OK... this post was buried in a Project Announcement thread that isn't even mine. Initially I didn't want to start a new thread since I don't have detailed drawings/measurements but after receiving several PMs I've moved it here.
I will take some measurements tonight when I get home so people can copy this but there's nothing fancy to it. I basically looked at the one mountain used to make his jukebox and tried to copy it.
PART 1The first thing I did was lay out the pattern I thought would work.
Then using a combination of my jigsaw and router with flush cutting bit and a straight edge I cut out the shape. Finally, I cut out a second piece about half the size using my pattern cutting bit.
This last pic shows how the two pieces will fit together.
I still have to cut out a block and drill a hole in it for the pin. This block will slide up and down in the center groove. I'll also cut a smaller groove in the smaller panel (just wide enough for the shaft of the knob to fit through which will be used to tighten the block/pin into place).
More updates to follow.
PART 2The next step was to cut the 1/4" slot for the smaller panel. This was a bit tricky to set up with my router due to the small surface area of the panel but I managed to figure it out.
After that was done I glued it to the larger panel. The brown board in the middle is a spacer to make sure the groove stays at 1/4" wide during the glue-up.
Next, once the glue dried I used my router and a round-over bit to smooth over the edges of the jig (purely for decorative purposes).
The final steps will be fabricating the center block with the knob and pin which will slid in the groove. Then I'll drill the holes for mounting the router.
Almost finished!!!
Finally some progress. I was on vacation 2 weeks ago and then last week I was working like crazy to catch up AND I had the stomach flu so I got nothing done. I was able to sneak out of the house yesterday and mess around in the garage.
PART 3The next step for this jig is to drill holes in the circular section so I can secure the router in place. The placement of these holes depends on the location of the screws on the router's base plate. It was actually pretty easy to do.
First, I removed the plate from the base of my router's plunge base. Then I clamped it into place with come spring clamps. I just eyeballed the location here. Next I drilled three holes all the way through the material for the three screws which will hold the router in place.
Next, I drilled out around the holes using a foerstner bit - this provides room for the screw heads so the base can lie flush with whatever you are routing. Also, the MDF is considerably thicker than the plastic base plate so I had to drill down about 3/8" in order for the screws to have enough length to poke out of the bottom and grab onto the router. Go slow on this part and remove a little material at a time and check the screw position. When you are satisfied that there is enough of the screw sticking out of the MDF to grab onto the router you can stop drilling down. Make sure not to go too deep. Repeat this for all three holes.
That's all there is to securing the router in place. It's pretty easy if you have the right tools (isn't everything?). Anyway, here are some shots of the router secured in place as well as a sneak preview (in the last pic) of the sliding mechanism for adjusting the diameter of the circles which I will explain next.
One more step and this thing is finally finished!
PART 4One of the last things to for this jig was to manufacture the sliding mechanism for adjusting the radius of circles I'll be able to cut. I cut a small block out of MDF which fits in the large slot and lays flush on the bottom of the jig. I had to do a bit of sanding to get it to fit in there properly - I didn't want it to be too loose in there - a snug fit works best. As you can see from these two pictures, the block slides up and down the channel on the bottom of the jig.
With the block in place, I drew some lines on it through the smaller 1/4" opening from the top of the jig so I would know where to place the screw I will use for locking the block in place. It's not exactly centered but it doesn't have to be (although you should aim for that if you decide to build one of these yourself).
The next step was to drill a hole in the area I just laid out. This will be for the locking mechanism which is just a screw on the top and a tee nut on the bottom.
Next, I flipped the block over and used a foerstner bit to countersink the tee-nut so it is flush with the bottom (or even a little recessed). I had to tap it in pretty hard with the hammer.
As you can now see, the screw goes in the tee nut through the top of the jig and locks the sliding block into place. SO when I'm using this thing all I have to do is measure the distance from whatever router bit I'm using to the center of the pin and that will be the radius of the circle. Easy!
This shot from my last post shows the (almost) completed jig. I cut out a handle of sorts to help me slide the block up and down the jig as well as enable me to lock it into place.
Here is a random shot of some of the supplies I used in case anyone is interested:
I'm almost done. The final step is just to drill a hole in the block for a #10 nail which will act as the pivot pin. Unfortunately, I don't have a drill press and it is imperative that this hole be exactly perpendicular. Any deviation will throw off the radius of any circles I try to cut! I think I figured out how to drill the hole but that will have to wait until tonight and then I can test it out!
PART 5 - COMPLETE!After way too much time working on this thing I am finally ready to start cutting some circles! The circle jig is complete. The last step was to drill a hole in the sliding block for the nail which acts as the pivot pin. Drilling the hole was difficult without a drill press. I bought a drill guide but it was totally useless.
After finishing the jig I had to test it out. First, I drilled a 1/8" hole in a piece of scrap MDF for the pivot pin which acts as the center of the circle.
After placing the pivot pin in the center hole, I laid the jig on top and adjusted the radius of the circle until I had the size I wanted. Then I tightened the screw to keep the sliding block in place.
Next, I turned the router on and plunged the bit into the work piece. Finally, with one hand on the router and the other hand on the jig near the pivot pin to keep everything in place, I used the jig to cut out a circle!
Easy!
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Topic: How To Build A Circle Cutting Jig For A Router [COMPLETE] (Read 27699 times)
