How to Calculate Sewing Machine RPM?

 

Do you know the speed of your sewing machine? Do you know how to calculate the RPM (speed) of the machine? Read this post to learn how to calculate sewing machine RPM from stitch length and SPI.

Every sewing machine has a maximum speed limit. When a sewing operator performs a task on a machine, he does not run the machine at maximum speed (rpm). How fast a machine runs depends on the skill of the operators and the difficulty level of the operation.

When it comes to machine rpm measurement, you can find out

- The maximum speed at which a machine can operate or

- At what speed the operator drives a machine

- Average machine speed

I have written answers to all three.

 

1. If you want to know the maximum speed limit of a machine read the machine manual

Or stickers attached to the motor.

 

2. If you want to know how fast a machine can run, use the following steps this is a reverse process of calculating machine rpm.

Cut a fabric strip 2 meters long and 15 cm wide. (eg length of loop = 200 cm)

Make a loop & mark a dark line across.

Set machine SPC (ie stitch per centimeter = 4)

Thread needle and bobbin

Run the machine at maximum speed (press the presser foot flat).

Record Time – Record the time taken to complete one cycle (2m long) eg cycle time is 12 seconds.

Now, use the following formula to calculate the RPM (maximum limit) of the machine

          Machine RPM = (SPC X Loop Length X 60)/Cycle Time

          In this case machine RPM = 4X200X60/12 = 4000

 

3. If you want to know what average RPM the operator is running a machine, the easiest way to find the speed is with a laser tachometer. Use this tool to record the machine's RPM (maximum running speed).

 Some Machine & RPM

MACHINE	RPM	SPI	NEEDLE
SN-LS	3500-5500	10-12	DBX1
SN-LS MANUAL	2800-3500	10-12	DBX1
S/N W/CUTTER	3000-3500	10-12	DBX1
S/N CHAIN STITCH	2800-3500	10-12	UYX128
OL-3TH	4000-5000	14-16	DCX1
OL-4TH	4000-5000	14-16	DCX1
OL-5TH(CS)	4000-5000	14-16	DCX1
OL-6TH(CS)	4000-5000	14-16	DCX1
DN-LS	2500-3000	10-12	DPX5
F/L SMALL C/BED	3500-4500	16-18	UYX128
F/L  C/BED T/S	3500-4500	16-18	UYX128
F/L  C/BED ROLLER	3500-4500	16-18	UYX128
FLAT LOCK  FLAT BED T/S	3500-4500	16-18	UYX128
F/L F/B BINDING	3500-4000	16-18	UYX128
F/L C/B BINDING	3500-4000	16-18	UYX128
F/L WAIST TUBE	3500-4200	16-18	UYX128
F/L F/B R.EDGE CUTTER	3500-4200	16-18	UYX128
F/L HEM CUTTER	4000-4500	16-18	UYX128
FOA 4 NEEDLE	2500-3500	14-16	UYX128
MULTI NEEDLE T/S	2500-3000	16-18	UYX128
BARTACK	2000-3000	N/A	DPX5
BUTTON ATTACH	1800-3000	N/A	DPX17
BUTTON HOLE	2000-3500	16-18	DPX5
VELCO	1600-2200	18-20	DPX5
1 STP ZZ-LS	2800-3300	12-14	DPX5
3 STP ZZ-LS	2500-3000	12-14	DPX5
1 STP ZZ-LS(Under cutter)	2000-2500	12-14	DPX5
OL-Blind stitch	1500-2000	12-14	DCX1
OL-Elastic attach	3500-4500	12-14	DCX1
LETUCE		20-22	DCX1
EYLET HOLE	1000-1500		N/A
EYLET ATTACH	1000-1500		N/A
FOA-2 Needle	2500-3500	12-14	UYX128

 

Thanks

IMRAN HOSAIN