SWFLholsters

Servo Motor Mod: Diy Easier Speed Control

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I am new to sewing and recently purchased a Seiko STH 8BLD-3 and I have spent many hours reading here on Leatherworker.net, on HotRodders.com, and on DIYTactical.com, and thank everyone for sharing their experiences.

I hope, with this post to pay back a little and make a few people really happy like me. This MOD for me ranks up there with best Xmas present ever... in July, no less.

In my research to learn more about my new sewing machine I ran into a lot of posts of people unhappy with their servo motors speed control, this included me.

I was lucky one day and found a post here on Leatherworker.net where a member named DDahl - Dave had used a paper and pencil gradient MOD to give a wider more controllable range to the speed controller of his servo motor. Here is the link to DDahl's post that motivated me to make this how-to. (Thank You! Dave)

Amazing to me, Dave's post didn't stir much conversation or motivation, I attributed that to peoples fear of modifying things.

I made this video and how-to to show how easy this MOD really is and hopefully make a lot of people happier with their machines.

Enjoy!

In addition to the video I have photos that can be use as a guide while preforming the modification. I will also post updates and tweak the how-to as needed and if people participate, post a list of servo motor models that work well with the modification.

Servo Motor MOD: DIY Easier Speed Control

I tried to embed the YouTube video but failed, if it is possible please PM me and I'll update this post to include the embedded video.

P.S. I am not a writer and struggle with things like this, if anyone sees errors or has suggestions on how I can improve my writing to be more clear please let me know. :-)

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Bravo!! Very nice. I admit, I was sceptical it would work, figuring the paper itself would be too opaque to allow any slow speed control. Guess I need to give it a try now!

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Bravo!! Very nice. I admit, I was sceptical it would work, figuring the paper itself would be too opaque to allow any slow speed control. Guess I need to give it a try now!

Thanks!

I promise you won't be disappointed. :-)

Just use 22lb or thinner paper and you should be good to go.

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Very awesome. Thanks for spending the time to make such a well form tutorial. I will be looking forward to modifying mine in the next couple of weeks.

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Great job,

:You_Rock_Emoticon:

I will definitely give you the credit for teaching us this, thought Dave was the inventor. You did a great job explaining this mod for us. Seeing how easy this mod is, makes me wonder why they have not fixed this issue? You dealer watching this have to order a repair kit for it, made in something more sturdy than paper, if that will work?

I saw the post the first time, but I did not want to take my motor apart. I also have some experience with motors much harder to control than this that is why I did not bother. Apparently, the slow start option works differently on these motors, mine works as it should and is best on setting nine. I have an other issue with mine, it will not stop when you turn of the switch, maybe that slow start option works as a kind of capacitor, storing the current and slowly lets it go. That kind of makes sense to me,

I will play around with after I have done the mod and we will see.

Thank you

Trox

I am new to sewing and recently purchased a Seiko STH 8BLD-3 and I have spent many hours reading here on Leatherworker.net, on HotRodders.com, and on DIYTactical.com, and thank everyone for sharing their experiences.

I hope, with this post to pay back a little and make a few people really happy like me. This MOD for me ranks up there with best Xmas present ever... in July, no less.

In my research to learn more about my new sewing machine I ran into a lot of posts of people unhappy with their servo motors speed control, this included me.

I was lucky one day and found a post here on Leatherworker.net where a member named DDahl - Dave had used a paper and pencil gradient MOD to give a wider more controllable range to the speed controller of his servo motor. Here is the link to DDahl's post that motivated me to make this how-to. (Thank You! Dave)

Amazing to me, Dave's post didn't stir much conversation or motivation, I attributed that to peoples fear of modifying things.

I made this video and how-to to show how easy this MOD really is and hopefully make a lot of people happier with their machines.

Enjoy!

In addition to the video I have photos that can be use as a guide while preforming the modification. I will also post updates and tweak the how-to as needed and if people participate, post a list of servo motor models that work well with the modification.

Servo Motor MOD: DIY Easier Speed Control

I tried to embed the YouTube video but failed, if it is possible please PM me and I'll update this post to include the embedded video.

P.S. I am not a writer and struggle with things like this, if anyone sees errors or has suggestions on how I can improve my writing to be more clear please let me know. :-)

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And thanks for showing me that the Enduro motor is the same as the Cobra motor, I was about to buy one for my 441 from Keystone. Luckily, Greg has not answered any of my email. That makes my choice easy; I will buy an Efka 1550 from Europe instead.

:specool: Thanks

Trox

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I did this mod today and it made a HUGE difference. It definitely requires experimentation. I don't think I landed on the perfect version because I can't get full range of speed control (1-40), but it works excellent at 1-15. I'd never set it at 40 anyway. Next version I'd like to try is a custom blade replacement with an angled end that covers the light more gradually.

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1. Seeing how easy this mod is, makes me wonder why they have not fixed this issue? You dealer watching this have to order a repair kit for it, made in something more sturdy than paper, if that will work?

2. Apparently, the slow start option works differently on these motors, mine works as it should and is best on setting nine.

3. I have an other issue with mine, it will not stop when you turn of the switch, maybe that slow start option works as a kind of capacitor, storing the current and slowly lets it go. That kind of makes sense to me,

Thank you for the kind words.

1. I doubt that the manufactures see this as a problem. I can see some of the dealers possibly doing the mod in-house for customers that request this. I think as the number of successful mods increase the dealers may be more inspired to look into it.

2. What motor do you have? On my Enduro Pro the slow start works but not in the way I would have hoped. It adds a delay that only complicates the short range of travel. You end up pressing the treadle too much because nothing is happening and then bang you are going too fast. There is a noticeable delay but it seems to be more of a delay than a slow ramp up of speed. However, on my motor the bigger issue is that the slow start setting seriously messes with start up torque, the torque difference between L-9 and L-0 is very big.

3. If I understand correctly your motor does not turn off when you hit the power switch? My Enduro Pro has this problem, when you switch the power off the motor is still active for 10 to 12 seconds. That to me is a design flaw, but I can live with it.

I am sure the Efka 1550 is a great motor but with this mod I am more than happy with my Enduro Pro. However, I am only using it on a Seiko STH-8BLD and not a 441.

I wish you much success.

Larry

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I did this mod today and it made a HUGE difference. It definitely requires experimentation. I don't think I landed on the perfect version because I can't get full range of speed control (1-40), but it works excellent at 1-15. I'd never set it at 40 anyway. Next version I'd like to try is a custom blade replacement with an angled end that covers the light more gradually.

Awesome! I am glad it worked.

I am not sure we can get the complete 1-40 range of speed. Mistakenly I didn't try for it, I was happy with a 1-20 range as it covers all of my needs. When I get some free time I'll try some more testing

A member named Cronko on HotRodders.com had success with his SewQuiet 4000 but he had to use thin cardboard instead of paper because his optical sensor was so bright the paper would not work. He then layered the sicky side of postit note paper on top of the cardboard to create a gradient of paper and then used pencil marks to fine tune the paper gradient and that worked for him. So it sounds like each brand of servo may require a different approach to the gradient.

Link to post at HotRodders:

http://www.hotrodder...tml#post1577862

What brand and model servo do you have so I can add it to the list?

Cheers!

Edited by SWFLholsters

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My motor is a TN-411 - that's all it says. Not sure what brand that is.

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My motor is a TN-411 - that's all it says. Not sure what brand that is.

It's a WhoFlungDung motor.

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I have sent this to a few guys that have had trouble with the lack of adjustment. Years ago I worked as a tech in the printing industry. We had these optical switches all over small offset press. We had the same lack of adjustment problem and made a new part of out a frisbee. It was stiff enough to last and when you thin it down enough light will start to pass through it. It is a trial and error type thing for sure but we got it lined out. Of course the factory said they didn't have any problems with other machines around the world (this is THE standard answer you always get). The following year I was at a training class and someone brought the very problem up and all the sudden the room lit up with everyone having the same problem. About 1 month late the factory had to admit it and sent out an updated complete assembly.

It's to bad such a good machine (from what a saw last week and have always heard would have such a flaw. I guess it is at least operator fixable, but if it is operator fixable it is dealer fixable if they wanted to. If this was a car it would be recalled for safety reasons, as I bet some lawyer could have a field day with it. Think if your car pedal worked this way.

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I gave it another try a few minutes ago - this time with the post-it-note method. I gotta say - this might be the best method yet. It's very easy to adjust the spacing of the pieces of paper. I might try again with a bit tighter spacing and more layers. With this version, I can only utilize 1-22 out of the max speed of 40. I'll NEVER go that fast with this machine, but it's not working 100% so I'm not ready to give up yet. This spacing is roughly 1/16" spacing - it probably needs to be 1 ever 1/32" since I'm already hitting the max range of travel with this size/spacing. A darker paper color might help too, which will change the spacing too....

smugshot3486222-L.jpg

Edited by particle

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I shot a little video last night of me sewing one of my pancake holsters using the post-it-note mod shown in my previous post above. What you can't see in this video is that I now have FULL use of the entire range of motion on my foot pedal to control the speed. Granted, with this particular color of paper an the amount of layers I'm using, I can't make full range of the maximum speed of the machine. But, 22-23 (out of 40) is still pretty fast for this type of work - much faster than I need to be using. Honestly, if I was able to utilize the entire speed range from 1-40, the pedal would be twice as sensitive as it is now (with the post-it-note mod installed). So, even though I can't use the full range of speed, the pedal is effectively twice as controllable since it's half as sensitive as it "should" be (to utilize the entire speed range of 1-40 over the same foot pedal range of motion).

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Very nice! Tried it, works as described. :notworthy: Used yellow post-its. Took 3 tries to get it like a wanted it. Maybe 30 minutes total messin' with it. I totally encased my post-its with scotch tape to protect it from heat and humidity and such, then adhered to arm. Seems like manufacturers could come up with somethin simple like this as an upgrade. My wife who is a seamstress and has several machines, never liked mine because of the speed control. She says that it is more like it ought to be now. Thanks for info and videos. Uncle George

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Very nice! Tried it, works as described. :notworthy: Used yellow post-its. Took 3 tries to get it like a wanted it. Maybe 30 minutes total messin' with it.

Glad to hear it worked.:spoton:

What motor are you using?

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I shot a little video last night of me sewing one of my pancake holsters using the post-it-note mod shown in my previous post above.

Eric, great video, I love your holster work and really appreciate your video how-to's, thanks big time for sharing.

I can't wait to add a Cobra 4 to the holster tool box.

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Glad to hear it worked.:spoton:

What motor are you using?

Year and a half old Cobra 4. TN 421. On my machine I had about 1/8 inch actuator arm travel from low to high speed. The actuating arm is a little different shape than in the videos and it is not removable. It has a set screw keeping the arm tight to the pivot shaft but I noticed that there is a pin that is not removable that keeps the arm from being lifted up off the pivot shaft. I didn't try to remove it as there is no need to remove it. There's a small "L" shaped metal plate attached to the arm with two screws. The "L" shaped plate is removable and adjustable with these screws. One end of the "L" shaped plate is the part that moves under the light beam. I taped the post-its to the "L" shaped metal plate. Sorry no time for pics and better detailed explanation. I think anyone who opens theirs up will see how to do it. Outside cover comes off easy with just 3 screws instead of 4. It is not mechanically connected to anything on the inside of the motor case, just 3 wires attached to the actuator that have enough slack in them and don't get in the way. Very easy. Much more control now. I loved this machine before the modification as I had gotten used to the speed control and it has been great!. It's even better now. :thumbsup:

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This is a great idea. Guess I stopped back in at the right time.

Was thinking would a piece of plexi that had a gradient color work as well? Thinking it would be a little tougher and would have very fine control. Gonna have to play with this.

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I tried transparency film with a printed gradient. Barely engaged the motor at the darkest point. Printed another one, but printed on both sides to make it even darker. Not much change. Switched to vellum. Not much better. I wanted to try a spray paint gradient but didn't have any on hand. It takes quite a bit of light blockage before the motor activates at all.

Edited by particle

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Has the dealer asked about the fix and are they planing on fixing it at least for future machines? I understand no machine is perfect but when I fix is available to what I hear is a fantastic machine it seems it should be upgraded. I did try an Artisan and a model 4 side by side and that was the first thing I noticed is the Artisan had full range of pedal and the model 4 had almost full speed with the pedal barely moved. Having said that both had a great stitch and unless something else comes along I will be purchasing one of these.

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I shot a little video last night of me sewing one of my pancake holsters using the post-it-note mod shown in my previous post above. What you can't see in this video is that I now have FULL use of the entire range of motion on my foot pedal to control the speed. Granted, with this particular color of paper an the amount of layers I'm using, I can't make full range of the maximum speed of the machine. But, 22-23 (out of 40) is still pretty fast for this type of work - much faster than I need to be using. Honestly, if I was able to utilize the entire speed range from 1-40, the pedal would be twice as sensitive as it is now (with the post-it-note mod installed). So, even though I can't use the full range of speed, the pedal is effectively twice as controllable since it's half as sensitive as it "should" be (to utilize the entire speed range of 1-40 over the same foot pedal range of motion).

I have a Cobra on order from Cobra Steve. It's supposed to ship in about 3 weeks. In the video that you shot above, what speed range were you sewing in? Something like 1-4 maybe?

I haven't looked at the other links that are shared in this thread, but after looking at them, I'm going to email them to Steve at Leather Machine Company. I can't imagine from what I've heard about him that he wouldn't make this mod to machines that he sells.

I also have a Highlead GC0618-1sc with a servo. Even though it sews good, I'm thinking this will help it too. Guess I'll find out after reading more about it. Thanks for the info!

c

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I had the motor set at 40 when I started my current batch of ten orders. My post-it layering is only allowing a max of about 22 - still way too fast for this type of work. But, towards the end I put the servo at 15 after I noticed it was still set at 40 (maxing at 22 because of the post-it setup I have right now).. Without the mod, there is no way I could leave the machine set at 22. About 7 was all I could risk because of the lack of control.

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Year and a half old Cobra 4. TN 421. On my machine I had about 1/8 inch actuator arm travel from low to high speed. The actuating arm is a little different shape than in the videos and it is not removable. It has a set screw keeping the arm tight to the pivot shaft but I noticed that there is a pin that is not removable that keeps the arm from being lifted up off the pivot shaft. I didn't try to remove it as there is no need to remove it. There's a small "L" shaped metal plate attached to the arm with two screws. The "L" shaped plate is removable and adjustable with these screws. One end of the "L" shaped plate is the part that moves under the light beam. I taped the post-its to the "L" shaped metal plate. Sorry no time for pics and better detailed explanation. I think anyone who opens theirs up will see how to do it. Outside cover comes off easy with just 3 screws instead of 4. It is not mechanically connected to anything on the inside of the motor case, just 3 wires attached to the actuator that have enough slack in them and don't get in the way. Very easy. Much more control now. I loved this machine before the modification as I had gotten used to the speed control and it has been great!. It's even better now. :thumbsup:

Thanks for the update and info on how you accomplished the mod, I am sure this will help others down the road.

I will add your servo motor to the list.

SewQuiet 5000

SewQuiet 4000

Skyrit TN-411 (looks very similar to a Consew)

TN-421 (no name)

Enduro Pro SM600-1

Do you mind if I add your procedure to the end of the how-to?

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Hello. We too have experimented with the motors. We have been in contact with the factory and are waiting to hear from them. They have all the info that they will need to correct this problem. Just like others that have posted pictures and videos, we have done the same with our factory. We will keep you updated when we have more info. Thanks, Steve

Edited by Cobra Steve

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