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Posted

Gentlemen,

So as expected, David at Leather Sewing Machine Co. has gone above and beyond. Honestly, I have never received customer service at this level.  He simply just wants to make his customers happy and is willing to assist with sincerity.   He wants to get the machine back so they can inspect.  It seems to me there might be a tight bearing or bushing somewhere but I am no sewing machine mechanic.    After more heavy oiling,  I was able to get the machine to sew more smoothly.  However, to get that top stitch loose loop out, I had to almost tighten bottom bobbin all the way.   This as expected required more top tension.   So, sewing with that much tension seemed to be adding more binding in the thread and sewing in general.  

David and I spoke in details about options.  After looking at the leather weight I sew with Fire Department Front Shields, we decided it may be better to upgrade to the Class 4.   It arrived yesterday and I started setting it up.   This thing looks like a beast.   Cant wait to get it up and sewing. 

Thank you all for your response to these forums.   Your knowledge and suggestions helps so much when us armatures are working thru adjustments and tuning. 

Yes lets talk thread and needles for Turn Out Gear 

 

Posted (edited)

There's a video shot at LMC showing them running in a bunch of class 4 heads prior to sale. They must not do the same for the class 26 because there's no way you could miss that noise.

Obviously, they're going above and beyond to get this one resolved.

4:30 of this video:

https://m.youtube.com/watch?v=KOLNoN1sVI8

Edited by AlZilla

“Those who can make you believe absurdities can make you commit atrocities.”
- Voltaire

“Republics decline into democracies and democracies degenerate into despotisms.”
- Aristotle

Posted (edited)

As soon as I heard that distinctive noise it hit me it’s something I’ve experienced before, but for the life of me can’t recall what caused it - maybe once some more coffee kicks in it will dawn on me.

. . .

It came back to me what that noise was in my case - it was a two piece adjustable brass bushing in an old piece of equipment that would make that noise when adjusted a little on the tight side.   It must be the harmonics of the stick and slide, stick and slide of brass on steel.   I’m sure with a little use it will go away completely.

Since your noise is consistent with hand wheel rotation and doesn’t change as needle bar slows and changes direction so I’d bet it’s a  contact point on the upper shaft of some kind on the other end opposite of the handwheel.

In industrial settings, to track down minuscule  machine vibrations too faint to be felt or heard by a human, an oscilloscope  reads electrical impulses from tiny acceleration sensors (see photo).   Two of these can be held onto two sides of a part, or two separate parts with magnets and it will show which has more vibrations.   With inexpensive portable oscilloscopes and sensors this is also really changing how automotive noises and vibrations are traced.   

1BE6CFE9-0BD1-44EA-9354-5A33F3675937.jpeg

Edited by DonInReno
  • Members
Posted

@Bullduke  the customer service is exactly what I bought a 26 from them a couple of years ago.  I had a problem with mine (no where near as bad as yours) that was self induced.  But when I called up LMC they took the time to walk me through the repair and even sent pictures of the parts I needed to adjust.  I’m glad to hear that they were so helpful.  I for one would love to know what they found with the machines when they got them back.  Now that you’re moving to a Class 4 you might want to get with some of the members about a part that RockyAussie sells for the 4 that expands the sewing capabilities. 

  • Moderator
Posted
15 hours ago, Bullduke said:

Yes lets talk thread and needles for Turn Out Gear

I'm your Huckleberry!

Firefighting gear has to withstand temperatures that will melt bonded nylon or polyester thread. A simple lighter on the thread test confirms this. I sometimes use lighters to melt the ending thread stubs to lock them down. You cannot sew turnout gear with nylon or polyester thread that will melt in the heat of a firefight.

In response to the need, Dupont developed a meta-aramid fiber that can be spun into sewing thread that is called Nomex. This thread has a very high heat (~ 675 degrees F) and flame resistance (it chars, but doesn't melt in flames). However, this heat and flame resistance comes at a price. That price fluctuates from time to time, but ranges between $100 and $200 a pound (for new stock). During the California fire season, the price per pound may go through the roof. In the off-season, it may drop.

Different areas of a turnout suit require different thread sizes to keep the pieces together, oftentimes under tremendous strain. Less stressed decorative areas can be sewn with Tex 27 or 40. More stressed seams may require Tex 60 or Tex 80. Really thick seams may need Tex 90, 105, or thicker Nomex thread. I have used all these sizes on a turnout suit, using the thinner thread on reflective tape that came loose and heavier thread on suede cuffs on the bottom of the legs.

One of my primary sewing suppliers, Wawak, carries Nomex thread in Tex 40, in black and natural, in 6000 yard spools.

 

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.

Posted
22 hours ago, DonInReno said:

It came back to me what that noise was in my case - it was a two piece adjustable brass bushing in an old piece of equipment that would make that noise when adjusted a little on the tight side.   It must be the harmonics of the stick and slide, stick and slide of brass on steel.   I’m sure with a little use it will go away completely.

This is called dry friction.  It generates random vibration frequencies that excite the natural frequencies of connected parts (causing resonance and high vibration amplitudes).  So needs to be lubricated.  Brass bushings may be oil-less self lubricated or not.  Self lubricated type are often used in fractional horsepower motors.  If memory serves me correct, these shouldn't be oiled.  I don't know if oiling would result in increased friction as the oil is dispersed, squeezed out or thrown out.

  • Members
Posted
9 hours ago, Wizcrafts said:

Firefighting gear has to withstand temperatures that will melt bonded nylon or polyester thread. A simple lighter on the thread test confirms this. I sometimes use lighters to melt the ending thread stubs to lock them down. You cannot sew turnout gear with nylon or polyester thread that will melt in the heat of a firefight.

One of my primary sewing suppliers, Wawak, carries Nomex thread in Tex 40, in black and natural, in 6000 yard spools.

 

Boy, am I glad I read this. I have a whole bunch of family on my wife's side that are fire fighters and first responders. I've had in the back of my mind some designs for radio and gear belts that I could make for them but didn't consider that the thread would require fire retardant properties in order to function in the heat of battle. I did find that The Thread Exchange had a wide variety of Nomex threads in many weights, spool lengths and colors besides black and natural and prices seem competitive. Their offerings also include Spun Kevlar thread but I'm not sure it's as robust as the Nomex for the most demanding situations. I'd be interested in your opinions on the Kevlar thread and best uses, if you have any, and whether or not these Nomex threads are comparable to the ones offered by Wawak.

Ripper70

  • Moderator
Posted

@Ripper70

Spun Kevlar and Nomex are not as strong as their bonded nylon/polyester counterparts. In the lighter weights, the differences are not important because both threads are strong enough for seams and patches. In the heavier weights, strength often matters and Kevlar is usually the better choice. However, Kevlar thread is abrasive and will eventually wear grooves into posts, guides, tension disks and springs, the hook and the take-up lever. Any sewing machine used a lot with Kevlar thread will need to be rebuilt, or replaced more frequently that machines using standard industrial thread.

I haven't noticed any ill effects from running Nomex thread in my machines, repairing turnout suits, or those belonging to a friend's blackout window blind sewing operation which I was commissioned to set up.

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.

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