Members Dallas Cowboy Posted June 3, 2012 Author Members Report Posted June 3, 2012 As I stated earlier, the bumps are not the main concern. The main concern for me and others was the lack of a full range of motion in the peddle. Yes the peddle moves quite a bit and has a travel range of about 3 inches or so. But the motor only uses about 1/4" of that range. Its not like the full control of a gas peddle in a car where the motor reacts to the entire range of the peddle. Instead this motor goes from zero to full blast all within a 1/4". It can be controlled by adjusting the max speed way down but it would be nice to be able to keep the max speed up and have a peddle range of motion that is much larger so you can creep along or haul butt depending on your needs.
Members busted Posted June 3, 2012 Members Report Posted June 3, 2012 This is probably a foolish thought but why not put a speed reducer pulley on the machine. Restrict the machine to around 800spm or less if you want to. You will not loose the starting torque and you will control the range of speed. Just a thought. I made my own speed reducer 8"x 21/2" with a 3" on the motor. Works very good. As I stated earlier, the bumps are not the main concern. The main concern for me and others was the lack of a full range of motion in the peddle. Yes the peddle moves quite a bit and has a travel range of about 3 inches or so. But the motor only uses about 1/4" of that range. Its not like the full control of a gas peddle in a car where the motor reacts to the entire range of the peddle. Instead this motor goes from zero to full blast all within a 1/4". It can be controlled by adjusting the max speed way down but it would be nice to be able to keep the max speed up and have a peddle range of motion that is much larger so you can creep along or haul butt depending on your needs.
Moderator Wizcrafts Posted June 3, 2012 Moderator Report Posted June 3, 2012 This is probably a foolish thought but why not put a speed reducer pulley on the machine.... The topic is about a Cobra Class 4, which IS already equipped with a speed reducer pulley. My Cowboy CB4500 uses the same pulley (~3:1) reduction system. By the time the small output pulley feeds the large one on the flywheel, we are looking at anywhere from 8 to 9 times speed reduction and torque multiplication (depending on motor and flywheel pulley diameters). I am hopeful that this discussion will lead to the development, or discovery of a better motor for these machines; one which won't drive the price up too much higher. There are already better motors available, but they cost a lot more than the servos included as standard equipment. I can assure you that our dealers are discussing this matter and looking into possible alternatives. However, these new motors need to be tested under load for prolonged periods of time to ensure they can stand up to the heavy loads imposed by big machines sewing heavy leather, with big needles and thick thread. Posted IMHO, by Wiz My current crop of sewing machines: Cowboy CB4500, Singer 107w3, Singer 139w109, Singer 168G101, Singer 29k71, Singer 31-15, Singer 111w103, Singer 211G156, Adler 30-7 on power stand, Techsew 2700, Fortuna power skiver and a Pfaff 4 thread 2 needle serger.
Members Ken Nelson Posted June 3, 2012 Members Report Posted June 3, 2012 (edited) This is probably a foolish thought but why not put a speed reducer pulley on the machine. Restrict the machine to around 800spm or less if you want to. You will not loose the starting torque and you will control the range of speed. Just a thought. I made my own speed reducer 8"x 21/2" with a 3" on the motor. Works very good. The Class 4 Cobra comes with a speed reducer. As far as the content of this thread goes, I am astonished how many people here are expressing "Bright Ideas" that have no idea of what they are talking about. Seems "funny" that one or two people are having problems with a machine that the rest of us that own and use them get along great with. If you think you are having a problem with Cobra Steve's customer service, "you might bear in mind, that your are in a teeny-tiny minority!" I have been doing business with this man before he had his own company. In fact I have bought machines from him on 5 occasions totaling more than 5, some new-some used. I have had a couple of little problems with two of them and it has been taken care promptly and graciously. Once someone forgot to pack in some extra attachments I had ordered, one used machine had a motor problem, and I caused a couple of problems by letting Newby's sew on my machine. He didn't charge me for talking me through adjusting my mistakes either. As stated earlier, There is a definate learning curve on learning to sew on a sewing machine. Is it possible for the motor to be bad on the sewing machine in question, of course it is. Is it possible there is some user error here. Probably. Is it possible that it is a combination of motor problem and operator error both? Could be. If you are using a household Singer sewing machine, you may well not know how to sew with a heavy leather sewing machine or stitcher. If you haven't sewn quite a lot on a heavy stitcher, you probably have a lot to learn. Properly preparing your work to be sewn on a sewing machine is very important. Having your tensions set incorrectly can cause real problems. Not oiling your machine can cause problems as well as shortening the life of it. For an experienced sewing tech to say a machine is easy to sew on is different than saying doing a good job on a certain sewing machine is easy. I sew belts and skirts on saddles pretty slow. I know guys that burn through them 9-0 and theirs look as good as mine do. They started a long time ago when they were kids and do more of them than I do. Some machines are easier to sew with than others. As far as the bumps on the bottom go, When I apprenticed under a pretty damn good saddlemaker, we dampened every stitch line in veg tan, tapped it to make it look just a little better. I still "set" the stitch line on about every project I sew. I was told," it is a matter of workmanship" The motor set up on my Class 4 suits me just FINE! I don't need an upgrade. Just my 2 cents worth! Ken Edited June 3, 2012 by Ken Nelson
Members Dallas Cowboy Posted June 3, 2012 Author Members Report Posted June 3, 2012 The topic is about a Cobra Class 4, which IS already equipped with a speed reducer pulley. My Cowboy CB4500 uses the same pulley (~3:1) reduction system. By the time the small output pulley feeds the large one on the flywheel, we are looking at anywhere from 8 to 9 times speed reduction and torque multiplication (depending on motor and flywheel pulley diameters). I am hopeful that this discussion will lead to the development, or discovery of a better motor for these machines; one which won't drive the price up too much higher. There are already better motors available, but they cost a lot more than the servos included as standard equipment. I can assure you that our dealers are discussing this matter and looking into possible alternatives. However, these new motors need to be tested under load for prolonged periods of time to ensure they can stand up to the heavy loads imposed by big machines sewing heavy leather, with big needles and thick thread. Yes!!! Thank you very much. I guess there are only a few people that are recognizing this issue.
Members Ken Nelson Posted June 3, 2012 Members Report Posted June 3, 2012 (edited) Yes!!! Thank you very much. I guess there are only a few people that are recognizing this issue. Maybe a few inexperienced people are blaming their lack of skill and experience on the equipment instead of learning how master their machine? When I started building saddles there were only clutch motors and we mastered sewing with them. I still have a couple of them on sewing machines I use. I get along fine with them but the students have HELL with them. Put a clutch motor on the machine in question, you may like it better! Ken Edited June 3, 2012 by Ken Nelson
Members Dallas Cowboy Posted June 3, 2012 Author Members Report Posted June 3, 2012 Really?? Wizcraft is an expert and he recognizes the issue.
Cobra Steve Posted June 3, 2012 Report Posted June 3, 2012 (edited) Really?? Wizcraft is an expert and he recognizes the issue. Hey Dallas. Ask Wizcraft what he did to his Class 4 at work to make his motor respond better. I think it was a minor adjustment. Steve Edited June 3, 2012 by Cobra Steve Thank You Steve Tayrien Leather Machine Co., Inc. 2141 E. Philadelphia St. Unit "U" Ontario, California 91761 1-866-962-9880 http://www.leathermachineco.com cobra@leathermachineco.com
Moderator Wizcrafts Posted June 3, 2012 Moderator Report Posted June 3, 2012 Ken brought up some really good points and suggestions. Newbies would do well to read through his post, #44, in this thread. I never claimed to be an expert. I am just an experienced sewer-rebuilder, with some time as a worker bee in an industrial sewing machine store (Juki machines galore). I've put in hundreds of hours sewing everything from cloth, to vinyl, to leather. I have rebuilt many sewing machines, including two Union Lockstitch machines and gone through many machines that were supposed to sew leather, but did so poorly. Until recently, all of my machines had clutch motors. I learned to feather the clutch to sew slowly and can still do so. I can adjust the action on a clutch motor to allow the range of free motion I prefer, where it releases the brake, but before it engages the drive. Most of the servo motors lack any such freewheeling/braking adjustments. The exception is the SewPro 500GR (now sold as the "Toledo Sew Slow") motors sold by Toledo Industrial Sewing Machines. I currently own two of those motors and have adjusted to behave much like clutch motors (release brake-engage slow-go quick-go fast). It's too bad they are (currently) a little under powered for a long arm 441 or Adler! I have a Cowboy CB4500 at home and sew on a Cobra Class 4 at work. Both have common servo motors. Both are now into their second motor. I can feather the speed control on both motors to sew around one stitch per second, or one stitch at a time. One of the motors is touchier and drops out with a violent shake if I try to sew under one/second. This is a design quirk in the electronics that controls the unit. There is nothing that can be done, other than try to avoid that awkward spot. The other motor sews more slowly, about one every other second, then simply drops out with a whimper, rather than shaking the entire table and machine. Both of the motors I use on these 441 machines are somewhat temperamental and have a rather limited range between just on and full on. Still, there is enough range of motion if I am careful with my foot and keep steady pressure on the floor pedal. Thankfully, I have a steady foot, but recognize that others may not be so fortunate. They will have a harder time controlling their motors than I do and their concerns need to be addressed. Art once referred me to an SCR servo motor system that has tremendous torque at even the slowest speeds and Trox speaks highly about the Efka motors he uses. Both cost much more than the servo motors that ship on the 441 machines. Some of our dealers, or non-member dealers known to us, already stock higher-end servo motors, which they will happily sell to anybody. But, this topic is about the motors that are included as standard equipment on new machine purchases. I promise you that this is being worked on. <rant> They copy, but do not improve our machinery and electronics! Sometimes, their QC is lacking. Sometimes they use the cheapest marginally acceptable components, such as light sensors. They know who they are. Their alphabet is known in code-page as the Big 5. </rant> Posted IMHO, by Wiz My current crop of sewing machines: Cowboy CB4500, Singer 107w3, Singer 139w109, Singer 168G101, Singer 29k71, Singer 31-15, Singer 111w103, Singer 211G156, Adler 30-7 on power stand, Techsew 2700, Fortuna power skiver and a Pfaff 4 thread 2 needle serger.
Members Ken Nelson Posted June 3, 2012 Members Report Posted June 3, 2012 Really?? Wizcraft is an expert and he recognizes the issue. I bow to your knowledge and experience. Apparently you are more knowledgable and a better leather craftsman than Troy West, Bill Gomer, Jessie Smith, Don Buttler, Pete Correll and Bob Klenda. If you are unfamiliar with the above gentleman, I would suggest you research their work and if you look on the Leathermachine Co website, you will see all of them own and endorse a Cobra Class 4. By the way, since you are an expert, how about posting some of your work. Ken
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