CMT's Crown Molding Set These bits combine to allow you to make many different crown moldings. Here is my first use of this great set C.M.T. UTENSILI S.p.A. Via della meccanica 61122 Pesaro - Fraz. chiusa di Ginestreto- Italy Tel. #39 0721 48571 Fax. #39 0721 481021 e-mail info@cmtutensili.com www.cmtutensili.com
Wow!!! That was my very first impression when I opened this box. I am used to some fancy boxes storing CMT bit sets, but this set is astonishing. Part of that astonishment is because somebody thought it all out, and I don t mean the box but all the cutters. They are shaped upside down more on that in a minute. This very unique cove cutter is the key to the whole set. It is a 7 wheel with 6 carbide cutters and balanced so well that it simply hums. And while that may be interesting, what really counts is that it gives such a smooth finish to the infinite number of cove shapes it can do. The shape drawn on the wood is the bar rail that I cut when I used the prototype cove cutter. That was a gem You control the shape of the cove by setting fence angle and blade tilt angle. Of course, you also control blade depth. With these variables, the combination of cove shapes is tremendous. I have developed the chart at the right just to give you an idea what fence angle and blade tilt angle play in shaping the cove. For the cove pictures above, I used a very handy program called Your Shop Helper - Cove Cutter. 2
Unfortunately, the Blade Dia. field accepts 8 to 10 not the 7 that the CMT Cove Cutter measures. The program is still useful to give you an approximation of the shape. The illustration at the right shows 8, 9, and 10 blades at 45o at a common depth (1 ). You can see that there is very little difference. That said, I went to the shop to cut out actual, real coves at some different settings actually, I used the same fence and blade angle settings as in the composite picture above [45o, 35o, and 20o fence angle and 0o, 15o, and 30o blade tilt.] Now, with these cut I can set out to make any molding I want and without guessing. Before I do that, let me show you how I have set up the cove cutter. The cove cutter comes with a thick spacer (arrow). This is mounted on the inboard side of the arbor and moves the cutter away from it. It is very important to have this spacer in place to keep the cove cutters from contacting the internal blade guard. It is a good idea to rotate the cutter by hand to make sure that it has good clearance. I had cut the zero clearance plate for this cutter when I did the bar project. If you are starting with a brand new plate, simply clamp a piece of wood over the plate and with the saw on, raise the cutter slowly through the plate. [Note: I am showing the plate in this picture. When actually cutting the plate, your board should cover the opening and be securely clamped.] 3
This is the setup I used for setting the fence angle for the bar rail project. It was simple and worked. For the new cutter, I wanted to set up a fence that would give me all angles. The Incra Miter Gauge is limiting me to about 45o. Also, the angles we want will be measured off the blade path rather that perpendicular to it. I looked around the shop to see what I could make a special fence out of I came across the vertical fence that I used to use on the router table. It had a hole in the center to allow for the router bit. Since I wanted a smooth surface for the wood to glide along, I used spray cement on a piece of glossy white hardboard (bathroom shower surround material.) I am pressing it in position. I have mounted a flush cutting bit in my CMT router table and am trimming the excess white panel from the fence. This view gives you a better look at the construction of this fence. The side I am using is 6 while the side that is vertical here is 12. It will make a great fence for the cove cutter. I want to mount this fence so that I can adjust the angle and location and still lock it in place. I decide to use an Incra Miter Slide that fits in the miter slot and can be locked in place. 4
I have attached the miter bar to the fence at one swivel point. Here, I am tightening the locking screw to hold the fence in this position. You can see that I am using a protractor to set the angle between the fence and the miter slot (blade.) Once I have everything set, I add a heavy duty wood clamp to firmly fix this fence in position. The screw that I tightened seemed to lock the bar pretty well, but this clamp is necessary considering some of the forces cutting will place on it it just makes sense. With the fence secured, I place holddowns and guides to keep the stock smoothly against the fence. The Grip-Tites are idea for use here. I am using a scrap piece of stock to help me set them and the featherboard in place. I want very little pressure on any of these guides. Running the stock smoothly over the cutter gives a wonderfully smooth cove cut. Both the box cover and the instruction sheets show three basic moldings you can make from this set. Considering all the cutters and angle of coves, the actual numbers of shapes is infinite. Using my test/samples, I find a cove that is similar to the one on the box. 5
I draw the cove profile on a hunk of cherry I will use to make my first molding. Having set the fence angle to 40o and no tilt on the blade, I use the sample to approximate the fence position. As I did earlier, I add a clamp to the fence. This setup really worked well for me. I am attaching a shopmade feather board to the fence to put downward pressure on the wood. I have positioned the two Grip-Tites to keep the wood against the fence. Fact is, I found the cutter to work so smoothly that little force was needed to keep the workpiece in line. 6
I start cutting the cove. It is important to follow the manufacture s instructions and cut only a little bit on each pass. I am cutting cherry and find that raising the cutter just less than 1/8 each time works very smoothly on my table saw, about 1/2 turn of the height adjustment crank gives me the elevation I want. On several occasions, I have made cove cuts with the saw blade. There is no comparison. When using this cove cutter the operation is smooth and quiet and feels very safe. I have my cove. It is an exact copy of the template that I had used. And, it is smooth. I made the last pass a smoothing pass by raising the cove cutter about 1/16. Even then, I sent the board through for one more pass. It takes a second and really smoothes out any minor bumps. If you wonder what I am doing, that makes two of us. For the life of me, I couldn t figure out how to use those upside down cutters to finish off my wonderful cove. So this very smooth sample may go into the Lucas Trials Hall of Fame. This is a new blank that I am using to test this cutter. Clearly, this is the way it is meant to cut. So, what I did was to cut the smaller profiles first maybe I will be luckier in cutting the cove after. At least, that is my plan. 7
I cut the small profile on the other end, too. It still seems insane but maybe, just maybe, I am getting closer. Now I use my template to draw the cove between these two edges. Back at the table saw, I am making my first passes. You can see the line I drew. It will take a number of passes to get there. In fact, I got close by raising the bit 1/8 each turn, but near the end, I also started to add tilt. I did a very little bit of tilt (10o) each pass. Well, I have molding. I didn t say this before, but this block is a piece of mahogany, and it not only mills nicely, it looks wonderful. My nice cove ends right where the small profiles start. One molding doesn t make me an expert, but I like doing the cove last there seems to be more adjustments and controls to this than with the fixed profiles. 8
It takes very little sanding to prepare it for its finish. While this molding is useable, it is not cove molding at least, the type that fits as crown molding on top of entertainment centers, kitchen cabinets and the like. Clearly, I have to re-read the instructions. I am missing something. Well, it is a new day and maybe, just maybe I have a clue how to make crown moldings with this fancy set. What I did was read the instructions. Before you go and say that I should have done this before, let me say that I had... many times. But, the instructions are somewhat sketchy not wrong, but brief. For example, the Step One at the right is all that is said, for step one. Well, I didn t do this before, so I will start a new. My supply of big blocks of fine woods is dwindling, so I have glued together some MDF to make the next run. Actually, this is a good choice anyway. I do think MDF can be machined beautifully for painted applications, like those all white kitchens. And it is the perfect material for making samples. I didn t make the proposed Vee block but instead tilted the bandsaw table to 45o and then jury rigged a little to increase the angle. 9
My bandsawing didn t give me exactly the profile I wanted, so I pass the piece through the rip saw to give me a good edge for shaping. Once I get this all figured out, I will come back and make a jig or two to remove the guess work. Well, there is my MDF block, the instructions and the complete set of cutters. It is definitely time to make some profile cuts. The instructions say to cut the cove first. Having done it that way (unsuccessfully), I will try to cut the router table profiles first and then the cove. Before I move to the next step, I want to show you a couple of things about these cutters. First, the three on the right are the same basic shapes - round over/beading shapes and the three on the right are roman ogee bits. They vary mainly by their overall diameter, more than their individual shapes. They also vary in height. What this all means is that 2 or more can be used in concert without resetting the height. I was amazed to find this out and will show this in a frame or two. It is time to start making some shapes on the router. My trusty bent wrench to the rescue. seriously, if you are not yet using the bent wrench, you should be. 10
The RouterRaizer still works fine for making height adjustment. Frankly though, I wasn t quite sure where this first bit should cut. I set it so that the bottom was just at the table level. I cut the profile on the bottom of the molding. Well, it is a start. Next, I have to figure out how to cut the shape(s) at the top. I install one of the ogee bits. 11
I skipped ahead with this photo. I have made two cuts. Do you remember my saying that the cutters were different widths and heights, well this is the result. The narrower one gives the #1 shape and then the wider one, gives the #2 shape and without changing fence depth or router height. So, all I have to do now is to make a cove cut That is the end view and I have sketched the arc in having found one of my templates that fits. Now to the table saw and the great cove cutter. The template I used to sketch the arc said that the fence angle was 45o and the blade tilt was 0o. This setup should be simple. It was simple except for one thing, it is hard to figure out how far the fence should be away from the cutters. I guessed as best I could and lowered the cutter to begin making multiple passes. What do you think? If I continue to make passes and simply elevate the cutter, will I end up on my sketched cove line? 12
Well, to make a long story short, I shifted the fence a bit to correct the cove and totally missed. I think the fence has to be set accurately for the entire cove cutting operation and not fine tuned along the way. I said a while ago, that the instructions say to cut the cove, first and then the router shapes. That is what I will do next. I am now using the other half of the piece that I cut diagonally on the bandsaw. I have taken more care and used my last cove cutting experience to guess where the fence should go. As before, I ripped a bit off so that I can have a square edge on this side. I cut the profile with the last bit I had installed. 13
And then the rounding over on the other edge. Maybe, just maybe, I have a piece of molding that will work. Frankly, it is quite nice, even if in MDF. I have had success, but there is a lot for me to do before I have any comfort level with this great set. Here is my short list: 1) I want to cut a paper or plastic template for each of the shaper cutters - not just the shape but the height and bearing position; 2) I have to invent a way to measure and set accurately the fence position either measured from the front of the table, or better yet, from the center point of the cutter, and 3) I will make that holder jig for the bandsaw. This set of cutters is absolutely beautiful, but I won t rest until I can get repeatability into the equation. but just look at that last molding! 14