To start with I used an old Norelco (Philishave outside the USA) razor. The first, and most obvious thing to do is to ditch the metal razor head and the trimmer. What is left is the razor with just the three plastic drive sprockets/heads (or what ever you want to call them) I took the razor apart and drilled a hole in the center of each sprocket the size of stiff wire. Bend a small hook on the end of a short piece of wire (I happen to use some annealed wire). Put the wire through the hole, leaving the hook just a little above the plastic, and glue into place (I used the thick cyanoacrylate glue).
While you have the razor apart there are two other modifications that I made. The first modification was to put in a switch to reverse the motor. This is very easy. The motor is a DC motor so the only thing you need to do is to reverse the leads. To do this I used an old slide switch I had. It has been a while, but I believe it is a double pole, double throw switch. What the switch looks like is a slide switch that has 3 pairs of legs.
_
| | <-------- slide
--------------
----------------------- <----- switch body
left pair of legs ----> | | | <------ right pair of legs
^
Center legs
Slide the switch to the right and the center pair are connected to the right pair. Slide the switch to the left and the left pair are connected to the center pair. Wire the leads from the motor to the center pins. Then wire the leads from the going to the motor to the left side and then the right side, reversing the polarity.
This will be very useful. The first thing I noticed when I first put the rope walk together, without any modification, is that the heads spun in the wrong direction for the thread I was using. After making the modification and working with different threads and string I found that they are not always spun in the same direction, so reversing became a necessity. I also found that I sometimes needed to back off the twist in the lines a little as I was spinning up a line.
The second modification is a speed control. Left as is, you will be able to spin rope effectively, but I found that the motor ran to fast for my liking. I went to Radio Shack and bought the smallest resistance potentiometer they had. This was still much more than I needed, but it gets the job done. I wired the potentiometer into one of the wires going from the center pole of the slide switch to the motor so it would be able to control the amount of current to the motor. This will allow infinite control of the speed of the motor. The only problem I found with this is that at a slower setting there is enough current to run the motor, but not to start the motor. There are two ways around this. One is to always start the motor at 3/4 to full speed and slow it down. The other is to put a momentary switch in to momentarily short the leads of the Potentiometer out. This gives the motor a full shot to start it, then it will slow down to the setting that was being used. I found the momentary switch works best.
OK, after reassembly (and finding places to mount the switches and pot) the razor is ready to go. I built a small rectangular frame to mount the razor in that was the width of the razor and the height of the razor. (a little extra height is OK, it can make longer runs of rope easier to make up) I mounted the razor with two screws through the plastic where the trimmer was, just behind the head. There is a rim around the depression the trimmer retracted into and it is perpendicular to the head. This made it an ideal mounting point. I built a second frame of the same proportions for the opposite end of the rope walk.
The follower was made from a model airplane nose cone. The wide end
of the nose cone is about 1 1/4 inches in diameter. I drilled three
pairs of holes evenly spaced around the circumference near the
edge of the wide part of the cone. I then glued short pieces of
brass wire in the holes. These form the guides for the string. (They
will approximately line up with the heads on the razor when mounted
on the rope walk. The next part is by guess and by golly. I drilled
holes directly opposite each other about 3/4 of the way from the nose
to the back of the nose cone. The holes also need to be made so the
guides will approximately line up with the heads on the razor and will
allow the cone to be balanced in a horizontal position. The drawing
is the best I can come up with here. You have to imagine the
diameter of the circle the guides are mounted on.
Run a stiff wire (I used a thin brass rod) through the holes and glue it in place. bend the ends of the wire in the same direction at a 90 degree angle. the distance between the bends should be about the width of the frame used to mount the razor, a little larger is OK. The nose cone needs to be in the middle between the bends.
Screw in eyelets on each side of the frame at about the middle of the head of the razor. Mount eyelets on the sides of the second frame at the same height.
Now find a piece wood you can mount the frames on that are the length you want to make the string (I used a 1 x 2" board). After the frames are mounted tie a piece of heavy nylon fishing line to the eyelet on one end and then, pulling the line tight (use reason here) tie it to the eyelet on the other frame.
Repeat for the opposite side. The wire through the follower will ride along these lines. I found that if I balance, or at least come close to balancing the cone so it is parallel with the lines this works best. I tune the balance by bending the wire that carries the follower forward and back to get as close as I can. (This is why the location of the holes about 3/4 of the way back is a by guess and by golly thing.)
On the second frame, at the end opposite the razor, mount (glue) a piece of wood you can put an eyelet in at the height of the 2 eyelets previously put on. Screw an eyelet in the center of the piece of wood.
One last thing to make up..... For this last piece I use a snap swivel used for fishing line with part of the clip end cut off so it forms a hook. (actually I use it for my kites) Tie a light piece of nylon fishing line about 1/3 the length of the distance between the frames. fasten a lead fishing weight on the end of the line.
Confused???? I hope not. Describing this is a lot harder than I thought. This concludes the making of the rope walk. None of the dimensions are critical so I left it with approximations. If more detail is needed I will have to use a medium that will allow me to use drawings to give better examples. Now you are ready to spin some up on your own line. One very large warning, this will take a lot of experimentation, but when you get the adjustments right, it works great.
To start with, run the line with the weight on one end and the swivel on the other through the eyelet that is in the center of the frame opposite the razor and let the weighted end hang. This will be used to keep tension on the line as you are spinning it up. Take a thread/string and tie on end to a hook on one of the heads. (A simple overhand knot will do fine.) Make the string about the length of the distance between the frames. Repeat this for each of the other two heads. Now begins the tricky part. Starting from the heads, take all three lines together and, sliding them through your fingers to keep even tension on all three, move you hand to the other end. Keeping even tension on all three threads (this is the tricky part) tie them together in a knot. If one line is tighter or looser than the other two it could cause kinks, or other problems with the lines.
Hook the snap swivel in the lines at the knot. (It is not necessary to tie the lines onto the hook, just slip it around a string at the knot). The weight on the end of the line should give some tension on the lines. At least enough so they do not sag down and touch the board or each other.
Now set the follower in the lines so it rests on the heavy fishing lines it will slide on. Position it so the lines go through the guides and the nose of the cone is at, or very near the knot.
Now start the razor. The first thing to check is to be sure it is spinning in the right direction. If the string is unwinding it is the wrong direction. As the strings begin to spin tighter you will notice that the strings will begin to shorten. be sure not to allow the stings to spin so tight that they knot up on themselves. I find that If I keep the cone a little distance from the knot I can see when the lines begin to spin together. This takes practice. I also find that if I watch the string and see that it is getting tightly wound I give the follower a little push to see if the string is ready or maybe the follower just needed a little push to get started. This is where running the motor slower really helps. If all this sounds a little touchy feebly, it is because it is. If the weight on the line with the snap swivel is too heavy the line might spin too tight, if it is too light, then it will spin loosely. This is not as critical as it sounds, but it will call for some experimentation. There is a point when the twist is tight enough for the strings to wrap around each other, then the cone will slide down the line and the string spins together. I can not emphasize it enough that you will need to be watching what is going on and you will have to give the cone a tap here and there keep it going. As the rope spins together you will notice that line gets shorter.
When the follower gets to, or near to, the heads shut the motor off. To finish, grab the line at the nose of the follower with a pair of forceps, or some other clamping device, and cut the line and tie a knot in the end. If you don't it will fray out and unwind at the end. I usually soak the line in water and then let it hang to dry. This will help set the line so it will not fray on the end when you cut it.
The string you use can and does make a difference, no two are exactly alike. A longer run also seems to be more difficult to get right than a shorter run. With this in mind you might want to start by making shorter lines to get used to how it works. I would recommend making the rope walk shorter, about 3 to 4 feet long, to start with, then try to make longer runs.
I have also spun up multiple thicknesses with this. Instead of running one thread from each hook I have run up to 5 lines from each hook to end up with the desired thickness of the finished line. I have made up sample cards marked with the type of thread. How many strands, and the resulting size of the line. This cuts out a lot of guess work when it comes to figuring out what you need to make up.
Phew, this turned out to be a lot longer than I thought. I know there is more to say about this, but I hope this gets the idea across. I tried to proof read this as I went along. I am out of time again so I am sending it off as is. If you have questions about this, or if I left something out let me know.
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