Advice On Cobra Class 4 and Getting Another Machine For Lighter Stuff

[Art]

4 hours ago, Singermania said:

HI, yes winding the pressure knob all the way up is the first step, I presume by banana slide you mean the adjustment on the back???  Nothing wrong with taking a coil off the tension spring, you wont do it with wire cutters, but an angle grinder will work.   We at Cowboy in Australia would be ok with it, but you'd want to check with your supplier to see if it upsets the warranty.

Not sure how it works in the Southern Hemisphere, but up here, if you cut a coil off, you increase the rate, and if you add a coil you decrease the rate.  Is that what you are trying to accomplish?

Art

[Singermania]

Art if you cut a coil off you decrease the compression on the spring....simply because the spring does not reach as far and therefore the knob does not begin to bind down upon it so early, it doesn't matter what hemisphere you live in, we're not flushing toilets....

Depending on how much you cut off, the knob may not even come in contact with the spring until wound further down and therefore be no pressure on the foot at all.   As most of the feed is accomplished by the needle this is not a problem.    regards Steve

 

[JMWendt]

Are you sewing damp leather when you are having this problem?  I've sewn successfully with my machine (same machine, different company) on leather down to 4 oz without leaving marks-- wallet innards made from 2 oz pigskin.  I used the slotted plate without the feed dog.  You have to "help" the material feed, but the pressure is less and there is no tendency of the material to be crammed into the hole.  I was using small needles and 69 thread.  I only had to barely adjust the tension from the setting I have it for sewing 277 thread on beefy thick holster leather.

[Art]

4 hours ago, Singermania said:

Art if you cut a coil off you decrease the compression on the spring....simply because the spring does not reach as far and therefore the knob does not begin to bind down upon it so early, it doesn't matter what hemisphere you live in, we're not flushing toilets....

Depending on how much you cut off, the knob may not even come in contact with the spring until wound further down and therefore be no pressure on the foot at all.   As most of the feed is accomplished by the needle this is not a problem.    regards Steve

 

I am referring to a spring in torsion or compression; and I stand by my statement.  When you add a spring rubber to a spring, it "deadens" one of the coils and increases the spring rate which makes for a "firmer" ride.  When you compress a spring with a screw, as the coils bind against each other, coils are effectively "removed" as one collapses against the next, and the spring rate increases.

Art

[Singermania]

I understand the theory, I also did engineering, however if nothing pushed against a spring then not a lot of anything is going to happen.   This is not a motor vehicle where the vehicle depresses the spring at all times, in this case cutting a coil off is effective or if you want to go with your logic then a lighter spring would also be good.

Art I wouldn't suggest this if I didn't know it worked, your theory is nice but flawed as we are talking about putting less pressure on the spring, not decreasing the resistance of the spring.   What you are imagining is that the spring has no load at the top position of the knob, however if you unwind the knob completely it will fly off, by shortening the spring it does not fly off......therefor lessening the downward pressure.    If you could increase the length of the bar, ie have the knob wound up higher you would achieve the same result.... but that would be more difficult.

Whilst you are correct about altering the rate of the spring, it is so long that one coil wont make much difference to its sensitivity.

I can only make suggestions from years in this business, things that I know work, if you want to dispute it then I suggest you try it first.

[zckry]

We typically use 207 thread for our leather 

[Art]

3 hours ago, Singermania said:

Whilst you are correct about altering the rate of the spring, it is so long that one coil wont make much difference to its sensitivity.

I can only make suggestions from years in this business, things that I know work, if you want to dispute it then I suggest you try it first.

The only thing I said was about altering the rate of the spring not about anything else which you incorrectly read into it.  I have altered and made many springs in my day, I don't need to try it first, been there, done that and don't need suggestions from you.

Art

[Art]

On 4/18/2016 at 2:50 PM, zckry said:

Do they provide smooth feed dog and presser feet like with the CC4? I didn't see it anywhere on the listing page and haven't contacted them.

Those machines use 111 feet, and smooth feet are available, but I would suspect they are provided on the leather version of the 227R.

Art

[Singermania]

Art if you have a problem with me then you should be man enough to say what it is, if not then I suggest you watch your language in future or remove yourself as moderator... you were the one that jumped in on my reply to someone else.    You clearly have no idea of how a 441 works, you should keep to what you know and have some respect for heavy leather sewing machine professionals that give their time and experience free of charge.

 

Edited April 20, 2016 by Singermania

[Art]

20 minutes ago, Singermania said:

Art if you have a problem with me then you should be man enough to say what it is, if not then I suggest you watch your language in future or remove yourself as moderator... you were the one that jumped in on my reply to someone else.    You clearly have no idea of how a 441 works, you should keep to what you know and have some respect for heavy leather sewing machine professionals that give their time and experience free of charge.

 

My Language????, did I spell something incorrectly????.  BTW, I have two 441 clones, and I clearly have as good a depth of knowledge of how the 441 works as you do.  I was in this conversation before you were.  You are trying to bully the wrong person.

Art