Having trouble finding the 90 degree bit in a jig

[Mike58]

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



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.
The 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!