The lift spring broke today and sounded like a 22 rifle when it did. After it snapped, the grinding wheel fell dead down on the saw chain and caught me by surprise. Quite a shock.
I ordered a new spring from Tecomec and it should arrive in a week or so. Meanwhile, I thought maybe I could make a temporary repair so that I could keep going. I've got a dozen dull chains backed up. So, I thought perhaps I could use a door spring or big rubber bands to pull it back up and let it down. For several reasons, that failed.
Then I remembered that gravity might help. I added an 18" long hardwood board, about 1" square to the back of the bench mount platform that I use to hold the grinder, using a 1/4" bolt so that I could easily position it. Then I attached a rope pulley to the end of the board with a screw eye. Finally, I tied a 5-lb weight to the lower end (an old splitting wedge) using 1/4" twine and tied the other end to the sharpener's handle. Here are three Pics that show it all. The left Pic shows the sharpener all the way up and the center one shows it in the sharpening position:
In the sharpening position, the 5-lb weight is about a foot off the floor. This works so well that I almost wish I could cancel my order for the new spring. The reason is because the force supplied by the weight is constant as the grinding wheel drops down. This is really comfortable as you work. The spring, on the other hand, increases the lifting force as the grinding wheel and motor drop down. Also, I doubt that this mechanism I made will ever break. The $10 spring already did.
WDYT?
I ordered a new spring from Tecomec and it should arrive in a week or so. Meanwhile, I thought maybe I could make a temporary repair so that I could keep going. I've got a dozen dull chains backed up. So, I thought perhaps I could use a door spring or big rubber bands to pull it back up and let it down. For several reasons, that failed.
Then I remembered that gravity might help. I added an 18" long hardwood board, about 1" square to the back of the bench mount platform that I use to hold the grinder, using a 1/4" bolt so that I could easily position it. Then I attached a rope pulley to the end of the board with a screw eye. Finally, I tied a 5-lb weight to the lower end (an old splitting wedge) using 1/4" twine and tied the other end to the sharpener's handle. Here are three Pics that show it all. The left Pic shows the sharpener all the way up and the center one shows it in the sharpening position:
In the sharpening position, the 5-lb weight is about a foot off the floor. This works so well that I almost wish I could cancel my order for the new spring. The reason is because the force supplied by the weight is constant as the grinding wheel drops down. This is really comfortable as you work. The spring, on the other hand, increases the lifting force as the grinding wheel and motor drop down. Also, I doubt that this mechanism I made will ever break. The $10 spring already did.
WDYT?