|Gould & Eberhardt 32" Shaper|
It has been said that a lathe is sort of the piano of metal working. It is the base instrument that will do almost anything. If you could have only one machine tool and had to use it to build the others, likely a lathe is what you would select. While there are many kinds of lathes, the pretty much have a single thing in common. They like to make things that are round.
Sometimes, however, you need to do flat work. Shapers use cutters similar to lathe cutters but instead of turning the work against the cutter, you fasten the work to the table (anyway you can but solidly) or clamp it in a massive 'shaper vise' such as the one featured which is bolted to the shaper table, and you put the cutter in the tool holder on the end of the massive sliding arm.
The arm is on a big crankshaft inside the case and it slides back and forth cutting on the forward stroke. The cutter is on a hinge so it swings out of the way on the back stroke. The length of the stroke is adjustable, and this being a fairly large shaper as shapers go is capable of up to a 32" stroke although normally a few inches is all you need. YOu adjust the depth of the cut with the crank on the top of the machine. If you are cutting down you will advance it with every stroke. The table itself has a feed screw and if turned on the table will move sideways between each stroke so you can get a new bite---thus allowing flat work. With a little imagination you can make anything that can be manufactured by straight scraping. Thus you can make gear racks or even gears with a shaper and all kinds of groves including keyways.
While it is possible to scrape a keyway with a lathe by locking the spindle, turning your cutter on its side and cranking the carriage back and forth, a shaper is actually made to do that.
In the modern world shapers have largely disappeared, due to the milling machine. The shaper is a simple brute force machine that uses simple cutters---typically the same HSS steel cutters that you may use in your lathe. Cheap, simple and crude. Milling machines use expensive rotary cutters, and will do anything that shaper will do (and more), which probably has something to do with the fact that shapers are pretty historic machine tools and not something that has been in popular use for the last 50 years, but a shop full of low cost machine tools isn't complete without one.
For more information on shapers see: The Rhodes Shaper page
|G & E Shaper at Work|
|Ram Moves to and fro|
|For inside work instead of using a lighthouse type tool holder attached to the clapper you use a boring bar. You insert it from the back side into the clapper so the flange seats in the counterbore on the back side of the clapper. Then secure it with a jam nut on the front side of the clapper. I then drilled the adapter and installed a couple of set screws allowing small round boring bars that might be used in a lathe to be inserted. I built this adapter because I ended up with a 'cutter set' for a shaper that had a series of cutters that needed a 5/8's holder. I built this combination to cut a small keyway in a fairly small hole. As with a lathe, if your work hole is larger, then you can use a larger boring bar.|
|This is a 32 inch stroke shaper---a fairly large one.|
|A peek inside the crank case. the bevel gear in the middle rotates the ACME screw that adjusts the stroke of the shaper essentially by sliding the 'rod bearing' in/out in a grove in the offset of the crankshaft.|
|Made for a flat belt drive, this shaper is actually powered by a 5hp 3 phase Allis Chalmers motor through a couple of V-belts. An over center clutch is in the middle of the drive pully, just in case you happen to have a line shaft handy in your shop and a flat belt dropping down from the ceiling.|
|the long upper handle is the master clutch. The short vertical lever with the round knob is the 'back gear' shifter, while the horizontal lever is a 4 speed shifter.|
These two photos on the right show the shaper in action. Here the task at hand was to cut this boring bar holder for a lathe so it was flat on the bottom (It's upside down in the vise because I am working on the bottom of it) so it would sit on top of the lathe compound.
As you can see the Shaper has a tool holder and a HSS (high speed steel) cutter similar to those used on lathes. If you are doing internal work there is a 'boring bar' type holder that sticks out and slides back and forth inside of your project, but here I needed to do classic 'flat work'. I just wanted to flatten the surface by taking the 1/2" raised area off.
Here I just clamped it in the vise and went to work. Conceptually one could have done the same thing with a milling machine, the modern replacement for a shaper, but the job here is a classic one for a shaper---a big flat area that you just want cut away.
The ram moves forward on the cut stroke, and drags the cutter (which is hinged) back across the work, while a ratchet device slides the table sideways for the next stroke. An the end of a pass, the operator cranks the table back, lowers the cutter for the next pass, and engages the ratchet to start the table moving.
You can adjust the amount of table movement per stroke, and of course can control how far down you crank the cutter (equivalent to turning the the cross feed on a lathe). Other adjustments on the shaper allow you to control the length and speed of the stroke. You need a lot of different speeds depending on the length of the stroke. The shaper will stroke once per 'RPM' but since the stroke is adjustable on this model from near nothing to 32" the speed that the ram must go to 'get there' varies radically. Cutter bits survive based on a FPM (Feet per minute) calculation.
Many shapers are only capable of an 8 to 12 inch stroke, but this one is a bit of a monster as shapers go which explains why it has many gears to allow it to compensate for the various strokes.