AlZilla Report post Posted July 2, 2023 5 hours ago, Ana1234 said: Just one more thing, with everything fitted and I've achieved that slow stitch how fast will I actually be able to go after that? I went to the pulley calculator and entered in my setup on the 2 set calculator. At 200 rpms it says I should have 57 rpms at the hand wheel. I counted 52, so close enough. Then I raised the motor speed to 5000 on the calculator and it says I should have 1429 rpms. I'd be pretty confident in 1400 or so top speed, based on that. There's a real world data point for you. Quote Share this post Link to post Share on other sites
kgg Report post Posted July 2, 2023 23 minutes ago, AlZilla said: I'd be pretty confident in 1400 or so top speed, based on that. There's a real world data point for you. I think the slight difference between actual vs the program is the program numbers are based on the inside diameter of the pulley rather then the outside dimensions. I did edit my previous post to show I assumed a 85 mm diameter hand-wheel pulley. kgg Quote Share this post Link to post Share on other sites
dikman Report post Posted July 2, 2023 Regarding top speed, servos have various parameters that can be set in the control box. One of them will be setting top speed. When sewing leather most will set this lower, as high top speed is generally not a consideration, but if you feel you need a higher speed at some time you can set this parameter higher and then drop it back after. With a reducer fitted it still won't be super-fast but may be sufficient for your needs. If you only have one machine then setting it up will always be a compromise. I have fitted my motors from underneath, once you have the clutch motor removed it's pretty easy. BUT be careful removing the clutch motor, they are very heavy! Stick with a reducer, like kgg linked to, it will be the simplest option. Forget about building your own reducer and/or replacing the handwheel for now, I only mentioned that to show what options are available, they're not for the beginner. If you're getting the tech to do it then fitting a servo and that reducer should be a pretty easy job. Quote Share this post Link to post Share on other sites
AlZilla Report post Posted July 2, 2023 (edited) 4 hours ago, kgg said: I think the slight difference between actual vs the program is the program numbers are based on the inside diameter of the pulley rather then the outside dimensions. I did edit my previous post to show I assumed a 85 mm diameter hand-wheel pulley. kgg Well, especially with my 3.5" hand wheel, which I laid a ruler across and eyeballed. I thought 57 vs 52 was pretty close. Any of those pulleys could be slightly off exact claimed spec. These are really not precision parts we're playing with. I think with all the data in this thread, anybody could get a very close estimate with high confidence. Edited July 2, 2023 by AlZilla Quote Share this post Link to post Share on other sites
xnikolaos Report post Posted July 3, 2023 (edited) I'm a bit of a latecomer but I'll share my experience. I have bought three 750watt servomotors from AliExpress, duty free, and I was pleased. Company VEVOR on alliexpress. It has two pulleys 45mm and 70mm and an automatic needle positioner. You need someone with basic DIY knowledge to install. 120€. I live in Greece. Edited July 3, 2023 by xnikolaos Quote Share this post Link to post Share on other sites
dikman Report post Posted July 3, 2023 Vevor obviously don't make everything they sell but the quality of the goods they sell appears to be very good. I bought a Vevor air compressor and I'm impressed with the build quality. A chap I know bought the same compressor and a heavy duty demolition hammer and he is very impressed with the quality of both. Probably a safe bet if you're not sure who to buy from. Quote Share this post Link to post Share on other sites
Ana1234 Report post Posted July 3, 2023 Thanks for tip on the servo. I will check that brand out! OK good to know I can increase the speed a bit although having fitted the reducer. It's really not a lot I'm talking about but I would need to work up the speed from time to time. A German distrubitor has these servos - KF 800 W (kraft sewing) €170 Hightex HVP € 235 I prefer buying from a dealer rather than Ali express, Ebay or Amazon in case I need some support or if something goes bad. Perhaps any of these are good?! Quote Share this post Link to post Share on other sites
kgg Report post Posted July 3, 2023 1 hour ago, Ana1234 said: A German distrubitor has these servos - KF 800 W (kraft sewing) €170 Hightex HVP € 235 What is the price for a 550 watt servo motor? I can see going with a 750 watt if their is only a few dollars in the difference but for your machine which appears to be very similar to the Juki DU-1181n a 550 watt should be able to do the job nicely. kgg Quote Share this post Link to post Share on other sites
Ana1234 Report post Posted July 3, 2023 The 500w is 100 eur Quote Share this post Link to post Share on other sites
dikman Report post Posted July 3, 2023 The price seems pretty good? A 550w will be more than enough for your machine. Those Kraft servos are what I would term generic, as in the only difference between them and other brands will be mostly cosmetic. The Hightex appears to be much the same as the first one you asked about. Quote Share this post Link to post Share on other sites
kgg Report post Posted July 4, 2023 1 hour ago, dikman said: The price seems pretty good? I agree that is a decent price. kgg Quote Share this post Link to post Share on other sites
xnikolaos Report post Posted July 4, 2023 Some Chinese companies, such as VEVOR, sell their product through European deposits. This means that the taxes have already been paid in the EU. As for the quality of the servos, in my opinion it is good but by no means comparable in quality to a good name brand European or American product. But as I searched I couldn't find a European servo motor manufacturer with reasonable prices for my pocket. Those who sell, that is, the sewing machine sellers, follow the same process as me. That is, they find a Chinese product, of dubious quality but cheap and sell it to customers at a low price with the guarantee of the store and not of the manufacturing company. I'm a hobbyist looking to find an inexpensive motor to play with and have fun with. If I were a professional I would have to allocate thousands of euros to meet my needs in a reliable product. Quote Share this post Link to post Share on other sites
Ana1234 Report post Posted July 4, 2023 (edited) Found this - https://m-eur.vevor.com/ac-servo-motor-c_11222/sewing-machine-motor-220v-750w-brushless-energy-saving-servo-motor-industrial-p_010611078687 Seams ok! The 550w is only 20 eur cheaper. Thanks for the tip. Free delivery! That's unusual... I'm just starting out so I'm on a budget as well. Edited July 4, 2023 by Ana1234 Quote Share this post Link to post Share on other sites
xnikolaos Report post Posted July 4, 2023 20,00€ Shipping Fees for SLOVENIA. Quote Share this post Link to post Share on other sites
xnikolaos Report post Posted July 4, 2023 (edited) From my experience. It is better if you go with this address (photo) and through AliExpress,. Delivery from Germany to SLOVENIA with DHL and without taxes and delivery costs. Edited July 4, 2023 by xnikolaos Quote Share this post Link to post Share on other sites
Ana1234 Report post Posted July 4, 2023 Ok thanks!! Did you buy a speed reducer by any chance that you installed with the servo? Quote Share this post Link to post Share on other sites
kgg Report post Posted July 4, 2023 42 minutes ago, Ana1234 said: I'm just starting out so I'm on a budget as well. We all have to start somewhere and as your needs / wants / ability changes you will probably either replace or add another machine. Being new to this venture or should I say addition I would get the 550 watt servo motor and not bother with getting the speed reducer for now. My reasoning is that I think you will find that just changing to a servo motor from a clutch motor you will be able to control the sewing speed fairly easily. The advantage is that you will very quickly figure out the sewing ability of the machine without the worry of over torquing the machines internals because of the additional torque (punching power) that the speed reducer will give you. Try some simple sample items in fabric and then leather. Give yourself a month to figure out the basics and quirks of your machine. Figure out how thick of what materials the machine can handle, best thread size to needle combination in different material of different thicknesses and what type of accessories that would make your projects easier like presser feet, binding / folding attachments etc. If after a month you are still struggling with the sewing speed and not what the machine can punch through then add a speed reducer. If you are unable to sew certain projects chances are the machines internal parts weren't designed to handle them and forcing the machine to do so by adding a speed reducer then nasty / expensive repairs are probably going to happen. The 750 watt servo motor I think is more suited to the upper end of machines in the upholstery class like the Juki DNU-1508 (and clones) and the 441 class machines like Juki TSC-441 (and clones). kgg Quote Share this post Link to post Share on other sites
xnikolaos Report post Posted July 4, 2023 (edited) Νo. No need for a speed reducer when using a 45-50mm small pulley servo motor (photos). You can manually operate the sewing machine (Hand crank) if you want an even lower speed. I will make a reducer for my pleasure (photos), from cheap Chinese materials, but it is not necessary. I can punch 5mm, chrom tanned leather at lowest speed (100-200Rpm) with easy, with 750watt chinese noname servomotor. Edited July 4, 2023 by xnikolaos Quote Share this post Link to post Share on other sites
dikman Report post Posted July 4, 2023 kgg offered some good advice. Start simple, get the best value servo you can (doesn't matter if it's 550w or 750w, either will work) and go from their. If you have some mechanical skills, which I suspect you have, then you should be able to fit a servo yourself, it's not difficult. Get some help to remove the clutch motor, though - unless you lift weights. Quote Share this post Link to post Share on other sites
Ana1234 Report post Posted July 5, 2023 10 hours ago, xnikolaos said: with 750watt chinese noname servomotor. What is this no name about? I went to the local sewing shop to take a photo of a servo motor. Owner whom is not at the shop currently said I should wait for him to get back as he has a servo motor in stock for me. I went there to check the brand to do some research but they could not give me a number, name or anything??! They took out a box but didn't open it for me or tell me any specs of the motor (other than that it is a 750w motor). Found that shadey... Quote Share this post Link to post Share on other sites
Ana1234 Report post Posted July 5, 2023 (edited) 7 hours ago, dikman said: - unless you lift weights I do but I'll get some help anyways. Mechanical skills I have non! But in the times we live in you can learn anything if you have wifi Edited July 5, 2023 by Ana1234 Quote Share this post Link to post Share on other sites
Ana1234 Report post Posted July 5, 2023 10 hours ago, xnikolaos said: I can punch 5mm, chrom tanned leather at lowest speed (100-200Rpm) Then the Vevor is to fast? It starts on 500rpm?! Quote Share this post Link to post Share on other sites
Ana1234 Report post Posted July 5, 2023 10 hours ago, kgg said: If after a month you are still struggling with the sewing speed and not what the machine can punch through then add a speed reducer OK! I'll go with this option then. You guys mentiond in the beginning that I should do both at once but I guess problem solving runs it's course and it takes time to get to the right decision. It's good though as I have learnt a lot! Quote Share this post Link to post Share on other sites
kgg Report post Posted July 5, 2023 14 hours ago, Ana1234 said: They took out a box but didn't open it for me or tell me any specs of the motor (other than that it is a 750w motor). Found that shadey... With some of the generic / no name / unbranded equipment like for servo motors the information isn't included other then the very basic. Technical information like how many coils the motor is constructed with or the torque rating probably will be non existent. kgg Quote Share this post Link to post Share on other sites
xnikolaos Report post Posted July 10, 2023 Chinese companies sell their products in Europe without any warranty but in consultation with the buyer. They do not have a representative office in any European country. The sale is almost illegal in the European Union. The selling store is obliged to give a guarantee of at least one year for the products it sells. Quote Share this post Link to post Share on other sites
