Mission Impossible (well almost).

[hutch--]

I need to make myself some guys underwear so recently I bought 10 metres of 120 gm/m cotton Lycra and while it is an excellent fabric with a massive amount of stretch, its a genuine nightmare to handle as just handling it stretches it which in turn messes up the seams. I can manage to overlock it together after dropping the foot tension as well as both needle thread and both looper threads but it does not have enough stretch to match the fabric so its not usable.

With much experimentation I have managed to get a seam type that actually works which is done on my old Elna using an unusual cam. Lay the two layers face to face like normal and then use a stitch that multi-steps from one side to another for about a wide zig zag width. When this is done, trim the outside edge to about 1mm from the outside stitch line. Then lay the seam over and again stitch it flat using the same stitch type and I get a clean tidy edge that has close to the same stretch rate as the fabric.

Now the edging is almost as much PHUN. I tried out using the 8mm raw rubber which you zig zag onto the Lycra, trim the edge, turn it once then zig zag it flat but it was to heavy for the fabric so I shuffled off to E M Greenfields and bought a box of 6mm raw rubber (1000 metres) and tried this out and its about right for the fabric weight so I now have both seams and edges worked out. The last trick that I have yet to work out is how to do the waistband. Its easy to do on the old fashioned nylon Lycra but I suspect that it will need more creative genius to get it to work properly on this light weight cotton Lycra.

[Henry Hall]

You have a lot of patience Hutch. I couldn't  work with this sort of fabric and remain in a good mood. I'd sooner knit some underwear than attempt to make anything close to what I could buy.

[Schneiderfrei]

Mmmm knitted underwear,  in raw Corriedale

[Henry Hall]

In heavyweight Harris Tweed 

[jeffrey]

Have you tried flatlocking? I find that I can control gummy/overly stretchy fabrics better with a two thread flatlock stitch than with a traditional 3 or 4 thread overlock stitch. The seams lay flatter and don't stretch out as easily, and if they do stretch a bit they can be un-stretched with a warm iron and a little steam.

http://gotosew.com/2013/11/guide-to-flatlocking-on-your-serger/

[hutch--]

I do have a machine that can be set up as 2 or 3 thread flatlock but its not a collarette machine and the gap is not really wide enough to be useful. What I have tested successfully is an unusual stitch that I can do with my old Elna with a cam that stitches from side to side in 4 steps then feeds forwards. Its slow but does not stretch the 2 layers. It involves trimming the outside edge carefully after it is stitched and then layed over and stitched again with the same process. A bit slow but I get a strong high stretch seam that is flat when finished. I also have the edging done OK and only have to work out the waistband on the high leg cutout versions. The normal square shaped ones are simple.

Once I get the basic design right I will make up some patterns and do a run of both types. Thanks for your suggestion, its useful to know other successful techniques.

[Greger]

Some people use paper where it is practical. After sewing tare the paper away. The paper doesn't stretch.

[Henry Hall]

Do you have to attach the paper or just machine stitch with the paper on the fabric under the presser foot?

[jeffrey]

the paper would be difficult to remove with such a complex stitch

[Greger]

Do you have to attach the paper or just machine stitch with the paper on the fabric under the presser foot?

Paper goes underneath the cloth. Less presser on the presser foot, too.

[spookietoo]

You have a lot of patience Hutch. I couldn't  work with this sort of fabric and remain in a good mood. I'd sooner knit some underwear than attempt to make anything close to what I could buy.

OK, we REALLY  need a "Like" button!

There's a lotta stuff I have patience for, making my own undies isn't on the list.  But its always nice to know the process "just in case".

[hutch--]

Here are a couple of images on the best I have been able to do on a seam yet.


The two layers are laid face to face like normal then stitched with an unusual cam my old Elna's have that is 3 stitches one way then 3 back. This has worked OK because it does not crunch up the seam like a zig zag of the same width and it has a high level of stretch which is desirable with a high stretch fabric like this.


Because the fabric is a knit, it does not fray of a cut edge so you can get away with just trimming it reasonably close to the stitch edge line. The very light weight of the fabric ensures that it is no joy to trim as its like handling water but as long as you trim it reasonably accurately, you have a strong seam that maintains a high stretch level which is much the same size as an overlocked seam.

I have also done a similar seam using a 4 step wave stitch with a very short stitch length which works OK but the outside edge looks a bit notchy in comparison.

[Schneiderfrei]

Love that stitch pattern. How do you get it?

[hutch--]

Its a cam that I put into my old Elna, I have about 100 different types and while some of them are not my style (ducks flowers etc ...) some of the technical stitches serve unusual purposes. If you have a machine that does a 4 stitch wave pattern, you can do much the same if you run a short stitch length.

The idea is to have a multi-stitch from side to side which makes the seam strong enough but it does not stretch the seam inline. The problem with a zig zag on a very soft fabric is it pulls the two sides together and crunches up the seam.

[peterle]

You could also use cam Nr.01 multi zig zag. it´s my favorit for overcasting edges too. (no need for 3 cones of right coloured thread).
Cam Nr 165 works also for jerseys.