Having trouble finding the 90 degree bit in a jig

I read the article about using the fence boards and thought I would try something along those lines myself. So I made a jig from 3/4" MDF that will allow me to place new cedar fence picket boards up to about 41 inches long in it. I have 1-1/2' wide side rails fastened on both sides and fixed end pieces 3-1/2" wide on both ends of the jig with a floating center piece that can be moved as desired to accommodate various length boards, also 3 - 1/2 " long. The jig itself is 48" long overall. I even laser engraved it to help me remember placement as was explained in the article. Pictures below show the jig with a cedar board in it (the same board I have attempted to carve many, many times without any success as yet). I purchased the DXF importer software add-on specifically because of the article and hoping to do some sign work myself

Attachment 79517Attachment 79518

I have created a text design in Corel Draw that I saved as a .dxf file. I then imported it into the software and created 4 boards. Here is the general idea but also showing the layout of the boards that were generated by the software.
Attachment 79519The board is 24" long, 5.5" wide, and 0.5" thick. In the DXF importer no added length added to the board, and 1.5" added on each side as was noted in the video on the fence pickets for the side rails of the jig. In Designer the board is set at 24" long, and 0.5" thick. The top rails an ends of the jig are 1.5" thick total.

The ONLY bit for each of the 4 files was the 90 degree v bit set to 0.125" depth as described in the article on using the fence boards to give a 0.25" wide groove. All loaded to the card at normal quality and the jig with the pictured board loaded into the machine with the center floating block with masking tape on it under the z truck when the pattern was loaded. The jig measured, and everything seems to go right. The machine says to load the 90 degree bit, which several times was already loaded. Bit spins then goes to the keyboard side and bobs up and down ( it goes below the top surface of the jig, but not down to the bit plate) then goes to the far side where it does contact the plate that moves out. I think twice it goes down to touch the plate then goes up and moves down slightly then goes back towards the keyboard side to find the surface. I hit stop every time and job over to the cedar board in the jig. The bit bobs up and down on the board 3 times every time I think, then moves back across towards the sliding plate and says to load the 90 degree v bit again. At this point it is stuck in a loop. I have gone thru the steps time and time again. Occasionally, after repeating the steps several times the machine will stop and display bit depth mismatched and prompt to continue or reload bit. Continue starts the process over again with never going thru the finding the bit depth and ready to begin carving.


Hopefully someone can explain the problem here so I can move on. I have spent hours trying to get past the finding the bit stage.

Also note that I just replaced the original sandpaper drive belts with rubber ones I got around Christmas. I had started this before with the sandpaper belts and had the same issue. After I replaced the sandpaper belts I did a carving on the new top porch step that used the standard carving bit and it ran perfect. Afterwards thinking I was back in business, I again tried the cedar board. Same issue, never get past finding the bit. I also noticed some times the bit didn't seem to go down to the plate that swings out. I worked the z truck up and down and it seemed rough. This led to partially disassembling the machine and discovered the idler roller for the z truck was nearly seized on the shaft it rotates on. I had to pry it off and oddly enough the bronze bushing seemed dry and the pin was rusty it rotates on. So some cleaning and lubing got it to spinning freely. I also sprayed a little WD-40 with a long nozzle on the y axis roller and worked it too. Everything moving freely, so now I am thinking I can at last complete ONE board MAYBE!

Yet after reassembly and getting to the finding bit part even though every time now it contacts and pushes the swinging plate down slightly it still doesn't seem to find the 90 degree bit. Z truck moves up and down with ease, as does the Y axis. Kind of out of ideas. I have thought about trying a different bit, but I HAVE used the 90 degree bit before doing conforming vector text on a contoured surface several times and had no issues.

Sorry for long post, but trying to give all information. May have still left something out relevant, but don't think so. Hoping for someone to have some direction on the issue. It's sure frustrating to be stuck in a loop without understanding why!

I would say the problem is that your board is lower than the jig sides. The touch on the board can not be more than around 1/4" lower than the rollers (top of jig) or you get into the loop. You need to raise the board or lower the sides of the jig.

Thank You Sir.

It's interesting to hear that. The article about v carving the fence pickets showed using 3/4" plywood to make the jig and rails that he put the fence boards into. The new ones I bought at Home Depot all are 1/2" thick. So that does make a 1/4" difference in the height. I spent too much time making that jig to rework it with 1/2" material for rails and end blocks so I will use some 1/8" hardboard or Baltic Birch plywood I have and build the area up the board sits in. It maybe a problem even doing that, as I have 1-3/4" long screws ran thru the rails in countersunk holes to hold the board in the jig. I think 4 on each side. Tip of screw in the edge of the board so no holes in the backs.

I appreciate the advise. Will go to the shop now and see how to raise up and test again. BTY - that knot in my chest is easing up some. ;)

I was going to suggest setting your depth of cut a quarter of an inch deeper; making it .375 instead of .125 and then touching off the top of the jig. My thinking is it will be cutting air but the final depth will end up the desired .125 in the board. I use jog to center for most of my projects and move my pattern placement within Designer if needed, even when I use a sled but there's always more than one way to do most things.

If you decide to shim up the board (probably the easiest fix) those long paint stir sticks for the five gallon buckets that they give away measure .255 thick. Two of those would be plenty of support for what your doing. I also keep a stack of the gallon sized paint stir sticks around for shims. They measure .125 thick and are made out of quality wood.

Attachment 79526

that was the problem it seems. I cut a piece of 1/4" MDF with my laser that fit inside the jig and raised the area for the board up were the top of the board was more or less even with the rails on the jig. Worked right off the first try. 4 boards 5-1/2" wide and 24" tall using Corel Draw to do the text then saved as DXF file which was imported into the DXF importer add-on to create the 4 files. Nice

The font didn't do so great; but hey, after spending hours trying to carve ONE board I am quite happy to get all 4 done in less than 30 minutes. I can try again on other boards or even run something over on the back side of these. ;) Wife arrived home for lunch just as the 3rd one was nearing done. I did the last one which only took 3 minutes so I could take them all in a show her. She seemed to like the results.

I was sure it was something simple (which it was) but not knowing WHAT was getting the best of me. Probably said a few cuss words trying to sort it all out........

Thank you for the coaching.

That came out looking great, Mike!

I'm impressed at how well everything lined up. Great job.

yes, my thoughts too! I couldn't wait to see how they lined up when the second board finished. Not knowing exactly how things would go; I did what instructions said. Jog to corner or place on corner it said, so I thought I would manually be jogging to that corner myself. When the finding bit finished and the machine began carving I sort of paniced as I was expecting to manually jog.
Thinking the first board was surely carved totally wrong, I was reluctant to do the second on figuring the boards would be wasted. I was quite surprised and happy to see them line up just as I had pictured in my mind.
Now working on next project which will be more involved and detailed (complicated) and kind of excited about what I think it will turn out looking like.

Wouldn't it be easier to use the Carvewright to make the cutouts outs using 1/2" MDF and mount it on another piece of 1/2" MDF? I do it for most of my sleds.