Best Festool way to cut a perfect circle?

[Grasshopper]

I was all ready to start cutting circles using my MFS700 for the first time, and I realized I must be missing something.

What do y'all use as a "template guide" or "copying ring" and what size to keep the bit from grinding on the MFS guide (pictured below):

[attachimg=1]

And is this easy to find (i.e. do i have to order this, and if so, what is an alternative way to cut this?)

I may attempt a jig if this is a special order item.

I considered the Carvex circle cutting jig, but it seems to not be reviewed too well (and would be money wasted if my MFS could work).

Thoughts?

 

[Phil Beckley]

Hi
You need a 30mm copy ring on the base of the router which can be O.F.1010 (the copy ring will need to be centered) , O.F.1400 maybe a bit big but also the O.F.2200.
rg
Phil

 

[butzla]

Just invest .80 in a longer screw for the parallel guide knob.  Nothing to it!

 

[Grasshopper]

BRILLIANT!!!

Thank you a TON.

By the way, your profile picture is awesome.  It was like getting a response from Nick Offerman!

Just invest .80 in a longer screw for the parallel guide knob.  Nothing to it!

 

[JCLP]

Great idea Jim. Thanks for sharing. Will definitely use it for a project coming up in the new year.

 

[ear3]

What bit are you using (or the optimal bit for circle cutting)?  I was going to be making some circles myself with the 1400.

Just invest .80 in a longer screw for the parallel guide knob.  Nothing to it!

 

[butzla]

Glad to help, guys.  The plastic knob splits for easy access to the screw.  I'm not sure of the size, it's metric.  Just bring it to Home Depot and get one about a 1/4" longer.  I also bought some longer rods for larger circles.  1/4" will work.

 

[butzla]

What bit are you using (or the optimal bit for circle cutting)?  I was going to be making some circles myself with the 1400.

Just invest .80 in a longer screw for the parallel guide knob.  Nothing to it!

I use a 1/2" shank, 3/8 diameter up cut spiral bit (Whiteside RU4900).  Woodworkersworld.net is a great source.  Free shipping over $30.

 

[Grasshopper]

I just got back from the box store.  The size is M6 for those who want to know.

After setting it up, it works pretty slick….

…unfortunately it will only do larger circles.  Looks like the tightest radius you can do is around 7 1/2" or so.

I need a way to cut a 6 3/4" circle.

Any other thoughts?

 

[nclemmons]

If you want to cut a small circle, watch this video on the MicroFence attachment.  I have the unit and it's great for circles.  You could easily made a similar attachment for the 1010 or 1400 router that would slide on the two rails and allow you to make a circle with a diameter that is smaller than the base of the router. 

Take a look and see if it makes sense.  You could certainly purchase the full MicroFence solution, but if you are only cutting a couple, it's certainly easier and cheaper to make up a simple jig.



neil

 

[teocaf]

microfence is very cool.  but if you already have the mfs 700 then you just need the 30mm copy ring (if you're using the OF1400 router, the part number is 492185 and it's $15). i also saw that infinity tools has a circle and oval jig for the router but i believe they're backordered until mid january.  does anyone have any experience with the quality/accuracy of the infinity product? 

 

[Throwback7r]

I just use the carvex and the circle cutter. It works for what i need to do .

 

[Grasshopper]

Thanks to both of you.  I just ordered the 30mm copy ring for the future.  I still may come up with a jig in the interim so I can just get this build down the road.  We shall see.  Maybe it will ship fast, fingers crossed!!!

Hi
You need a 30mm copy ring on the base of the router which can be O.F.1010 (the copy ring will need to be centered) , O.F.1400 maybe a bit big but also the O.F.2200.
rg
Phil

microfence is very cool.  but if you already have the mfs 700 then you just need the 30mm copy ring (if you're using the OF1400 router, the part number is 492185 and it's $15). i also saw that infinity tools has a circle and oval jig for the router but i believe they're backordered until mid january.  does anyone have any experience with the quality/accuracy of the infinity product?

 

[Grasshopper]

Update,

I flipped the parallel guide handle around, which brought the 6mm screw closer to the center of the radius which brought the radius down.  This will now work for my 6 3/4" circle.

Thanks again for the tip!!!

 

[Grasshopper]

OK,  next question. 

What do y'all do to cut a really small circle?  (say 2 1/2" diameter).

From what I can tell, the MFS will be limited to a 3" diameter for it's smallest circle.

I ran to the big box store and bought a hole saw bit and was appalled by the amount of tear out on my scrap piece.

Surely there is a better way...

 

[Stoli]

Templates?

http://www.ptreeusa.com/router_jigs_templates.htm#1057

 

[teocaf]

a forstner bit should cut much nicer for you.  festool has the top end Zobo set, but you should be able to get individual bits at the store from brands like milwaukee, dewalt, etc.
or you could sandwich the material you're drilling with your hole saw bit tightly between two sacrificial pieces of wood to reduce tearout top and bottom.
there's also the annular cutters like you would find for a mag drill.
or make a larger pattern with your mfs that will accommodate a uniformly circular router base.
edited to add:
i saw you already worked it out but i just thought of another way:  an adjustable radius fly cutter for your drill

 

[Grasshopper]

OK,

So I went to the box store, and paid up for the better hole saw bits (2 1/2" and 1" sizes).

I drilled 1/2 way through from the bottom side first, until the pilot bit came through.  I taped the good side with painters tape and flipped the plywood around and used the hole saw bit IN REVERSE to plunge through the "keeper" side.  This completely eliminated tearout and came out looking just right.

Thanks again for all your help!! 

Couldn't have done this without the FOG!