The outside diameter, bearing recess and circlip groove have been machined and the job being parted off. The material is a scrap piece of 431 stainless steel. The diameter of the flange is 60mm and the tensioner diameter is 52mm, the original is 40mm.
Parting completed. This end of the idler is 24mm ID.
Just faced and chamfered this side.
Removing original idler pulley.
Side by side for size comparison. The bearings are 12mm ID x 28mm OD x 8mm wide.
New one installed, runs true and smooth, looking good. With the tensioner in slack position it's just touching the v belt, it is not exerting any pressure on belt and with the motor running it doesn't cause the spindle to turn. The benefit I was chasing with this larger tensioner is that the drive starts to come on with less movement of the "clutch" lever. The original tensioner had flanges at both ends, I watched the belt running on the original in all belt positions and during different drive load conditions and I didn't ever see the belt go anywhere near the flanges. I recon that the flanges aren't really needed at all but I put one on the back end anyway. The practical reason that I left it off the front is because with this larger idler it would interfere with easy belt changing. I made the tensioner slightly longer as well. I use CRC Belt-Grip on my belt and that makes the belt tend to jump around a little on BC2 and BC3 when the "clutch" is off with motor running and often in this condition the belt would jump off the v groove. The larger idler holding the belt downwards just that little bit more seems to have eliminated that problem. I am very happy with this simple and quick modification. Maybe also the extra weight will act as extra dampener to the tendancy of the arm to jump up and down on intermittent cuts. I already have good dampening on the arm by way of a hard fibre washer on each side of the support plate and I have the nuts adjusted so there is a good friction resistance to easy movement.
This should be a new window, minimise or close it to return to Home Page or press