Arched Crown with a router?

[Russell Tribby]

I have a display case that I have to build which will have an arched top. I need to top it with crown. I don't have shaper or a moulder, is it possible to do this with a router? I haven't looked too closely at outsourcing this yet but I'm not ruling that out. Has anyone done this before without the benefit of a shaper or moulder?

[Scott Rollins]

A bearing guided bit can create a cove moulding on an arched surface. You will be limited to a small selection of bits though. You could also carve out a shape with a 1" ball mill in a hand held grinder. This was illustrated on Woodworks in a dipaly cabinet. You can find it on Diynetworkdotcom.

[Chip Lindley]

I remember a jig in Fine Workworking mag which held the curved blank and let it arc past the cutter (like a clock pendulum) at the exact radius of the moulding needed. But, you are limited by router bits available to make a very wide crown moulding.

*IDEA*!!! Design a moulding which resembles crown, but is several pieces *stacked* together to give the illusion of a solid moulding. Each profiled strip can be routed in a straight line, then bent to form the curved *faux crown* you desire. Larger pieces could be steam bent to follow your radius. Might be worth your consideration, if a router and no shaper is available!

[David DeCristoforo]

You can attach your arched stock to a bench (hot melt.. heavy duty double stick tape, etc.). Then rig up a compass jig for your router. By using various combinations of bits and radius settings, you can get very close to your profile. Cove, bullnose (core box) and small straight cutters work well for this. Bits with pilots are problematic. You can also get a lot of different un-piloted bits with different profiles. Once you have gotten as close as you can, you can finish the arched piece with scrapers and sandpaper. I have a number of bits that have had the pilot ground off to enable them to be used in this manner.

[Russell Tribby]

You can attach your arched stock to a bench (hot melt.. heavy duty double stick tape, etc.). Then rig up a compass jig for your router. By using various combinations of bits and radius settings, you can get very close to your profile. Cove, bullnose (core box) and small straight cutters work well for this. Bits with pilots are problematic. You can also get a lot of different un-piloted bits with different profiles. Once you have gotten as close as you can, you can finish the arched piece with scrapers and sandpaper. I have a number of bits that have had the pilot ground off to enable them to be used in this manner.

This sounds doable. I thought about bending but I don't really have the space/time to build a box just for this one job. I'll have to take a look at the profiles I have to see what I can come up with.
I've included a sketch of what I'm shooting for. It's a golf ball display case for a customer that I've done work for in the past.

[David DeCristoforo]

There is also a technique that involves ripping two pieces of moulding into strips, offsetting the kerfs so that one complete piece can be stacked using every other strip from both pieces. These can then be laminated to form the arch. This is very difficult with a crown however, because of the angles involved. Also, (steam) bending mouldings is not always so simple because they tend to "roll" and deform because of the imbalance caused by the "missing" material (removed from square stock to form the moulding). I would think the "router compass" method would be your best shot here considering that there is only one piece of crown needed. If you were making multiples, that might be a different situation altogether.

[Joe Chritz]

The question isn't "can I do it?" but more can I do it reasonably and cost effectively?"

If this is a commission outsourcing looks very promising. A google search revealed several companies that specialize in just this sort of thing. Order the piece then build the unit to fit. Time is money in commission pieces.

Now, if you want to do for the sake of being able to do so that is another thing all together and I full understand.

Joe

[Russell Tribby]

The question isn't "can I do it?" but more can I do it reasonably and cost effectively?"

If this is a commission outsourcing looks very promising. A google search revealed several companies that specialize in just this sort of thing. Order the piece then build the unit to fit. Time is money in commission pieces.

Now, if you want to do for the sake of being able to do so that is another thing all together and I full understand.

Joe

Point well taken. I have a company that I've been looking at but I haven't looked into pricing yet. I have a friend who gets this type of work from a company in Cali and then matches the profile to the inventory of a local company for the straight stock. That may be the route I go.

[Peter Quinn]

In the back of most FWW classifieds there is a company called BH Davis custom moldings, he specializes in curved work, I have used his services and his work is great. Curves are his speciality. Might be worth a look if the commission supports a custom outsourcing. He has a decent web site (http://www.curvedmouldings.com/) He is local to me but ships nationally. I am not affiliated with him, just a happy customer.


Make sure to draw this one up carefully so the curved crown profile meets the straight molding correctly regardless of the method you choose. Perhaps a cradle approach with a crown cutter on the router might work? I have never tried it on a router but It might work with light passes and good hold downs?

[Gene DiNardo]

Russ,
I may be misunderstanding but, why not do it as you would a gooseneck moulding or a bonnet top.
Cut the shape on the edge of a board of suitable thickness and width,
rout the profile in stages,or at least get it close enough to be able to be cleaned up with a shop made scraper, then cut it away with a bandsaw.
Duplicate the profile for your straight returns.
Gene

[Lee Schierer]

I don't know how big or elaborate your molding will be but you can do it with piloted router bits. That's how I made this one!
http://home.earthlink.net/~us71na/kristin1.jpg
Cut the molding to size and smooth out the curve. Then rout the various edges. The one in the photo was actually done in two layers and then glued together.

[Russell Tribby]

In the back of most FWW classifieds there is a company called BH Davis custom moldings, he specializes in curved work, I have used his services and his work is great. Curves are his speciality. Might be worth a look if the commission supports a custom outsourcing. He has a decent web site (http://www.curvedmouldings.com/) He is local to me but ships nationally. I am not affiliated with him, just a happy customer.


Make sure to draw this one up carefully so the curved crown profile meets the straight molding correctly regardless of the method you choose. Perhaps a cradle approach with a crown cutter on the router might work? I have never tried it on a router but It might work with light passes and good hold downs?

Thanks for the link. I think I'm going to end up going with the company that my friend has used in the past. I plan on making a full scale drawing for the crown. I can't afford bungling that cut at the transition.

[Russell Tribby]

Lee, nice job on the bed. The crown I'm using is close to 5" so I decided to outsource this part of the job. Money typically isn't a problem with this client but time usually is. I'll have to learn how to do this at some other time. Thanks for sharing.

[Joe Chritz]

Lee, nice job on the bed. The crown I'm using is close to 5" so I decided to outsource this part of the job. Money typically isn't a problem with this client but time usually is. I'll have to learn how to do this at some other time. Thanks for sharing.

Wise man once told me you have three options. Good, fast and cheap. You can always have two but never all three.

Good luck, I can't wait to see the finished product.

Joe

[Peter Quinn]

Wow, I've been combining through my stack of old FWW mags, inspired by a discussion on another thread, and I just ran into an article about how to do a curved crown molding on......you guessed it, the RAS!:eek: never thought of that!

They used a 5" molding head and an interesting jig with multiple passes to create a stunning swan's neck crown in walnut for the top of a victorian high boy. Not sure the method would satisfy the safety culture that exists today, but it seems it will work.

If you have access to it check out Wally Kunkel's article "Curved molding on the RAS" in FWW issue 36. Might give you food for thought.