Wood is poplar, 3/4" thick, about 12" x 23". I expect to use a plunge router and a round-nose bit to make 5/8" or 3/4" wide grooves about 18-1/2" long, cut with the grain, and about 1/4" apart. There will be 12 or 13 grooves across the board. I need to make some kind of jig to help me do this, which I anticipate as nothing more complicated than a rectangular cutout in some 1/2" plywood the width of the router housing and the right length to make the grooves I want, and I will clamp the router and wood to a bench while I do the routing. After routing the slots I will rout straight grooves across the slots so I can inset some 1/4" stock, to divide the grooves into 3 sections. The groove sections will each hold one fountain pen. Each board will end up fitting snugly into a shallow metal drawer, one of 13 in a metal cabinet.
I also plan to make three additional round grooves across the otherwise-unused far end of the board, for additional pens. If I use the 5/8" bit on the long grooves, the cross grooves will be wider, to hold some larger pens that might not fit the smaller grooves. They will also be further apart.
I am not experienced in this kind of routing. I have used a router either in a router table, or else doing edge routing. I do understand the principle of making gradually deeper cuts to avoid chipping and other issues. I will practice ahead of time on some sacrificial wood.
Here are questions that I hope experienced router-users will be able to help with:
Do you see any danger signs in my description, e.g. the grooves are too close together, wrong choice of wood (it will be covered up, so appearance is not an issue), etc.?
How deep is it safe to rout a groove in 3/4" thick poplar? I don’t want the pens to roll out of their grooves when I open the drawer.
What have I forgotten?
Thanks in advance for the benefit of your experience.
The jig could be something as simple as a straightedge clamped to the board. But you’ll need to be very careful to keep the router pressed against the straightedge through the whole cut. Any slight movement away from the straightedge will leave a wobble in your cut. If you really want a jig that exactly fits the router base, I would make it by attaching two straightedges to two perpendicular support pieces at either end, and fit it around the router base while you’re building it. It will be a little tricky to make it fit the router base with no play, but also no binding as you move it along. I would probably just go with a single straightedge.
If you’re concerned enough about the appearance that you want the ends of all the grooves to exactly line up, you may want to design your jig so that there are stops at each end to limit the router’s linear motion, or at least easily visible marks to show you where to start and stop.
Since the wood will just be sitting flat in a drawer, with no mechanical stress on it, I don’t think you have to worry too much about going too deep. Leaving a quarter inch of wood underneath the groove seems safe to me, as long as the finished product isn’t getting picked up and messed with. You could also glue on a piece of 1/4 plywood to the bottom of it to avoid any issues of the wood under the groove being too thin.
Since you’ll be raising and lowering the bit multiple times, make sure to use whatever feature your plunge router has to provide a positive stop for the final depth of the cut. Intermediate cuts can be done by eye, but the final cut should be exactly the same depth for all the grooves. In the unlikely event that your router doesn’t have a depth of cut stop, you can use a board exactly as thick as the depth of cut. Cut a hole in it that the router bit fits through, place the board on a table and the router over the hole, then lower the bit until it touches the table.
Poplar seems like a reasonable choice of wood. Make sure there aren’t any knots in a position that might weaken the final product.
I found out there’s a name for this type of routing (more or less), it’s called fluting.
Rockler has a jig that is this close to working for this project. It’s designed to make dadoes in series, any distance apart from 1/8" to something over 6". But they say it only works with square-bottom dadoes, not rounded ones (or “flutes”). Oh, and it also doesn’t work with plunge cuts. I don’t know, it might be worth $70 bucks to get one and see if I can make it work.
Assuming I have to make my own jig, I’m going to put in some time to fuss with it to get it right, including two sides and end stops, making it square and just the right width. I have to cut 130 flutes, and if they don’t have to be machine perfect they need to be darned close. Then I have another 30 to make of a different width and length, so that will be different end stops probably on the same jig.
The toughest part will be avoiding tear-out on one side of the router bit. Most routing is done on an edge and you move the router so the bit is turning into or away from the wood on one side, depending on the bit and the wood. When routing flutes you’re cutting the wood on both sides which can be problematic. However, taking shallow cuts with a carbide bit at high speed will reduce those problems significantly. Poplar may leave a rough surface after routing but also should sand out easily. I’m sure you already know to try the process out on scrap wood first and make adjustments.
If your router table has a fence, I’d just use that. Make sure to have a way to ensure even spacing as you move the fence away from the bit for each flute.
Poplar should be excellent–you may be left with one “hairy” edge of the cut but that will sand off easily. Beech would be another good choice. Practice your speed of advance on scrap–too slow and you’ll burn, too fast and you’ll get a rough cut. Use a new high-quality (Freud, Bosch) bit.
I haven’t tried this on a router table, but not being able to see the wood while cutting could be a disadvantage. I think not much of a problem in this case, but it’s the kind of thing I’d prefer to do face up.
You won’t get good results with a Freud bit unless the wood wants to be cut.
We often have to make up one or two pieces of fluted custom molding when doing repairs. I think your idea of a two sided jig is a good practice, the router needs to have nowhere else to go. Way better than repeating the process when the router goes wild.
I do prefer a router table for this sort of thing.
Ive always set up spacers when cutting multiple flutes rather than multiple jigs. You do need a way to secure them though.
@TriPolar Whats the issue with the Freud bits? I have always thought them decent quality, not the best maybe, but not bad.
I disagree. Tommy only goes the route of a custom knife as a last resort, as for an old molding profile that there is no other way to reproduce in sufficient quantity. He would be able to whip up a perfect jig out of some scrap wood and other bits and pieces he apparently has lying around.
Thanks everyone for the suggestions, excellent food for thought and possible changes in plan.
Regarding the router table, I will have to look into that. it’s pretty small, and the bit sits pretty close to one side, so I would have to run the piece in the opposite direction for half of the board, I think. That might be okay, But the advantages are several, if it can be made to work, and I don’t mind working upside down as long as I can get the spacing right.
Could you elaborate on that a bit? Do you mean leave the fence in place, and put a spacer next to the fence to move the piece over the correct amount (on a router table)? Or is this to do with using the router separately with a jig?
I have found three fluting jigs online, of which only one is wide enough, from Infinitytools dot com for $90. Anyone have any feedback about that company? It’s kind of tempting and looks pretty easy to use to get accurate placement.
Infinity Tools is an excellent company. Pricey, but excellent products.
Instead of the word “spacers” think of the word stops. With power off on the router table place your work piece where you would start the groove. Secure a stop block on the right hand side. Move the work piece to where the groove would end. Secure a stop block on the left hand side.
Now when you use the router you can slide your work piece from right to left and have perfectly grooves every time. You would of course need to bump your fence back for each subsequent pass.
I mean spacers and stops. You definitely need stops if you want consistent ends. But I think spacers are more consistent than moving a fence or jig for each path. Whenever I have tried to to router parallel paths by moving the fence I’ve ended up with variation in the spacing. Maybe someone with more finesse could do better, but Ive learned my limitations.
I leave the fence in place. Then make spacers at 1", 2" etc, whatever the spacing is. I have made custom cold air return grilles this way that turned out very well. (and produced a sea of MDF dust). Once this is set up it is going to be faster and more consistent if there are multiple pieces.
If you are using the plunge router free instead of on the table I would make a box jig or some guide so the router is restricted and can’t jump out away from the fence, and then move the whole jig with spacers for each row.
You do need to be able to lock everything thing down in place with clamps, dogs, screws, whatever works.
On further reflection, I realized the router table is not long enough for me to have end stops in appropriate places for an 18.5" cut on a 23" board. However, I am also planning some 7" cross cuts at the end of the board, which I could use the router table for.
So I went ahead and ordered the Infinity jig. It’s going to take two weeks to get here, so I will have plenty of time to practice with the plunger base, and maybe even do those cross grooves on the router table.
I had a heck of a time getting the router motor into the plunger base, mostly because the teeny tiny, and not enlargeable, drawings that DeWalt provides in their instructions were no use whatever. But I finally got there.
I’ve not used my plunge router in a few years, Bosch, but I remember it has a rotating stepped stop on the base that lets you make several passes to reach the final depth of cut. Does your DeWalt have that feature?
This would be a breeze on a router table. I have done similar work on mine. Whether on a router table or freehand with a jig, a secret for plunge routing is to use a drill start where the router bit will enter the wood. Router bits don’t like to be used for starting holes.
The current DeWalt plunge router is very similar in design to my now discontinued Freud router. I used that feature a few times for incremental routing depth. I would measure three marks on the side of a board like maybe 1/8" or 3/16" apart, then with the bit hanging over the side of the board it’s easy to adjust the 3 screws for the plunge depth to reach each mark. After setting those screws I’d use the knob to lower the head down until it was just above the board surface. I found it easier to control the router with a short plunge instead of coming all the way down from the top. I hope yours has a soft start, mine doesn’t and I use it less and less because it’s easy to ruin something with the kick it gives at startup. I plan to mount this one in a router table because of that.
ETA: If you want good results using a Freud router …