After writing my last article on gap control, a business acquaintance of mine asked me if Babbitt grinders (some call them Guide Dressers) played an important role in maintaining the gap. Well the answer is—YES. For years I have been visiting customers and looking at their Babbitt grinders, some were good, but others were definitely not doing the best job. So what makes a Babbitt Grinder good? I’ve compiled a checklist.
7 Key Requirements for a Babbitt Grinder
- Sturdy construction
- Highest accuracy possible
- Easy to adjust
- Clamping mechanism that is quick to change to various styles of saw guides and easy to use
- Built with materials that are not affected easily by temperature
- Cutters that are easy to replace and do not put a lot of cutting pressure on the saw guide
- Ability to grind/mill the saw guide babbitt as quick as possible
Let us quickly review each of the points.
A Babbitt Grinder must be sturdy so it can mill or grind off the babbitt and not shake. It’s a bad sign when the grinder shakes while cutting because you’ll have variation in the accuracy of the cut, which will likely cause sawing problems.
Since you normally leave only a 0.0015” gap between the Babbitt and the saw blade, it is important that the grinder is very accurate. An accuracy of 0.001” is probably not going to be good enough. You’ll need higher accuracy in order to give you consistency in the Babbitt/saw blade gap.
A Babbitt Grinder should be easy to adjust. If it’s not easy to adjust then the extra step of fine tuning needed to create an accurate Babbitt/saw blade gap will probably be skipped due to the extra time required. I believe, in many cases, adjustments are not made simply because the grinder is not easy to adjust.
Since many sawmills run more than one style of edger, and therefore have various styles of saw guides, the clamping mechanism on the Babbitt Grinder should be able to clamp various guide styles easily. I’ve seen companies buy more than one Babbitt Grinder just because it was too difficult to move from one saw guide to another.
Since many Babbitt Grinders are found in confined areas where temperature can vary extensively in a matter of hours, it’s important that the Babbitt Grinder is built of materials that will expand or contract quickly. This is imperative when you have a lot of saw guides to mill/grind and you cannot do it in a short period of time. This will probably cause a lot of variation between the saw guides in terms of the Babbitt/saw blade gap.
I have also seen many Babbitt Grinders that use a cutter arm that has too few cutter inserts (1 or 2) and are difficult to change. When a cutter arm has limited cutter inserts the surface finish of the Babbitt pad will be very rough due to cutter inserts taking wider passes over the Babbitt. This roughness will cause variation in the Babbitt/saw blade gap. If the cutter inserts are not easy to replace, and therefore harder to adjust, there may be an unevenness in the setting of the inserts, causing uneven milling and contributing to roughness.
With the rising employment costs of a saw filers combined with the increasing expense of sawmill downtime, it’s critical that the Babbitt Grinder grinds and mills the Babbitt as quickly as possible. I’ve seen upwards of 4–5 minutes on some, and this doesn’t include getting the saw guide on and off the grinder. Slow grinding and milling leads to higher labor costs and higher downtime costs if the saw guides aren’t ready to go during scheduled saw change overs or when there are problems with the edger.
Babbitt Grinders are an important part of the filing room, so consideration of the above requirements are definitely worth your time. I hope this helps. If you have any questions please do not hesitate to email me.
Author: Udo Jahn
