Tuesday, March 10, 2009

Plastic Pipe (CPVC) Swift

I recently embarked on a project to reclaim laceweight cashmere from a commercial sweater. I quickly realized that I had no interest in skeining approximately 3500 yards of yarn onto my niddy-noddy. Matt to the rescue -- with plastic pipe of course (other plastic pipe projects to his credit include a woodwind instrument, a laundry airer, the niddy-noddy, a footstool, and a yarn rope maker).



I used the swift to skein the yarn directly off the sweater, which was a fabulous boon. While this swift was inspired by the need to make yarn into skeins, it also works well for winding yarn off of skeins.

After Matt made this swift, I thought to search online for other PVC swift projects, and found this one. It's very nice, and superior to Matt's in some ways: it is easier to load with a skein of yarn and it may not require a clamp to hold it in place. But Matt's swift folds up smaller for storage, has a handle, and adjusts easily to different skein sizes, all of which are important features to me.

Here are Matt's write-up and project pictures. They're not a step-by-step tutorial (I certainly couldn't build a swift from them), but if you know your way around a workbench, they should get you headed in the right direction.

Matt's notes

I built this in about half a day. I had most of the parts on hand, though I did have to make one run to the store.

Dimensions and skein size range

When opened out so that the verticals form a square, the sides of the square are about 12" long and the diagonal of the square is about 17". The smallest skein it will accommodate (with the arms all the way closed) is about 3' in circumference. The largest skein it will accommodate (with the arms opened out all the way) is about 6' in circumference.

This is about as big as you'd want to make the swift out of 1/2" CPVC. Under tension the arms twist a little, allowing the verticals to lean inward slightly. This is inelegant but has not proved to be a problem yet.







Materials

  • 1/2" nominal CPVC pipe (5/8" O.D.), fittings, and pipe cement
  • 2x4 and scrap wood
  • self-adhesive felt (found at the hardware store alongside the furniture casters and glides)
  • all-thread rod, machine screws, washers, and wing nuts (see below for specifics)

Central pivot

I drilled a 5/8" diameter hole through the 3 1/2" dimension of a 2x4 and inserted a CPVC pipe axle through the hole to make the pivot. I did not oversize the hole because I didn't want the finished swift to wobble. The fittings on either end of the axle are cemented in place to prevent it falling out. I lubricated the axle with a little petroleum jelly. It turns smoothly and easily without wobbling.



Adjustable arms

I used a drill and a file to make corresponding slots in the fittings at the hinge locations, through which I inserted #6 machine screws with wing nuts. Once the arms are adjusted to the desired angle, the wing nuts are used to compress the fittings and hold the arms in place. To use, loosen the wing nuts, set the arms where you want them, then tighten the wing nuts enough to resist the yarn tension. Re-tighten the wing nuts if the arms start to fold inward as you wind yarn onto the swift.







Verticals

One of the four verticals is longer than the others and serves as a handle. The other three verticals have tee fittings on top which are not glued on. The tees keep yarn from riding up past the ends of the verticals. They are removable to make it easier to put a skein on or take it off the swift.



Clamp

The goal was to use the materials I had on hand to make a clamp that would work on the 2" edge of a typical counter or on any tabletop less than 2" thick . All I can say is, it works. It's big and ugly, but it's strong and stable. If I make another swift I'll probably try adapting a commercial clamp of some kind (here's an interesting example).

The lower jaw has a slot in it rather than a hole, so that its angle can change as the clamp is adjusted. The chunk of dowel keeps the wing nut and washer from lodging in the rough-edged slot. If I'd had something smaller than 1/4" diameter threaded rod or if I'd made a neater slot, the chunk of dowel wouldn't have been necessary. The self-adhesive felt prevents the jaws from marring the table or counter.





Possible improvements

Skein Loading
To put a skein on this swift you fold the arms in enough to pass the skein over the vertical pipes, then open the arms out enough to put some tension on the skein, all while managing the skein itself -- a somewhat fussy proposition, because if there isn't enough tension the skein falls down. One solution would be to extend the horizontal pipe members out past the verticals by 2-3" to give the skein somewhere to rest while you're fiddling with the adjustable arms. You might want to make the extensions removable so they don't get in the way while you're turning the swift.

Handle Placement
With the handle as currently configured, short persons winding miles of laceweight will get tired of reaching for the handle at the far end of its circuit. With the swift opened out to its maximum circumference, reaching the handle while standing clear of the arms is awkward for anyone. Rather than having one of the verticals that carry the yarn do double duty as a handle, you could mount a separate handle closer to the pivot point (you could even allow it to slide along one of the horizontal members so that its distance from the pivot was adjustable). This would reduce the distance between the user and the far end of the handle's circuit. Just don't place the handle too close to the pivot point, or it will be difficult to turn the swift smoothly.

4 comments:

Anonymous said...

I really love your swift. It's small and simple, and suits my needs much better than the big fancy ones I've seen that were also made of PVC. Thanks so much for sharing. I haven't made mine yet, but was thinking of a simple solution/modification to keep the yarn from falling down on the verticals. Maybe drill small holes all the way through the verticals? That way something could be inserted to hold the yarn. For small skeins that could be a pipe cleaner, a plastic straw, or a wire inserted crosswise so the yarn would have a place to rest? Or perhaps something even better than what I'm coming up with? I'm still thinking about it too. Thanks again!

sharonmattnadia said...

With use, I've found that keeping the yarn from falling off the verticals isn't that big a deal. Once you have the swift moving, physics tends to keep the yarn up.

Calming Influence said...

Matt, very nice design! I really like how adjustable it is, and that clamp is very cool as well.

And Sharon, thanks a lot for sharing this. I've been Googling for an hour for a swift I could put together myself, and there doesn't seem to be a lot out there - this was a very lucky find!

sharonmattnadia said...

I just posted a compilation of many of the DIY swifts I have come across in my researches on the question. Some of them require no tools at all (think Legos or Tinker Toys).