Singer 320K2, Singer 306K Bobbin Case Conversion for Standard Needles

I recently had the good fortune to pick up a Singer 320K2 sewing machine.  This is a swing needle zig zag machine that has a range of built-in fancy stitches activated by a series of keys on top of the machine, and also uses externally fitted plastic cams to provide additional stitch types.  Its a fantastic design and so far, I’m really thrilled with it. You can download a copy of the manual for the 320K2 here.

Singer 320K2

I also have in my collection, a Singer 306K.  This is likewise a swing needle zig zag, more or less identical to the 320K2, but it’s a flat bed machine and doesn’t have the inbuilt fancy stitches (Still creates fancy stitches using the same external cams though.)

Both of these machines are very versatile and can churn out 1500 stitches per minute.  A major drawback however, is that both of these machines, as well as Singer’s zig zag model 206 and 319 machines utilise a needle design (206X13) which is a departure from the far more common domestic 15X1 or the industrial pattern 16X231.

The 206×13 needles are becoming rare, with only two sizes and only one style readily available.  Being less common, it is impossible to find these at anything like a bargain price. I like to play around with leather, as well as various materials, so being limited to just normal sewing needles in smaller sizes was a major limiting factor for me.

Just why these few machines were designed to take these weird needles is something of a mystery.  I have read that it was perhaps a ploy to prevent owners from being able to buy non-Singer needles for their machines.  Whether there is any truth in that, I have no idea but certainly, the difference between the 206×13 and the common 15×1 is limited to nothing more than the length of the actual needle point, below the eye!  Here is a photo of the two needle types, revealing that the point of the 15×1 exceeds that of the 206×13 by almost 2 millimeters.  There doesn’t seem to be any other significant difference.IMG_5141

A problem arises however, if one should try to use the cheaper and more common needles in any of the swing needle models mentioned.  The problem occurs, due to the longer needle point striking the inside of the bobbin case when the needle swings to the extreme right or left positions, during zig zag or other fancy stitch patterns. Before This image shows a 306K machine with a common 15×1 needle fitted. There is minimal clearance between the needle tip and the bobbin case, where the needle descends beside the bobbin, due to the circular shape of the cut-out section of the bobbin case.

An alternative view of the bobbin case and I have indicated with arrows, the areas which will be impacted by the needle tip when it reaches full descent and maximum swing (deflection) during the making of zig zag or fancy stitches.IMG_5147cropped33

A simple solution to this problem, is achieved by simply modifying the bobbin case slightly, by grinding out some of the metal to provide greater clearance for the needle tip, as indicated in the next image The half moon shape of the recess needs to be ground out to something more like a square shaped letter ‘U’.


Grinding out the bobbin case to provide additional needle clearance was a relatively straightforward job.  I used a rotary tool with a small grinding wheel.  This particular tool, which is really intended for sharpening chainsaw blades, rotates at 24,000 RPM.  While the speed of your grinder is probably not critical, the quality of the grinding stone certainly is.  It only takes a couple of minutes to grind out the unwanted metal.  I imagine that the same result could be achieved using a small round file. IMG_5163Here’s a photo of the grinder that I used.

And some images of the bobbin case before and after the modification and also showing the ground area.


And finally, the bobbin case inserted back in the machine, showing the increased needle clearance at full deflection of the needle.


I apologise if the images aren’t as clear as they might be.  Achieving clear images of these tiny parts proved to be a bit beyond my limited photography skills.

DISCLAIMER:  Please note that I am NOT suggesting that you should attempt to modify your bobbin case as I have done.  If you DO decide to go ahead with this modification, I will not accept liability of any kind for the results of that decision.  Wearing appropriate safety clothing and eyewear is obviously essential.  If you are not familiar with the safe operation of grinding or other workshop equipment, you should refer any such work to an appropriately skilled and qualified person.

FURTHER DISCUSSION:  There are several articles on the internet, discussing various modifications of these machines, to allow the use of other than the intended 206×13 needles.  I find that having carried out this modification on both my 320K2 and 306K machines, I am able to use both the common domestic 15X1 or the industrial pattern 16X231 needles.  That gives me access to a full range of needle sizes and, more importantly for me, needle types (leather, ball point etc).

One issue that was raised in discussing this with other enthusiasts was the possibility of the longer needle causing difficulties due to it either :

1    entering the fabric being sewn while it was still being moved by the feed dogs or

2.   Failing to exit the material before the feed dogs commenced moving the fabric.

I have read that some people modify the timing of the machine, apparently in an attempt to enable the longer needles to be used.  My observations are that altering the timing in any way will NOT prevent the longer needle tip from striking the bobbin case on full deflection.  Only removing metal from the bobbin case will provide the necessary additional clearance.  Further, since the needles are exactly the same proportions, except for the amount of metal beyond the eye, any alteration of the standard timing will interfere with stitch quality.

I have tested both my machines fairly extensively and would suggest that the only time a problem would be likely, due to the needle remaining in the material too late or entering the material too soon, would be if the thickness of the material being sewn was well beyond what would be reasonable for this class of machine.  Certainly, I experienced no problems whatsoever in stitching four layers of heavy denim at full stitch length and in both straight and zig zag.  When I attempted to sew eight thickness of the same material at the maximum stitch length, the only effect was that the stitch length lever raised itself slightly and the machine produced stitches that were finer than the maximum stitch length.  (The stitches were perfect though.)  I’d point out that trying to sew this thickness of material was bordering on abuse of the machine, in my opinion.

I am not an expert sewer and I’m certainly not a qualified machine technician.  I cannot state categorically that this modification would be advisable for anyone else.  Neither can I state, beyond any doubt, that this modification won’t cause some problem not yet identified.  You should exercise your own common sense in deciding if this is likely to be helpful for you.  My advice would be, if you are doubtful, then don’t do it.  For myself, I’m extremely pleased at the results and it is a great thing to have access to a full range of needles and needle sizes for my machines.

For information regarding alternative bobbin case for these machines, see

I hope that this info will be of some help to other owners of these wonderful pieces of Singer history.

Best Regards,

Andrew. 2014_09_12


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Thank you, Andrew.


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53 thoughts on “Singer 320K2, Singer 306K Bobbin Case Conversion for Standard Needles

  1. Pingback: Singer 306K/320K Using standard needles - With Pictures -

  2. Thank you for posting this!!! I am considering purchasing a singer 319w and after a lot of research, the lack of needle availability was really a concern. I saw a post from a woman in Australia and her comment led me to keep investigating as she said that someone did something to her bobbin assembly that made it possible to use any needle without adjusting timing. I’ve been trying to figure out what that “something” was. Your post finally explains it. I’m sure my flex shaft will be able to handle the adjustment. Thanks again!

    • Hello Wendy and thank you so much for your feedback. As I have indicated in my posts, I own two 306k’s as well as a 320K. The 319 is the flat bed version of the 320 (free arm) and I am hoping very much to find one myself.

      There is a particular internet forum where I tried to discuss the issue of bobbin case modification. I also indicated that alternative bobbin cases are available which provide the same needle clearance that is created by modifying an existing bobbin. (have a look at Obviously, I didn’t invent the idea of modifying the bobbin case and people have been doing so for a long while. I simply did the mod, found it extremely successful and sought to explain it in the hope of encouraging other owners. The resident ‘experts’ on that forum lambasted my posts, stating categorically that my information was incorrect and that dire consequences would befall anybody who followed my advice. This was despite the fact that I provided detailed information with photographs and that I had stated that I use my modified machines regularly with zero problems. I even provided a sampler made up of eight layers of heavy stretch denim on which I had created a range of stitches on both the 306 and the 320. No amount of evidence and no proof of obvious facts was ever going to convince those ‘experts’ that they aren’t the last word on every aspect of every Singer ever made. The sad thing isn’t that such people are ignorant and closed-minded. The real shame is that people who share our interest in this hobby might forego a really wonderful machine, based on inaccurate advice proffered by well established ‘experts’.

      In my opinion, this family of Singers is historically noteworthy, not to mention that they are extremely capable, reliable and versatile. The bobbin mod seeks only to enable the use of standard needles, rather than the hard-to-find, expensive-to-buy 206X13’s. It isn’t seeking to expand the capabilities of the machine to something that it was never designed to do. To limit these fine machines to what is now available (one needle type in only two smaller sizes) is to tragically reduce it’s functionality. Avoid messing around with the standard machine timing. Totally the wrong approach.

      If the 319 that you are looking at seems to be in good condition, then I heartily recommend that you snap it up. I’m certain you will find that it is an outstanding, capable machine that is fun to use and that will provide very satisfying results. I’m not an expert in anything. I’m just a bloke who owns these machines, uses them regularly, has done the modification that I recommend and has proven that it works ………. really well!

      I am telling you all this in the hope that you will be encouraged to try the 319 and that you will prove for yourself that the machine will work with the standard needles. Hopefully, you will become a champion for the voice of reason and common sense and share your actual experience of this machine with others. Experience beats book learning and theoretical ‘knowledge’ hands down and these wonderful machines deserve to be used and enjoyed.

      Thanks again for your feedback and I do apologise for the lengthy reply. If I can be of any help whatever, please don’t hesitate to contact me.

      Kind regards,

      Andrew Caddle

  3. I have just bought one of these and plan to modify the bobbin case for the same reasons you stated. I am thinking of asking an engineering company to grind the bobbin for me. I have been buying old stock of available smaller needles so will use these first before making the amendment. Presumably once the amendment is made, smaller original needles won’t work unless you buy a spare original 320k solely for their use. Presumably you can swap the bobbin cases as needed. I hope that makes sense. Thank you for your explanation and photographs.

    • Hello walterpr12ce and thank you for your feedback. There is no need to use a different bobbin case for your 206X13 needles. A bobbin case that has been modified to enable the use of 15X1 (standard) needles will still work perfectly with the shorter 206X13’s.

      I hope you enjoy your 320K. They really do occupy a special niche in the Singer lineup. It will be a very great shame if these swing needle machines become rare, simply because of the inaccurate but ingrained belief that you simply must use the original needles … which are already in very limited supply. Even though these machines work perfectly with standard needles once an appropriate bobbin case is installed, I still see posts on forums stating categorically that the universe will skew out of alignment and you will die a horrible death if you try to use standard needles.

      The good news is that because of this ingrained and willful stupidity, these machines are probably much more affordable, for those of us who dare to flout the conventional inherited wisdom.

      Please will you report back when you get your own machine working and share your results with other readers here? Perhaps if enough of us share our successes, we can help to keep more of these wonderful machines out of landfill.

      Thanks again for your post.


      • Hi Andrew, Thank you so much for responding so quickly. I will definitely update you on my progress. I will buy an adapted bobbin case from the ebay link in your blog and try it. I am new to this sewing malarkey. I bought a cheap machine from John Lewis (UK department store). I love it but it is plastic and is an entry level machine. This 320k purrs and is beautiful to look at. It is way beyond my ability but I am determined to try to use it. In the last week, I have bought 2 more 1960 Singers, and 2 vintage children’s singer machines, for no good reason other than they look fabulous and I believe they are better than my new entry level machine.

        Thank you for sharing so much information. I will do my best to share your blog.

  4. Hi Andrew
    Really enjoyed reading your page. Very interesting.
    I have just bought a 306k. I did research model and it said it was good for sewing on leather. I will be sewing badges into leather jackets. Can you tell me what size needle would you recommend I use.
    Many thanks

    • Hi Nicky and thanks for your question.

      Congrats on your 306K. I just know you will love it. They’re a wonderful machine.

      When sellers claim that a machine is good for sewing leather, it’s a bit meaningless. The reason is that the word ‘leather’ covers such a wide range of materials. Kid gloves, for example, are made of leather and so are horse saddles. But a machine that is suitable for sewing kid gloves would be completely useless for sewing horse harness and vice versa.

      Any decent, antique machine that can sew a wide range of fabrics will happily sew the kind of leather you’d use for garments or upholstery. If you are wanting to sew horse harness, you really do need one of those Industrial Singer 133K type machines, to achieve a professional job and to avoid damage to the machine.

      A 306K will be fine for garment type leather. However, sewing on embroidered badges is quite a challenge for any machine, simply because some badges are themselves, quite thick and heavy. Sewing fabric badges to leather is also combining two dissimilar materials, for which you’d ideally be using different needle points.

      Here’s what I recommend. Use a size 14/90 or 16/100 needle with a normal sharp point, Don’t use a leather point needle because you’d probably cut the embroidered threads in the badge. Use a good quality polyester thread. You can’t really pin your badge to the leather jacket so I suggest you use some double sided tape to hold it in place while you sew. I use double sided tape very often in my leather and vinyl work. I wouldn’t use the electric motor for this kind of work. I very often operate my machines by turning the hand wheel by hand. It’s still infinitely faster and neater than hand sewing (for me, anyhow).

      Good luck with your project and I hope this information is of some help.

      Kind regards,


  5. Hi Andrew,
    Just got given a 306k22 (i think) and noticed that the needle touches the bobbin casing when I turn the wheel. This happens even without the bobbin case in there. The needle seems to be more forward in location. Not sure if this has been retimed though. Any thoughts?

    • Hi Katrina,

      I wonder if it would be possible for you to photograph this problem and send me some pictures. I have tried to visualise your issue based on your description but I’m afraid its beyond me.

      Also, would you feel confident to attempt adjustments to your machine? If so, I can help you obtain a full service manual for your machine without cost. It might help you to identify the problem yourself. However, the copy that I have is rather poor in terms of scanning quality.

      You can email me directly at

      Thanks for your question.


  6. Tnx for all this. Before trying out your suggestion, I’m wondering why you didn’t consider cutting off the longer needle at the top. It seems it would still leave enough of the semi-round section to have it hold. Any comments? Tnx

    • Hello Sissi and thanks for your question.

      Standard 15X1 needles are dimensionally identical to the 206X13 needles that the swing needle Singers use, in every respect except for the distance between the eye and the needle point.

      If you remove metal from the upper end of the needle shaft, this will have the effect of raising the eye of the needle from its standard position.

      The position of the needle eye is critical to the machine’s timing and to its ability to form a stitch.

      So the short answer is that I don’t think the machine will work with a needle that has been modified in the way that you suggest.

      Kind regards,


  7. I am really glad to find the info you have posted on here about bobbin modification. I found a really nice black singer 306k and bought it before I found out about the needle situation. I bought the machine to do auto upholstery work and realize I probably need a #18 needle which isn’t available. I am totally new to sewing. I have tried the machine out and it runs beautifully and smooth. I am going to try your bobbin mod so I can use other standard needles. If I am going to sew vinyl and leather what size would you recommend after the mod is done? Thanks

    • Hi Frederich,

      Congrats on getting your hands on a black 306K. Mine are tan and brown coloured and I’d much prefer a black one. They seem to be very rare in my part of the world. I’m certain that a 306 will be an excellent machine for sewing upholstery vinyl and light, chrome-tanned leathers of the kind you’d use for upholstery. I’ve certainly done quite a lot of vinyl and leather work on mine.

      Do you have an instruction manual for your machine? If not, let me know and I’ll get one to you.

      Please be aware that the bobbin case modification idea isn’t new and there are also alternative bobbin cases out there that will fit the 306K and that will provide the necessary clearance for using a standard 15X1 needle. Many machines that are available on the second hand market might already have a suitable bobbin case installed.

      To check your own machine:

      “in testing your existing bobbin case. There really isn’t much to it.

      Unthread your machine and remove the bobbin (put in an empty bobbin, if you have one handy).

      Reinstall the bobbin case, with or without an empty bobbin installed.

      Select your basic zig zag lever (319 or 320 models) or instal your #1 zig zag cam (306 model) and set your stitch width to maximum.

      With a standard 15X1 needle installed, tilt the machine back in its cradle, so’s you can see the bobbin case and turn the machine handwheel over towards you by hand. You will see the needle descend into the hollow area in front of the bobbin case (beside the bobbin). As you turn the handwheel, the needle will alternate between the extreme right and left needle positions.

      You simply need to watch the needle point as the needle descends. If it doesn’t touch any part of the bobbin case at its maximum descent, then your bobbin case is suitable for use with standard needles. Check the descent on both sides of the needle swing (i.e. turn the handwheel through quite a few revolutions).”

      You might well discover that your machine is already “standard needle capable”! You will need to perform this same test with any bobbin case that you modify.

      I recommend you use a #18, leather point needle for both leather and vinyl. That is actually the largest size that you can use in these machines anyhow, according to the manual. I use #40 bonded nylon thread. It is strong enough (by far) for upholstery work and fine enough that it will feed through your machine without problems.

      If I can be of any further help at all, please don’t hesitate to email me (

      Kind regards,


  8. I have a 306K which I just replaced the timing belt on and because that was so difficult to do, ie many belts tried before found the right one, somehow, the bobbin assembly is now freewheeling and the needle does not make any connecton with the thread in the bobbin case. I can adjust the bar and make the bobbin case not move but that doesn’t fix the problem.
    What is the bobbin case and bobbin supposed to do when the machine is working properly? Any ideas on a fix? Thank you Terry

  9. Re 306k: bobbin assembly and holder do not move or connect with needle and thread. How do I fix? Bobbin assembly either freewheels or is solid depending on how tight I set the set screw, but still upper and lower do not connect. Is the bobbin assembly supposed to move when the machine sews properly? Thank you Terry

    • Hello Terry,

      Sorry to hear you are having difficulties with your 306. If you stick with it though, I’m sure you’ll manage to get it running and you will have what is (in my opinion) one of the best sewing machines that Singer ever made.

      There is a repair manual available from the ISMAcs site that will provide you with all of the information you need. It is a 16 Megabyte file but worth having. The link is

      As I understand it, the short answer to your conundrum is:

      The sprocket that is driven by the main drive belt (what you are calling the timing belt) drives the shaft that connects to the gearbox from which the hook assembly is driven.

      When the machine is working normally, the hook assembly should rotate as you turn the hand wheel. The spindle part of the hook assembly, onto which the bobbin case clips is held stationery by a metal ‘finger’. So the hook rotates but the bobbin case should not.

      The hook assembly is held onto its drive shaft by two screws and it is these that are loosened, when you adjust the hook timing. When they are tight, the hook will rotate as the hand wheel is turned. The hook assembly should never ‘free wheel’ but, when it is set up properly i.e. when the two screws that secure it to its drive shaft are tightened) the hook assembly should rotate, driven by the gearbox that is attached to the lower drive shaft which is in turn driven by the lower sprocket of the main drive belt.

      If you download the service manual, I’m sure you will be able to figure it out. Trying to work on machines without access to the proper service information would make for a very difficult task.

      If I can be of any help to you, please email me ( and I’ll do my best to assist.

      Best of luck with it,

      Andrew Caddle

  10. Interesting your modification of the bobbin on the 320K, but if the difference between the 206 x 13 needle and the 15 x 1 is only the length. Would it be possible to just grind off 2mm from the end of the 15 x 1 needle, to make them the same length ?

    • Hello Roger and thanks for your question.

      The two needle types are dimensionally identical in every respect, except the distance from the hook eye to the point.

      To ‘convert’ a 15X1 needle into a 206X13, you’d have to grind that 2mm off the point of the needle. While it might be technically possible, I don’t think it would be practical. You’d certainly be hard pressed to refashion the needle point into something resembling the point that was required. If you ground the extra length from the needle shank, you’d effectively move the needle eye up 2mm which would throw off your machine’s timing.

      Also, modifying a bobbin case is not difficult and requires that you perform that modification only once ….. as opposed to having to modify each and every needle that you wanted to use.

      My personal preference is to exchange the bobbin case with a replacement one that already has the necessary additional space to accommodate the 15X1 needles.

      Modifying the bobbin case is not a new idea. In fact, most of the machines that I have purchased here in Australia, already had bobbin cases (either modified or after market) that were suitable for 15X1 needles.

      The first step in ‘converting’ a machine to use standard (15X1) needles, is to test to determine if it has already been carried out. Instructions for testing your own machine:

      “in testing your existing bobbin case. There really isn’t much to it.

      Unthread your machine and remove the bobbin (put in an empty bobbin, if you have one handy).

      Reinstall the bobbin case, with or without an empty bobbin installed.

      Select your basic zig zag lever (319 or 320 models) or install your #1 zig zag cam (306 model) and set your stitch width to maximum.

      With a standard 15X1 needle installed, tilt the machine back in its cradle, so’s you can see the bobbin case and turn the machine handwheel over towards you by hand. You will see the needle descend into the hollow area in front of the bobbin case (beside the bobbin). As you turn the handwheel, the needle will alternate between the extreme right and left needle positions.

      You simply need to watch the needle point as the needle descends. If it doesn’t touch any part of the bobbin case at its maximum descent, then your bobbin case is suitable for use with standard needles. Check the descent on both sides of the needle swing (i.e. turn the handwheel through quite a few revolutions).”

      You might well discover that your machine is already “standard needle capable”! You will need to perform this same test with any bobbin case that you modify.”

      Hope this info will help.

      Kind regards,

      Andrew Caddle.

  11. Hi I have just inherited a 320k2, which was my grandmothers. She had it from new and it has all it’s accessories and is in good condition. I was very interested to read you post on modifying the bobbin case as I am desperate to be able to use this beautiful machine and remember watching my grandmother use it when I was a child. My only other concern is that it may need rewiring, if that is at all possible, as the wiring is also original and possibly doesn’t conform to current standards!

    • Hi Ursula, It’s really nice to know that your grandmother’s machine is staying in the family and that you know its history. That will doubtless add to your enjoyment of your machine.

      Personally, I’d much rather obtain an alternative bobbin case that already features the necessary design modification. If that isn’t available though, then I can assure you that modifying the existing bobbin case is no great difficulty to anyone who is handy with mechanical things.

      Perhaps check out the Australian Ebay trader that I’ve referred to. If she is willing to post overseas, I think you’d find her prices and service very satisfactory.

      It is certainly possible to have a machine rewired and it isn’t a particularly difficult operation. However, it is a job for a competent, trained electrical tradesperson. In many jurisdictions, it’s illegal for non-qualified people to work on electrical cabling.

      Having said that, unless there is some visible evidence that the existing cabling is suspect, it should suffice to have it tested. No point mending that which isn’t broken.

      I do hope you’ll enjoy your 320K2. I have one and it is a pleasure to use. They are a grand machine and I think they are a significant Singer from an historical perspective.

      If I can be of any help whatever in getting your machine sorted, please don’t hesitate to email me.

      Kind regards,

      Andrew Caddle.

  12. My 306k appears to work fine with the standard needles, although I have not tried zigzag. My wife used this machine most of life with the standard needles. She never even heard of the special needles.
    I am presently involved in a project to do some upholstery work on my own car, and I can’t seem to increase the stitch length enough. When I count the stitches per inch, I get more than the machine setting of 6. I have looked at the mechanism that controls the link and it doesn’t appear worn. I also have a walking foot adapter installed. Is there any way I can increase the stitch length?

    • Hello Ted,

      I’m sorry it has taken me so long to reply to your message. The fact is, Ive spent quite some time trying to locate an email exchange that I had with another Singer owner regarding this issue but I haven’t been successful. So all I can offer is my fuzzy recollection that, in that case anyhow, the lever which regulates the stitch length control was actually bent and was preventing the full range of stitch length being selected. The owner was able to straighten the lever and it worked fine thereafter.

      With respect to the use of standard needles, the modification that I advocate isn’t new and has been used for many years, especially here in Australia. These machines are very old now and there must be many thousands of them that were modified to use standard needles a long time ago. I have four 306K’s, a 319K and a 320K2 …. and almost all of them came to me, already modified for standard needles.

      I am attaching an extract form a service manual for swing needle Singers. Although the illustrations aren’t at all clear, I hope that the information might be of some use to you.

      With kind regards,

      Andrew Caddle

  13. Amazing site, thank you for your efforts Andrew. I love my 306W so much I have recently ordered a 306K. The decorative stitching is best of any other Singer machine I have seen. Have pulled my hair out over the needles, until I realized that HAx1, with a new modified bobbin case work fine in 90% of situations. What I have used as a successful substitute is industrial DBx1 needles. They are identical to 206×13 in all respects, except they are round shank and not flat. They physically fit into the needle clamp, you must pay careful attention to the orientation of the needle with the long scarf in back and the eye facing forard. I find inserting the needle with a pair of flat tweezers holding the 2 flat areas of the needle around the eye, allow easy insertion and orientation. So far have used DBx1 sizes 9BP, 16 and 18 in the 306w with no issues.

  14. Thanks for your work.
    For better photos, you can simply use a good hand magnifying glass, in front of your camera lens. You can use x3 , x6 etc. And x20 put on smartphone lens. Some hypermetrop spectacles also. Also lenses taken from old camera lens : dont put it to dishes !

    • Hello Jerome and thanks for the suggestion.

      The problem with photographing the bobbin area of the machine wasn’t that I didn’t have a suitable close-up lens. It is simply impossible to get the camera’s lens close enough to the bobbin area. There is very limited space when the machine is tilted back on its hinges. I agree that better results could probably be obtained with something like a mobile phone or even a computer web cam. However, I thought the images were adequate to demonstrate the principles that I was trying to explain. I hope the information was of some help to you.

      Kind regards,


  15. Hi Andrew, I own a Singer 320K2 which I bought from a retro shop. Do you know anything about getting a replacement belt? Thanks for your blog! Alegria

    • Hello Alegria,

      To my best knowledge, the Singer 206, 306, 319 and 320 machines all used the same timing belt.

      I’m only aware of one supplier in the United States who currently lists this belt:

      Your alternative would be to find a donor machine that has a belt in good condition. In my experience, there are a great many of these machines that don’t appear to have seen much use and they can often be picked up on Ebay and Gumtree very cheaply. Your local rubbish dump recycle shop is also a likely source.

      It really depends on how seriously you want to restore your 320K2. They are a relatively rare machine though and it would be a real shame if it wasn’t restored. The other models that I’ve listed are much more common and are therefore a likely source of a donor belt. Personally, I reckon I’d be checking out the above supplier and opting for a brand new belt …. given the relatively modest cost and the fact that the real ‘expense’ would be in the effort of fitting it. A donor machine belt, no matter how good, will nevertheless be very old already.

      If you simply can’t source a replacement, please let me know and I’ll see if I can’t conjure one up locally from down here in Tassie.



  16. I’m going to check out a 306 (not sure of the model letter) in the coming week. Is the modification needed if only a straight stitch is to be used? -Sue

    • Hello Sue, The short answer to your question is no. If you are only straight stitching with the needle at the central position, there’s no danger of it striking the bottom of the bobbin case. The problem only manifests itself when zig zagging and the needle comes into contact with the sides of the recess in the bobbin case.

      I suggest that you make sure by simply turning the machine over gently by hand with no thread in the bobbin or needle and with a standard needle in place. If the needle doesn’t contact anything during a couple of full cycles, then it won’t when you are actually sewing. Try this on zig zag too. You just never know. Your bobbin case might already have been exchanged for one that can accommodate standard needles.

      It would be a great shame though, to have a 306 and to only use it for straight stitch. They’re such a versatile and capable machine.

      Kind regards,

      Andrew Caddle

  17. Thank you for your response. I picked up the machine today, turns out it is a 306w. I brought some vinyl to sew and it sewed beautifully, through 6 layers. I did try the zigzag and nothing hit, the woman said she put in a new needle (she didn’t know about the needle issue). Anyway, I saw the motor belt was looking pretty bad, and it did snap. I took the machine home (no charge) but am hoping that you have a source that shows how to replace this belt. It is a round one, I’m sure no where near original. I did find the manual online.

    • Hi again Sue, you can download a PDF file of instructions for changing your drive belt from:…/Sewing%20Machine%20Belt%20Size%20and%20instal There are lots of sources for replacement drive belts but the folks who produced these instructions are probably worth a look if they are in your country.

      The 306 is certainly a robust machine. I recall sewing zig zag with almost zero stitch length through a foolish thickness of stretch denim, just to make a point. I’m not sure that I’d want to make a habit of it though. I did feel that I was abusing my machine. If you are talking upholstery weight vinyl, six layers sounds like a lot although any machine worth its salt should routinely cope with four. I make a lot of vinyl items including piping and my machine will sew four layers happily. Even better though, is an old cast iron 103K treadle … which is my go-to vinyl machine.

      Did you really get your 306 free of charge? That would be just wonderful. I paid $60 AUD for my first one and it was missing parts. I had never seen one way back then though and didn’t know what I was getting into. the 306 is easily my favorite swing needle Singer now.

      Is your machine the model that uses the ‘fashion disks’? And if so, do you have them?

      Would love to hear how you are getting along with it.

      Kind regards,

      Andrew Caddle

  18. I liked this question and answer;
    (thank-you for the discussion, before I forget my manners!);
    whilst I agree that the practice of grinding new needle points might take some time to perfect, I think it is a useful skill to have as any needles can then be sharpened – in preference to being disposed of – and (the sewer) should be mindful of a needle\’s condition, together with other regular maintenance for their machine *whilst avoiding distractions from their sewing, such as a new grinding hobby….!

    • Hello and thanks for your nice remarks. I agree completely, that sharpening used sewing machine needles is a worthwhile thing to do. The idea that needles should be disposed of as soon as they become dull is symptomatic of much that is wrong with our world today. In times past, people who sewed in factories for a living were actually required to provide their own needles (at a penny each, apparently). Resharpening needles on a small stone was routine. They didn’t just throw them away when they became blunt. One of my machines, a Singer 66 treadle, came with a small sharpening stone in one of the drawers and it has a distinct groove worn in its side from regular needle sharpening.

      I’m not sure that I’d bother trying to refashion the point of a needle though, to have it perform some alternative function. Creating or maintaining the correct profile for (say) a leather point needle would, I imagine, be extremely difficult. No doubt, a standard 15X1 needle could be re-ground at the point to make it into a home grown 206X13 but I think the bobbin case mod is a far more logical approach.

      I spend a great deal of time sharpening all manner of blades …. chisel and plane blades, knives …. even scalpels and utility knives that are intended to be disposable. There is a real pleasure in taking time over this process. I do sharpen my sewing machine needles but wouldn’t attempt to re-grind one.

      Apologies for being so tardy in responding. I’m afraid I don’t spend as much time on my website as I once did.

      Best regards,

      Andrew Caddle.

  19. thank you verrrry much my friend.. Recently acquired a 306K from folk who wouldn’t sell to “traders”.. lucky me. She’s a beauty (black, I may let you stroke her) running smooth and quietly powerful. I wanted those specific things only her and her sister 319 can do. Just why they are dismissed I cannot fathom. They were obviously designed as commercial and a real gift to the domestic market. My favourite, of 14 machines.

  20. I came by a 320k eleven years ago and it worked well enough after a bit of oiling but the lack of modern needle options and some dire warnings about the limitations of the machine made me think it was rather weaker than it looks. A month ago I had a go at turning it over by hand with a 15X1 needle and saw that the damage on the top of the bobbin case has nothing to do with the extra needle length. This led me to your excellent blog posting about gaining the clearance in the bobbin case half moon and a quick removal of about 1mm from the right side with a mini grinder did the trick. I also ordered a second bobbin case from China which turned out to be Taya brand. In the listing the half moon looked a bit asymmetrical so I hoped it would work without modification but in fact the tip of an 18 universal needle will touch with the backlash taken out anticlockwise so I\’ve taken a little out of the new bobbin case too.
    The machine is running well and the longer sharper point of a jeans needle penetrates tough fabric with less of a thump than the 206 X 13. The hook area is a bit noisy but I haven\’t found out yet how to take out end float from the shaft that takes the hook. The 319 service manual identifies end float here as a source of noise. The instructions mention a collar adjustment for this purpose but the collar doesn\’t exist on the 320K as far as I can see. There is a screwdriver slot in the exposed end of the shaft which could be related but I I\’m loath to put much force on it without more information. If you have access to the 320K service manual, an exploded parts diagram or any ideas on this adjustment I would welcome advice.

    • Hi Jay and congratulations on your web site ( I did enjoy having a browse there.

      I’m always attracted to the notion of making do with what we have at hand and your approach to shortening machine needles sounds very much ‘up my street’. However, I wouldn’t recommend modifying sewing machine needles for use in swing needle Singers. Doing one simple modification to the bobbin case enables the use of the full range of standard needles thereafter. The construction of sewing machine needles is a rather specialised business and there’s a surprising variation in point styles. There’s a good article on this issue at

      While I’m sure a ground down needle would be perfectly functional for many uses, I doubt it would provide the kind of optimal performance that many sewing folks require. I can’t imagine it would be possible to duplicate the many point styles that seem to be on offer. Achieving a level of sharpness and smoothness that a factory produced needle will provide would likewise be problematic.

      Just out of curiosity, can I ask what machine you are using the ground down needles in and what kind of work you are doing with it? Also, what style of points you are able to achieve.

      Kind regards,

  21. Hi Andrew! Great info, I have an obsession with 306ks and own 7 of them! I love returning them to tip top shape. I have found a DBx1 needle to be a great replacement. It is round shank instead of flat, but with a tweezer it is really easy to insert the needle and get the short scarf perfectly aligned to the rear. Never had a needle strike on unmodified machines, plus the full range of DBx1 is available. I purchase off the auction site from Maimintechnology, he sells 30 for $6.75. I started a blog on the 306 range, the page on the Singer lawsuit has some very interesting info gleened from the legal papers about the genesis of the 206, 306 and 401 ranges. Have a look!

    • Hi Scott,
      Yes, I’m aware of the DBX1 needle sudstitution. It has been around for awhile×13-needles-t220672.html (just the first Google result I pulled up).

      The truth is, people get all excited when you start trying to inject common sense into this debate. There’s even a vintage singer machine site where discussion of this topic is taboo …. That’s right, rational discussion is actually banned because it conflicts with the ‘conventional wisdom’ of the ‘gurus’ who run the site.

      I am getting towards the latter end of my life and I decided that I don’t want to waste any of the precious moments that I have left, trying to educate people who choose to be willfully ignorant. So I have given up trying to convince people.

      I can only say that I USE 15X1’s with zero problems (using a modified bobbin case). You USE DBX1, apparently with zero difficulties. The gurus SAY that you can only use 206×13 (but I doubt they USE these machines at all).

      Thanks so much for taking the time to share your information. I have shared it here in the hope that it will be of help to others.

      My experience is that despite extensive experience in actually using these wonderful machines and despite presenting compelling evidence in support of needle alternatives, you will NEVER convince the self-proclaimed experts. One of the chestnuts that you’ll constantly read is “If Singer could have made these machines to work with that needle, they would have”. The fact that they might have been trying to lock other needle producers out of selling needles for Singers is totally lost on people. Whatever the truth, the 206×13 needle ‘experiment’ was very short lived but the swing needle Singers (206, 306, 319 and 320) represent a critical point in Singer history. That’s good enough reason to preserve and love these wonderful machines and to do all that we can to keep them in service. I wonder how many perfectly good machines made it into landfill because of the dogma that you must use 206X13 needles.

      Kind regards,


  22. Hi Andrew! Great info, I have an obsession with 306ks and own 7 of them! I love returning them to tip top shape. I have found a DBx1 needle to be a great replacement. It is round shank instead of flat, but with a tweezer it is really easy to insert the needle and get the short scarf perfectly aligned to the rear. Never had a needle strike on unmodified machines, plus the full range of DBx1 is available. I purchase off the auction site from Maimintechnology, he sells 30 for $6.75. I started a blog on the 306 range, the page on the Singer lawsuit has some very interesting info gleened from the legal papers about the genesis of the 206, 306 and 401 ranges. Have a look!

  23. Hi Andrew, Thanks a lot. I bought a 306k last week and after finding out about the needles I was lucky to find your information. Very clear and the modification is a peace of cake. It works fine now with a standard needle.

    • Hi Alex and thank you for taking the time to share your experience. Perhaps if enough people followed your example, we could encourage others to enjoy these great machines ….. without being put off by all the mis-information that has been propogated by the ‘Gurus’ on other websites.

      Many thanks,


  24. Hi Andrew i picked up a singer 306k and did what you suggested with regular size needles and the needle never touched the bobbin case so i think the case has been modified which is good. Lovely machine smooth and quiet.

    • Hi David, I don’t know where you’re located but most of the machines that I’ve collected here in Australia already had aftermarket bobbin cases that, as you say, provided ample clearance for standard needles. I have a 320K, a 319K and several 306’s and they all perform flawlessly with standard needles. The endless claims that these machines can’t perform correctly with standard needles (despite overwhelming evidence to the contrary) just amazes me. Thanks for sharing your experience.

      kind regards,

  25. Very happy to read about that Bobbin modification…I’ve a collection of machines including a 319 and just bought a 306k in a table. I suggest the reason Singer shortened the needle tip was simply because it was cheaper or faster to modify the needle line than it was to alter the bobbin line. The bobbin mod is simple for just one Bobbin but if you need to alter multiple machines in different parts of the world it can become quite expensive.
    My new $50.00 306K came with a cabinet which has been raided for its fittings. I purchased printed copies of the pats manual, the service manual and the deluxe operating manual but cant seem to find a manual or parts list for the table. Its the rather plain table with single folding lid and single fold out ‘draw’. I now have everything except the lift mechanism but don’t know what sort or which orientation (left or right sprung) to get. My mother had an identical machine which went to my sister when she updated in 1980 and was subsequently sent to vinnies…and my vague memory is that the lifter plate was flat with maybe one hole but those online have two holes which match nothing and I can’t find the screw locations in the cabinet. Are you able to help>

    • Hello Michael,

      I’m afraid I can’t be of much help when it comes to machine tables. I’m not aware of Singer machine cabinets that incorporated a lift mechanism, except for the ‘parlor cabinets’. Is it possible that you’re referring to an aftermarket machine table, like say a Horn brand? I have several simple tables where the machine folds down into the table but none has a lift mechanism. The machine simply swings on its hinges from the stored to the upright position.

  26. Hello everybody,
    here another newbie!! I just got my first machine. It is a 306k. It works well with the original sized needles and i am able to use 15×1 needles to, BUT…

    I only can use 15×1 needles in the most right needle position (zigzag center to the right) otherwise my needle strikes the hook assembly. The bobbincase is working well. What to do … retime the hook or grind a larger slot in the hook assembly?

    Thanks in advance

    • There is no circumstance where it would be appropriate to either re-time your machine or modify the hook mechanism. The symptoms you describe suggest that your machine has an original bobbin case, a design that was intentionally fashioned to prevent the use of any but 206X13 needles. You need to find an alternative bobbin case or modify the existing one, as discussed elsewhere on this site.

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