How to cut an inner radius

[Raymien]

After a bit of advice please. I've been asked to make one of these, which is simple enough, but I was wondering how you guys would go about cutting the inner radius on the panels?



They're 40mm radius. My initial thought was to make a template and then use this with a flush trim bit on the router. Is this the best option? Am I missing something better? I've looked online for router templates (to remove the pressure of creating the perfect template) but can only find ones for the outer radius, not the inner one that I need.

Any advice?

Thanks

 

[Bigegg]

40mm hole saw, then cut the straights

 

[Gordon Tarling]

He'll need an 80mm hole saw to cut a 40mm radius.

G.

 

[Bigegg]

He'll need an 80mm hole saw to cut a 40mm radius.

G.

oops

 

[Raymien]

Bloody hell. Of course!! Thank you. I knew there was a reason I posted on here

 

[TRITON]

I'd make the template, that way its all the same and theres no f'ing about should something go off by just a smidgen.
Then you can hang the template on the workshop wall which as we all know looks very professional

 

[Fitzroy]

Templates all the way for me too. Double sided tape is awesome for holding templates whilst routing, if you didn’t already know.

 

[doctor Bob]

Do you need the radius, I'd do it as a 5 piece door.

 

[Raymien]

Do you need the radius, I'd do it as a 5 piece door.

I would normally too, however I’ve been asked to replicate an existing piece with one exactly the same. The existing has the radius as a design feature so I have to add them.

The cut outs at the top and bottom have the radius too, I’ve just not drawn them in.

 

[Droogs]

40mm radius is rather large, definitely not 40mm diameter; especially if the cutouts are the same radii

40mm radius is counter top territory

 

[Raymien]

40mm radius is rather large, definitely not 40mm diameter; especially if the cutouts are the same radii

40mm radius is counter top territory

The customer sent me measurements of the existing one and the cut outs are 45mm deep, so I’ll need a radius of 40-45mm.
The image I shared is drawn to scale in SketchUp, with the dimensions of the other components given by them and those radius are 40mm. I’m thinking an 86mm hole saw to make a template and then router the panel from that. Removes the pressure of having to drill each ‘radius’ in exactly the right spot.

 

[Droogs]

In that case I'd suggest the below for the radii and then router with top bearing straight bit for the rest

https://www.amazon.co.uk/Adjustable-Hole-Circle-Cutter-120mm/dp/B00BL17I5C

 

[AFFF]

Forstner bit, been there - done rhat

 

[Bigegg]

Forstner bit, been there - done rhat

3¼"?
That's a BIG Forstner bit.