Fuck it. I did not expect to have to write this.
Works were progressing nicely, I ran several tests and optimization rounds. I got the thicknesser remove material in parallel both across and lengthwise with several iterations that I won’t write about now because they are moot. It was working adequately. Also as I wrote, I did try to plane one board across the grain manually and it worked just fine. I really did not expect any significant problems. I was ronk.
Today I glued sacrificial sides to all my kitchen boards and decided to try to flatten those. The first one I tried to push under the thicknesser, removing barely 1 mm of material – BOOM. And the planer was broken. When I disassembled it I found out that for some reason the wood bent the steel knife of the planer, thus it bit into the housing. Subsequently, the propulsion shaft broke off and the aluminium cylinder for the knives got deformed too.
Apparently, planing hardwood across the grain is even more pernicious than I expected. Now I don’t have an electric planer anymore. That would not be a problem since I do not really need one. However, I still do not have a thicknesser, which I do need. And I have several glued-up boards which I cannot finish with a reasonable amount of work. This is a huge setback and I am at a loss about how to proceed.
I can buy a new hand planer but it won’t fit in the stand I built. I can’t buy the same one because it is no longer on sale and it is no longer possible to get replacement parts to fix it. Not to mention that when I removed the cover, so many metal parts were bent out of shape or broken that repair is probably not feasible. Now I am even afraid to run these boards through any kind of thicknesser whatsoever. If I bought a thicknesser for 500,-€, and found a way to fit it into my workshop somehow and this happened, saying that I would not be happy would be an understatement of the year, I would be ruined.
Sorry to hear about your problem.
To me it is suprising that a planer knife would bend. The ones I’ve worked with were properly hardened steel that would break rather than bend. If you take a file to the planer knife material, it should skate right over it instead of biting into it.
The answer to “how do you thickness an end-grain board” seems to be “with very light passes”; way less than 1 mm.
So, as to a possible solution, do you have a handheld router? Because then you could flatten your boards using a router flattening jig. See e.g. here or here.
In any case, the router method seems less prone to chip-out or even breaking the board.
@rsmith, I do have a small handheld router. It is not very powerful and I do not use it very often so I have very little experience with it. In fact, I have used it only two times over the almost twenty years since I bought it. It might be safer and more reliable for this kind of work. I will try to use it.
Oh no, how frustrating. I hope the router idea is helpful.
There are special so-called “planing” or “surfacing” bits for routers. They can even have indexable and replacable carbide cutting surfaces and can have a diameters of 20―40 mm.
One thing to keep in mind is that these large diameter cutters generally have a maximum safe speed that is significantly lower that most routers can reach, so you need a speed adjustable router for them, because they can break when spun too fast.
It is a lot of rotating mass, so I’m not sure if I’d like to use them in a handheld router.
It’s disappointing enough when an experiment doesn’t go as planned, and gutting when something ends up ruined.
On the other hand, at least you didn’t destroy a really expensive piece of equipment.
Onwards and upwards!
@bluerizlagirl, that is not entirely accurate, the handheld electric planer was not exactly cheap. It is expensive, just not ruinously expensive as a tabletop thicknesser would be.