Problem with router – wood breaking
I’m fairly new to woodworking and really appreciate all feedback. I’m using a charcuterie board handle template (see photo), a jigsaw to cut out the majority of the 3/4″ cherry stock, then a palm router with a 3/4″ diameter, 1/4″ shank, 1″ carbide cutter to flush trim against the template. Unfortunately, the handle has broken as I was running the bit along it. The circular portion of the handle is 3/4″ wide (it’s the narrowest part of the handle). I thought it possibly broke because I’m trying to take too much material off at once and it’s causing the bit to snag/catch on the wood. After a huge chunk of the handle broke off, I tried it again on another board of 3/4″ cherry, this time being careful to make multiple passes and not run the bit bearing along the template all at once. On this 2nd attempt, the exact same thing happened — I broke the handle again, with a huge, 3″ section of the handle breaking off. There’s probably only 1/8″ of wood remaining along the template that I’m trying to remove with the flush trim bit, which doesn’t seem like that much to me. What am I doing wrong and why am I ruining these beautiful pieces of cherry? What would cause a bit to snag and then violently break the wood? Could the bit be dull (I got it used from the previous owner of the router and I’m not sure how much it’s been used)? Is the router speed too fast or slow for this bit (I was running it at 20,000 RPMs which seems OK based on my research)? On my next attempt, I’m NOT going to remove the center of the circular handle before I try to flush trim the outside of the handle pattern — I feel like that will give the handle more strength since this portion will no longer be 3/4″ wide/thick; but still, what is causing enough resistance to make this happen in the first place? Thanks for all comments/suggestions.
Replies
There are a few spots in that design that have really, really, really short lengths of grain. It takes very little pressure for that grain to snap. Even if uou successfully rout your pattern, the board is going to snap while in use. Solid wood just can't do what you are asking it to do.
If you try again without cutting the hole first, it may rout OK. But then it will break when you drill the hole.
It's pretty, but you'll need to redo the design.
John is right, no way that survives as solid wood. The first alternative that popped in my head is bamboo plywood.
It's a nice design, but as others have said, is flawed because it does not consider the properties of the material with which you are working - it would be fine in an homogeneous material such as plastic, but wood is weak across the grain and tends to break where you have the 'short grain' as mentioned above.
You could improve your chances by orienting the grain so that it is along the thin neck, but you'll still get weak spots and it will detract from the effect.
I have made turned rings using home-made plywood, sandwiching the layers in opposite directions and found that they are very strong indeed, even though they are a bit smaller than your neck and loop there.
Your best bet would be to cut the wood into thin sheets and glue them back together, but I'm guessing you have not got a band saw or drum sander, both of which are really needed for that job.
Instead, if you do want to keep at it, you could consider using a mortising bit. These are only 1/4 inch deep and have a top bearing. You take a series of shallow passes, and as you go down deeper into the wood, the bearing starts riding on the template then uses the wood as a template to complete the cut. This can work as it takes such light cuts and a good bit of this kind is always useful.
If I were determined to do this and wanted it to be at least mostly one piece of wood, I'd glue the whole thing to some scrap 1/4 inch ply, rout it out then cut the scrap off with the band saw or plane it away. To strengthen the handle, I would cut a kerf in the handle at the table saw and insert a spline of a contrasting timber with the grain oriented at 90 deg (this is best done before the routing)
Thanks all for the comments. The problem appears bigger than I was hoping, in that, the overall design is flawed. Bummer. I bought this acrylic template from a website that sells may different styles of similar handles. Maybe I should have gotten one that didn't leave such thin sections of wood. Interesting thing -- I used this template on two pieces of hard maple and it was successful. I'm guessing the maple was a harder species versus the cherry that I'm currently having issues with? Thanks again for the perspective!
Years ago my kids and I made some intricate, scroll saw trivets from walnut as Christmas gifts. Being afraid that the fine details would break off with the grain I added a contrasting piece of thin maple between two pieces of walnut, oriented 90 degrees to each other - essentially making 3 layer plywood. Worked well and looks pretty good. Maybe you could try something similar?
If you laminate hardboard to the bottom and then bevel-in the edges, you might reinforce the handle enough and roughly stay within the look and feel of the original design.
The amazing thing about that design is that someone markets a template like that! Your photo shows a successfully routed board. One that didn't explode in process but be as that may it's going to break in use.
Maybe, just maybe, if you laminated in the way someone suggested you might be able to create enough support to prevent breakage.Theres short grain though in every layer so your down to maybe a stack of 1/8 ths. I can't see 3 1/4" layers giving you the strength that you need. This is a utilitarian thing,its going to carry some weight even if just a cheese plate. It's going to get washed. Pretty different than a Christmas ornament.
I do a lot of stuff with bent lamination and to do that handle would be possible but that tight circle would be tricky, and I mean REALLY tricky, and with the forms involved wouldn't be worth it for a one off. If you started now and spent the time and developed the jigs and forms to make one and then made a trunk full to sell at a craftsfare you might have enough done for the Christmas season and the time involved might be well spent!
Jere Osgood did some articles related to bent lamination that are in some ancient FW magazines that are available here.
You need a different template. One with a straight(er) handle without that big cutaway and then maybe just a hole big enough for hanging on a hook. What's that big hole for anyway? A cup holder?
Thanks again for all who have chimed in. I really appreciate the feedback and I've come up with a few solutions (hopefully they're long term solutions). I just successfully finished 2 of these charcuterie boards without them exploding. The biggest design change is that I didn't cut out the large round hole yet. I just routed out the long handle. I know, that handle is now the weak point with its short sections of grain (I'm hoping that holds up to some abuse -- I will be banging it around a bit over the next few weeks). They look great though! Using my drill press and a medium sized forstner bit, I'm going to go back now and bore out a hole in the handle so the board can be hung. I'm going to make that hole much smaller than the ~3" hole the template suggests -- I agree, Pantaloons868, why is that so huge?!? Another change I made was -- using a oscillating spindle sander, I got much closer to my pencil line before I used the flush trim bit and router -- I was probably 1/32" from the line. I also used a different bit that I believe is much sharper. I think the original bit is too dull. Again, thank you all for your perspective and suggestions!
Not sure the thickness or other dimensions of your board but might it be possible to drill say a 1/4” hole from the board into the handle and then insert a steel pin? May also be able to insert a wooden plug to cover the entrance hole.
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You're in a tough area with the grain failing to support the torque and cutting edge of the router bit. The router ends up splitting wood instead of cutting it. By the way, not sure the wood type and grain is the issue. The wood looks thick enough for its purpose. You don't mention if the failure is on the front edge (closest to the board) or back edge. You need to reverse the travel of the router for each side. There are a couple of ways you can successfully tackle this issue. I'll get some grief here for suggesting this but here goes. Try making the sensitive grain failure cuts by violating the rules of using routers by doing a climb cut in this area. This removes the material before the grain can fail. Also, try to make the cuts in succession by using a larger bearing for the pattern and reducing the bearing size until you are at the true pattern size. Removing a smaller amount in each pass reduces the chance of grain failure. However, using a straight cut pattern bit can still result in tear-out even if the grain doesn't fail. If you're not feeling safe doing this, or it doesn't work out, and are willing to invest a couple of bucks, then try using a Spiral Cut pattern bit. An up / down type works well. Spiral cut bits were developed to help overcome some of the issues you are facing. They also reduce or eliminate tear-out and, for the most part, leave a ready to finish surface. Most of the router bit manufacturers make this type of bit. Once you get experience using one, you'll most likely quit using the standard pattern cut straight edge bits. Here's one example of a spiral cut bit: https://www.whitesiderouterbits.com/products/udc9112?_pos=198&_sid=ba3bbda48&_ss=r
Spiral cut pattern bits are expensive but will save you a lot of headaches. With the cost of wood these days it may not be all that expensive to invest in a tool that eliminates failure. Good luck to you. Let us know how this works if you try it.
Thank you all, again, for the continued suggestions. I had success with 3 of these boards yesterday and today, but unfortunately another one broke on me today. I stopped cutting out the big hole in the handle before I used the flush trim bit and that seemed to be helping...until the latest break. I am becoming more convinced that I need to change the design of the handle -- not that I didn't believe all the earlier posts, but it hurts a little more when I just bought that acrylic template offline and really wanted to make it work. And thank you RevBob for the suggestion of the upgraded router bit. I was thinking of buying a new template bit anyways, so maybe an upgraded one is a good idea.
I'm trying to fully understand how the wood grain works (and fails). Humor me...Hypothetically if I had a template like the one in the attached picture (I just grabbed this picture from their website), could I still expect to experience the same issues with breakage? Since the handle is not curved like the one I currently am using, and the wood grain runs continuously from one end of the board to the other, through the handle, would that provide enough wood grain stability, in theory? If this still would not be ideal, is anyone able to provide an illustration or picture to show an example of a handle that would be more stable? Thanks again all!
That template should be fine. I would drill the hole last.
A spiral bit will cut cleaner. Try a smaller diameter too. A 3/4 inch bit in a small 1/4 inch shank is too much.
Wood grain. Did you ever split a piece of firewood, or see it split? One whack with the axe can split a log in two. That's wood grain. Hit that same log going across the grain, and it will never split. Just like your cutting board can split with the grain, but not across it.
Take a ruler and put it running along the grain on your broken cutting board. Move it from side to side, but always along the grain. Up near the hole, you've got two sections that are only about 1/4 inch long, on the same grain line. It's super easy for that to split.
Put your ruler (or visualize it) on that new pattern. There is one spot at the top of that that the long grain is short. But it's still longer than on the first template. But the other side of that hole is all long grain, all the way down the full length of the board. That's very strong, and reinforces the one weak area at the apex.
JC2, nice explanation using the ruler, I'll be stealing it.
Nice tip with the ruler.
Pay attention to the grain direction as you move the router. If you move the router from the board out along the handle and back you'll find yourself working with the grain in one direction and against the grain as you return to the board. Watch this video from Stumpy Nubs on various router movement and proper cutting techniques. In this video (@ 3:40 )he explains the benefit of a climb cut I mentioned in my previous note to help prevent grain tear-out and splitting.
https://youtu.be/9IBn1iXpzdU
Direction of movement is important but the thickness of the material is as well.
Again, good luck on your journey.
Great explanation JC2 -- that helps give me a better visual. And thanks for the video RevBob...I just watched it and that makes a lot of sense. There are so many factors at play here. Grain direction, router bit selection, thickness of material, router direction, etc. I'm hoping if I use a new template, go with a spiral trim bit, take off a very minimal amount of wood with the router, and pay attention to the grain, I'll be in better shape and won't get any more breakage. Fingers crossed! Thanks all for your tips.
One more mountain conquered and a million more to go on this journey ....... grasshopper.....
Late to this party but some observations on the topic. I have made a bunch of charcuterie boards and here are my observations.
RE original design: I am not a fan of the large hole design. The intent of a charcuterie board is to load it up with tasty things for folks to enjoy. With the large hole design it is just a lot of wasted space and wood in my opinion. But it is not what I like but what someone else wants.
The topic of weak joints and router issues has been covered in detail and I have had similar issues with some of my designs.
I had this piece of curly/spalted maple laying round and about the only thing I could do with it was to make a board. To maximize usable area I went with a saddle joint handle and cut a space for it to fit in. Handle cut on scroll saw, shaped with rasps and scrapers. The slot - 'tenon' - was cut with router and finished with chisels. The handle 'mortise; was cut with a jig on the table saw.
I used some woodworking skills to make a routine item, more fun that way. And I did not have enough wood to do anything else.
So to the PO'er, enjoy the experience, it is a journey.
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