Out of flat and unaware

Ever have a serious problem pop up with a power tool, only to realize that it’s not a new condition, but something you’ve been cluelessly working with for a long time?

My combo sander has served me well for years, or so I thought. It’s not the biggest around – it’s a 6” x 48” belt paired with a 10” disc – but it suits my needs. I use it a lot, but just discovered that the belt’s table isn’t coplanar; for lack of a better description, there’s a “twist” in it.

I’ve used this belt hundreds of times over the years without ever noticing the issue until a couple days ago. I don’t normally need or use it for truing-up projects, but a box I made last weekend had some rough rabbets on the bottom. I finish up all my boxes with hand sanding, but I’d made these rabbets a bit too big and thought I’d level them on the belt first. The task took only a few seconds, but when I set the box on my worktable it wobbled. I assumed I’d accidentally put too much pressure on one corner while sanding and went back to the belt to flatten it, more carefully this time. No change.

Perplexed, I grabbed a block of 2”-thick oak, about 4” wide and 6” or 7” long, from my scrap bin. I checked it carefully for square then set it on the flattest surface in the shop – my table saw – to double-check. Flat and rock-solid as could be. But after a few seconds on that belt sander that previously flat block of oak wobbled like a rocking chair.

I’ve used this belt for countless projects without once noticing this before. As such, I have no idea when the defect formed or how it occurred. I checked the machine over and all seems in order, so I have no idea how to correct it without doing a bit of research.

I’m sure I can fix this thing so it’s flat again, but what’s really bugging me is that it’s apparently been this way for a long, long time and I never noticed.

Till next time,

A.J.