The other day, I posted about a DIY singled ended electric bobbin winder.  In November – couple of months after I built that first prototype – I found 4 used End Feed Shuttles (EFS) which suddenly made the single ended winder a little less ideal.

By responding a little too slowly, I just missed out on a used double ended electric winder from the same seller.  Having missed out on that , I decided to start plotting a way to modify my winder into a double ended bobbin winder.  Naturally, winter in central Alberta isn’t an ideal time to be trying to go outside into the unheated garage to woodwork, so the project got put on hold until January – which is still not an ideal time for wood destructor shed projects! January is when I started my next weaving project (the one I talked about in the last post.)  That project showed me that while the current winder could wind pirns, I didn’t enjoy it (I mean, as much as you’d ever enjoy winding bobbins/pirns?)

Once again, the point my mind was stuck on was the mandrel portion of the winder.  Additionally, it needed to be very smooth turning – which is why some companies moved to using bearings in the non-motor side.  Like this winder from Leclerc:

How could we do something like this at home with minimal jigs and specialized tools?  Prototype #2 needed to use only simple cuts that  I could send out to the garage with Ryan, because naturally, I decided to do this in a cold snap.  No router, no bandsaw, no special cuts.  Prototype #3 can be pretty, #2 only needed to function until spring.

I present to you a walk through (not a step by step tutorial but some of the main points in detail and a parts list) of a DIY double-ended electric bobbin winder.

So, let’s recap, Act 1 of this play ended with this:

A perfectly good working single ended bobbin winder.

What we needed though was something that had a second end that would turn freely to support the bobbin when the power of the motor was applied.

In the end, this is what I came up with (keeping in mind that we’re still doing a temporary build with minimal tools and time outside to do cuts and reusing what we can from the original single ended build.):

The build list (as built in V#2):

1. (1) Motor (with bracket) and controller that work together.  Electronic or resistance style, either is fine.
2. (1) 10mm x 25mm bolt, threads unimportant
3. (2) washers to fit a 10mm bolt
4. (14) wood screws – ranging from 1″ to 1 ¼” depending on the type of feet used on the bottom of the base.
5. (3) 3″ wood screws
6.  (1) bearing with a 26mm OD 10mm ID – the box for the one I have here was labeled: 60002NSL.  This project would probably also do just fine with a 608 type bearing used for rollerblades and a 8mm or 5/16″ bolt instead of the 10mm bolt.
7. (1) 6″ extension spring
8. (1) 5 ½” piece of 3×1 maple – this is the board from the previous build.  If you want to incorporate the improvements I am planning for version #3, see below.
9. (1) 12 – 15” piece of 4×1 maple – this is the board from the previous build.  If you want to incorporate the improvements I am planning, see below.
10. (1) 2″x4″x4″ block of wood (ideally this wood will match the rest of the pieces but for now what’s in the photos is spruce).
11. (2) off cut pieces of wood to build the “sled” the not-motor side of the winder will move on. See the build instructions for more.
12. (2) m3 x 10mm socket head screws (or (4) – see improvements below). I had 12mm long bolts here and they’re what’s in the photos.  Proper set screws would be better for balance.
13. (2) m3 square nuts(or (4) – see improvements below.)
14. (2) mandrel ends – one for the bearing end, and one for the motor end.  One will need to fit our 10mm bolt and one our sewing machine motor shaft. The ones in the photos are 3d printed out of a semi-rigid material – with updates to come. These could probably also be turned out of wood, or machined out of metal if you had that capability.  Both of those materials may need a rubber bushing for traction as in the original Leclerc winder.   I’d love to hear other “off the shelf” ideas too – to make this project more accessible to folks. If you’d like a set of these 3d printed mandrel ends, drop me a line here.  I’ll need to know the size of bolt you’re using and the diameter of the motor shaft to make adjustments to the CAD files and print them for you. Also, see below for the improvements I’m planning for these ends.
15. (2) fender washers (the ones in the photos are 3d printed but there’s no reason regular fender washers wouldn’t work.)
16. (4) feet – these are printed in the photos because I didn’t have any store bought feet here.  Version #3 will have the slot routed into the board so the feet can be lower profile – but for version #2, they need to be tall enough for the spring to move freely.
17. Some sort of sealing for the wood. I plan to use Tung oil, because I still have a TON of it!

So, as you can see, there are a number more pieces to the build than the single sided.  Most of the parts here I had already, so my increased cost in the build was less than $10 and some time in CAD to design the printed parts.  Well worth the upgrade.

The method (highlights reel only):

1. Mark and cut your hole for the left side of the winder to slide back and forth.  In the spring, I will redo this as a routed slot but this works for now with simple hand tools. This is what worked for me. It needs to be wide enough for a 3/4″ board to be able to slide along this slot.
2. Mount your motor as above.  Ideally, you will drill and screw the 2 boards together from below so the screws aren’t visible from the top.  That’s what I’ll do with V#3 in the spring.  In the photos of this winder, the boards are offset because I was reusing the wood I had used for the first winder.  That mean the base was a 12″ board.  If you want to make it so the motor doesn’t hang over the end, but otherwise keep the dimensions the same, you’ll want a 15″ board. 
3. Assemble the non-winder side.  10mm x 25mm bolt, washer, bearing, washer and mandrel end.  If there’s a set screw to tighten this down, tighten it now.
4. Now let’s prepare the board for the non-motor side of the winder.  Drill a hole the same diameter as the outside of the bearing that’s as deep as the bolt head, washer and bearing. In my case, the bearing was 26″ in outside diameter, and the hole drilled was a 1″ (25.4mm) The height of this hole will depend on the motor and bracket you used, so measure carefully and use a level if you can.  Next, cut a relief cut so you can “tighten” the wood down onto the bearing so it won’t move.  My spring edition will feature this board turned 90 degrees, more like the Leclerc one.  It won’t seem as “closed in” in use.
5. Install your bearing assembly into the board and screw it down from above.  Make sure it’s straight!  Once installed, it won’t move easily without unscrewing things.
6. Install your “sled”. This piece rides in the slot we cut in the base of the winder. Leave the smaller piece off for now. The dimensions of this piece was 2.5″ x 3.5″ and the board used was a 1″ board (so 3/4″)
7. Next, we’ll install the non-motor side onto the base, using the fender washers. These don’t need to be too tight and you’ll probably be adjusting these after step #9 anyway.  This is also a good time to install your feet.
8. Now the spring that will exert tension on the whole assembly
9. Stand your winder up and put the small piece of wood on.  This stops the sled from diving down and keeps it running straight toward the motor instead. You just want this as tight as needed to keep it from wobbling.  Still a little tight and doesn’t snap back when you let the side go? Loosen your washers on the bottom a half turn and try again.
10. Install the motor side mandrel and your winder is complete! Happy winding!

And here’s a video of it in operation:

Improvements to be made in version #3:

• Appearance
• Shorter set screws – actual set screws would definitely look better here and have better balance – and probably 2 per side
• A longer base – not just enough to mount the motor solidly, but also possibly enough to extend the length of the bobbin that can be wound on the winder.
• Shorter spring or if a longer base is used, it will be mounted further back.  Tension is great on the longer bobbins but ever so slightly loose on the shorter (4″) bobbins but even those bobbins wind just fine on the winder – they just slip periodically and that’s what’s created the wear on the mandrel ends so far.
• The mandrel ends are likely to become a hard plastic and a rubbery bushing (possibly built into the hard plastic part) used instead of the semi-rigid material (soft PLA) I printed with.  This will prevent the type of wear I’m seeing on the ends already, but I plan to try another semi-rigid material (TPU) first – it’s a much stronger material but more challenging to print.  I’m also waiting to see how these ends wear so I can update the shape accordingly.