Monday, July 25, 2011

Engineering a Bow Tie


  


I purchased this sewing machine from the local recycle center a couple weekends ago for $5.  I bought it for another project I am working on that is unrelated to sewing, but I needed the motor.  Well, I was so impressed with how cool the machine looks I couldn't bear to scavenge the motor and discard the rest.  Instead, I decided to get the sewing machine to a working state and modify the design of my other project so that I could leave the machine intact.  I will still use this sewing machine for the intended project but now, after a couple of minor tune ups I also have a sweet looking sewing machine.

All I really had to do to get the machine working was reinstall the thread tensioner, oil it and replace the motor brushes.  And with a little help from my Mom and a friend of mine I was able to understand better what all of the different parts of the machine do.  Sewing machines are really incredible.  They have all kinds of interesting cams, connecting rods and leavers.  One source of amusement for me during this process has been learning the new terminology.  For instance I still have a tendency to call the "stitch length" "feed rate" instead.  If you are wondering what goes on beneath the bedplate of a sewing machine have a look at this lock stitch gif.

Now that I have a working sewing machine what will I make?  Since I wanted to stitch something manly and easy and since I needed to get a bit fancy to go see my friend Linda in a play this weekend, I decided to make a bow tie.  Which got me thinking; bow ties are better!  Especially for hands on type people, comparing a bow tie to a neck tie the benefits are obvious.  Bow ties don't dangle down and get caught in rotating machinery or get soiled as they flap about in the breeze.  Bow ties don't have to be thrown over your shoulder to pee.  Bow ties send the message that you are fancy, but ready for action at any time.  Bow ties don't dangle into stove burners when you are cooking.  I have never burned a bow tie with acid.  And empirical evidence has proven I get more compliments wearing a bow tie than I do with neck ties.

Before we make the bow tie I will offer this disclaimer.  I am not a seamster.  I felt much more at home working on the machine than with it.  In fact, this is my first time using a sewing machine really and as such there may be better ways to do things.  Probably like how to sew the left and right halves together for instance.  So, if you have any thoughts feel free to offer your suggestions in the comments below.  I'd love to hear them.  Also, I have made three bow ties now, some of the pictures I may use here are from different ties but were selected to best illustrate the steps.  Don't worry if the fabric print changes on us half way through the blog.

A sewing pattern is a template used to cut out your fabric pieces prior to sewing.  I looked online for a bow tie pattern, but I found none suitable.  Instead I looked at an untied bow tie and a diagram of how to tie them.  This led me to conclude that the knot size is a function of the neck band width and the minimum distance between the two concave radii on the outer ends determines the bow "pleats" or how much it crunches down when you cinch it up.  With this in mind I fired up my favorite drafting program AutoCad and made some critical points.  I used the spline tool to connect them which is similar to a French curve for the old school drafters.


UPDATE:
In case you really want to get nerdy I made a new pattern.  I call it a "cosine function bow tie pattern" because the shape of the bow tie I designed is 2 cosines.  I wrote the functions on the pattern in case you want to know what they are.  You can download the cosine function bow tie pattern here.  Both patterns use the same instructions outlined below.


You can download a PDF of the original pattern I made here.  You will notice that there is one "bow tie end" and two neck templates.  I only needed one neck template, but there is another one included for larger necks.  Once everything is cut out, tape the neck template to the bow tie end where the arrow points to a line.  The arrow is coming from the text that reads "shirt collar in cm between here and other side".  Do tape it so that the neck template remains in line with the bow tie template.  Below is a picture of how I lined up the template.  Using a sheet of paper that touches a tangent point on the bow center and the intersection of the neck template line and the sew line on the neck template, the paper projects off to the right and makes a line to line up the neck template.  The extra sheet of paper is removed and I taped the two templates together.




From here you can mark your neck size.  My neck is 42cm circumferentially and since the pattern makes half of the bow tie, I marked 21cm on the template.  Er, pattern, I mean.  If we call this the left or right side, the 21cm mark marks a line of symmetry.  Each half of the bow tie should be sewn together at this line and it will fit your neck just right.  I decided against an adjustable neck strap because I feel my neck is probably done growing, I can make another one is necessary and ease of assembly with my limited sewing skills.  Here is a picture of the 21cm line marked and the neck template taped to the bow tie template.




A couple words on materials.  Firstly there is this stuff called interfacing.  It is a horrible scratchy stiff material.  It feels like wax coated coffee filter papers or course tyvek.  I comes in an optional iron on version whose glue I presume would affect the color of your fabric.  The purpose of interfacing, to my knowledge, is to stiffen up your sewn piece so; it is supposed to be good for things like...bow ties.  I didn't use interfacing for interfacing and chose a fabric called muslin instead.  It is soft and pliable and with two layers of it in between my outer bow tie fabric, it stiffened it up just enough to hold its shape and still bend out of the way should your chin ever come in contact with your tie.  Safety first.

The second thing to note about fabric is that it stretches more on the bias, 45 degrees from the fabric threads.  When you lay out the pattern on the fabric for cutting, place it so that it runs 45 degrees to the grain of the fabric.  Pin the template pattern in place so it won't move when cutting.  I cut out all of the pieces at once.  This is probably not the best way to do it especially since my scissors are a bit dull from cutting a PCB days earlier.  Here is a picture of the pattern pinned in place, on the bias, ready for cutting.  In total there are 4 pieces of muslin and 4 pieces of outer fabric.




Cut out the entire pattern outline.  You want to leave material beyond the neck circumference mark you made earlier so you can sew the halves together later.




Here are three versions of neck seams I made.  The brown one in the center is probably the best design wise but the yellow and blue are easier and covered by your shirt collar anyway. 
 



For the yellow and blue I started by sewing the left and right halves first around their perimeter and turned them right side out.  For the blue one, I overlapped the halves at the neck seam mark I made on the neck template and ran it thru the machine then chopped off the "tag ends".  For the yellow, I laid the left and right halves on top of each other and ran it thru the machine at the neck seam mark, then ironed the tag ends flat.  For the brown one, I did not sew the left and right halves together first.  Instead I sewed the top or front, left and right halves together first, ironed that flat then sewed the perimeter.  Perhaps a photograph can best illustrate the brown neck seam.




Still talking about the brown one, I then sewed the perimeter leaving the vertical slit open for turning the thing right side out and hand stitched it closed.  I guess it is a good time to mention you do all of the sewing possible inside out and turn it afterwards so it hides the stitches.

Back to the yellow and blue ties and sewing the perimeter.  Prepare the left and right halves inside out so that the fabric sandwich has two pieces of muslin, one each on the outside and your two pieces of outer fabric, good side facing each other are on the inside.  Pin the whole thing together and sew around the perimeter.  I used the presser foot on the machine as a guide to know how far in to stitch.  Below is a picture of this step.  The photograph also shows the two concave radii that I was talking about earlier that will increase the pleats in the tied bow if you increase the distance between them. 




Once the perimeter is sewn you will want to cut incisions around the perimeter wherever there is up or down concavity and at inflection points.  That is, anywhere the sewn line is not intended to be straight, cut some incisions to help the flat fabric bend in the curves when you turn it right side out.  I imagine this is less necessary when you sew as close to the edge as I did, but I guess it is still good practice.  I also imagine I put more incisions than are necessary.  This is also a good time to trim fabric from what will be internal corners of the bow tie.  Just trim the fabric kind of close to the stitch line, but not too close that the fabric unravels, where the internal corners will be to reduce fabric bulk.




Now, whether you chose to do the brown bow tie neck seam or the easier blue or yellow style neck seam it is time to turn the tie right side out.  To do this I used a chopstick.  I also used said chopstick to poke the corners of the bow out to sharper points before ironing the thing flat.




Once the bow tie is turned right side out I ironed it flat and turned to youtube to learn how to tie a bow tie.  Turns out its pretty easy.  I'd say it was less difficult to learn to tie a bow tie than it was when I learned to tie a neck tie.  In fairness I was probably 8 back then and my only bow ties were clip on.




So, if you feel like getting fancy and are tired of the limitations inherent to neck ties give bow ties a try!  Let me know if you give it a shot, I would be interested to get some feedback on the pattern as well as technique.  Here are a couple of action shots and one of my sewing 'rig' because I like the way it looks.























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