Monday 23 April 2018

The Overlock League (Part 1) - Time Trials

One of my main reasons for getting the overlocker was to speed up some aspects of my sewing. So I thought I'd test this theory out.

Take my standard capri leggings pattern, in identical fabrics (but different colourways), elastic and blue ribbons, one Janome 7025 (or Janome 525s if you don't shop at John Lewis) and one Janome 9300dx.


Sewing Machine Workflow


  1. Fold hem up once, zig zag and trim
  2. Sew inseams using a zig zag
  3. Trim inseams, change foot (to overedge foot) and set machine to stitch G (an overcasting stitch), stretch setting. Finish inseam edges.
  4. Change foot (to normal foot), return to zig zag stitch and sew the crotch seam (replace the bobbin as it has just run out)
  5. Trim crotch seam, change foot (to overedge foot), use stretch overedge stitch G to finish crotch seam
  6. Change foot (to normal foot), fold down the waist once to create a casing and zigzag into place. Leave a gap to feed elastic, trim edges.
  7. Feed elastic through casing using an elaborate system of safety pins.
  8. Join elastic edges using a zig zag stitch
  9. Close casing using zig zag stitch. Trim.


Done. 32 minutes.







Overlocker Workflow


  1. Unthread right needle
  2. Fold hem up once and sew a "ladders up" flatlock hem. Tug into position.
  3. Rethread right needle
  4. Sew inseam
  5. Sew crotch seam
  6. Join elastic ends
  7. Attach elastic to inside of top edge
  8. Unthread right needle. Fold waistband down again and sew a "loops up" flatlock from the right side. 
  9. Tuck in thread chains using a chenille needle. 


Done. 37 minutes.





Initial Thoughts

Oh.

That wasn't the plan. I had such high hopes.


Analysis

So I guess I've disproved myself?

This was surprisingly fast for my sewing machine workflow. I think I've optimised the process so much that everything is autopilot, even if it is very fiddly in places. I switch back and forth between stitches several times and trim seams by hand before finishing the edges. In the past I've cut open the fabric by accident, and forgotten to reset my stitching which has caused the need to to smash into the foot or the plate below. It's also very thread-heavy so I've included the time it took to change the bobbin. On other projects I'll often be changing the bobbin, rewinding it and maybe even replacing the spool thread. On this race I also made sure that the casing was wide enough for the elastic - generally I eyeball it - and sometimes get it wrong - and feeding it through can get very tedious if the casing is slightly too small.


The overlocker result being slower was a big upset. Plus, the quality is lower than the sewing machine standard. You've got the XL photos at the top of this post so you can see the dodgy stitching. So I'm keen to reflect on what has happened here.

Firstly, I think I got arrogant and impatient. Just before starting the race I realised that I didn't remember how to sew a flatlock. While I did look it up outside of the timekeeping, I didn't practice it. My steps are not quite in the right order. I think sewing the hems in the round works better here compared to hemming when flat. I unthreaded and rethreaded a needle twice and I included the time to fix it when I had threaded it incorrectly.


At 22:44.7 (Lap 1 time) I'd finished a "ladders-up" flatlock on the waistband and technically the leggings were done. A lot like The Omelette Challenge, this could have counted if we're only talking about racing. Except, I spent the next 14 mins and 31 seconds unpicking and resewing! I mean, they at least have to be wearable. And they barely achieve that standard now.

The same pattern, the same notions, the same size, same finishing. Different machines, different workflows. Optimising for speed only, the overlocker wins on a lower-quality result. The sewing machine is slower but gave me a better result. Or: the sewing machine is faster to achieve a particular quality standard.

If we consider a "fair" contest as what I can do on autopilot, then I have a lot of practice ahead of me on the overlocker. If we consider that I've made dozens of knit garments on the sewing machine, and still only a handful on the overlocker maybe it's not fair to blame the equipment entirely. Revising flatlocks and practicing before the time trial would have worked in favour of the overlocker. But I don't really need to practice in the same way for the sewing machine. Would it have been more fair? It would (almost certainly) have changed the result, and given me the result I wanted to see.

Conclusion

Human error. More practice needed. Maybe I'll do another of these for a different item in a few months. Any requests?

K

2 comments:

  1. I am curious about your order of sewing. I tend to do my crotch seams first, and then do the inside legs. This is because I have an aversion to posting one leg inside the other. I am not sure what difference, if any, it makes to the finished garment.

    As for speed, I think a lot more practice with the overlocker would make a difference, but I would also think, overlocking the pieces before you start, and then sewing the major seams on the standard machine might give you a different finish again, which you may be happier with?
    I think it is blending the equipment, not going for one over the other may give the best end result. But I am open to contradiction!

    xx

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  2. Ah, and another thought! You may have the settings slightly wrong for the fabric you are using. It is well worth playing before you start to adjust the various tensions, and foot pressure. The overlocker version looks like it may have benefitted from a gentler foot pressure on the crotch?? But I am talking through my hat here... ;-D

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