Thread: Circle cutting jig for router table

I would have thought that the router bit should rotate in to the timber (or against the rotation) to avoid tear out. The other way it's climb cutting. Same as any normal cut isn't it ?

Originally Posted by Gumby

I would have thought that the router bit should rotate in to the timber (or against the rotation) to avoid tear out. The other way it's climb cutting. Same as any normal cut isn't it ?

So you are saying anticlockwise?? This just blows my dust extraction as the dust comes out the back- ie towards me (I have a port to catch the dust from the front when I am trenching)
Back to the drawing boards with my dust extraction on the router table??
Thanks
Gumby

If you've got the video, it's on that. It's the same as feeding timber straight across the table, as you do normally from right to left. That would mean anti clockwise.

Barry Burgess,
Any chance of a pic or a description of your jig ?? please

There's one in the latest newsletter (August edition)

www.tritonwoodworkers.org.au

just a board, clamped to the table with a nail coming through very sligthly from underneath to create the pivot point.

Ahh, the KISS principle..... I like it, thanks !

P.S I couldn't find anything in the August newsletter...

"There's one in the latest newsletter (August edition)"

Originally Posted by Pestmaster

Ahh, the KISS principle..... I like it, thanks !

P.S I couldn't find anything in the August newsletter...

"There's one in the latest newsletter (August edition)"

It's on the top of page 9. It has a photo of one used to cut the chipboard rings. It's only a short reference to it but the photo will give you the idea of how it's done. This one shows a bandsaw but the principle is the same.

Originally Posted by Gumby

I would have thought that the router bit should rotate in to the timber (or against the rotation) to avoid tear out. The other way it's climb cutting. Same as any normal cut isn't it ?

Gumby,
surely it depends on which piece you are going to keep. if you are keeping the frizbee from the middle its the opposite way from if you want to keep the board with the circular cutout. one side of the blade is climb cutting whichever direction you rotate the piece, if im not mistaken.

No Doug I disagree. (sorry )

On the bandsaw or jig saw in the Triton table, you can make the cut from just about any shape but let's say it's from a square bit of stock. You just rotate it around and make the cut. On the router table, most of the cut should be done initially with a jigsaw by hand to get a rough shape and the final bit on the router table is a trimming operation using a circle jig. Like Sir George used in the video. Or it could be done using a flush trim bit with a round template underneath. I'm not saying that the whole cut should be made on the router table. It could be done that way I agree but I don't think it's the best way.

Originally Posted by Gumby

No Doug I disagree. (sorry )

On the bandsaw or jig saw in the Triton table, you can make the cut from just about any shape but let's say it's from a square bit of stock. You just rotate it around and make the cut. On the router table, most of the cut should be done initially with a jigsaw by hand to get a rough shape and the final bit on the router table is a trimming operation using a circle jig. Like Sir George used in the video. Or it could be done using a flush trim bit with a round template underneath. I'm not saying that the whole cut should be made on the router table. It could be done that way I agree but I don't think it's the best way.

i follow what you are saying gumby, my post above was assuming cutting either a circular hole or a circular disk in something thin like, say, mdf up to about 6, maybe 9, mm thick. obviously with thicker material it would be roughed out with something and finished with the router. i havent seen the jig under discussion and assumed it was cutting the circle in one or several passes of the router from untrimmed stock, in which case one side or other is being climb cut

Originally Posted by Pestmaster

Barry Burgess,
Any chance of a pic or a description of your jig ?? please

attached picture its simple as gumby said but needs to be well fixed to prevent movement as a fair amount of pressure is applied far more than if using a band saw.

Originally Posted by Gumby

No Doug I disagree. (sorry )

On the bandsaw or jig saw in the Triton table, you can make the cut from just about any shape but let's say it's from a square bit of stock. You just rotate it around and make the cut. On the router table, most of the cut should be done initially with a jigsaw by hand to get a rough shape and the final bit on the router table is a trimming operation using a circle jig. Like Sir George used in the video. Or it could be done using a flush trim bit with a round template underneath. I'm not saying that the whole cut should be made on the router table. It could be done that way I agree but I don't think it's the best way.

It was a quick and dirty for me as I needed to cut 2 circles for a lid of a 60litre drum to make a dust bucket. I was using 12mm laminated chip board(scrap) and just cut it square on the saw. I did four passes (3mm) each to cut the circle. I did the first circle anticlockwise and the results were just about OK so I did the next clockwise with about the same results hence I asked the question. I think the problem was the chip board - I should have used MDF but did not have the size.

Thanks Barry and Gumby !

I posted this some time ago in another thread but it sems it may be worth repreating...
Had to build a wind chime for SWMBO and I came up with a jig similar to that mentioned in this post. I needed a 200mm dia piece to suspend the chimes from and a 100mm dia striker both of which I roughed out with the jigsaw from a piece of 18mm kwila. The 200mm piece worked a treat but there was lesson to be learned when trying to finish off the 100mm striker. Because of it's smaller size the roughed out piece was "rougher" so there were more lumps and bumps on the circumference. The smaller diameter also meant that more pressure was need to keep it feeding past the cutter. I was about a quarter the way around this piece when a high spot caught the cutter. The piece was immediately spun up on the jig to several thousand rpm. Finger tips pressed firmly agianst the piece copped a real beating!!. Lots of brising and blood oozing from pulpy finger tips - so be careful folks. I suspect there's a minimum safe diameter for this type of job and I think 100mm is probably on the wrong side of this