Making Curved Crown Molding.

09/29/2017


From original questioner:

I have a library job to do that is going in a round room. I was able to create the parts for the casework but I would like to machine the crown out of solid stock on the CNC to conform to the casework.

On caveat, all of the bookcases have finished ends and I would like to machine the crown with the 90° return rather than making the piece long and field cutting the curved piece on site.

From contributor Pa


The curved crown will have to match the straight crown. I have done this, it isn't really too hard if you have the equipment.

I lay up the solid stock, cut it with my CNC to match the shape and run it through my Micron molder. I also have a Weinig molder, so I use the same knife to run both the straight and curved crown. If the crown is an outside curve, that can present some issues.

Just for reference, I charge a $1,000 per arched crown. Also, plan on cutting the miter on site and make the crown long.

From contributor DJ


Thanks.
I can outsource to Walzcraft or a local millwork company but I would prefer to machine it in house instead as that would be more custom.
I don't have any molders or other millwork equipment.

From contributor Pa


When I think of a Library, curved crown, in a home, I think wood and more wood. If you visit my web site, we show a library with a curved wall, curved crown and everything that goes with it. We got about $90,000 for that room and that was 10 years ago. There is no way I could possible do that room or any library I can think of without woodworking equipment.

If there are wood moldings etc in your library and you are going to do the job, I would suggest you partner up with a local millwork shop. Also, most millwork shops do not do finishing and if you do find a shop you can work with, make your decision based on the quality of their product, not price. You can burn through a lot of time and money sanding poor quality moldings.

If you do not know how to judge the quality of the moldings, hold the molding up, pointing it toward a light in the ceiling and look at the cut. Chatter, etc will jump out at you. Another thing you can do is to close your eyes and run you hand along the molding. With your eyes closed, your feel will be more sensitive and you will feel the chatter etc.

Good luck.

From contributor ja


I can and have done curved Crown on my CNC with a 2 rail sweep file in 3d. if you have and use a program capable then you can do this. it has been a few years for me as we went all commercial in 2010. It is fun to learn yet easier to outsource if you are not set up to do radius crown, (IE a marcon type moulder) the question is how much how often will you do this. Sell one job, then if you get another consider the machinery. Below is a 24" diameter file i did some years ago

From contributor DJ


Paul,

I have gotten by just fine in the past 20 years with the equipment that I have in the area I live. I had quite a bit of equipment until a health issue caused me to close my shop a few years back. I was able to recover to the point where I am getting back on my feet but can't do it all right away due to the cost of that situation. A builder that I have worked for for years needs this project done as the guy they originally hired walked away and left them high and dry.

I have a CNC which is perfectly capable of doing what I am looking to do, I just do very little if this type of thing so I am looking to outsource the programming part to someone who may have more experience in doing it so I can focus on the rest of the things I am doing.

From contributor ja


There are some parameters, What machine do you have (Post Processor) do you have a dxf of the profile in full scale ?

From contributor DJ


I do have a dxf of the profile created in fusion360. I also have the radius of the curve which is 81".