Needle And Awl Machines

[Cascabel]

I frequently see mention of "needle and awl" machines in this forum. Can someone please explain exactly what they are, and how they work, and their purpose ? I don't think I need one, but I'm really curious about what they are....

[oltoot]

Briefly, N&AMs operate a little differently than single needle machines. The main drive is split into two equally robust drives, upper and lower. In operation a solid awl is driven straight down through the material, punching the hole. A needle with an open barb comes up from the bottom through the hole. The upper thread is fed into the barb with a system of loopers or fingers. The presser foot lifts up. The needle with the thread in the barb feeds the work to the rear, ready for the next cycle. The needle then is pulled down through the work and as it begins its travel upward it makes a loop in the top thread which the hook, rotating around catches and then carries the top thread around the bobbin where the lower thread is. Different machines handle the tightening and locking of the stitch in different ways but somewhere in between awl thrusts, rollers or some other device lock down on the top and pull the stitch tight. In the downward part of the needle cycle the needle travels back to its home position in perfect alignment with the awl. Their purpose was to sew the tightest possible stitch with whatever thread was being used and to have uniform stitch length in varying weights of material. I have one and wouldn't trade it for the world but if I were starting out on a limited budget, the 441 clones for ~ $3000 complete and delivered with great support and service would look quite attractive, especially if I were going to be working with fabric as well as leather. My 2 cents

[Wizcrafts]

There are two different transport systems used in needle and awl machines.

The first is needle feed, wherein the awl moves in a static vertical position, stabbing the hole, with the needle coming up and moving the work as the foot lifts. At the end of its travel, a looper feeds the top thread into the barb. When the needle descends, the hook pulls the top thread off the barb and around a huge round bobbin (about 2.5 D x 3/4 inches W). The thinner the needle, the more it can flex under thick or heavy loads, which affects the stitch length to a degree. Needles are usually one size smaller than the awls.

This system is used in the Union Lockstitch machines. They are the fastest production needle and awl machines in existence and pull the tightest stitch imaginable.

The other system is awl feed, where the awl stabs the hole, the foot lifts and the awl pulls the work back. Then the needle comes up and down in its static vertical axis. The awls are more solid than the needles, which must be one size smaller than the awls. There is less flexing, hence more consistent stitch length across heavy, thick leather projects..

The Campbell-Randall Lockstitch machines are awl fed and have boat shaped shuttles and long, cylindrical bobbins. Slow and steady, making a sound like tapokita, tapokita, they are the cream of the crop in my opinion.

[Cascabel]

Is there anything that can be done with a needle and awl machine that cannot be done equally well with a properly adjusted 441 clone ?

[oltoot]

No and yes. The answer depends on whether good enough is good enough. If it is then the answer is no. If it isn't and things like stitch tightness and seam durability come into play then the answer is yes. And if you want to work in fabric as well as leather, then the 441 clones can actually be "better" meaning more versatile. The N&AMs can lock the stitch tighter in a smaller hole, thus having a greater holding power when the thread wears off on top of the piece as can happen with various types of skirt and plate riggings and other tack applications but again, the 441's can do good enough and are getting more affordable. I still wouldn't trade though. I would rather be in a position to afford one of each than to have to choose.

[Wizcrafts]

Is there anything that can be done with a needle and awl machine that cannot be done equally well with a properly adjusted 441 clone ?

• More closely resembles appearance of hand stitching on bottom
  
• Uses linen thread, run through liquid wax, or bonded polyester. Union Lock can use bonded nylon also.
  
• Thread size is dependent on needle and awl size. Needles are currently available to take about 10 cord linen, or #600+ bonded thread.
  
• Needle and awl machines are usually square drive, moving the feeding needle or awl absolutely horizontally, not pendulum driven from a pivot point on the top. This means that all layers are moved the same distance, no matter if the work is thick or thin. Pendulum drive machines lose stitch length on thick stacks of leather, or items sewn on the raised holster and stirrup plates.
  
• Sews Biothane better than closed needle machines.
  

Depending on the brand of machine, there can be a lot of accessory presser feet and throat plates available to do specialized sewing. These may include (based on my previous Union Lockstitch experience):

• Single toe left and right
  
• Double toe, open or closed end
  
• Knife in front to cut a stitching channel
  
• Right or left toe stepping feet, for various stitch lengths. These feet have an arch on the back that sits on top of the thread holes, pushing the thread down on the ends for a perfect top appearance.
  
• Available channel cutting knife on the needle bar on Union Lockstitch machines. This cuts a groove on the bottom to bury the stitches for horse gear.
  
• French Box sewing attachments for stitching across intersecting corners
  
• Throat plates of every imaginable configuration. Long, short, high, low, narrow raised, stirrup, long narrow slot, short narrow slot, etc.
  
• Raised roller swing away edge guides. Lets the bottom layer pass under the roller, while securing the top layers for edge stitching. Good for items that have oversize liners on the bottom, to be cut flush after sewing is done.
  
• Some make a pleasing tapokita tapokita sound as you sew. This makes you feel like Walter Mitty.
  
• Made entirely in the USA!
  

Edited November 4, 2013 by Wizcrafts

[Wizcrafts]

The cons of a needle and awl machine vs a closed needle machine include:

• No reverse. You must turn the work clockwise, 180 degrees, and very carefully place the barbed needle to the outside of the previous stitches, or else... Backtacking is tricky with a barbed needle machine.
  
• The barbed needles will pull out the bottom of webbing, unless you use the minimum size needle that will hold the top thread long enough to form a stitch (my trick). A completely filled barb doesn't usually have enough sharp edge sticking out to catch the ratable material on its way down.
  
• With the exception of the Union Lockstitch machine, most needle and awl stitchers run at only a couple of stitches per second (between 2 - 4). Only the Union Lockstitch is able to sew fast. Mine pounded away at about 13 stitches per second, flat out. Shook the whole house! Sounded like a farm thrashing machine. But, got er done!
  
• They don't fair as well with thin thread as thicker thread. I got my ULS to sew with #138 bonded nylon, but that was it. They prefer 4 cord linen or larger = #277 or larger bonded thread.
  
• Not really meant to sew thin stuff, under about 6 to 8 ounces. Of course, a good operator can make anything happen.
  
• Tricky to change stitch length. Could require re-adjusting needle starting position, depending on your clearances.
  
• Expensive! Used, but not shot, they sell for up to $3,000. A factory rebuilt Union Lockstitch Machine can cost you up to $4500. A new one, $6,000. A Campbell Randall is almost $7,000, fully set up.
  

[Cascabel]

• "Some make a pleasing tapokita tapokita sound as you sew. This makes you feel like Walter Mitty."
  
• 
  
• Well..... I gotta admit, "tapokita-tapokita" can be pretty important !!! LOL :thumbsup: