Thread Tension Part 1

Tension-Dial
Kenmore Tension Dial

Thread tension is a bit of a challenge: without it nothing works. Getting it right seems to take a bit of fussing.  There are many good descriptions available of how to adjust the thread tension.  The point of this post is less about setting the perfect tension than it is about understanding what is going on with thread tension. My goal was to measure the thread tension directly.   Having  access to a force sensor and some other incidental equipment that I usually use in the physics lab where I teach, it occurred  to me that I could use the force sensor to measure the thread tension on the sewing machine.

Kenmore-bwI took my Kenmore into the lab and spent Friday afternoon playing around with this. The results are as follows:

Kenmore Mara 100 Tension.xlsx

As one would expect, the higher the tension setting number the higher the thread tension.  The standard unit for measuring tension is  Newtons (or mN): here I have converted  the measurements into grams, another common way to measure tension.

The data here are the numbers I measured.  I have no idea of what they should be.  I have not been able to find any clear reference as to what should be expected for the top tension.

BobTenI also measured the bobbin tension. I found the tension to be about 35g.  I used a digital scale purchased for under $10.

I did find a reference for this: the TOWA bobbin tension gauge.

It suggests the bobbin tension should be 25-30g

Having calibrated my top tension and the bobbin tension,  I made various sample stitches to determine which setting gave the best results.  The sample consisted of three layers of  cotton muslin,  Gutermann  Mara 100 polyester thread,  and a 65/9 needle. The best results were achieved with a tension setting of 5 which corresponds to a top tension of approximately  68g and a bobbin tension of 35g (I used a microscope to photograph the following pictures).

Set5Top
Sample top: The dark spots are the bobbin thread just visible
Set5bot
Sample Bottom, The dark thread is the bobbin thread

The microscope tends to reduce depth perception so I attempted to cut away the fabric to look at a cross section. You can just see the loop formed inside the fabric.

Crosssection

My best guess as to why there is a difference between the top tension (68g) and the bobbin tension (35g) is the resistance of the fabric.  That is, some additional top tension is necessary to pull the lock-stitch into the fabric.  However,  I am no expert, these are only my observations.

Based on the above observations, I’m assuming that the correct thread tension depends on the following parameters:

  • Thread type and size
  •  Fabric and weave
  •  Needle
  • The desired properties of the stitch to be sewn

My next challenge is to explore these other combinations.

Thanks for reading.

Picking Up Where I Left Off?

SingerButton
Singer Buttonhole Attachment on a Kenmore

Well sort of.  I have had time over the summer to reassess my goals for my sewing and designing projects.  Most definitely I am not going to try selling the patterns.  As I complete them I will make them available for  downloading — my contribution to the creative commons concept.

Susan is now focused on her own projects which can be found here.

I am fully taking over the blog for Partlan Pattern Designs (PPD)  as of this post.

To make this transition,  I thought I would provide a little back story.

I wanted to learn how to make my own clothes.

Kenmore
Vintage Kenmore 158.14001

Why? Partly because I like to make things and partly because I felt that the ready-to-wear (RTW) industry was not producing garments I liked or that fit.  And, an additional consideration was that the mass market RTW industry has a reputation for employing  garment workers in abysmal conditions  (though certainly not all of it).

I started sewing and found there was a lot to learn:  sewing technology & techniques, fitting techniques, fabrics, threads, equipment, photography and social media. All of which have steep learning curves.

Surprisingly, on the sewing front, I was able in a fairly short time to produce a garment that was crude but passable enough for me to wear. In my work (teaching physics at a local community college) casual clothing is appropriate most of the time.

This was enough of a success to encourage me to keep going.

As I wore the garments that I had sewn, I found that in wearing them one begins to really  understand the fit and function.   When I had time I modified the designs and tried again.  As Susan says, I am a tinkerer.

My first shirts left much to be desired.  However, I felt I could improve on the implementation, and have.

 

As I was tinkering with aspects of shirt design and fit, I became interested in designing my own complete shirt pattern.  Basically a pattern self-drafted on me, until I got  the form.

Because I had experience with AutoCad in my past I was able to fairly quickly get the design into a pattern software program (using Pattern Works).

So far so good.  At the time it seemed like this might be a plausible business,  hence the name Partlan Pattern Designs

Then,  the tunnel at the end of the light appeared in considering how to grade the pattern to all other sizes, and, in my naiveté, thinking there might be many of them. Another barrier to producing a viable pattern business is to produce an intelligible set of instructions for the pattern. Susan spent several months on that part of the project in addition to managing the communications, social media and the infrastructure required to actually sell the patterns.

In the end for reasons she discussed here,  we decided to close the business.  I am taking the pattern design on as my personal hobby.  I do plan to release the shirt pattern, probably sometime in the summer of 2015 as there are a number of revisions I want to implement between now and then.

 

Me-1
My Shirt, (Brooks Brothers Shorts, Dobbs Hat)

As I begin my blogging adventure, I plan to reflect on the learning curves and share some of my experiences.

Up coming blog topics will include what I learned about:

  • threads and needles
  • fabric (natural fibers)
  • sewing the different parts of the shirt (multiple)
  • drafting a pattern
  • grading a pattern

I will intersperse these with posts on some sewing projects I am working on.

Thanks for reading.

New Directions!

dressone

Partlan Pattern Designs is closing. Martin does not have adequate spare time to work on the business and as it turns out, given a number of new church and other commitments in 2014, neither do I.

We considered outsourcing the pattern making and just focusing on designs. In exploring that option we realized we don’t have a robust business marketing strategy. For example, we don’t really have a collection of designs for a specific target market. The few designs Martin has in mind are fairly general and classic. The engineering behind apparel construction was always of more interest to both of us than the designs themselves.

It’s possible Martin will resume development of the Shannon pattern and other classic menswear designs when he retires from teaching. Or maybe it will just be an ongoing hobby. As noted in previous posts, it became pretty clear after our research that there isn’t likely to be much profit in selling menswear sewing patterns. Putting it another way, it looks like we would have to invest more capital and time than we’re prepared to invest in order to make it profitable.

In the coming days, I’ll be removing and archiving the content on this blog to prepare the blog for deletion.

We’ll still keep sewing, but I won’t be blogging here or elsewhere about sewing or style. So this is the last sewing related post. What you see in the first picture is a dress in progress that is a copy of this dress Miley Cyrus wore to the Bambi awards last year. This post on Wendy’s blog is where I learned about the dress.

Here’s a close up of the sleeve in my version of the dress.

dresstwo

I constructed the velvet cuff using 1 inch piping cord covered with two layers of cotton batting.

When not busy sewing and working on church projects we’ve been busy adjusting to life as new dog owners. For those who saw the previous tweets and facebook posts about our mixed terrier rescue dog Coco, here’s a snippet I posted on facebook Wednesday that explains what happened with Coco.

Sadly, Martin and I had to surrender Coco back to the SPCA this afternoon. She’s been increasingly prey-focused (squirrels, birds) and aggressive towards the cats, other dogs and certain people since we got her 3 weeks ago. She attacked Brownie kitty twice (jaws on neck) and has extreme difficulty controlling herself whenever he’s around. Yesterday Coco got vicious with a boxer mix dog at the dog park. The boxer provoked her first, but even after the owner got that dog under control Coco kept attacking with viciousness. Like she was another dog, not the one we first met 3 weeks ago. Today, a friend came with a sweet dog to play in the back garden. All was well for the first few minutes, then Coco attacked (bared teeth, growling, etc). We leashed her, settled her. A few moments later she tried to attack the dog again. The dog was just sitting there, and was obviously afraid. Martin & I talked over the various incidents over the last 3 weeks, e.g., leash aggression, near bites of our hands that felt uncomfortable because of the look in her eye, the aggression towards the post man, gardner, etc. It turns out we’ve BOTH been concerned. The little things adding up. Just in case the garden incident was a fluke (protecting her turf), we went back to the dog park. More attacks, this time with NO provocation. It’s almost like a “switch” went off in her brain sometime this week and now she feels free to attack. When we surrendered her, I mentioned that there was nothing cautionary in the notes about her behavior at the time of adoption and that we said we had a cat. In fact the notes indicated she was a cuddly lap dog who likes to lick your face. The surrender intake volunteer said she knew Coco — she knew Coco could be a real problem. It kind of shocked me. I asked why this wasn’t in the notes? She said they only record what is known from the previous owners, which in this case didn’t apply because Coco was found abandoned. So the SPCA knew she was a risk, and didn’t let us know because of protocol. Very sad.

This was a terribly upsetting experience for us, but we know we’re meant to become doggie parents. We’ve been busy since Wednesday researching reputable breeders from which to purchase a pure bred dog. I’m happy to say we are very likely to become the proud parents of an CKSCS-USA and AKC registered Cavalier King Charles Spaniel puppy born Nov 14 next Friday Jan 17, assuming all questions are answered to our satisfaction and the puppy’s health records are in good order. It’s sort of going in the completely opposite direction buying a certified pure bred dog, but Martin and I feel really burned by the SPCA rescue experience with Coco. We understand there are more reputable rescue organizations out there using foster parents who really get to know the dogs before placing them with families, but we’ve decided we do not want to do another rescue adoption. This way we know for sure we’re getting a healthy dog bred for companionship, not a special-needs dog we can’t trust around other dogs and small children let alone grownup people like the gardener and post man. It’s not that we don’t support rescue adoptions, just that we personally do not want to do another one.

We have already named her Annie :). If I do blog again, it will be a different blog about Annie, involvement in the daily and weekly work of my church and the wider community, and about living as a committed Episcopalian trying to make sense of life without getting too religious (in a doctrinal sense) but hopefully spiritual enough, open enough to receive the wisdom necessary to age with grace and self respect.
I’ll leave this post up for a couple weeks to give people a chance to visit and then I’ll take it down and delete the blog. I do miss reading blogs but am finding that spending less time online and more time outside, e.g., playing with the dog, walking the dog, gardening and so on is healthier for me, both physically and mentally. I will keep in touch on facebook and will visit blogs from time to time.
I wish you all the best in your endeavors and we thank you very much for your support and interest in our sewing pattern project!