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In The Small Shop #1: Making Molding with a Molder Head

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Blog entry by bkhop posted 2149 days ago 5675 reads 2 times favorited 3 comments Add to Favorites Watch
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This tutorial is for setting up a molder head and creating molding on a Shopsmith Mark V, Model 520. Obviously, much of the information here can be “translated” to a different model Shopsmith or even to a stand-alone table saw. When done properly, with proper setup and appropriate safety precautions, using a molder head on a table saw is perfectly safe and produces beautiful molding. I couldn’t even begin to guess how much molding I’ve created for window frames, picture frames, case moldings, etc.; I’m guessing somewhere in the neighborhood of about a thousand feet. If you’re making your living by cranking out custom molding, then yes, there are quicker ways to produce mass quantities of molding (but it comes with a price tag!) If you’re a hobbyist or amateur woodworker, however, the molder head may be just the ticket. If you’re wondering, also, why such an “archaic” tool hasn’t been replaced by the router… well, I’ll answer that in the tutorial – but let it suffice to say that the router has its place in my shop, too. The molder head, though, has more versatility is a couple key areas. So, let’s get started…

Sharpening the knives

The first thing to consider is the knives. Any seasoned woodworker will tell you that if your chisels, for example, aren’t sharp, your job is more frustrating, time-consuming, and downright dangerous; the same is true of saw blades, router bits, and so on. –Molder knives are no exception.

Sharpening the molder knives looks like it ought to be a rather difficult task – in fact, I wonder if a lot of woodworkers don’t bother trying a molder set because they think sharpening the knives might be overwhelming. Well, here’s some good news! If you’ve got a set of sharpening stones, you’re ready to go and you can sharpen molder knives! As I’m doing in this picture, simply “lap” the front of the knives through the grits of your stones. (I use a “figure 8” pattern.)
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When your knives are new, they will most likely be unsharpened. Start with a lower grit and work all the way through the stones. They should be like little mirrors when you get done.

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(The initial sharpening will take a bit longer.) Subsequent sharpening should only require the last few grits, unless you’ve really nicked one of the knives or some such thing. I make it a general practice to give each of the knives a quick honing before I start a molding run. It only takes about 5 extra minutes, but the results are well worth it.

Setting the knives

The next area we turn our attention to is the setting of the knives in the molder head itself. The locking system is so incredibly simple yet effective it still boggles my mind. Place the knife into the throat and a ball bearing drops into the hole in the knife.

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As you tighten the setscrew, no matter where the knife was originally seated, the ball bearing will automatically align the knife by dropping into the counter-bored hole in the knife.

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Repeat this for each of the knives. Voila! You’re ready to go… and each knife is perfectly aligned with the other!

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- Also, a word about knife direction – the knives, when mounted in the molder head, should be angled toward you.


Setting the table

Before running any stock through the molder head, it is necessary to change the throat insert. While it should be obvious that a standard blade insert will not work, do NOT try to run stock without an insert. Yes, I have actually heard of people running a piece of stock through a dado head without an appropriate insert. That is just foolish and dangerous and should be simple common sense. But maybe it isn’t – so I’ll say it: whether you’re using a dado head or a molder head USE AN APPROPRIATE THROAT INSERT! I use a zero clearance insert and wouldn’t cut molding without it. Now, on to the cutting depth. Whether you use a stand-alone table saw or a Shopsmith, the knives cannot take too large a cut in each pass. Setting the knives to take too deep a cut will result in a very bad experience! (I personally wonder if most of the horror stories about molder heads aren’t because the knives were simply set to take too big a bite.) In my experience, I have found that the knives cut the best and give the cleanest cut with the least amount of chipout when set to take no more than ⅛” in each pass… or less.

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On the Shopsmith, a recent addition to setting the table height is the adjustable stop collar. If you don’t have one of these for your Shopsmith – consider getting one! One full turn of the nut raises or lowers the table a mere 1/16”! What I do when cutting molding is set the table to the full depth of cut. (Now, obviously, I won’t be attempting to cut all that, but it gives me a reference for the stop collar, locking the set screw at that point.) With the table set, I lock in the stop collar and “lower” the nut (raising the table) and then work my way back down to my pre-set position.

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Setting the speed
If you are using a molder head on a stand-alone table saw, you can skip this section.

When running stock through the molder head, the recommended speed is R for softwood (3500rpm) and Q for hardwood (3250rpm). I have found with many operations, this speed setting really is a “recommended” speed. If it just feels too fast, then dial it down a bit. If it feels too slow, then dial it up a bit. Sometimes the wood itself will “tell” you what speed to use – the same is true regarding feed rate as well.
Also, regarding speed, don’t get spooked by the “whoosh” you hear from the spinning knives; the knives are moving a lot of air and make a pretty toothy sound.


Running the stock

Everything is set up… now it’s time to run some stock and make some molding! Square and flat stock will always give the best results; if you take the time to joint and plane the stock, your experience and results will be much better. Run the stock as you would anything else on the table saw. I have found that featherboards

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(especially if you can set up your saw, or use a jig, to give a downward-pressured featherboard) work quite well – you must, of course, use a push stick. What I have found to work even better in this operation, though, are GRR-Rippers®. When these are set up with the “balance support”
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side legs (as they are called by the GRR-Ripper® manufacturers) they make a superb way to run molding. -The same GRR-Rippers® work for most other table saw operations as well as on the jointer, bandsaw, router, and other tools. I in no way work for Microjig or am getting any compensation from them, but I have found their GRR-Rippers® to be a great way to handle material for precisely this operation. If you’ve got a system that works better for you, super! -But please, be safe! A word about feed rate… as with most other cutting tools, too fast and you’ll not get a clean cut; too slow and you risk burning the wood. We’re mostly concerned about the “ridges”
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from the cutterhead, especially from feeding the stock too quickly. With proper feed rate, while you won’t eliminate the ridges completely, you can certainly reduce them and make your job easier later. If you run the stock too quickly the ridges will be very defined and will take more work to sand/scrape them out. (The above picture shows the ridges – I’ve “highlighted” them by rubbing a piece of chalk down the length of the stock.) Finding the right feed rate will probably not come without some practice, especially until after you move to the next step…

Clean-up of molding

After you get done running your stock, the good news is that you’ve got all that beautiful molding; the bad news is that you’ve still got work to do! The molding will need to be sanded and prepared for the finish to be applied. You will have ridges or scallops in the wood from the knives. No matter how perfectly you fed the stock through the molder head, these ridges are inevitable. No matter how small they might look (or even if you can’t see them at all), if you put a finish over the top without sanding (or scraping) you WILL see them in the finished piece. -Here’s a way to see the ridges – and also to check your progress at removing them – rub a piece of chalk down the profile. If you’ve still got ridges, you’ll see them instantly.
There are a couple of options for removing any knife ridge-marks and preparing the molding for a finish. Sanding, of course, is a perfectly suitable way to remove the ridges. Variously-shaped sanding pads (usually sold in multi-piece kits)

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do work very well for sanding molding. However, if you can get a curved card scraper to match the profile in your molding, a scraper is a remarkable tool for molding!
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With a good burr on your curved card scraper, getting rid of the molder knife ridges is quick and also leaves a glass-smooth edge. Now that you’ve removed all the ridges, etc. from your molding, take a step back and enjoy your new creation!

Why use a molder head instead of an electric router?

Electric routers are great tools. The bit profiles that are available are dizzying. (Interestingly, though, most guys I know only use (maybe) 15-20 different profiles to accomplish almost every job.) Electric routers are screaming-fast and with sharp, clean bits leave a pretty decent edge. However, most of the tricks up an electric router’s sleeve are for edge-treatments. There are a few bits that are designed for use in the center of a panel; but they are pretty few in number. (Yes, you can do some of these cuts with hand routers, such as a Stanley 71.)
Molder heads, on the other hand, are designed to be used on the table saw. This allows you to use the molder head to cut a profile anywhere you could cut a piece of wood with a blade in a table saw Try running a bead down the length of a panel, in the center of that panel on an electric router. A very difficult task on a router; near impossible on a shaper. On a molder head, though… not a problem.
Now let’s think that through… if you are running the molder head on a table saw and you run stock through it like anything else you run through a table saw, then you would remember that you can also tilt your table saw blade (or table, in the case of the Shopsmith.) This now gives you amazing flexibility and creativity when using the molder head. There are some newer “multi-profile” router bits available, but you are still limited to a vertical bit position. With a molder head, you’ve got vertical positioning as well as angled positioning choices. You’re limited only by your current knife selection and your imagination.
In closing, I realize that a lot of woodworkers have sworn off a molder head on a table saw after a bad experience and won’t ever try one again – and those horror stories spread – and a lot of guys who have never tried using one properly “just know they’re bad.” And… I suppose there’ll be some folks who feel compelled to voice their opinion about a Shopsmith. That’s okay. Not everyone does things the same way… the same results can be achieved different ways in woodworking. But for me, the proof’s in the pudding. When set up and used properly, the molder head is a safe and viable option for many hobbyist and amateur woodworkers.


-- † Hops †



3 comments so far

View lew's profile

lew

9915 posts in 2339 days


#1 posted 2149 days ago

Thanks for the tutorial.

I started using a molding head cutter on my old RAS- man that was a trip!! On the table saw with a zero clearance insert and hold downs- as you have shown makes using it a lot safer!

Lew

-- Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.

View Shopsmithtom's profile

Shopsmithtom

780 posts in 2778 days


#2 posted 2149 days ago

What a great tutorial! As a “Smith” owner, I always love to see other things that can be done on the machine. As a “Smith” nut, it’s just a reinforcement that it’s the coolest machine on the planet. (there, that’ll get the old combo vs separate tool dialog going again)
On a general note, I hadn’t given the molder much thought, but after seeing your terrific tutorial, I might just have to get yet one more attachment to use. -SST

-- Accuracy is not in your power tool, it's in you

View spunwood's profile

spunwood

1193 posts in 1420 days


#3 posted 1238 days ago

Thanks, great tutorial. I am dooing a project with them on a TS now. I need some hold downs to improve cut quality and safety.

-- I came, I was conquered, I was born again. ἵνα ὦσιν ἓν

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