Having Problems With Servo Motor Speed Control?

[Trox]

Thank you Steve and Tom in the house of the Cobra, mod recieved and motor works very well.

Happy sewing.

Trox

[KatRides]

Mine is controlled electronically, no black knob there :0(

turns out the computer board needs replacing.

Artisan is in the middle of a big relocation move so Gerry will be tough to reach if anyone is interested.

Yeah, on mine there is a little black knob. You turn it to control the speed. It's an ESM 400-2 motor.

[bullrope braider]

If I recall correctly, the problem was the machine hit top speed right off...there was no way to tweek the speed at the pedal, is that right?

So what did the fix consist of?

Jake

interesting post, like some others here I thought it was normal for my Cobra to just take off right away even though I was easing into the pedal. looks like I'll contact Tom about my EPS motor about this mod, It'll sew slow but I cant get the slow crawl I need going around corners or turns and is making me miss my stitching lines. also with this EPS needle positioning system to get it to stop needle down takes a heel tap on the pedal, if I just take my foot off the pedal it'll stop needle up. is that right?

[Trox]

Hi Mr. Bullrope braider,

I do not have the EPS Cobra motor, I do have three Efka position motors and the regular Cobra servo. It has the same manual (Instruction sheet) as the EPS.

You should be able to choose what position your needle stops in.

Turn on your motor and sew a couple of rotations (might not be necessary).

When it stops press the up button (near the motors led display), the display then shows ” POS. u”, then press the down button and the led will show ” POS. d”.

Your needle will now stop down as it should do, with a heel back it will return to up position.

If the motor is a bit quick to accelerate you can try to adjust the ”slow startup speed” (the acceleration time on the motor from 1 to 9)

Turn on motor and press down button for several seconds until led shows ”SET.1”, then the up button once; the led shows ”SET.1”, then press the down button. The number in the display now shows your startup speed (acceleration speed, default value is 6). You can now adjust the speed with the up and down buttons, 1 is fastest and 9 slowest. This function might not work after you have done the modification, before installing the mod. try out this function first.

Good luck.

Trox

interesting post, like some others here I thought it was normal for my Cobra to just take off right away even though I was easing into the pedal. looks like I'll contact Tom about my EPS motor about this mod, It'll sew slow but I cant get the slow crawl I need going around corners or turns and is making me miss my stitching lines. also with this EPS needle positioning system to get it to stop needle down takes a heel tap on the pedal, if I just take my foot off the pedal it'll stop needle up. is that right?

[bullrope braider]

Hi Mr. Bullrope braider,

I do not have the EPS Cobra motor, I do have three Efka position motors and the regular Cobra servo. It has the same manual (Instruction sheet) as the EPS.

You should be able to choose what position your needle stops in.

Turn on your motor and sew a couple of rotations (might not be necessary).

When it stops press the up button (near the motors led display), the display then shows " POS. u", then press the down button and the led will show " POS. d".

Your needle will now stop down as it should do, with a heel back it will return to up position.

If the motor is a bit quick to accelerate you can try to adjust the "slow startup speed" (the acceleration time on the motor from 1 to 9)

Turn on motor and press down button for several seconds until led shows "SET.1", then the up button once; the led shows "SET.1", then press the down button. The number in the display now shows your startup speed (acceleration speed, default value is 6). You can now adjust the speed with the up and down buttons, 1 is fastest and 9 slowest. This function might not work after you have done the modification, before installing the mod. try out this function first.

Good luck.

Trox

thank you, I printed this out and will give it a shot here shortly

on edit: didnt take but a couple minutes to fix the needle position. thank you for your help. also the speed is re set now so it's not haulin it when I step on the pedal. thanks again

Edited September 17, 2012 by bullrope braider

[Trox]

Thats good, then you do not need to install the mod.

Glad I could be of help.

Thanks

Trox

thank you, I printed this out and will give it a shot here shortly

on edit: didnt take but a couple minutes to fix the needle position. thank you for your help. also the speed is re set now so it's not haulin it when I step on the pedal. thanks again

[LeatherWerks]

The guys at the Leather Machine Company are likely the best around when it comes to customer service. Now, if they could find a speed control solution for my Cobra 4 with the EPS system, they would be considered gods.

Steve

[Trox]

Exuse me Steve, have you read the entire topic, or just the last page? The EPS works the same way as the motor without position. It seems to be some difference on how the speed control work on these motor`s. Thats may be related to the voltage and hertz, or just the batch of prodution. However they all have the same simple light control. The acceleration time of the motor can be adjusted in nine steps (see the last posts in this topic) It is explained in a bad way on the instruction sheet, it is easy to miss. If that does not improve your motor, send Cobra an email and ask for the modification.

You did know about this from before or not?

Trox

[Cobra Tom]

Dear Trox, please don't take this the wrong way but I recall you writing that you do not have the EPS motor which we sell for the COBRA Class 3, 4 or 4-25. I am sorry, but I do not have any experience with your Efka motor, so I can't comment on your suggestions.

The trouble with the speed control mod on our EPS motors is in the design of the actutator that interacts with the light sensors. Basically, there are 3 functions with the EPS motors. 1) Putting your toe down makes it GO like the non-EPS. 2) Taking your toe off makes it STOP with the needle down. 3) Putting your heel down makes it do half a revolution to STOP with the needle up. The non-EPS motors had a single actuator but the EPS motors have two opposing actuators as part of the same lever. It was not possible to move the GO actuator (like the non-EPS) without affecting the opposite actuator. Installing the modification is possible but it requires trimming both the actuator and the modification to make room for the modification without changing the proper operating position of the STOP actuator.

I spoke with Steve from Missouri on the phone yesterday after sending him the modification and explaining this to him.

If anyone wants to attempt the modification on their EPS motor, we can send the modification, but it will require you to alter the lever and the modification by cutting both of them. Some may decide that it is not worth the time and effort of removing the actuator and sensor both, then cutting the GO actuator and the modification to fit into the sensor. If anyone with an EPS motor is curious to see what I mean, open the motor housing to better understand what would be necessary to install the modification. For those who are curious but have no EPS motor to open see the photos for a better look.

[Trox]

Dear Tom,

No problem, that is right. I do not have the EPS motor myself, however my friend has one (see picture). This motor is also a 220v and has a different style actuator arm than the one in your picture, the arm is individual adjustable. On this one, you can install the mod. and adjust the light control for stop position afterward or vice versa. I thought every EPS motor had this style of actuator arm, but apparently not. My motor (who is a 220v without EPS) has this double plastic actuator arm, same as in your picture. I understood it was for an EPS and cut the extra light barrier plastic off. (I had too in order to install the mod) I see your point; with the double plastic arm, it will be difficult to install the mod. Your other 110v EPS motors do they all have this plastic actuators? Changing them to the aluminum style would allow installing the mod. It still requires a bit more adjustment to install the mod in the EPS motor. I would have locked the position (metal) arm with a piece of tape, when I installed the mod on the other side of the arm. You can take off the speed side of the arm without moving the other side.

I do not know if these metal actuators are available for you, or why they not are installed in the 110v motors.

Buy the way; I have installed my new Efka 1550 motor on my 441. The German dealer that sold me the drive sent me the wrong control box. They sent me a Dürkopp Adler control for the Adler 205-370 machine (and others DA machines). This control has only parameters for Adler machines and made it difficult to program for a Juki 441. I called Efka for support, they answered; no matter where you bought your motor, it is our job to help you until your machine is ready to sew. So they called me with Skype video call, went true all parameter until my machine sewed perfect.

Thank you Manfred in Efka Germany

The first thing he told me was to take off my speed reducer, he said that they had made these motor strong enough for every lockstitch machine without help of a gear reduction, up to 1800 watt and 8 Nm torque. The speed reducer will only disturb the control computer. He told me about what parameters I have to adjust if I need more power; I only use half of its capacity now. These motor work best if they are installed on the machine head with a short flat belt. They are so small that they can be hidden inside a machine head. On the new Dürkopp Adler 867 M type machine, they install this motor inside the head as a direct drive motor. The position head mounted on my hand wheel is only for calculating belt slippage. (On older motors they was used to terminate the needle position) Because of the wrong control, this setup was taking much longer than usual. With the right control, you can use a USB memory stick or a laptop to install the parameters. This is the reason I have not sent you any email, I have just finished setting it up.

Trox

[LeatherWerks]

Trox, since you ask me a specific question, you deserve an answer. Yes, I read every single line of every post in the entire subject before I made my comment. Thanks for asking.

Steve

[Trox]

I am sorry Steve, I tought every EPS motor had the same metal adjustable actuator arm as my friends motor has. I now see why your motor is hard to modify.

Thanks

Trox