I show how to make an easy adjustable Circle cutting jig. Having a something that you can cut round profiles with in your shop is important. In this post I'll give you the easy step by step instructions to make one for your router.
Materials Used
1/4" MDF
Tools Used
1. Cut Material To Width, Drill Holes
I started off by cutting the MDF to the width of the base of my plunge router then i removed the base of the router and used it for the reference holes so I knew exactly where to drill the holes for the screws and countersink them.
I used the head of the screws to determine how deep to countersink them and then counter sunk and drilled the holes
2. Route Track For Pivot Point
I needed to use my plunge router but I needed to create a template or a mold for the plunge router to slide into and not be able to move. Once I had a nice looking mold for my router to slide into I got my plunge router all set up to the correct depth using 1/2" router bit and I routed a dado into the MDF about 1/8" deep.
then I cut a through dado right in the center of that 1/2" dado with a fourth inch router bit this will allow the screw for the assembly piece to go through the middle of the track creating a pivot point.
3. Pivot Assembly... Assembly
Here is everything you need to get the pivot assembly setup!
To get the brass piece set inside the knob you're going to heat it up with a blow torch on the screw that screws into it.
And then just put it inside the knob and pull it until it gets all melted in there eventually the plastic will harden up again and you'll have a perfectly set little knob with the right screw size
The post cap is a little long so I cut it with some of my bolt cutters and then sanded it down so it wasn't so pointy and rigid.
4. Drill Hole And Attach To Router
Next it was time to drill a hole through the top for the router bit to plunge through this method was super easy i just used one of my Forstner bits to mark a hole and then used my drill to drill that hole through.
Next I got my router all set onto the router plate it's easiest to do this kind of upside down by putting the first few screws in and then you can flip it over and finish up tightening it to the router.
5. Set Distance, Stick on Sticky Tape Measure
I just used a scrap piece of wood and drilled a hole where the pivot point started and then plunged my router bit down into the piece of wood this gave me two holes that I could see the distance between these two holes.
I could see the distance between these two holes and set my tape measure correctly now. Obviously this distance is the radius of the circle not the diameter so wherever I put the pivot point the circle is always going to be two times that size these. sticky tape measures are pretty easy to apply you just peel back the sticky back and press it on.
6. Cut A Circle
I was super excited to test this thing out I found a scrap piece of plywood and found the center of it with the straight edge I drilled a hole right in the center for the post to go into.
Then I got the router all set up to the right radius, and then just started to make my circle.
I'm super excited to have this in my shop I can finally make round cutting boards and really anything that has a round profile on it. There are a lot of jigs that you need in your shop and I would say that this is kind of one of those ones that's at the top of the list. It's important to have something that you can cut around profile with and this jig does the trick!