Equipment MLS: How to Buy Shapers

How to Buy Shapers

The shaper operates like a planer but on smaller work pieces and the work is fed sideways at the beginning of each tool stroke. The shaper can produce all surfaces consisting of straight line characteristics whether they lie in a horizontal, vertical or inclined plane. There are two basic types of machines: horizontal and vertical shapers. There are different types of shapers included in each group.

The standard horizontal shaper is the most common shaper. Its horizontal ram interchanges cutting speed. The toolhead is on the front of the ram and carries a cutting tool. The ram stroke's position and stroke are adjustable so the tool can be set to cover any part of the maximum stroke and not travel any more than necessary. The slide carrying the tool on the toolhead can be swiveled and clamped at any angle in a vertical plane on the front of the ram for angular cuts. The slide consists of a plain table which can be supported by a table support at the outer end. A crossrail can be adjusted up and down and is mounted on ways in front of the column. It supports the table. The table slides crosswise on the rail and can be fed manually or automatically. The work is fed before the beginning of each ram stroke. Some tables can be swung horizontally on an axis parallel to the ram ways for angular cuts. A standard shaper can usually take a two inch cut with a 0.030 inch feed. The universal shaper is different because of its table action. Its table is equipped to swivel around a vertical and a horizontal axis parallel to the travel of the ram. Now planes can be produced at any angle without special workholding fixtures by simply adjusting the table position. The drawcut shaper is constructed similar to the standard shaper but is much heavier. The cut is taken toward the machine rather than away from the column. A heavier cut can be made with less vibration and strain on the fasteners and table. Due to the drawcut, form tools which can chatter, can be used with less than normal vibration and a better finish is produced than on a conventional shaper. Some drawcut shapers use an overhead ram support to prevent the deflection of the ram on the outside end of the stroke. The tool starts to cut on the outer edge of the workpiece and the operator can see and control the cut more easily than on a conventional shaper. The drawcut shaper is used for heavy cuts.

Vertical shapers are usually equipped with rotary tables which can be moved by power or hand. The table sits on a saddle which slides on the bed and provides horizontal adjustments to feed in two or more directions. Work can be mounted on a rotary table and indexed for various operations. Also the work can be turned continously on it to produce an arc. A slotter is like a vertical shaper but has only vertical movement of its ram while the vertical shaper allows adjustment of the ram from a vertical position to about 10 degrees from the vertical. Keyseaters is a specialized vertical shaper for machining internal keyways. The cutting tool is mounted on a cutter bar above the interchanging ram and is pulled rather than pushed through the work. This provides great rigidity. An adjustable overarm provides outboard support and guidance for the long cutter bar.

PRIMARY PARTS

Base - The support where all parts are mounted.
Column - It's a housing for the operating mechanism and principal support for all other component parts. The bull gear and mating units of the mechanical crank shaper are housed within the column. The column is mounted on the base. In a hydraulically driven shaper, the hydraulic mechanism is housed in the column.
Ram - Carries the toolhead and travels in ram ways giving straight-line motion to the work.
Table - Is fixed to an apron or saddle moving on rails feeding or giving cross motion to the work. The crossrails are mounted on another saddle which moves up and down on ways on the column face to allow positioning of the work to the tool. An elevating screw gives the crossrail its vertical motion. A cross feed screw provides cross adjustment to the work. The elevating screw is usually hand operated while the cross feed screw may be power or hand operated. After the table is positioned vertically, clamps are tightened to prevent further movement while cutting. Heavy duty shapers have a table support bolted to the outer end of the table and is on the machine base. This table support provides rigidity.
Toolhead - Holds the tool and in some applications positions it. The toolhead has a toolslide and feed screw for adjusting the tool for depth of cut without changing the table height. Some shapers provide an automatic feed for the tool consisting of a roller attached to the head engaging a feed bar mounted along the ram ways. The roller feeds the tool downward a certain percentage for each stroke. The cutting tool is held in a tool post. The tool post and tool block fit into a clapper box which is hinged at the upper edge to allow the tool to lift up on the return stroke. The slight frictional tool drag lifts the tool block out of the clapper box to prevent the tool from tarnishing the work. The toolhead swivels to take angular cuts. The swivel proceeds in degrees so the tool can be positioned at any angle. Some horizontal shapers have wide spacing between the ram ways to provide a greater angle of head tilt.

Holds the tool and in some applications positions it. The toolhead has a toolslide and feed screw for adjusting the tool for depth of cut without changing the table height. Some shapers provide an automatic feed for the tool consisting of a roller attached to the head engaging a feed bar mounted along the ram ways. The roller feeds the tool downward a certain percentage for each stroke. The cutting tool is held in a tool post. The tool post and tool block fit into a clapper box which is hinged at the upper edge to allow the tool to lift up on the return stroke. The slight frictional tool drag lifts the tool block out of the clapper box to prevent the tool from tarnishing the work. The toolhead swivels to take angular cuts. The swivel proceeds in degrees so the tool can be positioned at any angle. Some horizontal shapers have wide spacing between the ram ways to provide a greater angle of head tilt.

The shaper's main feature is the reciprocating single point tool. It provides economical and simple tooling. A shaper is easy to set up and be used on any flat or angular surface. Due to its single point tooling, the shaper is not suited for production work. With only one tool cut the amount of metal removed is insignificant when compared to other machining methods. The shaper is limited in holding close tolerances because of the long unsupported overhang of the ram at the end of each stroke. Shapers are used mostly in toolroom work where precision can be maintained in lighter and shorter cuts in small runs of parts. The tables on most horizontal shapers can be fed crosswise the length of the stroke. conventional shapers rarely exceed 36 inch strokes because ram overhang is generally considered excessive beyond a longer stroke. The crank and hydraulic drives are the two type drives for the shaper. In the crank type, the ram moves by a slotted arm which is driven by a crank pin being pushed by the bull gear. The bull gear is driven by a smaller pinion gear getting its power by gears or belts from the motor. In the hydraulic type, a constant speed motor drives the hydraulic pump which delivers oil at a constant pressure to the line. The shaper initiates a regulating valve timed to the stroke pushing oil under pressure to the opposite end of the piston to return to the oil source. The piston is connected to the ram by a piston rod pushing the ram carrying the tool as it's pushed by oil. The tool travels at different speeds by constant pressure under varying load conditions. The shaper's quick return stroke is due to one end of the piston being larger in surface area than the other so the larger area moves at a higher speed. The mechanical drive system has an advantage over the hydraulic system on a shaper because it's easier to reverse at high and varying speeds and loads. The hydraulic system is smoother than a mechanical system and it stops when pressure meets its maximum point whereas a mechanical system surges to the end of its stroke. The hydraulic system is variable for speed and feed within its range, length, and position of stroke are easily adjusted. Also hydraulically driven shapers accelerate and reverse faster and it's far more flexible than the mechanical shapers.

There are attachments for shapers to make your work more productive and efficient. A tool lifter that automatically raises the tool to clear the work in the return stroke. It's suited for carbide tools. Index cutters space shaper cuts around the workpiece. Profiling and duplicating attachments reproduce surfaces of a curvature. A finger or follower on the bracket is attached to the toolhead and passes over a surface as the tool travels over the workpiece. The finger rises and falls in tracing the surface while the tool is raised and lowered simultaneously by hydraulic means and duplicates the profile of the workpiece.

INSPECTION

NON-POWER

Check for cracks, breaks, welds to repair in the machine's bed and housings. Machines with structural damage may not hold close tolerances.
Check the bed for levelness both transversely and longitudinally. Unlevel conditions may indicate structural damage or uneven weight distribution.
Test the table top for flatness in two directions for structural alignment. If the table is not level, the machine can't do precision work.
Make sure the table top is parallel to the bed ways.
Examine the table for visible signs of excessive wear. Check all ways for wear and scores, scoring on the ram, wear in the clapper box, scoring on the toolhead, and any nicks, burrs, dents, and gouges.
In a mechanically driven shear make sure there are no welded repairs on the bull gear.
Inspect all hoses, cables, and plugs for damage in hydraulic systems.

UNDER POWER

Run the machine and listen to all gear boxes to find out if the gears are running smoothly. Be sure there are no grinding or grating sounds.
Operate the machine in all speed ranges. Make sure all speed selectors and feed selectors are functioning properly and are adjustable.
Cycle the machine completely and check all systems.
Look for any hydraulic leaks on a hydraulic machine.

This is one article in a series of How to Buy Metalworking Equipment. Each article showcases and explains a particular type of metalworking machine. They were originally published in the Metalworking Machinery Mailer published by the Tade Publishing Group.

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