We are being asked to make a hybrid door with wood stiles and rails and MDF raised panels.

I could certainly cut the blanks on the router and raise them on our existing door equipment (with separate tooling) but I was wondering if I could raise them in the nest and route them out to size. There would be a lot of waste on the opposite side of the raise but the labor/handling savings should easily offset it.

Is this possible? The second set of tooling is quite expensive so before I took the plunge I thought I would explore all options.

Any help is appreciated.

It will be interesting to see what others have to suggest on this but it seems to me that a single RP cutter is going to be taking an unreasonably large amount of material out in a single pass. The size of the cutter shank and the dust collection both would be areas of concern needing to be addressed. Unless you had an aggregate head that would hold a shaper cutter you are probably also talking a custom cutter/bit.

A better solution might be to have custom cutters made that did the RP with two smaller bits..........one to cut the inner portion of the RP profile with the lip up to the center field, and then one to cut the outer section of the detail and (typically) 1/4" thick panel edge. This will reduce the stresses on the cutters (bits) making for more reasonable shank size, reduce the amount of dust generated while cutting and significantly cut down on the waste area. Since the single cutter idea would likely require multiple passes anyway this system might not even take any longer to produce the panel.

BH Davis

Thanks for the reply. After I posted that I came to the same conclusion. That would be several custom router bits. I still think it would be a net savings as far as labor and perhaps tooling.

I’d still like to hear some input from people who make mdf doors.

Bill,

This is actually a good way to make a set of doors. I did it myself a while back on some paint grade doors. 1 3/8" poplar frames and 1 1/4" MDF for a double sided panel raise.

The benefit is the stability of the MDF panels. They do not cup or expand and contract thus leaving no chance for call backs on unpainted exposed panel edges. The only thing I'd do different now is use soft maple instead of poplar for the rails and stiles for better frame stability.

BH Davis

As I consider this more I wonder if I can get a good enough finish on a router? I know it is good enough for RTF doors but paint hides less?

My only concern would be the overlap of the various bits. You should be able to work with your customer tooling shop to design a clean cutting cutter set. The cutting diameter won't be as large as a shaper cutter (large cutting diameter = cleaner cut) but personally I think it should be more than adequate.

Being MDF though some sanding will most likely be required. Then a good MDF primer such as ML Campbell Aqualente will help a lot.

BH Davis

we can do it very easy one click with
polyboard + knest

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View higher quality, full size image (1366 X 768)

View higher quality, full size image (1366 X 768)

Nearly any nesting router with accompanying software can do this. The rub is how you value the TIME. You could get some custom cutters or use the software you already have to model the profile and cut with existing bits. if you have a small end mill and a small ballnose, then you can cut nearly any profile you like. If the stepover is small enough, it'll be ready for paint. BUT, this approach will take time on the table. How many of these door panels do you need to cut? How busy are you on this machine? If you buy other cutters for these, how fast will the cost offset be recouped. All these questions will be unique to your shop and the job in question.

There are plunge cutting raised panel bits, but they are hokey IMHO, but they make panels quickly. I've run the end mill/ballnose approach with tiny stepovers and made beautiful panels, but they take a few hours a sheet to do. I know that I can maneuver my work around the time on the table so I don't mind. I'm also only doing at most a few dozen of these. Just my experience. I think running a typical shaper style panel raiser (huge) on the CNC is goin to be wasteful because of the overcut on the opposite end of the cutter (material and tool life).

Not being a door guy, I don't quite get all the terminology.

Can you post a profile?

I would not go at this with a ball nose, this is production. We would write the software in house to put the parts and nest the blanks out.

I would have multiple bits made to make all the profiles I need. There is a link to show how tools of that nature work. I would not make a complete MDF door just the raised panel

Shown are generic raised panel profiles.

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Examples of MDF panel cutters