Bertram Binder 2 String & 4 String Versions Operating Manual V 4.2 Cork Disc Tension Control Visit www.quinchat.webs.com for videos Binder Manual v 4.2 page1
Binder Design Change This edition of the operating manual, version 4.0 as well as 4.1 & 4.2 cover a design changes. The change evolved from trials with nylon thread and the realization that some manufacturer s spools do not unwind well from the end of the spool. Consequently binders shipped after August 1, 2011 have spools that unwind by rotating. Previous binders had stationary spools that were unwound from the end. This change also makes it easier to tune the binder and there is less chance for tangles. New binders are shipped with National nylon rod wrapping thread on pro spools. Should you prefer to use a cotton or polyester thread which has less stretch, these items can be obtained at any sewing store in appropriate size spools. Owners having the original design binder using the 1200 yard cotton spools should refer to version 3.1 of the operating manual. Owners having the original design can easily convert to the new design by purchasing a few low cost hardware items. All binders have the necessary tapped holes for this conversion. If you wish I can supply the necessary parts for $10 including postage. Effective Sept, 2013, minor changes have been made to allow the binder to run at lower tensions. Binders are now shipped with 45 grams/thread tension on both 4-string and 2-string versions. Effective 2/1/15, the thread tensioners were eliminated and replaced with cork disc tension control on the spools. Binder Manual v 4.2 page2
Two & Four String Versions 2 & 4 String designs shown with Nylon pro size spools The 4-String version of the binder produces a near even force on the blank since the clockwise windings are applied at 180 degrees to each other. As long as the thread tension is the same, the blank stays centered in the tube. The same applies to the counter-clockwise wraps coming from the other disc. The 4-string advantage is that the blank tends to stay centered in the tube without manual intervention. The 4-String version is offered for those customers having good results with 4-string binding, but wanting the advantages of a compact design, a mechanism protected from glue contamination and the ability to guide the blank right at the point of thread application. The 2-string version is built with the identical mechanism but with only 2 spools and associated tensioners and guides. There is some side to side movement when the 2 threads are in phase however it is not considered a detriment since you will want to guide the blank with your fingers anyway to assure all six strips are correctly aligned. Binder Manual v 4.2 page3
Since wraps are applied nearly on top of one another, there is no twisting force on the blank with either the 2 or 4 string versions. The 4-string can operate at less tension than the 2-string. Experienced operators advise that better results are obtained with lower tension since the blank is easier to straighten. If more binding force is necessary to close glue joints (possibly in the area of a swell) this is best achieved by spacing the wraps closer together or even overwrapping the troublesome area. Binder Manual v 4.2 page4
Safety Considerations Always keep the cover closed when operating the binder. Although it operates at relatively slow speeds, if contacted, it can cause significant injury. When threading or adjusting tension or any maintenance work, disconnect the power cord. Binder Manual v 4.2 page5
Operating Instructions Features With this binder the point of application of the string is in a window on the left hand side of the machine. The rotating mechanisms, thread spools and tension controls are inside the box, fully protected from dripping glue. There is a replaceable CPVC tube inside the structural steel tube. It is easily removed for cleaning out the glue residue. Two strings, or with the 4-string version 2 string pairs, are wound in opposite directions and with equal tension thus eliminating any twisting of the blank. Since the two strings are applied within 1/4 of each other, at the end of the CPVC tube, it eliminates any twisting force on the rod section. The mechanism is coved with a clear polycarbonate shield to prevent inadvertent operator contact with the rotating parts. A foot switch allows two handed manipulation of the cane. The nylon strings provided with the machine are National pro size spools approximating 1.5 dia X 2 tall, A size on the 4-string and D size on the 2-string. Other compositions such as polyester and cotton in comparable spools sizes can be used. Placing a rubber pad under the binder will reduce vibration, noise and keep the machine from moving during operation. Binder Manual v 4.2 page6
Set-Up and Maintenance The binder is shipped completely set-up and ready to run. The short CPVC tube is provided for testing and to become familiar with the operation. If you desire, you can purchase a ½ tube long enough to support the full length of the section you are binding although I don t believe it is necessary. Once you pick up a bound section it is going to bend under its own weight anyway and you will take out these bends when you roll it on a flat surface. The end of your tube should be sanded smooth to assure threads do not hang up on a rough edge. Position the end of the tube mid way between the two tip-tops that guide the threads. Secure the lateral position of the CPVC tube with set screw shown in the right hand photo. Note that the red thread rubs against the plastic tube as it is applied and the white thread is applied about 1/4 to the left. The drive pinion should be moderately squeezed between the two discs. Adjust this squeeze by moving the thrust collar. The pinion will wear over time and a length of 1/2 x 1/8 rubber hose is provided for replacement. Simply press it on. The ridge on the end of the pinion keeps it from slipping off If the binder turns hard after long idle periods, apply 3 in 1 oil to the bearing surfaces. Binder Manual v 4.2 page7
Notice the thread routing. An orange cord is used in the photos below to more clearly illustrate the correct path. The photo is of the left hand disc set up as a 2-string binder. The thread comes off the bottom of the spool, thru the eye and then wraps around the tensioner The right hand spool s arrangement is the same with the thread being routed thru a hole in the hub. A threading tool is provided. Binders shipped after Sept, 2013 have a nylon sleeve over the spool post to reduce friction and assure that only the tensioners are controlling the thread especially at low tension settings. When installing a new spool, ream out the spool s hole with a J drill (.277 ) to properly fit the post. Note that the Delrin tension washers are mounted with the crowned surface facing each other. The main 3/4 support tube is made of carbon steel. A light application of 3 & 1 oil will keep the tube from rusting. Binder Manual v 4.2 page8
Effective with binders shipped after 2/1/15, the tensioning design has been improved. Tension control is now accomplished with a cork disc drag mechanism on the spool axis. The spring loaded washer tensioning elements have been eliminated in this new design. The old design had 2 elements that, in effect, could control thread tension: The tension washer assembly plus any tightness of the spool on its mounting post. If the spool was tight on the post, it added to the tension. If it was too loose, it could free-wheel and cause a length of slack thread between the spool and the tension washers. If in loading the spool at the factory, the thread became somewhat untwisted, the loose thread could furl and jamb in the tension washers. Although a manageable situation, it is a delicate adjustment to keep the spool from free-wheeling and yet not add to the tension. In the new design the spool is mounted on a spindle that has an acetal brake surface on left end and a thrust bearing on the right end. The bearing housing is threaded and it is tightened against the spool to hold it firmly centered on the spindle. The binder comes with a 6-32 stainless steel stud secured to the rotating member of the binder. A cork-faced tension adjustment disc is threaded on this stud. Binder Manual v 4.2 page9
The spindle with its spool of thread is slid over the 6-32 stud with its brake surface against the cork face. A lock nut and a felt washer is used to tighten the assembly and apply pressure on the brake surface. Thread tension is adjusted by slightly rotating the cork faced disc to change the pressure on the brake surface. Thread routing is quite simple as shown here with orange thread for clarity. Binder Manual v 4.2 page10
Set all threads to the same tension by small medicine bottle and spring clamp with weight added to total 45 grams (1.59 oz) for the 4-string and 90 grams (3.17 oz) for the 2-string. Binder Manual v 4.2 page11
Orientation & Practice Before attempting to bind glued-up strips, it is best to practice. Practice is particularly important if you are working with quick set glues such as Titebond. Use a dowel to get a feel for the machine; i.e.. How much guiding pressure is required, securing the first few wraps, pulling out and tying off and the correct feed rate. Since there is no speed control and the machine is either on or off, it takes a little time to get used to. You do not have to synchronize the foot start with hand feed rate the first few wraps can be on top of one another. Also if you detect a problem you can stop the machine and let go of the cane tension will be maintained.. Now bind up a butt section without glue, inspect for open joints which will be glue lines in the final product. Pay particular attention to the start or end of a swell, if extra pressure is required, over-wrap that area in the binder with closer spaced wraps. With heavy swells, it maybe advisable to over-wrap using heavy cord applied by hand. A pipe cap with a 1/4 hole slipped over the 1/2 CPVC tube helps to control tip movement side to side. This cap can be easily made and is supplied with later versions of the binder. Next practice with a dry tip section that is secured at each end with a rubber band. Develop the feel of massaging the 6 strips as they are fed to assure proper orientation. Again, stop if there is a problem., correct, then proceed. Also practice rolling the section on a flat surface to remove bends. Also try whacking the blank on each of its 6 surfaces to even out the thread tension around the blank. This will make bends easier to straighten. This is demonstrated in the web site video. Binder Manual v 4.2 page12
Binding Procedure This procedure is intended as a guide for first time users of the Two or four string binders. This is how I do it. As you become familiar with the equipment you will refine items to meet your individual needs. Install the CPVC tube and position the end mid-way between the two tip-tops. The string tension should be set using the procedure on page 9. The settings do not have to be exact, just reasonably close. With about 3 inches of string exposed, hold them together and run the binder for about 3 seconds to form a twist. The binder is now ready to operate. I apply epoxy (Nyatex) to my strips while taped side by side and then roll them into a hex section. For butts, the tape can be removed and hand pressure will keep the strips aligned as they are being bound. For tips, after glue is applied, I place the individual strips into a hex fixture and then slide a rubber band off the fixture onto the assembled strips as shown below. Binder Manual v 4.2 page13
I can now make sure that all strips are enamel-out and in the right order for the node pattern.. I now work toward the tip and after aligning all strips, I place a small rubber band on the tip. Now for binding: I remove the rubber band from the large end, place the short length of twisted string on the blank under my thumb. Insert the blank into the tube about 1/2, turn on the machine and move the blank back and forth about 1/4 to lock-in the wraps. Hold the blank with the right hand next to the tube and feed the blank into the tube with the left hand. Feed at a speed that will space the wraps about 1/8 to1/4 apart. When you get to the end, over wrap with a back and forth motion to lock in the wraps. Stop the machine and pull the blank back out of the tube. Half hitch at the tip end and cut the string. After all blanks are bound, I roll them on newspaper to encourage them to nest and to blot the glue. If there is difficulty in straightening, I take each blank and whack them on each flat. Then grasp the opposite end and whack each flat again. Next I place the blank on a truly flat board and check to assure there is no twist. I then roll them again on this board to remove all bends. I then tilt the board with the strip on it to the vertical position and gently lift the blank by the tag end of the binding string. This prevents inducing a bend while lifting the blank from horizontal. Blanks are hung and dried for 12 hours at about 100 degrees F. The binding string is then removed and most of the epoxy is removed with the light touch of a scraper. I then rebind using the same tension settings. At this point, do any final straightening. For post cure, I wrap the sections on an MD fixture and heat for 3 hrs at 235 degrees F. For me, the MD fixture prevents any bends from developing in the oven. Binder Manual v 4.2 page14