Plastic 81X sawmill sprockets are primarily a molded product, this is to reduce delivery times as well as cost. The standard sprockets available from Redwood Plastics and Rubber have a hub that is 3-3/4″ wide (length-through-bore). Often these days customers want a thinner hub to fit into their sawmills and in most cases that’s fine! All we need to do is machine down the hub on our solid idlers.
In addition, our split idlers have special “short” hub that’s available that’s available which reduces the width to only 3.0″. Length through bore narrower than that; however, are not possible as there is no more “meat” to machine away – the bolt holes get in the way. You will notice there has been no mention of a “old style split idler” in this conversation that is because unfortunately there is no “short hub” design for that particular part.
For other customers, maintenance is limited and customers do not want to have to regularly grease the sprockets. In this case we can mold them out of an alternative version of the polyurethane used for our regular sprocket line. This plastic is called “Redco 750 SXL” and is lubrication-impregnated so it will not need to be greased. In the case of the solid sprockets, the entire sprocket can be cast as 750 SXL (including the split idlers). In the case of our new style splits where the A-plate and hub are separate, we can simply cast the hub as 750 SXL while leaving the A-plate as the standard Redco 750. Please note this will mean a mismatch in color, as the Redco 750 is red in color and the 750 SXL must be black due to the fillers it has.
The final sprocket modification we get asked for is to reduce the bore size below what is our standard (1-15/16″) or to provide a sacrificial bushing in the bore. This is somewhat uncommon, but it does happen. In that case we will design a simple Redco 750 SXL sleeve bushing and can press fit that in.
For assistance with your sprocket needs, please contact us today.