strip sander fix??
Posted: Fri Oct 02, 2015 10:34 pm
A short time ago I loaned my strip sander to the woodworking group to do some sanding on the Toys for Tots project. One of our members called me and said that they had a problem with it. One of the idler wheels had overheated and melted, the belt moved toward the cover grinding through the belt guard and eventually cut a slice in the cover. This was all caused by the poor design of the idler wheels that we all know about.
So I set about to design a fix that would be able to reproduce and also reliable.
First is to get two pieces of a hard wood such as maple and scribe some circles that are a bit larger than the original idler wheels. Be sure to put a mark on the pieces to mark the center of the circles.
Then take two of the blanks and glue them together with the center marks facing out and allow the glue to dry overnight.
After the glue has dried drill a small hole (less than 1/8”) through the wheel blank from top to bottom to locate the centers on both faces of the blank. This hole will help to locate the center of a Forstner bit later.
Use a 7/8” Forstner bit to drill two holes into the faces of the blank approximately 11/32” deep.
This depth is equal to the thickness of the bearings which are 1603-2RS from VXB.
The next step is to drill a 1/4”hole through the blank using the small dimple from the Forstner bit as a center. Then the blank can be mounted on a 7mm pen turning mandrel to be turned or if you do not have a pen mandrel a piece of 1/4” bolt will do.
After truing the wheel on the lathe return to the drill press and open the 1/4” hole up to 3/8”.
Then using the 7/8” Forstner bit again line up the wheel by inserting the 7/8”bit into one of the holes and drill to a depth of 11/32”. Check the depth by inserting a 1603 bearing into the hole and make sure that the bearing is flush with the face of the wheel and then remove the bearing. Flip the piece over end repeat the process on the opposite face to a depth of 3/4”. Note that this is NOT deep enough.
Fit both bearings into their bores and insert the OEM stepped bolt to check the depth. It will probably be necessary to tap the bearings into their bores.
After checking the depth the bolt will fall short and not come through the rear bearing. Remove the bearings and re-drill the deeper hole until you can get a fit like this.
More to come
Bill V
So I set about to design a fix that would be able to reproduce and also reliable.
First is to get two pieces of a hard wood such as maple and scribe some circles that are a bit larger than the original idler wheels. Be sure to put a mark on the pieces to mark the center of the circles.
- wheel blank.jpg (98.86 KiB) Viewed 752 times
After the glue has dried drill a small hole (less than 1/8”) through the wheel blank from top to bottom to locate the centers on both faces of the blank. This hole will help to locate the center of a Forstner bit later.
Use a 7/8” Forstner bit to drill two holes into the faces of the blank approximately 11/32” deep.
This depth is equal to the thickness of the bearings which are 1603-2RS from VXB.
The next step is to drill a 1/4”hole through the blank using the small dimple from the Forstner bit as a center. Then the blank can be mounted on a 7mm pen turning mandrel to be turned or if you do not have a pen mandrel a piece of 1/4” bolt will do.
- truing up the wheel.jpg (86.65 KiB) Viewed 752 times
Then using the 7/8” Forstner bit again line up the wheel by inserting the 7/8”bit into one of the holes and drill to a depth of 11/32”. Check the depth by inserting a 1603 bearing into the hole and make sure that the bearing is flush with the face of the wheel and then remove the bearing. Flip the piece over end repeat the process on the opposite face to a depth of 3/4”. Note that this is NOT deep enough.
Fit both bearings into their bores and insert the OEM stepped bolt to check the depth. It will probably be necessary to tap the bearings into their bores.
After checking the depth the bolt will fall short and not come through the rear bearing. Remove the bearings and re-drill the deeper hole until you can get a fit like this.
- final assembly.jpg (95.26 KiB) Viewed 752 times
Bill V