I had originally always thought of attaching the drag off an old reel, with little lugs that the plastic spool would grab onto to add tension. Then I was thinking about it yesterday, and thought that it just needs something soft to press against that will be smooth to wind against.
That's when I came up with the idea of the spool just pressing against some fabric. Simple, and the same idea as when we spool reels at work (except that's hand held).
I don't want to give an exact list of parts and dimensions, as it all depends on what you have on hand, dimensions of bolts, types of reels you will be spooling etc (game reel compared to a little trout reel). Plus the fact that this is easily done just by eye, nothing exact about it.
Parts I used was a bit of timber (old pallet bit in this case, doesn't matter what), long bolt, a few washers, 2 nuts (one to lock it down), a spring, some foam sheet for backing (probably not necessary), and some old cotton trousers for the fabric. I figured cotton would last better than a synthetic fabric with the friction and heat. I had to buy a longer bolt, as I had nothing in my boxes of bits, but apart from that it was all just stuff laying around. I used 3m 77 spray glue for this. Expensive as (or at least it is here in aus), but it goes a long way. Magic stuff
Step 1: Drill Hole
This is best done on the drill press, if you have one, so that it is square. We want the side of the spool to contact the material glued to the timber as evenly as possibly for the tension, hence the need to make it square. If you don't have a drill press I guess just do the best you can (and if your like me your holes will never be close to square-hence why I bought a drill press!).
Step 2: Attaching Material
For the tension part I'm using some old cotton trousers. I figured a softer base wouldn't hurt things, so I glued on some EVA (I think) sheet foam first. Forgot to take a photo of that part, but its not rocket science. 3M 77 seems like the best glue in my opinion for this sort of thing, but if you don't have any then any normal contact adhesive would work fine. Trim out the hole for the bolt to come out of.
Over that you want to put the material. Once again I used 3m 77. This area is one where you don't want to go too heavy with the glue, as we don't want it soaking through and gumming up the other side of the fabric. A light spray on this part was all I used, not sure on the options if you don't have the spray glue. Once again, use a knife to trim the fabric away from the holes so the bolt can pass through
I also decided to whack a few nails in to make sure everything stayed put. I covered the outside, which I thought would stop the material pulling away if it ever had the desire. The bottom part on the face was easy as it sunk below level due to the foam backing. Without that maybe just punch it in deep so the spool doesn't rub on it.
Step 3: Assembly
Pretty straightforward. Put the bolt through the hole. Depends on what bolt you have to use, but the large ones designed for timber get hammered in at the end to stop them twisting, with the square part digging in to wood. The one I had available was a bit poorer choice, with just 2 little angled bits. This one doesn't want to stay put, not that it matters much for our purposes, but its easier putting the washers and nuts on the other side if it doesn't move around. I've glue it in. If you have a hex head you could do the same as me with glue, or if your thread goes down far enough you could put a nut on the other side to hold it in. If you go this way, make sure you recess where the nut will go with a spade bit or similar, so that the nut is fully below the surface of the fabric, otherwise it will stop the spool contacting the fabric and giving the friction and tension that we desire.
You want to timber side of the spool to contact the material and foam as much as possibly, so if there is a choice, use the side that is completely plastic rather than with gaps.
On the other side of the spool, in order, you want a washer, spring, another washer, nut and a lock nut. If the threaded portion of your bolt is too short here, you could cut a bit of pipe or similar to make up a bit of room for narrower spools. No point putting all this on now though, put a spool of line first to give the thing a test.
Step 4: To Use
For use I just clamp it in the vice. Keeps it smaller and easier to store, and all my spooling is done in the garage anyway.
Take off all the nuts, washers etc off the bolt and put your spool on. As mentioned, if there is one side of the spool that has no gaps in the plastic then that's the best side to put against the fabric.
Put on one washer to sit against the spool, the spring and then one nut. Adjust the nut down until you have the tension that you like, and then lock it down with the other nut. I've found hand tightened is fine, but your experience may be different. Wing nut would be nice, but I didn't have one on hand.
That should add the tension that you need, which is especially important when using braided line. Then just tie on to your reel spool like normal and start winding away.
Spring tension is a hard one to know in advance. If you have plenty of room to tighten down, a softer one would still be fine. If the spring is too firm, it may either have no tension, or once the spring contacts have too much. I thought my spring would be too firm, but it was just right. If your only ever using nylon line, light spring should be fine as this doesn't need as much tension as braided lines.
For those that are new to spooling reels, how to know if your spooling up with enough line tension. I find the easiest way is just to press on the spool every once in a while. The line on the reel should feel hard and not crackle, move or be soft under your thumb. This is especially important with braided line, which can dig in on itself a lot easier than nylon. Just keep checking it, and if your unsure, pull it off and start again (bolt through the spool into the drill is the easiest way of removing line)
Step 5: Possible Improvements
One thing I've thought that this could do with is some tapered bits to centre the spool on the shaft and stop it shaking around. I don't think its imperative, and having the spool contact the full side of the fabric/timber means that its not rattling around, but it would still be nice.
Obviously, adding a base that can be clamped to a bench would help also.
Apart from that it seems to suit the purposes well. Long term use I'm sure will show up other things that need to be done, but so far so good.
Hopefully this has given some inspiration to others who have a need for something similar. Keen to hear of any improvements you can make on this basic design.
Now to get to work on the home made line counter/yardage meter that's been in my head for years now........... Oh, and fix my mates rod, and get the drill press finished, change belts on the car, the head gasket on friends car, transmission on other friends car, tidy garage......................