A couple of weeks ago I posted on a Facebook page called “The Collectors of Antique/Vintage Tools” about a Lion Miter Trimmer I just restored. A few people in the group replied to my post asking what the tool did. I was surprised that so many people weren’t aware of this tool, that I decided to talk about it here.
I’ve owned an AMT miter trimmer for over twenty-five years and love it. They are simple tools that were popular for people who made picture frames back in the day. You use it by swinging the arm pulling the knife through the piece of wood, slicing off perfect little curls precisely at whatever angle you set the fence at.
The miter trimmer has fences on each side that can be positioned between 90 -45 degrees. There are adjustable stops at 90 and 45 that can be fine tuned with a screwdriver. Once you swing the fence to whatever angle you want, you tighten the wing nut on top locking the fence in place. As you can see in the photo, this machine also has layouts for 60 and 67 1/2 degrees.
After fiddling with the machine for a few minutes, I positioned the adjustable stops precisely were they needed to be. As you can see, the stop is a little shy from the 45 degree scribe line on the bed. I’m not sure why this is, but the tool is probably over 100 years old, so it’s allowed to be off a little.
You can see how the tool slices off perfect little shavings. When I was restoring the tool, I took the knives off and sharpened them on my Tormek using the Tormek knife jig. Before I sharpened them, the knives couldn’t cut butter.
The main reason I love my miter trimmer is that it cleans up the cuts that are made from my miter box and saw. For safety reasons when doing delicate trim work, I like to use my little miter box instead of a powered miter saw.
However, the saw doesn’t leave the wood with a nice enough cut.
Not only that, the miter box doesn’t even produce a perfect 45 degree angle throwing the two pieces out of square.
Here are the two pieces after they’ve been trimmed up with the miter trimmer.
The proof is in the pudding here. All the joints fit nicely together and the frame is a perfectly square inside. No wonder why picture framers loved these things.
Another good use of a miter trimmer is doing outside corners like attaching molding to a bookcase or cabinet. Here is a piece of molding that I cut with one of my molding planes.
If I stick the piece in my miter trimmer and try to trim it up normally, you can see how the inertia of the cut pulls the molding off the bed. There’s simply not enough surface area in the front of the molding to keep the piece stable.
The cut it produces this way is garbage. Not only is it not 45 degrees, it’s not even a straight cut.
The way to get around this, is to take the body off a combination square and clamp it to the fence of the trimmer. Use a scrap piece of wood and cut a 45 degree angle to the end with the trimmer. Then use the cut as a gauge to accurately place the combination square under it. It’ll take a little time and a few test cuts, but once you have the combination square properly position, you’re ready to go. Note: You can buy an attachment from Grizzly for about $30 which does the same thing as this, but I’m not sure if it will work on old Lion Miter Trimmers.
Now you can use the bottom of the molding to rest against the fence for support and make a perfect 45 degree cut.
Repeat on the other side of the trimmer for the other side of the molding and you’ll get a super clean and accurate joint.
Unfortunately, the website for the original Lion Miter Trimmer no longer works which makes me believe they are no longer in business. http://www.lionmitertrimmer.com It’s a shame because the tool is truly an awesome piece of machinery.