4: Basic Functional Requirements
It has to be said that it is possible to produce perfectly good kites using a hand cranked machine solely capable of a straight lockstitch, and you definitely do not need the hundred plus different stitches that some machines are capable of producing. What you need is a machine which as a minimum has the following functionality:
- Lockstitch not Chainstitch
- ‘How do I know and what is the difference?’ You may be asking yourself. Chainstitch (Figure 1) was used in the very early machines and is only really used now for toy machines and on industrial machines for sewing sacks where the main failing of the stitch is used as an advantage, namely that if the correct thread end is pulled the whole seam will simply unravel. Additionally there is a front and rear to the stitch, whereas the lockstitch (Figure 2) is the same on both sides and is less straight forward to unravel.
- Straight, Zigzag and 3-step Zigzag stitches.
- Whilst straight and zigzag stitch capabilities are absolutely essential, the 3-step zigzag is less so, but it does enable wide zigzag stitch without the risk of puckering, and is particularly useful if there is no lower tension control.
- Reverse stitching capability on all stitches.
- Reverse stitching is the quickest and cleanest way to lock off the end of a seam, so having this function is a must.
- Proportional/variable speed control.
- With proportional/variable speed control, the more you depress the foot pedal the faster the machine sews and vice versa, thus allowing greater control on short and complex seams.
- Adjustable tension control.
- As a minimum you need adjustable tension control on the top thread, ideally you need tension control for the bobbin thread as well.
- Adjustable presser foot pressure.
- Incorrect presser foot pressure can cause puckering in the seam, thus being able adjust it is important. Generally the lighter the fabric the lighter the pressure required.
- Bobbin Winder.
- You will need to transfer thread from your main spool to the bobbin, and it is surprising how many machines do not have a facility to wind bobbins.