Travis Bishop. Submitted to: Dr. John Davis. Date: 3 December Course: ETME 310 Section: 004. Lab Topic: Milling Project (Vise)

Transcription

1 Travis Bishop Submitted to: Dr. John Davis Date: 3 December 2012 Course: ETME 310 Section: 004 Lab Topic: Milling Project (Vise)

2 Introduction: Purpose of Experiment: This experiment was conducted to teach the basics of using a mill by using metal materials to build a drill press vise. The mill is one of the most common machines used in metalworking. It is useful for making parts of irregular shape. Problems Being Addressed: This experiment addressed the problem of how different shapes required different processes to make them. It also addressed the problem of achieving accurate dimensions from milling operations. Scope of Experiment: This experiment required a drill press vise to be made from the student s own designs that were made in CAD. The processes required depended on the designs. The designs of this drill press vise required face milling, profile milling and grooving for the milled parts, as well as using a lathe for making the handle and threaded rod. Test and Evaluation: Apparatus Used Eye protection Part Prints Band saw Tape measure Shop rags Brush 0-6 caliper 0-1 micrometer Digital height gage (Figure 6) Machine oil Milling machine (Figure 1) Rubber mallet

3 Parallel bars Collet inch diameter end mill cutter (Figure 2) inch diameter end mill cutter Face milling cutter (Figure 3) Edgefinder (Figure 4) Grooving cutter (Figure 5) Drill chuck Center drill Bluing dye 21 size drill bit 29 size drill bit 7 size drill bit 21 /64 size drill bit F size drill bit E size drill bit Tapping handle thread tapping set 8-32 thread tapping set ACME 1 /2-10 drill and tap set Four /4 flat socket head cap screws Two /2 flat socket head cap screws /4 cup point set screw Single point tool File Deburring wheel Grinding wheel Vacuum

4 Broom Dustpan Process / Procedure / Sequence of Events Cutting Raw Stock The band saw blade was raised and locked. The raw stock was tightened in the vise with and extra 1 /4 to 1 /2 inch protruding past the end of the saw blade, using the tape measure. The feed force was set to a slow speed and the band saw was turned on. The band saw was unlocked and allowed to lower into the stock. When the saw had automatically shut off, the cut raw stock was retrieved and the remaining raw stock was removed from the vise. Squaring the Work Piece Two parallel bars of equal size were placed in the vice. The work piece was placed on top of the parallel bars and the jaws were tightened. The face cutter was installed in the chuck. The work piece was adjusted on the X and Y axes until the corner was under the cutter and the chuck was lowered until it was almost in contact with the cutter. The mill was set to 800 rpm and turned on. The work piece was adjusted on the Y axis until it made light contact with the cutter. The work piece was slowly adjusted on the X-axis until the cutter went past the other end of the work piece. The work piece was adjusted on the Z axis until almost all the cutter was cutting new material. The cutter was brought back on the X-axis slowly until the top face was completely clean. If the face of the work piece wasn t completely clean, another cut was necessary. The mill was turned off and the work piece was removed from the vise and deburred. The work piece tightened in the vise with the cut side facing the back of the mill. The process was repeated for this side. The freshly cut side was placed in the mill to face the back. As the vise was tightened, a rubber mallet was used to make sure the work piece was perfectly level. This was repeated for the last side. The work piece was tightened in the vise without parallel bars. A machinist s square was used to make

5 sure that it was straight. The process was repeated for this end. The other end was tightened in the vise with parallel bars and the rubber mallet was used to make sure it was tight. The process was repeated for this last side. The facing operation can be used to cut the work piece to its final outside dimensions. The digital height gage was set to the desired dimensions. Bluing dye was painted on the work piece. Using the height gage, a line was scratched in the paint where the final dimension is. The work piece was tightened in the vise and the side was faced. A caliper or the digital height gage was used to check the dimension of the work piece as it got closer to the final dimension. This was repeated as needed for the overall length, width and height of the work piece. Deburring The deburring wheel was turned on. The corners of the work piece were run across the deburring wheel to remove the burrs that had built up during cutting. The deburring wheel was shut off. An alternative method to deburr the corners of the work piece is using a metal file to take the burrs off. Edgefinding The work piece was tightened in the vise. The drill chuck was installed in the milling machine and the edgefinder was tightened in it. The milling machine was set to a slow speed and turned on. The work piece was slowly turned into the edgefinder on the X-axis until contact was made. As the work piece was moved into the edgefinder, the edgefinder got closer to rotating about its center. The edge of the part was found when the edgefinder kicks off the center. The mill was turned off and the edgefinder raised up above the work piece. The work piece was moved another inches on the X-axis to account for the diameter of the edgefinder. The X-axis was set to zero. The process is repeated to find the edge of the part on the Z-axis. End Mill Cutting

6 The end mill was slid in the 1 /2 collet and installed in the vise. The side of the work piece was painted with blue dye and lines were scratched with the digital height gage in the dye where the final profile was to be. The work piece was tightened in the vise. The mill was set to 1100 rpm for aluminum or 800 rpm for steel and turned on. The end mill was lowered and the work piece was raised on the Y-axis until the bottom of the cutter was about below the face of the work piece. The work piece was moved in the Z-axis until the cutter was on the other side of the work piece. The work piece was moved in the X-axis until the cutter was cutting mostly new material. This was repeated until the cutter was close to the line scratched in the blue dye. The work piece was raised in the Y- axis and the process was repeated. This was repeated until the cutter was close to the horizontal line scratched in the blue dye. The work piece was raised a smaller amount and the process was repeated, using a caliper to check the dimension after every cut. With the cutter at the correct depth, the profile of the cutter was run across the sides of the work piece until the width of the part matched the desired dimension. Drilling The center drill was installed in the drill chuck. The work piece was adjusted on the X and Z axes until the center drill was directly under the center of the hole to be drilled. Machine oil was brushed on the center drill and the work piece. The milling machine was turned on. The center drill was lowered into the work piece a little at a time until 2 /3 of the tapered part of the center drill was in the work piece. The center drill was raised up and the milling machine was turned off. The center drill was replaced with the correct size drill. Machine oil was brushed on the work piece and drill. The milling machine was turned on. The drill was lowered into the work piece a little at a time until the hole reached the desired depth. Countersinking

7 The 82 countersinking was installed in the drill chuck and installed in the mill. The work piece was tightened in the vise. The edge of the work piece was found using the edgefinder. The work piece was moved on the X and Z axes until the center of the hole was directly under the center of the countersinking tool. The mill was set to the same speed as drilling and turned on. The countersinking tool was lowered into the workpiece a short way. The countersinking tool was raised and the mill was shut off. A socket head cap screw was placed in the hole to check the fit. If the screw sat above the face of the work piece, the screw was removed and the process was repeated. This was repeated until the screw sat just below the face of the work piece. Grooving Bluing dye was painted on the work piece where the grooves were to be. The work piece was tightened in the vise. The edges were found using the edgefinder. The grooving tool was slid in the 1/2 collet and installed in the vise. The work piece was adjusted in the Y and Z axes until the point of the grooving tool was above the work piece at the center of the spot where the groove was to be. The mill was set to 2500 rpm and turned on. The work piece was adjusted up in the Y axis while it was moved back and forth in the X axis until a light scratch was made in the blue dye. The work piece was moved in the X axis to run the tool across the work piece. The work piece was raised and, using machine oil, run slowly back across in the X axis. This was repeated until the groove was at the correct depth. The mill was turned off and the work piece was removed from the vise. A file was used to clean the inside of the groove. Tapping The tapered thread taping tool was installed in the tapping handle. The work piece was tightened in the vise. Using machine oil, the tap was slowly turned straight into the hole in the work piece a short way. The tap was backed out 180.

8 This was repeated until the tap either hit the bottom of the hole, if there is one, or stuck out the other side. This was repeated with the bottoming tapping tool. Facing The single point tool was installed on the lathe. Using the tail stock with the live center, the single point tool was centered along the Y-axis. The raw stock was tightened into the universal chuck with about /2 inches protruding. The single point tool was adjusted to a 2-3 degree angle from horizontal toward the face of the work piece. The lathe was set to 835 rpm or 455 rpm (see Figure 6) for steel and turned on in the forward position. The cutting tool was brought in contact with the edge of the face of the work piece on the Z-axis and slowly advanced to the center on the X-axis. A second or third cut was required if the face of the work piece didn t completely clean up. The process was repeated for the other side of the work piece. Facing was repeated until the work piece achieved the desired length. Center Drilling (Turning) The work piece was tightened in the universal chuck with about /2 inches protruding. The drill chuck was inserted into the tail stock. The tail stock was extended a couple inches to tighten the drill chuck. The center drill was tightened into the drill chuck. The tail stock was moved to within 1 inch of the face of the work piece. The lathe was set at 835 rpm or 455 rpm for steel and turned on in the forward position. Machine oil was brushed on the face of the work piece and the center drill. The tail stock was extended into the workpiece a little at a time until the center drill is in up to 2 /3 of the tapered section. Straight Cutting Using the tail stock with the live center, the single point tool was centered along the Y-axis. If the length protruding was greater than 5 times the diameter of the part, the work piece was center drilled and the tail stock with the live center was used for support. 1 /2-1 inches of the work piece was tightened in the universal

9 chuck with most of it protruding. The single point tool was brought in contact with the side of the work piece. The lathe is set to 835 rpm or 455 rpm for steel and turned on. Machine oil was brushed on the workpiece. The cutting tool was adjusted past the edge of the face of the work piece on the Z-axis and in on the X-axis about inches. The cutting tool was moved across the work piece at a slow, constant rate until the tool was within 1 inch of the chuck. This was repeated until the desired diameter was achieved. After each cut, the micrometer was used to measure the diameter. Grooving The grooving tool was installed on the lathe. The grooving tool was adjusted to be perpendicular to the face of the work piece. The grooving tool was adjusted on the Z-axis to the desired position on the work piece. The lathe was set to 835 rpm or 455 rpm for steel and turned on. The grooving tool was adjusted on the X-axis and using oil, slowly moved into the workpiece until the desired diameter was achieved. The grooving tool was adjusted on the Z-axis and cut into the workpiece again until the desired width of the groove was achieved. Vice Base Operations 7 inches of raw 2.75 x 2.75 raw aluminum stock was cut with the band saw The sides of the work piece were squared and cut to a length of inches, a width of inches, and a height of inches using the face milling cutter The inside of the work piece was cut out using the inch diameter end mill The slots in the bottom of the work piece were cut using a inch diameter end mill for the bigger groove and a inch diameter end mill for the smaller groove Two holes were drilled through one side of the work piece using a size 21 drill bit

10 A hole was drilled through the other side of the work piece with the 1/2-10 ACME size drill bit The two smaller holes were tapped with threads The larger hole was tapped with 1/2-10 ACME threads Vice Jaw Operations 2 inches of 2.75 by 2.75 raw aluminum stock was cut with the band saw The work piece was squared and the sides were cut to a length of inches, a width of inches, and a height of inches. The guide was cut with the end mill The extension to hold the drive screw was cut with the end mill Two holes were drilled in the face of the work piece with the size 21 drill bit Two holes were drilled in the bottom of the work piece to a depth of inches with the size 21 drill bit A hole was drilled in the back of the work piece to a depth of inches with the size 21 /64 drill bit A hole was drilled in the top of the extended section of the work piece to the other hole with the size 29 drill bit The holes in the face and bottom were thread tapped The hole in the top was 8-32 thread tapped Grooved Plate Operations 2.75 inches of 1 /4 by 1 1 /2 steel stock was cut with the band saw The ends of the work piece were cut to the correct dimension with the profile of the end mill A vertical groove was cut to a width of.250 inches in the center of the face of the work piece A horizontal groove was cut to a width of inches, inches from the top of the work piece

11 Two holes were drilled in the center of the work piece with the size 7 drill bit and countersunk Flat Plate Operations 2.75 inches of 1 /4 by 1 1 /2 steel stock was cut with the band saw The ends of the work piece were cut to the correct dimension with the profile of the end mill Two holes were drilled in the center of the work piece with the size 7 drill bit and countersunk Bottom Plate Operations 2.75 inches of 1 /4 by 1 1 /2 steel stock was cut with the band saw The ends of the work piece were cut to the correct dimension with the profile of the end mill Two holes were drilled in the center of the work piece with the size 7 drill bit and countersunk Drive Screw Operations Five inches of 1 /2-10 ACME threaded rod was cut with the band saw The ends of the threaded rod were faced to a final length of inches The threads were straight cut off the end of the rod inches from the end The other end of the work piece was straight cut to a diameter of inches A groove was cut in the smaller end inches from the end to a width of inches A vertical hole was cut with the size F drill bit in the wider end of the work piece Handle Operations 2.50 inches of inch steel stock was cut with the band saw The ends of the work piece were faced to a length of inches One end of the work piece was center drilled The work piece was straight cut to a diameter of inches

12 The work piece was straight cut to a diameter of inches with a diameter, length section left The smaller end was slightly pressed in a vise to remove clearance with the handle stop Handle Stop Operations One inch of inch steel stock was cut with the band saw The work piece was straight cut to a diameter of inches The ends of the work piece were faced to a length of inches The end was drilled with a size E drill to a depth of inches Assembly The flat plate was attached to the inside of the vise base with two /4 flat socket head cap screws The grooved plate was attached to the face of the jaw with two /4 flat socket head cap screws The jaw was locked in the slot of the vise base with the bottom plate and two /2 flat socket head cap screws with the two jaw plates facing each other The handle stop was slid through the hole in the threaded rod and the handle stop was hammered onto the end with a rubber mallet The handle assembly was threaded through the hole in the vise base and the end was pushed into the hole in the jaw and locked with a /4 inch cup point set screw Findings Face milling with the face milling cutter produced short curly chips. Making more than one pass on the face of a part left a distinctive line on the work piece where the cuts overlapped. Face milling with the end mill produced similar chips to the face milling cutter and left similar lines where cuts overlapped.

13 Profile cutting with the end mill produced long, needle-sharp chips that were hazardous the exposed hands. It left a good surface finish on the work piece. Drilling created long ribbons of material similar to chips produced by a lathe. Tapping the ACME threaded hole in aluminum required much more force than tapping UN threads in steel Interpretation & Results The lines left by the overlapping face cuts with the end mill on the vise base interfered with the bottom of the jaw and had to be sanded smooth. The drilling operations left raised burrs on the faces of the work pieces that had to be filed smooth. The deburring wheel and grinding wheel took off too much material. This was countered by using a metal file instead. It was much slower, but left the corners of the work piece intact. Despite being inches larger than the hole in the handle stop, the handle was able to be slid in and out of the handle stop. This required the end of the handle to be slightly pressed in a vise so that it was larger than the hole in the handle stop. The first version of the handle was similar, but was meant to be threaded with 1/4-20 threads on the lathe. However, the part was too thin and the live center interfered with the threading tool. The threading process was begun, making sure that very small cuts were taken. After the eighth cut or so, the threading tool caught on the part and bent it. The threads were ruined and the part had to be discarded. The design had to be simplified and the threads replaced with a press fitted handle. The hole for the ACME threaded rod ended up slightly crooked. As the rod was threaded through the hole, it got more off center. This was fixed by turning down the end of the threaded rod to a final diameter of inches, instead of the given dimension of inches. Conclusions and Recommendations This experiment is the end of a year long project. The drill press vise was designed and drawn in CAD the semester before in ETME 203. These designs were used to make a drill press vise out of aluminum and steel. The majority of the processes were performed on the mill. A few processes,

14 however, required a lathe. The drill press vise was successfully able to be assembled and functioned. The designs for the fit of the handle and handle stop needed to be more closely examined. The shaft for the handle was too small and had to be altered to be press fitted in the handle stop.

15 Appendix Figure 1: Bridgeport milling machine Figure 2: End mill Figure 3: Face mill Figure 4: Edgefinder

16 Figure 5: Grooving cutter Figure 6: Digital height gage