Hi Bill, I understand the uneasy feelings about not having knots at the end.
Let me try to set your mind at rest. I cut off the strand that had the knots just after serving the ends and before centre serving. I cut the strands at the knot first so I can get hold of that strand and pull it away from the bunch, far enough away to cut just that strand and no others. Then I take each tail in turn and cut it to about 1cm from the serving so there is a little of the end showing as a fluffy bit. If the strand gets pulled into the serving it will disappear, yes? Even on my compound, the tails never get any shorter!!
My jig rollers are home made, yes. They are MK2 MK1 was a simple length of 15mm copper pipe loosely fitted over the posts so they were as tall but free to roll. MK2 was my serious attempt( heehee) I turned a thin end on the posts and made some PTFE parts to slide down the post as far as the shoulder on the post and a rolling fit as opposed to tight or too loose. The rollers have a shoulder at the lower edge to keep the strands form sliding off at the bottom.
When the strands are wound on and the knot made at the ends of the extra strand, I get hold of each half of the loop near the half way point and pull them apart from each other. Then roll the whole bunch a bit and repeat the pulling apart to try to equalise the tensions.
If you make a small string of ten windings or so, about 10cm long, by winding round a stiff piece of card, and knot the ends, you can take the windings carefully off the card former and hang the loop from the index finger of one hand. Then with the other index finger put that into the bottom end of the loop with your fingers pointing in opposite directions. You can roll one finger round the other, keeping the loop under tension all the time and you will see how the knot is rolling all round the system from top to bottom and so on, as you roll. You can also see the looser strands slowly getting pulled into the whole group as they are free to move. Soon, they are all looking equally tight and making a neat loop, with no baggy strands. My rollers try to mimic the way the string moves around as I roll my fingers in that little demonstration model. Each part of the whole string loop gets chance to be free from the extra grip exerted at the posts.
The only part of the rollers that is a bit sensitive is the shoulder shape on the rollers. If that is slightly rough, then the windings can snag and pull out some of the filaments from the strands as they are pulled round the rollers.
If you used bolts with a nut screwed part way down from the top to make a shoulder and then a washer, a small tube over that would make a roller.
The roller could really do with a narrow waist like a Coca Cola bottle, so the strands collect at the narrow section and don't go into the angle where the tube meets the washer. I can make those if you get stuck. It only needs two rollers per jig, as all the rolling is done round two of them not four.
My jig only has two posts as I don't need four, four is for serving loops.