| Hi, It has been a while since there has been a reason to publish a Digest, I hope because everyone's looms are humming along. I just took 20 yards of 20/2 cotton network draft shirting off the loom and decided that after five years of hard work the loom deserved a serious bout of preventive maintenance. So I waxed all the wood, wiped down with oil all the metal rods including the rods in the shafts that support the heddles, lubed the tie-up box and all the hinges in the treadles and overhead beams with WD-40, all the wood/metal interfaces with silicone, and greased the pulleys that hold the cables. In the process, I noticed that the bearings on the four pulleys that hold the front and back cables connecting the two treadles, as well as the bearing on the smaller horizontal pulley for the cable that runs between the right treadle and the tie-up box and is visible from the front of the loom were all worn out and loose and therefore needed to be replaced. Replacing them is straightforward with two words of caution: (1) temporarily detatch and move out of the way (to the East - no need to disconnect the cables) the board that holds the three microswitches to the back of the front panel of the loom before loosening the cables that run between the treadles. This will avoid damage to the microswitches if the treadle should slip, and (2) put blocks under the treadles since once the cables are loose the counterbalance they provide each other is no longer there. Once the cables are loose, the shafts holding the pulleys can be slid out by removing the two small wood panels (held in place by two screws each) on the wooden cross bar on the back of the castle. By the way, it is worth checking and greasing these pulleys regularly since there is a lot of force (weight) on them and consequently these bearings get hard wear. When retightening the cables between the treadles after replacing the pulleys, be sure that they are tight enough that the tie-up unit, when in the up position, is touching all of the lams. This will probably require a little more tension on the rear cable than the front. The cables will both be tight enough that they will 'sing' when plucked. When replacing the small horizontal pulley on the front of the tie-up unit, note that there needs to be a sleeve over the bolt that holds the pulley to keep the threads on the bolt from abrading the bronze bearing on the pulley. The correct adjustment of the shaft hangers for optimum shed is a taper of 1 inch/foot of the bottom of the hangers with the rear shafts higher than the front ones by that taper. This adjustment is made with the shaft hangers all raised. After I reassembled the loom and readjusted the tie-up box as per the instructions in J-Digest # 26, I found that there was a problem with some shafts misbehaving randomly and inconsistently. It turned out, after consultation with Dale, that this was caused by too much slack in the cable (visible from the front of the loom) that runs between the rear of the right treadle and the tie-up box. Since this is an adjustment and not a maintenance problem, I have decided to keep all the adjustment information together in J-Digest 26 which has now been amended. See http://world.std.com/~kcl/jdigest26.html. I particularly want to thank Dale for taking the time to go through these procedures and talk about the problems with me. I learn a great deal from each conversation and would not be able to share them with you were it not for Dale's forbearance with my many questions. Cheers, Tom. |