Machine Stitching 5. Connecting Piping


Let’s look at a machine that connects piping.
It is piping that string padding covers the bag line like the photo. Production method of piping can be divided into piping with string padding and piping without string padding.
The photo shows the piping without padding.
For reference, bonded part other than piping should be placed outer and piping should be place inside.
That means that the part of machine stitching is placed outside and when this part is turned upside down, it is placed inside, making not visible.

I connected the two pipings at the bottom.
A series of works such as selection of padding for piping, leather cutting, skiving, bonding and connection of piping are explained in separate another chapter.

The combination of the feet shown in the photo is for zipper matching stitching.

I will replace with the foot for piping. This is a set of two.

As you can see in the photo, the pressor foot is recessed so that piping can get stuck in the groove and be sewn.
You can purchase the foot according to the thickness of piping. Or you can customize it yourself. Teacher Mao used to sharpen and make the foot of Necchi machine by himself. It holds the piping more tightly than Adler which used the genuine piping foot.
For reference, I couldn’t purchase proper foot set, so I’m using the foot that is used for handle now. There is no problem working with it, but I’m going to purchase one soon.

Stitches of the piping machine don’t have to be dense.
Some people set the stitch too small to tighten the sewing, but leather may easily tear if it is too close.
5 stitches are enough.

Piping connecting machine can be divided into two.
First, start with machine that connects the piping to the body like the photo.
The guide interval would be about 2~3 mm at this time.
Set the guide interval as 5~6 mm for the second machine so that the stitches can’t be overlapped.

The first machine that connects piping to the main body is completed.
When the first machine is over, draw all the piping reference points. These can be the points which are to machine in the same position with the main body part during the second machine. These reference points should be centered on the point of inflection.
The photo shows the production process of Boston bag. The first work is to connect piping on the side and the second work is to connect this to the main body.
Here,
There can be few questions.
1. Do I have to divide into two times for machine?
2. Is it ok to connect piping to the main body first, not to the side?
I don’t think you should divide it into two steps. And there is no problem to connect the main body first.
But if you divide into two steps, you can make the entire line of piping more stably.
If you work the part which has a shape like the side first, you can check the shape you want and do stitching.
Just try it first and choose which method is better.

It is better to apply the reinforcement tape to the area for matching works like the photo when connecting to the main body.
You need to work with machine according to each reference point. At this time, the leather can be stretched and it can be longer than the originally calculated length.
If you apply the reinforcement tape, it is possible to connect to more accurate reference point with fewer changes in length.

You need to make sure that the position, length and size are correct with the tongs before making the final secondary machine.
You can verify whether balance of the bag is correct with the longer or shorter length.
If you work with secondary matching stitching, it may be difficult to precisely stitch by matching two reference points together. But you have to check time to time to match them as possible. And be careful that the first few errors in mm can increase up to centimeters as goes to the end.
Especially, in case of O pattern Boston bag, the beginning and the end are the same. Few errors at the beginning part may increase up to centimeters at the end.

Lastly, add extra stiffeners to weak parts such as zipper line.

The width of the piping guide should be tightened and stitched to the piping so that piping lines can be emphasized without floating from the main body.
In addition, the curved side of the side and body lines should be stitched to the same trajectory and length and all the reference points should be matched to make an even shape when turning upside down.
Piping is a useful technique for emphasizing the line of bag even though it is a relatively soft bag. It is somewhat difficult to stitch, but it is used for lots of bags with good effect on use.
It is simpler to just connect the two leathers, but it is good to have clear line by using piping.
You should try the piping stitching once.
