chrisash Report post Posted June 13, 2019 Just a experiment unless someone has tried before, and found it does not work I am willing to make a nylon replacement gear for say a singer 29K that is no longer available, for free including postage as a experiment to how long it would last Just need one person to supply image and full set of dimensions for the replacement both external and internal measurements and i will try to make a nylon copy, preferably something relatively small If someone has tried it before and it was not strong enough please tell me and i wont bother, but many modern machines have nylon gears that work ok if not under great pressure, hence my thoughts on the 29k especially say the small gears in the bobbin area Nothing ventured nothing gained, happy sewing Quote Share this post Link to post Share on other sites
Matt S Report post Posted June 13, 2019 I don't have a 29k but great idea! I'll keep you in mind for a few projects that I've got on the back burner, if you're amenable. Quote Share this post Link to post Share on other sites
chrisash Report post Posted June 13, 2019 (edited) Hi Matt Go for it mate, probably not long lasting on the heavy duty ones but a low cost probably under £5 say $6 not a great problem if they just last 6-12 months (who knows) and maybe keeps the old iron working Sample enclosed Edited June 13, 2019 by chrisash Quote Share this post Link to post Share on other sites
mikesc Report post Posted June 13, 2019 Domestic sewing machines ( modern ones, almost all brands, even the ones that cost more than an industrial clone, use nylon gears ) which is why they don't last long, and break, especially when sewing thicker than 69...many don't much like 69 ( most are not happy sewing with thicker than 45 )..nice thought though. :) Quote Share this post Link to post Share on other sites
Matt S Report post Posted June 13, 2019 48 minutes ago, mikesc said: Domestic sewing machines ( modern ones, almost all brands, even the ones that cost more than an industrial clone, use nylon gears ) which is why they don't last long, and break, especially when sewing thicker than 69...many don't much like 69 ( most are not happy sewing with thicker than 45 )..nice thought though. Yes but there are a lot of factors in the longevity of any mechanical part, such as gears. The material is but one. If I had a machine that I could not run without a certain part I would far rather have a short-life copy of a part I could afford to replace every so often than a part I could not afford to buy, or that was simply not available. For a hobbyist or collector simply being able to run that machine would be worth the price of entry. For a professional that part would help in producing enough product to replace the part with a "proper" part or upgrade to a better machine. Further, for many machines technical drawings for replacement parts are not freely available. Being able to rapidly and inexpensively prototype replacement parts in order to test design and function prior to investing the time and money in producing that part in proper material would be an enormous advantage. Quote Share this post Link to post Share on other sites
mikesc Report post Posted June 13, 2019 Yes, I'll grant you all of those points, but..bear in mind, if a nylon part is going to be made from a metal one, the metal one has to be perfect, unused, or, the nylon part will come with built in wear..and will last even less long..I don't think any of us has a perfect unused" gear from a 29K.. If anyone has, it would be better , IMO, to make a replacement in metal..Some parts ( I think even some gears for 29Ks ) are already available in metal..not used.. Quote Share this post Link to post Share on other sites
Matt S Report post Posted June 13, 2019 8 minutes ago, mikesc said: Yes, I'll grant you all of those points, but..bear in mind, if a nylon part is going to be made from a metal one, the metal one has to be perfect, unused, or, the nylon part will come with built in wear..and will last even less long. Only if you're making an exact copy of that worn part. Extrapolating the original dimensions, using a combination of all available evidence, experience, and some trial and error, is up to the individual. Being able to rapidly and cheaply produce iterative changes to that part design is a huge advantage and could make the difference between "viable" and "nonviable". Once you have a working prototype a bunch of them can be sent out for trials in other machines if you're wanting to produce in quantity (for different usage parameters and in a wider tolerance range). Once confirmed as final the drawing files can then easily be sent to a company with facilities for more appropriate materials (metal sintering 3D printer, or a CNC machining centre), modified to produce dies for metal injection moulding, or to a more traditional machinist who will turn the blank and mill the teeth. I acknowledge that it would be better to start from a NOS or at least functional original part though! Quote Share this post Link to post Share on other sites
mikesc Report post Posted June 13, 2019 (edited) If it were me, I'd go direct to CNC..The risk of a nylon part breaking during work and ruining the work itself , would not be worth it..to me.. But, nothing holding either of you back, using plastic for prototyping is one of the major benefits of 3D printers, but making / using parts that will actually be used in production, where the original part would be metal and meshing with other metal like gears...not a risk that I'd take, like I said above, almost all modern domestic sewing machines use nylon gears, and with threads other than 45 ( which is what they are designed to run ) the gears strip fast..and that is nylon on nylon..Whereas being used as replacements as per Chris's idea in his OP, the gear would be meshing with the metal gear rails..The reason that most people who do a lot of sewing ( and especially those who move into leather work ) move on to industrials, or old cast iron machines ( both zig - zag and straight stitch ) is that the plastic / nylon gears strip on their domestics as soon as they try running 69 more than occasionally..Nylon is very soft compared to metal, I think that the two gear rails would chew it up very fast.. However if the pair of you are going to try it as an experiment What it has made me think of , is that I should get some replacement metal parts made for mine ..and to keep looking out for additional Adler and Singer Patchers here, I can always stash them with a neighbour until I can make space for them, next to the cylinder arm that I've got to make space for in order to be able to buy it..I may have to extend the atelier..again..or..build another living room so as to be able to take over the current one for sewing machines, thus freeing up more space in the atelier for other things.. It is either that or make an offer for the semi-ruined villa on the land next to our garden.. Edited June 14, 2019 by mikesc typos Quote Share this post Link to post Share on other sites
Constabulary Report post Posted June 14, 2019 looks like a fine toothed gear for the 29K5X series. I think you could increase the longevity when you replace all 3 pinions and the rack with nylon parts. Quote Share this post Link to post Share on other sites
chrisash Report post Posted June 14, 2019 One area where Singer seems to help is that they have photographs of their parts in the parts lists, these can be imported into the cad software and adjusted to the correct dimension by using the data from the broken piece, but maybe replacing a worn part as worn might be a better solution as all corresponding parts are also worn , good arguments for either action. The reason i suggested the 29 was as its low speed, generally used on light leather and seems a lot of parts are no longer available for the popular No 4 series The cost of making is low compared to metal (which is coming down all the time), but few people will invest good money on making low moving steel replacements for retail Naturally its not confined to sewing machines, hobbyists have meen making them for years on different items Quote Share this post Link to post Share on other sites
