivity level of four and one half shirts per hour or thirty-six shirts per eight-hour day.
As you can see, the topic of equipment selection and production capacity relates directly to how you would like to spend your time. In our example, a single-head home embroidery machine produced approximately four and one half shirts per hour or a total of thirty-six shirts per eight-hour day.
By contrast, a commercial, multi-needle single head, automatic trimming embroidery machine would produce in the range of ten shirts per hour, for a total of seventy-seven shirts per eight-hour day.
5000 (stitches) 800 (stitches-per-minute) = 6.25 minutes (time per shirt)
60 (minutes in an hour) 6.25 minutes (per shirt) = 9.60 shirts per hour
To arrive at the production capacity for a single-head, multi-needle commercial embroidery machine, we used a sewing speed of eight hundred stitches-per-minute, which is a typical effective speed at which a commercial single head can be operated. This value will vary based on equipment, on whom you ask and the type of embroidery being done.
In general, commercial machines are heavier, more powerful and more stable than lighter duty machines and are designed to be operated at higher speeds. Automatic trimmers and multiple needles on commercial embroidery machines also result in higher productivity, as reflected in our example.
If we were then to calculate for a multi-needle, two-head, automatic trimming machine, the production level could be effectively doubled from levels attributable to the single-head, multi-needle, automatic trimming machine. Levels for the two-head would increase to in the range of twenty shirts per hour and to one hundred and fifty shirts per full eight-hour day of production.
The levels of productivity discussed here will vary in day to day production. As an example, a true eight-hour production day is rare. No matter who is running the machine, there are breaks, phone calls, unpacking of garments, shipping, receiving, and various other distractions that decrease actual production time. Eight hours of production may equate into a twelve-hour workday when the various related activities are factored in. In a one-person shop, the workday can be even more exaggerated due to the variety of duties to be performed.
Levels of productivity do not typically go up in direct proportion to the number of sewing heads that exist on a given machine when comparing machines larger than two heads. If we were to use a six-head machine in our example, we would not report a productivity level triple that of the two-head machine. This drop in relative productivity exists due to the increased level of related activities such as the hooping of the garment, removing the garment from the machine, folding, trimming and many others.
In general, if the operator of a multi-head machine can hoop the next group of garments to be embroidered while the existing group of garments is being embroidered, productivity will be optimal. However, on lower stitch count designs with a relatively short sewing time, the operator may not have time to hoop the next run while the existing run is being embroidered. This results in the machine being idle while the operator is preparing the next run, and in a decreased level of relative productivity.