306K Denim Photos – The Heretic With The Standard Needles

DSCF0869 DSCF0861These photos show my Singer 306K sewing a zig zag stitch with both wide and minimal stitch length …. and the finished piece..  The User Manual for my 320K2 recommends a size 18 needle and forty weight cotton for sewing denim.

Here, I am using a size 18 needle with #40 bonded nylon thread.  The needle is actually a 16X231 ….. i.e. it’s identical to a standard 15X1 but it has no flat section at the top of the shank.  You can even use these!  You have access to a full range of sizes (up to 18 maximum for this machine) and more importantly, a full range of styles (needle point, ball point, leather point).

This machine is sewing through eight layers of heavy stretch denim which barely fitted under the presser foot.  The finished stitched material is 1/4 inch thick!  The machine struggled to punch through this much fabric and the feed dogs were hard pressed to feed it through as well.  I had to provide a small amount of manual assistance to keep the material moving smoothly.

This machine has had its bobbin case modified slightly to allow the use of standard length (15X1) needles.  It isn’t modified in any other way.

I use this machine regularly and have altered garments, taken up jeans and made heavy, lined curtains on it.  In all that work, I have not once experienced any problem with ‘needle strike’.

I sewed this piece of fabric, simply to try to prove a point ….. that this machine can reliably use standard needles with no adverse results.  You can of course, achieve problems by doing the following:

Using a needle and thread that is too fine for the fabric under the presser foot;

Using a thread that is too thick for the needle that you’re using, but mostly;

By forcing your fabric through the machine in opposition to the action of the feed dogs.

I have yet to use a machine that will tolerate improper use.  In this case however, the experiment here was nothing short of abusing my machine and yet it performed admirably.

I can only state that I have used my machines (2 306’s and a 320 free arm … and more recently, a 319K) for a wide range of sewing, using standard needles and modified bobbin cases.  They have performed perfectly, using appropriate needle and thread sizes for the work being done and I’ve yet to experience the dreaded ‘needle strike’.

Despite posting several articles detailing the procedure involved and my experience using my machines, I still see posts on sewing machine sites, declaring that the modification of bobbin cases in these swing needle machines will NOT provide reliable performance.

My considerable personal experience with these machines, my careful documentation of this issue and testimonies from other users of these machines which mirror my own experience,  are apparently no match for the supposed  ‘qualifications’ of these detractors.

I can only appeal to anyone who is contemplating acquiring a 306, a 319 or (if you’re very fortunate) a 320 …. to consider this.  A simple modification of the existing bobbin case or, better yet, acquiring a suitable alternative one that will afford the necessary needle clearance, won’t alter your machine in any way.  You can try using standard needles (please use appropriate size needles and appropriate thread for your application) and just give it a go.  If you discover that the gurus are right and I am wrong, it will have cost you almost nothing and you can go back to using the original 206X13 needles which can still be purchased in (I think) two sizes …. neither of which are recommended in the manual for sewing denim or other thick materials!

Or you can just assume the sages are correct, ignore the considerable practical experience of myself and others, and limit your use of these fine machines to whatever you can achieve with two needle sizes.

I don’t think I can offer any further constructive advice on this matter.  I have been astonished at the apparent out-of-hand dismissal of this modification by persons who’s actual experience with the models in question is not clear …. and who’s objections seem to be based more on hearsay, speculation and assumption, than on any significant level of personal practical use.

I have no interest whatever in achieving some imagined status as a ‘guru’ on this or any other subject but I think its a grand thing that we can all share our experiences on forums and blogs, to the potential benefit of all.

Cheers all,

Andrew Caddle 2014-12-29



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