Forstner Bit

[Birdhunter]

I need a 40mm Forstner bit to mount a couple of MagSwitches. I have a set of Festool Forstner bits and I think they are fantastic but the set ends at 35mm.

Does Festool sell a 40mm bit? I doubt Festool makes the bits so, perhaps the maker sells the 40mm.

 

[chrisrosenb]

A 1 9/16" bit will work.

Carbide bit

Steel bit

 

[Cheese]

Zobo bits which Festool uses, provides bits from 15 mm thru 130 mm in 1 mm increments.
https://www.timbertools.com/ZOBO-System-3-CHROMIUM-drill-bits-METRIC-31-50-mm.html

 

[Imemiter]

Highland sells a 40mm CMT Forstner bit for $16usd

 

[ChuckM]

I use whatever bit I have that fits loosely as JD2720 suggested. The Magswitches are screwed down anyway.

 

[Birdhunter]

Thanks everyone. I found a 1 9/16 in my stuff. I’ll try it.

 

[Birdhunter]

The 1 9/16 didn’t work. Too tight for the MagSwitch to go in. Bought a 40mm from Highland Woodworking about $16. Perfect. Could not justify the $140 for the Zobo.

 

[Svar]

I use rabbeting router bits to enlarge holes to desired size. Drill with Forstner, rabbet referencing from the edge of the hole, repeat from the other side if needed, trim with flush trim bit. Right combination of starter hole and rabbet width usually gets you very close to what you need.

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[HarveyWildes]

The 1 9/16 didn’t work. Too tight for the MagSwitch to go in. Bought a 40mm from Highland Woodworking about $16. Perfect. Could not justify the $140 for the Zobo.

Glad you found one for a price in line with the intended use.  I needed one for two MagSwitches, and ended up with a Roman carbide bit from Amazon.  It did the job.

 

[PaulMarcel]

I got mine from Woodcraft. "WoodRiver" is their store brand. You can order them online if a local Woodcraft store isn't available: WoodRiver 40mm Forstner Bit. I only use it for my large MagSwitches.

 

[Birdhunter]

I was building a jig fixture for easier aligning my 8” jointer.

I was using a 48” by 2 1/2” Steel Starrett straightedge to measure coplaner. I had about 1 foot on the outfeed table and 3 feet suspended over the infeed table. Then using a dial indicator to measure between the top of the straightedge and the top of the infeed table.

My first jig used MagSwitch 95 units to hold the straight edge firmly against the outfeed table. But, the cantilevered weight of the straightedge was too much for the 85s to hold.

I modified the design and switched to the MagSwitch 150s. That worked.

I can move the straightedge anywhere on the table, clamp it and it stays stuck down hard.