Daz told me to by one of these bits 50mm which I did but I only some times use it Bit

 

Flap disc on angle grinder

 

Sometimes I just draw a circle where I want it and just use the flap disc but

I do use clamps to clamp it to the work table so I don't sand off my fingers

Just make sure the concave is away from the nest hole so the hen won't jump on the eggs.

Good luck

Hey thanks Kaz But that hole you see is not the finish product, you need to use the flap

disc to carve your circle now. I start from the outside working in going around in the circle.

Edited November 1, 200816 yr by KAZ

Here is a the hole half way through using the flap disc and the finished, notice that the wood is clamped down so it doesn't move and I used goggles to protect my eyes. I even round off the end of the false bottom that sticks out of the nest.

 

 

 

 

Edited November 2, 200816 yr by splat

My nest box has the concave under the box hole. Whats going to happen to that? Thats how I brought it.

Great job Splat

Great job Splat

 

Only thanks to you Daz

Probably a dumb question but just wondering why you couldn't just drill the circle out using the first drill bit and leave it at that. Why the need to smooth out the edges?

Probably a dumb question but just wondering why you couldn't just drill the circle out using the first drill bit and leave it at that. Why the need to smooth out the edges?

It's for safety reason's ...so bird's cant injure themselves on jagged edge's... and beside's it make's it look more neat & tidy

Probably a dumb question but just wondering why you couldn't just drill the circle out using the first drill bit and leave it at that. Why the need to smooth out the edges?

Sharpish edge......hen and an egg between her and the sharp edge.......broken eggs. Concave means eggs stay in the middle and no damage as such and depth is better.

great post splat

back to what this sights all about showing and teaching

did it take long for one

by way excellent job pat yourself on back

Recently when making my nest box's I also found making a concave something of an issue.Every hardware store I approached told me there was no such tool and that I would need to chisel it out myself.With thirty plus to do that wasn't going to be easy.

 

Fortunately I was put in contact with a member of the BSSA in Adelaide who shared with me his method and kindly did a run of them for me using a Rotary Saw.

 

Firstly he created a timber template with a hole in the centre for rotating and then placed my intended concave secured in the centre of the template.

 

Once secured he lowered the saw down in contact with the wood and rotated the template creating the circular concave pictured.

 

I was extremely thankful and somewhat amazed by this older chippy's speedy skill at doing something I was told couldn't be done.

 

I should add this method is not recommended for safety reasons in todays work shops.

 

Also sorry if my explanation isn't quite clear.

 

Most importantly the birds seem to like them!

 

http://i744.photobucket.com/albums/xx85/je.../P1020409-1.jpg