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How to choose depth of profile when ordering molding cutters?

Trboatworks

Diamond
Joined
Oct 23, 2010
Location
Maryland- USA
All-

I need to order a cutter to cut a profile on a Williams Hussey molding planer.
I've just purchased the planer and have never used one.

Question:

How much depth of the profile is typical when ordering a knife?
This is for a simple round over as pictured below.
I don't really know how these things work- in a profile like this is the stick of trim cut to exact width first and the stock is fed to match profile, or wider stock fed in and sawn after to the shoulders?
Is there any advantage to getting a knife cut which carries deeper into this and cuts some more of the vertical?
Is that question at all clear?

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Thanks all
 
I don't really know how these things work- in a profile like this is the stick of trim cut to exact width first and the stock is fed to match profile, or wider stock fed in and sawn after to the shoulders?

I would not use exact width until I tested a board.

The cutters are just HSS. Deep cuts just for reducing vertical height? The little planer is going to be working hard as it is. I would not go for deep cuts in one pass.
 
I think the WH has a DOC limit on the machine of 3/4" or so. Anything greater may interfer with the rollers or housing. As the DOC and width of the cutter increases, the thickness of the steel might also need to increase.

Increasing the DOC to trim more vertical doesn't improve your life as the machine will need more passes and that just dulls the knives more quickly. I always prepare the stock to the correct dimensions with planed edges rather than oversizing and trimming. The two ends on your picture may or may not be sharpened and even if they are, there isn't much steel to dissipate heat or support the stress of the cut. Dave
 
You need to learn about extension of swing and stuff like that. And you need to learn how to make your own cutters and get a beefy shaper for that. Ever run 6" radius corner round moulding on a shaper? Big freekin knives and you lay on the floor when you first turn on the machine. Sounds like a helicopter in your shop.
Anyway, take a protractor to your cutter body and measure the angle of the cutter. Take the moulding you want to make and cut it at that same angle. Blue the cutter blank and scribe the angle cut profile onto the blank and grind away.
 
Thanks all.
In the end I just sent out a section of the profile I am matching to the W&H grind shop who made up the knives for me.
I sent no instructions...
I would have done this on the shaper but prefer the molder for what wider work which might come along and key to this job the molder will cut the curved rail sections I need without much fussing about.
 
Trying to do the vertical part is not the best idea. You would need to under cut the side profile (think of a saw with set teeth) to prevent burning, and unless super sharp, still going to burn. When it burns it also heats the knife.
Sometimes you just need to do it but better avoided. Never had to do it when I had my Weinig 5 head molder with cutter grinder. But sometimes had to do it when I was doing restoration work. I was hand grinding cutters every day for a whole summer. My Go To cutter bodies were a Frued steel insert set, and an old craftsman molder head for a small table saw, maybe 4" dia. I had several pairs of dummy profiles and only ground 1 knife to profile. I selected a dummy profile close enough to balance it. Shaper was a big machine with 1.25 spindle so it worked well. All was done with a power feeder. Still have all fingers too.
 
So a update on how this all worked out.
The old Williams & Hussey turned out to be a very nice machine and up to the task.
Though bought as a working machine I ended up completely tearing down the molder and servicing the bearings etc just to make sure it would get through the material run I needed.
I started the job and the cobbled together 1 hp motor the old shop had on it packed up as it was not nearly enough power.
So a slight panic to find a new motor in town and with that installed I finished the job in time.
The cutter W&H ground for me worked fine and to the point in OP they had ground the shoulders so I could run somewhat wider stock as I choose.
I finished planed to 1/16” over and that left just a slight sandable bur on each side.
So for my use I’m happy with this molder coming into the shop- a occasional 100’ run of rail stock plus the sundry interior profiles I run across.

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