If you wanted to make enough trim to do a bedroom suite or a coffee
table, the molding head for a table saw might work OK. I have one, I
used it, I hated it. Not just a little, either.

1) When mounted on a ts, the head doesn't spin fast enough to cleanly
cut the wood. If you hit a tiny irregularity in the wood (that would
look good finished) you will have tear out, chipping, and in some
cases, this will be where the blade grabs your piece and goes for
launch. Make no mistake, either - unless your pieces are about 6 ft
long or less, this is a 2 man operation due to the necessity of
holding the materail perfectly agains the spinning head

2) If you are running presized material through the ts (like a 1X2),
then you have to use hold downs and featherboards on it (you should
anyway) not just to avoid shooting out of the shop, but when this head
hits the tougher areas of wood, it cuts slower and will lift the wood
away from the cutters, giving a more shallow profile

3) It is painful to sharpen the cutters, and they don't stay sharp.
Since the blades go slower and by their design don't cut as well, they
get dull MUCH faster. This is the death of your profile. If the
cutters get dull and you continue to use the tool, you will screw up
your material. When you sharpen, it will change the profile a little,
just a little, but sometimes that is too much. It is OK for some
ceiling moldings, but if you are matching trims on kitchen cabs it is
unacceptable

4) Even when mine was new, the blades were sharp, and the sun was
shining and the birds were singing, it didn't work well. The end
product didn't look really finished or consistent in the profiles.
The details of the profile were never really sharp and cleanly cut

The only one I know that still has this is one of my hardwood
suppliers. You leave him a drawing or a piece of molding you want
matched. He will take it back to his guy that will convert it to a
file for the CNC mill that will make the correctly profiled blades.
It is not cheap.

I ONLY do that when I have a remodel in an older home and we have to
match moldings.

I agree with the other posts, but with small difference. For a small
run, I buy something as close as possible to what I need. For a
medium amount of trim, the same. In fact, for all the trim, I buy
it. I have no clue how anyone makes money milling unless they can
really get their price for it.

Seriously though, if I were to have the urge to make moldings, I would
make small projects (a few cabinets) on my router table which has a 3
hp, 1/2 shank collet on it. I wouldn't consider anything smaller.

For a more than that, I would purchase a shaper. If you have a
sizeable order and will continue to use the machine, why not buy a
medium sized machine? The machine and cutter heads are expensive to
get into, but to me worth the quality of the end product you get for
the investment. Plus... it is much faster.

I don't know what is sizable to you since you didn't say. But the
last house I trimmed that had all custom molding inside had about 4500
+ of of molding in it. Two piece crown, two piece base (the six inch
with the colonial dust cap on it), 4" door jambs, profiled window
stool (think table top profile) with apron, etc. You get the
picture. To me that would have been a sizeable order to make. But to
trim out a house like that, it wasn't really that big of a job; the
house was just a bit under 3000 sq ft, so it wasn't like I was
trimming a monster.

For that much molding/millwork, a shaper is the ONLY way to go.

At this point with my experience with them, I would consider money on
one of those molding heads a complete waste.

Robert