Cobra Class 4

[Dallas Cowboy]

Ok, tonight i went to a new friends house (I don't want to give his name but he can if he wants to) and watched him work some leather. He is very talented and makes some great looking and fitting holsters. His holsters fit better than a glove, more like they fit like skin. He spends a lot of time boning and making sure every nook and cranny is fit to exact specs and doesn't leave even the smallest of wrinkles in the leather. Needless to say it was impressive.

I got to try his NEW cobra class 4 and this is a great machine but has some horrible flaws. As hyped as this machine is, it shouldn't act like this. First off the machine is great but the motor is a piece of crap. This thing has a peddle that has about 2" of travel and it only uses about 1/8" of the travel. I was fluctuating the speed by just flexing my big toe. Its stupid on how little of the travel arm it utilizes (Simply unacceptable). You can have it on a pretty slow speed but basically its all or noting (You can't control the speed hardly at all with the peddle). Also (I wouldn't have noticed this unless he pointed it out to me but being a perfectionist, he did point it out) it leaves a small raised bump on the bottom (Bobbin side) of the material. Its like the leather is raised and then sewn in the middle of the hump. The manual is basically fire wood starter and the slow start function is simply crap and just marketing hype!!!

I thought the Cobra Class 4 was supposed to be one of the top of the line machines. Don't get me wrong, I am still interested in eventually getting one of these machines they are a nice machine but the motor is a pile of crap!!!! Someone could have chosen a better motor instead of cutting corners on one of the most important pieces of the machine.

SOOOOOO......what options are there for holsters, belts and such. This thing will mow through some leather,but the motor and its lack of adjustability, would make me slit my wrist

And Please don't get me wrong, i am impressed and like the machine, i just don't like the cheap motor and its lack of adjustability. I liked the machine and its still one i will consider but if there is any other options out there that are just as good with a better motor, i would entertain looking at it as well.

[amuckart]

Buy one without a motor and put a Quick Rotan servo on it. Just be prepared to pay as much for the motor as you did for the machine.

[dirtclod]

Well if your lucky you might find one of the older Juki's for around 3,000.00 used or a new Ferdco for around 5,000.00. My Juki doesn't do the things your talking about. Then theirs a Campbell machine needle and awl. I think they sell for around 6 or 7,000.00 new. Their are two other dealers ( in the banners ) on here selling machines send them some leather and ask them to sew it for you. Heck theirs all types of new and used sewing machines around you just have to find them, or you can sew by hand. Plus their are several different makers of motors. So you have many choices of what you want to do.

[Wizcrafts]

A friend of mine has just ordered a special servo motor for his 441 clone and is going to put it through the paces. I'll let you all know how it performs for him once I hear more.

[gringobill]

I have a Cobra Class 4 for 2 years and the servo motor on it works perfectly. The pedal has quite a bit of travel and I total control of the speed, I can do one stitch at a time if I want/need to.

[Ken Nelson]

I have a Cobra Class 4 for 2 years and the servo motor on it works perfectly. The pedal has quite a bit of travel and I total control of the speed, I can do one stitch at a time if I want/need to.

I have used my class 4 for 3 years and it is extremely easy to sew with. The control is unbeleivable. Two people have used it to learn to sew on the last year and both were doing a good job in just a couple of hours. Several people in my area have put competition servos on older machines and none of them are a good as the servo on the Class 4. In fact several people have purchased the class 4 after sewing on mine. I would have to see what you are saying to beleive it. Ken

[K-Man]

I have a Cobra Class 4 for 2 years and the servo motor on it works perfectly. The pedal has quite a bit of travel and I total control of the speed, I can do one stitch at a time if I want/need to.

Same experience here. I've had mine for just over a year.

WRT the OP, I've got to wonder about the adjustments/settings in place on the machine; that coupled with the actual experience of the user(s) with the machine itself, and their experience sewing on these types of machines. A Cobra Class 4 (or similar) is about the most versatile machine out there, one that gives you the quality in all facets.

Edited May 26, 2012 by K-Man

[TwinOaks]

The "leaves a bump" part has me concerned. That is 100% user error.....the presser foot tension is wrong. That makes me wonder if the go pedal or the CHAIN THAT GOES TO THE MOTOR is installed/adjusted correctly. OP, have you considered that the machine you looked at wasn't correctly set up? Did your friend call Steve for help?

You're making an awful lot of accusations and assumptions about the quality of the machine based on ONE example, and you don't even know if it was set up correctly.

[bruce johnson]

From another thread going on this topic, sounds like it may be something with these motors. A few other folks reported the same deal - most of the control is in that first 1/8" of travel. I'd call Steve to see if a new batch of motors had something change or there is some adjustment thing. I have different machines and older servos. They have a dial that controls top speed. Even cranked up I have good control over a usable range.

[Dallas Cowboy]

Yes it's set up correctly. I wasn't saying the machine wasn't good. I was saying that the motor and it's lack of control ability is not what I was expecting with a machine that has this much hype. And this flaw is not new to these motors. There are a few people on the net with the same problem.

[particle]

Hello all - regarding the original post, he's referring to my machine. He came over last night to watch me form a couple holsters, and I showed him my Cobra Class 4 and my Tippmann Boss. I'll go ahead and address and clarify the things he mentioned, as well as provide photos and a video example.

First off, some of you that have had your machines for more than a few months - do you even have the same servo motor that I have (TN-411)? (for the record, I have NO idea how long this particular motor and its related internal speed switch have been supplied with these machines, but I think it's a fairly recent addition)

http://www.youtube.com/watch?v=QReQK-ipQjA

The tension of the chain has nothing to do with the sensitivity of the actuation lever. A looser chain just means the foot pedal is going to sag/hang closer to the table. Loosening the chain will not magically make the servo motor's switch work better and give you a broader range of motion on the lever.

Regarding the puckering on the back of the stitch - I'm not sure the OP was aware that was pretty typical for a sewing machine when sewing leather, as you rarely see it in final photos of holsters because they get smoothed out by various methods. That being said, there is a notable difference in puckering depending on the bottom plate in use on the machine. For example, with the standard bottom plate that allows the use of the lower feed dog, you get almost no puckering. But wait - is that really true? Yes and no. I've thought about it for maybe 30 seconds - what I assume is happening is you immediately get the puckering as soon as the needle is punched through the leather, but as you progress forward with your next stitch, the lower feed dog actually presses against the bottom of the leather to help feed the leather forward, while at the same time pressing the puckering back nearly flat. Also, you don't get the same constant elevated ridge due to the shape/design of the lower feed dog and its plate like you get with the holster and stirrup plate.

The puckering has almost nothing to do with presser foot pressure settings - I'll provide a photo example for those that don't agree.

Here is a photo showing the way the machine was sewing when I pulled it from the box. No adjustments had been made to the machine at this point. This was using the standard lower feed dog and its plate and the left to on the presser foot.

As you can see, there is minimal puckering.

Here you will see stitches with the machine in 3 different configurations.

A= My modified stirrup plate with an adequate amount of pressure from the presser foot.

B= My modified stirrup plate with NO pressure from the presser foot (the leather was lifting off the stirrup plate as the needle was retracted, resulting in skipped stitches - NOTE that I started pressing down on the leather with my thumbs to keep the leather from lifting and to stop the skipped stitches)

C= The holster plate with just enough presser foot pressure to keep the leather from lifting off the surface of the holster plate

As you can see, all three stitch lines exhibit the same puckering and elevated section, regardless of presser foot pressure, and this is directly related to the lack of the lower feed dog pressing up on the bottom surface of the leather to flatten everything back out. It's not a flaw in this machine or any other machine, but this demonstrates why the much more expensive needle and awl machines are so desirable.

This photo shows what the stitching looks like with my modified stirrup plate after being dampened and hammered flat with a smooth face hammer.

What's all this talk of my modified stirrup plate? Why don't I just use the holster plate since I'm making holsters? Why am I using the stirrup plate if I'm not making stirrups?

This photo shows the wrap on the back of my Avenger style holster using my modified stirrup plate. I'm sure some of you will think/say I'm building my holster wrong. yes, I could modify the belt loop to be narrower and stay further away from the bottom of the slide. Or, I could just use a custom "Holster" plate by modifying my stirrup plate that I would likely never use otherwise. The holster plate that ships with the machine is very long and wide, and snags on the edge of the reinforcement on the back side. The stirrup plate is the perfect size (very similar in size to the stirrup plate I was using on my Boss which my patterns were initially built to work around). If I use the standard holster plate, I would have to angle the holster to lift the reinforcement up and onto the top of the holster plate at various points along my stitch line. I could sew the opposite direction to put the narrow side of the holster plate towards the reinforcement, but I still have the problem of the leading edge of the holster plate snagging on the reinforcement.

I'm still able to use the double-toe presser foot because it makes contact on both sides, even if just barely. This may not be the case with all machines, as my presser foot doesn't quite seem centered with the needle bar.

Here is the stirrup plate as it came from Cobra.

Here is my modified stirrup plate that works PERFECTLY for my intended use. I've also included a comparison photo alongside my Tippmann Boss stirrup plate.

And here is a photo of a reinforcement sewn with it.

All in all, I am very happy with the machine. Like anything, there is a serious learning curve to using these machines. It took me a while to learn and 'perfect' the Boss, and it will undoubtedly take a while to master a powered machine. I just wish the servo motor was easier to control - it's simply not as "user friendly" as I imagined it would be.

Yes, I have contacted Steve but honestly felt like the conversation wasn't going anywhere because he simply didn't understand what I was talking about. Hopefully these photos clear things up for everyone.

Edited May 26, 2012 by particle

[dirtclod]

Have you tried changing where the spring hooks on the arm and tried moving the hook on the chain to another hole ? I don't know if that would change anything just wondering.

One machine i have has a servo motor and i have all kinds of control with it. Not sure what brand of motor it is. To tell the truth i never really have looked to see how it works.

[particle]

Yes - the spring just adjusts the resistance, while having the chain on the furthest hole provides the most control by giving you more travel to vary the speed. But when you're talking about such a small amount of effect travel range, it's practically no change at all.

[tnawrot2]

If you were to extend the lever that the "S" hook is attached to, by attaching a flat steel piece to the existing lever with two bolts and then attaching the "S" hook to the other end, you will increase the travel of the foot pedal that engages the motor.

[particle]

Yep - did that too. I didn't take any pictures of it, but I have a 1/8" x 1/2" x 12" aluminum bar that I mounted to the lever, and drilled holes in the aluminum every 1". With the hook at 12", the motor ran continuously (slowly) because the weight of the bar and the chain that far out was enough to actuate the motor. With the hook at 6", the motor stopped running on its own, but there was barely any increase in effective range of motion - not worth risking my 2 year old child grabbing onto the bar and giving it a good tug and bending it or breaking the motor's actuation lever.

[K-Man]

Yep, Particle, I have the same servo motor model you do. Though I have the holster plate, I've never used it to make our holsters, and we've made ones very similar to yours. The "bumps" have been a common occurence on whatever I sew with the machine and are very mild/slight. It happened with the Artisan Toro 3000; it's happened with every machine (441 style) that I've owned/operated.

Edited May 26, 2012 by K-Man

[Big G]

i have had my cobra for 1 yr this month , has the same model motor as yours , also the speed controller works just like yours . the display on my motor displays rpm, i usually sew at 600 rpm. i noticed yours displays 1-?. probably some way to change display.

i have had my cobra for 1 yr this month , has the same model motor as yours , also the speed controller works just like yours . the display on my motor displays rpm, i usually sew at 600 rpm. i noticed yours displays 1-?. probably some way to change display.

[dirtclod]

Particle i just came in from sewing some things and i checked my machine's pedal travel. It was around a 1/4 from stopped to full speed. It has a clutch motor and the pedal has rods instead of a chain. I can sew 1 stitch if i want to no problem. Personally i never had noticed it on my machine till it was brought up here. Now a guy i used to work for has his pedal set to where you have to really push the pedal before it will start sewing and it drives me crazy every time i have sewed on it. I guess it's just what ever you get used to.

[Cobra Steve]

Hello everyone. Regarding the motor issue. We are limited to 3 major motor factories. We have tested motors from all 3 of these factories. We chose this style because after testing them, they performed better than the other 2. Not only myself, but Bob from Toledo, Ronnie from Tech-sew, and most everyone else uses the same motor. Perhaps the circuit board is defective. If so, we will replace at no charge. This was a very interesting thread and I learned a couple of things so thank you all for participating. Please call me with questions if you have any. Thanks, Steve

[Wizcrafts]

I suspect that the problem with these motors lies in the quality of the movable light baffle, or maybe even in the light sensor module itself. If I can get my hands on one of these motors I will play with it and see what I can learn about any possible mechanical adjustments that can be made to spread out the speed over a wider range of motion.

Edited May 30, 2012 by Wizcrafts

[Steven Kelley]

I have a CB4500 that has the digital servo, and it works. It is a little touchy at low speed and sometimes hard to control when you want to go one stitch at a time. When I bought my 205-370, it had a clutch motor, which I immediately decided to replace. Knowing I didn't really like the digital motor that much for the speed sensitivity and I hate having to push all the buttons in a certain order just to change the speed, I decided to try one of these..... http://www.ebay.com/itm/NEW-Nick-O-Sew-NKS-5500-110V-Servo-Motor-BEST-QUALITY-/110886914518?pt=BI_Sewing_Machines&hash=item19d16009d6. It seemed to be a simple servo with dial speed control, and for $100 bucks I thought I'd give it a shot. All I can say is the speed control at super slow speed is FANTASTIC. I could not be more happy with the motor, and for $100, it's a steal. I'm sure some Chinese manufacturer sells these under dozens of different names, and I wish this type motor was an option on the 441 clones, instead of the digital servo. Maybe Bob and Steve even sell this same motor.

[Sylvia]

I don't have one of these sewing machines but..... the bump on the bottom looks to me like the needle is dull and is forcing it's way though the leather instead of puncturing it.

Have you changed the needle yet to see if it improves that issue?

[particle]

Brand new needles.

[Cobra Steve]

Hi. The bumps that everyone is referring to are common. When a leather point needle cuts through dense leather, all of the leather particles are pushed through to the other side. These paticles are being pushed not by the point of the needle, but by the shank. These particles have no where else to go but out the other side. This will happen on most thick leathers. On softer leather this will happen less because softer leathers absorb the paticles since they are so much smaller. If you take a heavy leather point needle and poke a hole in a piece of paper, you will see the same "bump" even though the paticles are still attached to the piece of paper. Steve

Edited May 30, 2012 by Cobra Steve

[Ken Nelson]

Hi. The bumps that everyone is referring to are common. When a leather point needle cuts through dense leather, all of the leather particles are pushed through to the other side. These paticles are being pushed not by the point of the needle, but by the shank. These particles have no where else to go but out the other side. This will happen on most thick leathers. On softer leather this will happen less because softer leathers absorb the paticles since they are so much smaller. If you take a heavy leather point needle and poke a hole in a piece of paper, you will see the same "bump" even though the paticles are still attached to the piece of paper. Steve

This thread is amazing, People that don't have a heavy stitcher and probably never used one, all seem to have an opinion. People that have sewn a bunch have something to say and it seems to be more constructive. People that have sewn just a little bit seem to think that purchasing a machine will make them an instant expert. No way an expert am I, certainly not in the league of Art or Wizcrafts but have owned several types of heavy stitchers and a number of chap machines, but I have learned a few things: 1. If it isn't sewing the way you think it should it is probably my fault, and not the machine's. 2. "If" you call the dealer you purchased a new machine from and ask for help on what I am doing wrong they will probably talk you through the problem and graciously. 3. If something is wrong with the machine they will make it right and be more than fair with you.

Rule of Thumb for me: Call the dealer first, Call the dealer back if I don't understand what he said. GO PUBLIC as a last resort, only after I have been treated poorly by the merchant I spent my money with.

Sewing is a skill that takes a lot of practice to get good at and sometimes after you think you have it mastered, it will "eat your lunch".

Just my opinion, not that it makes any difference. Ken