Constabulary Report post Posted June 16, 2014 (edited) After I had so much trouble with 2 different Servo Motors I was still using my old clutch motor - until today! Now that I needed spare parts for the restoration of my Singer 29K71 I thought I should give the JACK brand Servo Motors from College Sewing in the UK a try. I just got my order today. Ordered on June 11. - delivered June 16. by UPS. I have ordered Jack JK-561A-1 Servo Motor, 220V singe Phase, 750 Watts with needles positioning system. At the first glance the outer finish is very nice, it is well made and does not look cheap (not at all). Installation is very easy and it can be adjusted sideways over a good range so it is quite easy to add a speed reducer later (if desired). Unfortunately College Sewing has not much information on their website. So I did not know what size the pulley has. And they mentioned nothing regarding the highest and lowest speed settings. Anyway - it came with a 3" pulley. Top speed is 3500 rpm - lowest speed is 500rpm (regarding the manual) but this it the top speed at the lowest setting. So even w/o a speed reducer and with a 3" pulley it sews quite slow at the lowest setting and with my Singer 111 I can sew 3 layers of stiff military parachute harness without problem. And yet I don´t even need the speed reducer I recently have made. But I will install it no matter what. Needles positioning system works perfect (I set it to needle down) and them I push the pedal in the other direction the positioning system pulls the needle up - pretty cool feature! So from what I can tell at the moment it is an absolutely outstanding motor. For my purposes it works very well and with 750 Watts it has a lot of power - even without the speed reducer. I will test it a bit and will give more information in the days to come. Edited June 16, 2014 by Constabulary Quote Share this post Link to post Share on other sites
Constabulary Report post Posted June 19, 2014 I just finished the installation including the speed reducer. The lowest maximum speed setting is 500rpm but the motor starts at 200rpm regarding the digital display which is absolutely the slowest you can get with the pedal. No matter what the max. speed setting is - even at 3000rpm - you always can crawl at 200rpm and the speed reducer slows this down again. (Motor max. speed is 3000 rpm and not 3500 as I said at above post) Cool thing is that you can turn off the speed reducer permanently. On the backside of the control box it even has a socket for a 5V LED sewing light which is optional available. And I like that the control box is apart from the motor and speed regulator so you don't have to crawl under the table when you want to change settings. And it case something is damaged you don´t have to turn in the entire motor (just for the case). So I´m overall very very please with my purchase but I think I will order a smaller 50mm or 40mm pulley just to have the option to go even slower. Quote Share this post Link to post Share on other sites
VanRhodes Report post Posted June 19, 2014 I actually ordered the same one, right about the time you did and made a temporary install on my machine restoration project and I am very happy with the motor this far, plenty of power even at a slow speed and will easily handle 3cm of mil-w-4088 Type8 webbing. But what really made the difference for me was the fact that motor, controlbox and "throttle" were separated so that I can mount them where I please. Quote Share this post Link to post Share on other sites
Constabulary Report post Posted June 19, 2014 True! So far I really like it, though the included manual is really a pain in TA. holy cow - you are sewing 3cm webbing? Quote Share this post Link to post Share on other sites
VanRhodes Report post Posted June 19, 2014 Yeah, the included manual leaves alot to wish for, fortunantly its not a very advanced motor so the different features are fairly easy to figure out with the keys. I didnt get it with the needle positioner though, but I might very well order one and upgrade with it later. I did sew 3cm just as a test to see what its capable of but I doubt i will be working with that thickness later. I should probably update my thread regarding the machine I am working on when I get some time left over. Quote Share this post Link to post Share on other sites
Constabulary Report post Posted June 20, 2014 (edited) When you are sewing really slow you don´t really need the needle positioner because you can see where it will stop when you take the foot off the pedal. But it is a nice feature to have when you sew faster. BTW - I just noticed that the tag on my control box and the information on the shipping box say 563A-1 and not 561A-1. An updated model already? Edited June 20, 2014 by Constabulary Quote Share this post Link to post Share on other sites
VanRhodes Report post Posted June 21, 2014 Yeah, I have needle positioners on the machines at work but not on any of my own units as I am so used to them I dont really need it. But I am still considering a positioner for the heavy duty machine as I will mostly be doing W-W boxes and harness work with it. My box says 563A-1 as well. I remember College-Sewing sold the earlier 561A-1 a little cheaper to get rid of the stock they had so they would only have the new version on hand. Quote Share this post Link to post Share on other sites
Bertil Report post Posted November 10, 2014 Thanks guys this is really helpful, but I would like to know which other two servos Constabulary have tested and why they failed! I am in the process of buying a servo and need to know as much as possible before buying. My needs are focused on precision (slow stiching). Quote Share this post Link to post Share on other sites
Constabulary Report post Posted November 10, 2014 I had this one but with 400 watts http://www.ebay.de/itm/SERVO-MOTOR-mit-Nadelpositionierung-ZYT-250-W-/350886574903?pt=DE_Elektronik_Computer_Haushaltsger%C3%A4te_N%C3%A4hmaschinen_PM&hash=item51b2783b37 it made an unbelievable annoying "beeeeeeeeeeeeeeeeeeep" sound when it was running and the needle positioning system did not work properly (even without speed reducer) Not sure if they have updated the new models but I would not buy it again. The other one was unbranded and I don´t recall the model and I no longer see them for sell so I cannot provide a model name or a link. But it came from SEWTEX in Germany. It was a pain to deal with them - I finally got my money back from Paypal. The rest is history! I´m very very please with the Jack Servos and I recently have bought a 2nd motor. But if you have or need a speed reducer on your machine then the needles positioning system of the Jack servos will not work. But I figured I don´t need the NPS at slow speed as I can see where the needle will stop. So I ordered the 2nd motor w/o needle positioning system. Quote Share this post Link to post Share on other sites
VanRhodes Report post Posted November 10, 2014 Constabulary: why would the NPS not work when using a reducer? I ordered mine without it but I am considering ordering an NPS to try it out. Quote Share this post Link to post Share on other sites
Constabulary Report post Posted November 10, 2014 I think TROX or someone else explained in in an other thread, it is because of the belt slippage as far as I remember. I don´t know for sure if other sewing machines / other servos with NPS wok with speed reducers but my experience is that the Jack Servos do not! I´ll try to find the thread... When I look at the Cobra 4 and Cowboy 4500 it seems these machines also come w/o an NPS and both have speed reducers so I don´t know. I think it is a general issue when you are using speed reducers but I´m not sure... Quote Share this post Link to post Share on other sites
Constabulary Report post Posted November 10, 2014 (edited) Here is the thread: http://leatherworker.net/forum/index.php?showtopic=56955&p=365941 @VanRhodes Maybe it is different with your machine as far as I remember you have a fixed gear reduction mounted on your machine so there is no belt slippage... but I don´t know for sure. Just a guess. Edited November 10, 2014 by Constabulary Quote Share this post Link to post Share on other sites
VanRhodes Report post Posted November 10, 2014 Constabulary: I see. I do recall Trox mentioning that the NPS for the Efkas were there to calculate belt slippage, but as far as I can tell the NPS for the Jack Servos use indicators on the drive shaft/pulley to indicate the needle up and down positions, thus any reducers in between the motor and the machine should be irrelevant to the function of the NPS since one revelation of the drive shaft equals one cycle of the machine no matter how many rpms the motor is doing. Atleast thats the way I have understood it. No matter what, the price for the NPS addon to the Jack motor is cheap so its not that much of a loss if it doesnt work. Yes, I have fixed gear reduction and the additional reduction I am building has a timing belt with tooths as well. a Quote Share this post Link to post Share on other sites
Bertil Report post Posted November 10, 2014 My experience re. servomotors is from the packaging industry. The advantages with a servomotor compared to the normal electrical motor is that you can control: acceleration, speed, retardation and the exact position of the drive shaft. This should come in handy in a sewing machine. Obviously there are a lot of servos adapted for industrial sewing machines that don´t have these features. Since most sewing machine have belt drives you have to measure the rotation on the drive shaft. To calculate belt slippage is long term impossible. It will change over time and depend on the material you are sewing. It would also be nice to be able to control the acceleration on a sewing machine. Anyone knows a servo with that feature? Quote Share this post Link to post Share on other sites
Constabulary Report post Posted November 11, 2014 @VanRhodes I´m no scientist or electric engineer. All I can say is that it worked w/o the speed reducer and is not working after I added the speed reducer. That is m experience so far. I would make a video with and without the reducer but the belt cannot reach the motor pulley. I bought the 750Watts motor with NPS and the 550Watts w/o NPS. I will try if the NPS works with the 550Watts motor when I´m puzzling on my setup next time but that may take a few weeks. Quote Share this post Link to post Share on other sites
VanRhodes Report post Posted November 11, 2014 Constabulary, thanks! Since the NPS isnt very expensive at all I'll just order one along with additional needles and parts when I do my next order, I will also get back with feedback on how and if its working. Quote Share this post Link to post Share on other sites
Constabulary Report post Posted November 11, 2014 Sounds good. Maybe I´m just to dumb - you never know Quote Share this post Link to post Share on other sites
Bertil Report post Posted November 11, 2014 Constabulary post 9: I believe the "beeeeeeeeep" machine comes from this supplier: http://www.hmcmotor.com.cn/website/enproduct_list.asp?action=product&YGH=LookProduct&Product_Id=49&CPclass_Id=1 Quote Share this post Link to post Share on other sites
kolb Report post Posted November 24, 2014 Could you tell me the size of the pulley shaft ? Is it the 15mm straight bore with key ? And did it come with a UK plug terminal? Thanks Quote Share this post Link to post Share on other sites
Constabulary Report post Posted November 24, 2014 It came with a UK plug but it´s easy to replace and the straight bore is 13mm. Quote Share this post Link to post Share on other sites
Bertil Report post Posted November 24, 2014 You don´t have to be careful which is 0 and which is lead? Quote Share this post Link to post Share on other sites
Constabulary Report post Posted November 24, 2014 I´m not an electrician but yellow / green is alway earth and the other 2 do not matter where you put them on. At least in Germany but if you don´t know how to do it ask an electrician. Quote Share this post Link to post Share on other sites
Bertil Report post Posted November 24, 2014 OK! The point is that some servos, actually the control box, needs to be 0. If you put the lead there you might destroy the circuit card! In GB you can only put in the plug one way in Germany two ways and thereby switching the lead with 0. In GB the wiring in a house is standardized in order to avoid these problems. The best way is to read the installation careful and if they say 0 in one wire and lead in the other you better make a fix installation. PS! I am not an electrician but am very careful with electricity. DS! Quote Share this post Link to post Share on other sites
Constabulary Report post Posted November 24, 2014 I don´t know what is going on the control box but from my point into view it is an electronic device like any other else. And I think the manufacturer is aware of the "electrical situation" in different countries and that his product will be shipped worldwide. So far I have no problems - no smoke if coming of the box or the like. I guess the control box knows how to deal with alternating current. Quote Share this post Link to post Share on other sites
Northmount Report post Posted November 24, 2014 This electronics stuff is all smoke and mirrors. When you let the smoke out, it doesn't work anymore! Tom Quote Share this post Link to post Share on other sites
