Dangers of Shapers?

[Andrew More]

After the discussion about the most dangerous tool in the shop I'm a bit curious. Almost all of my tools feature some sort of motor which turns something at high speed with can turn fingers into mush, or fling projectiles at high speed.

Is there something about shapers that make them uniquely dangerous?
Is it that many of the DIY/prosumer models are underpowered?
Does using a power feeder address the biggest dangers, and is there something else that can be done to make them less dangerous?

[Kevin Jenness]

Probably the biggest dangers from shapers are from unguarded or poorly guarded hand fed operations and poorly understood or set up tooling. Whenever a power feeder can be used the danger can be lessened but they are often not suitable for curved work. The wide variety of tooling types and sizes, especially cutterheads with interchangeable knives, and the importance of setting them up properly and running them at the correct speed, can lead to safety issues. Most common woodworking machines have fewer variables to contend with. Routers and router tables can have similar issues but shapers involve a great deal more kinetic potential. No doubt there are many more tablesaw injuries but on an accident per man-hour basis I would guess shapers are near the top of the list.

[Jared Sankovich]

Generally if you don't stick your fingers into the spinny parts they don't cause too much trouble. Guards, feeders and limited tooling tend to promote safety, running without any of those increases the risk.

The size of the shaper is generally irrelevant to the safe use or non safe use of the machine.

[Mel Fulks]

Andrew, there are several ways shaper knives are held . The “smooth knives “ ( without corrugations )are considered the most dangerous as
they are held in only by pressure. The steel is pretty soft, and over tightening distorts the collars , thereby making them more dangerous.
The knife steel is sold in different heights but the sizes are nominal, so a piece from a bar bought last year will probably not pair up safely
with a piece off a new bar. Too many shops have let new guys use it just because they said “ I know how”. Most shop machines can only
hurt the operator, but a smooth knife that is not correctly seated and tightened can hit anybody, and that includes a customer -shop tourist.
Some injuries are just from sticking a finger into the sharp spinning knives.

[Mel Fulks]

Besides feeders a shaper needs some type of “spring hold- down”. I don’t know if you can even buy them now, years ago we had to have
them made if we bought a shaper without one. Short straight pieces can be run by lining them up face down and tacking a board on top.

[Jared Sankovich]

Good video on shapers https://youtu.be/4n6yTHMBX54

[Albert Lee]

After the discussion about the most dangerous tool in the shop I'm a bit curious. Almost all of my tools feature some sort of motor which turns something at high speed with can turn fingers into mush, or fling projectiles at high speed.

Is there something about shapers that make them uniquely dangerous?
Is it that many of the DIY/prosumer models are underpowered?
Does using a power feeder address the biggest dangers, and is there something else that can be done to make them less dangerous?

A lot of variables to check before you switch it on that shaper, different to other machines.

Feeder will address some issues but its not foolproof. I have made a mistake before where I simply forgotten to lock the feeder and I switched it on...

[Mike Cutler]

Andrew

There is no reason to be afraid of a shaper, or any machine. You need a healthy respect for any machine in the shop.
I first started using a shaper when I was probably 13 years old. I'm 63 now, and still have all of my digits. I don't use it as much as I used to, but when I want it, it's there.
Yes, a power feeder makes it "safer", but only because you can't get any part of your body within the rotation of the cutter. It's all blocked by the power feeder.
The video linked is a fairly good video for specific operations, but start out slow. Start with rabbets and edge joints, then progress from there. Don't go straight to shaping your own solid body guitar freehand. There are also cutters in that video that are no longer available for good reason, so just watch it to see the basic operations that can be perfomed
I personally would not want one less than 3hp, with a 1/2HP power feeder. There are tons of both all over Craigslist and Facebook Market place.
The shaper is a machine of thousandth's. It can be that accurate and repeatable. If you ever have the chance to edge treat a bunch of boards for a large panel glue up on a shaper, you'll never want to use anything else.
Get the right tooling for cabinet doors and you'll easily achieve great results.

[Richard Coers]

For me it's that large diameter cutter beating the air and creating one heck of a frightful sound. That and that big motor with so much power. Just perceived danger I know. A folk tail in my woodworking community about an old square head shaper in a vintage shop. One operator had a knife thrown, and it went through a little meat just about his waist. It went all the way through. After that, a plywood "sandwich board" with leather straps was worn over the gentleman for protection. That and he stooped under the table of the shaper upon starting the motor after a new setup.

[Mel Fulks]

Never walk away from a shaper that is partially set up. Something about that makes guys want to turn on the switch . Tourist family members
of shaper Captains also feel compelled to turn on stuff. Forward and Reverse needs to be read every time you get back from wherever you
went.

[Mark Hennebury]

Agree with what's been said, Knowledge is your best defense! Analyze and develop a process and checklist. Know where you're fingers are and where they might be should something go wrong, best they are on the good side not the bad. Checking speed is matched to tooling should be on that list.

There was an accident report that I read years ago, not about a shaper, but a large industrial pin router. dual speed 10,000/20,000 rpm.
Apparently a worker was making rosettes on a drill press and thought that it would go faster on the pin router.
He put a rosette cutter in the pin router and turned it on, It was on the 20,000 rpm pulley.
So a cutter went straight through him, and he died.
This was a few years back and i believe the cutters were held by the friction of two screws.

[Rick Potter]

Adding to what Mel said about being partially set up..........

I have posted this before and it involved a jointer, but still applies. I inherited a Craftsman 6" jointer from my father. Never used it, as I had my own, so half a dozen years later I gave it to my son in law. He turned it on once getting home, and a loose blade took out a large size hole in the cast iron bed of the jointer. Fortunately he was not injured.

I can only speculate that perhaps dad was adjusting or changing blades when he got called away for dinner or whatever, never returning to finish the job, and the machine got put in a corner. He died at 87, and the last few years he was overwrought because of mom's Alzheimer disease. Who knows?

[Greg Funk]

For me it's that large diameter cutter beating the air and creating one heck of a frightful sound. That and that big motor with so much power. Just perceived danger I know. A folk tail in my woodworking community about an old square head shaper in a vintage shop. One operator had a knife thrown, and it went through a little meat just about his waist. It went all the way through. After that, a plywood "sandwich board" with leather straps was worn over the gentleman for protection. That and he stooped under the table of the shaper upon starting the motor after a new setup.

I made a bunch of moldings for our house with this cutter. When it spins up you can feel it in your gut. I only ever used a power feeder but it's always a little unnerving when you make the first cut. After you've used it for a while, like anything else, you get used to it.ShaperHead.jpg

[Mark Hennebury]

Big tenon heads, can be on shapers, this set is on a tenon machine. PXL_20221031_215527221.jpg

[Kevin Jenness]

One shop I worked in had a rule for a time that shaper setups had to be checked by a second person before running. There are a lot of things that need to be done right. Some things to check:

Knives secured in the cutterhead
Spindle nut tight
Rpms correct for the cutterhead type and diameter
Spindle rotation direction correct
Fence and hold-downs secure
Powerfeed set correctly and all adjustments locked
Hand-guided jigs as safe as possible with solid handholds well away from cutters and good material clamping
Backstop in place if "dropping on" (non-through cut)
Guards in place where appropriate
Chip collection set up and on
In and outfeed support if needed
Nobody in the firing line