Tuesday, July 8, 2014

These Feet Were Made For Walkin'

Not exactly the Nancy Sinatra song "There Boots Were Made for Walkin'" but this post is about walking feet and walking feet sewing machines, the Pfaff 1222 with IDT specifically. IDT = Independent Dual Transport is the Pfaff way of saying "built-in walking foot system" instead of an attachment you put on the back in place of your regular foot. Here's what a regular walking foot looks like and then one on a Viking 1100:

Generic Walking Foot

Viking Walking Foot
The idea behind a walking foot is to keep fabric layers from slipping away from each other as you sew. In normal sewing, the feed dogs (those grippy things that stick up out of the needle plate) move the fabric along on the bottom while the presser foot keeps things steady on top. You might have noticed when you get to the end of some seams they no longer match up but the top is now  longer than the bottom, having slipped forward as you were sewing. What happened? The top layer did not move at the same pace as the bottom and this especially happens on multiple layers such as in quilting. Here's an example from a toaster cover I've been experimenting with:

Front: no walking foot on left

Back: no walking foot on left
On the front it's not as obvious but the top slipped down so now the top and bottom layers (with Insulbrite in the center) do not match up causing more trimming and waste. On the back side it's quite obvious that without a walking foot it did not feed right. The walking foot has the same kind of gippy surface you have on the feed dogs so now you have feed dogs on the bottom of your fabric layers and on the top for even feeding. Pretty ingenious!

So what's on the right of these examples? They were sewn with a Pfaff 1222 with the IDT functioning as it should, feeding the fabric evenly on top and bottom:
Pfaff 1222 with IDT
Why not just get a walking foot for the sewing machine you love best? That is a good plan but I found the machines didn't like the added-on walking foot, having tried it on a half dozen sewing machines. The Viking model did work well but it was quite a bit of a strain on the machine and I got the feeling if I used this as often as I needed to for my craft show side of the business it would cause a breakdown of the Viking 1100. The Pfaff is intended for use of a walking foot and handles this one perfectly. You can disengage the IDT with a release lever but I only did that once and said "Why not use it all the time?" and went back to using it for all sewing on this model. It should work well when matching plaids, to keep them matched as intended with careful pinning.

Here's what the sample toaster cover looked like in the end:
Waverly fabric with a food theme

Side front of toaster cover
Not bad as a prototype but will have to see if I can speed up the process and make them able to fit a variety of toasters. Do I go to the store and try mine on various models? Send it home with co-workers for test-toasting? We shall see but I'm making them all with the Pfaff and the "Independent Dual Transport" system engaged!

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