Lab 02: Manual Milling Operations

IENG 475Computer-Controlled Manufacturing Systems11/16/2018

Lab 06: CNC Lathe Operations

I. Purpose

A.)Provide an introduction tomanual CNCprogramming

B.)Provide experience designing and programming parts for production on the laboratory’s CNC equipment

II. Practice

Your lab team is to produce a CNC turning program file for your project cribbage pegs in preparation for automated production. The CNC lathe is not currently programmable by using the MasterCAM program, since the dimensions of our parts are so small. You are to document the process in your engineering notes.

The stock material for your cribbage pegs will be an acetal plastic, approximately 2.9” long and 0.5” in diameter. At least one end of the stock will already be faced. 0.625” of the stock will be held within the chuck, and the parting operation will consume approximately 0.085” of stock You will be doing the parting operation twice – following the plunge speed requirement will allow you to avoid an extra facing operation and further loss of stock material! You will only be able to get two pegs from each piece of stock. See the illustration, below.

Figure 1. Allocation of Stock Material and Workpiece Coordinate System.

Depending upon your design, you may need to perform some of the following tools. The tools and their tool numbers are listed in the table below. Tool one (T01) is used for the touch-off operation. All tool changes must take place 0.5” above the centerline of the workpiece and 0.5” from the current end of the workpiece in the + Z direction. This lab will use absolute coordinates for all moves (including circular interpolation center). Watch for tool holder clearance, plunge and feed rate limitations, and avoid rapid travel (G00) within the workpiece boundaries.

Table 1. Tooling Magazine for Lab

Tool / Description
T01 / Right hand profiling tool – 55o Diamond Insert (limit feed rate to 4 ipm)
T03 / Grooving tool – Square Insert (90o, limit plunge depth to .02” at feed rate of 1 ipm)
T05 / Left hand grooving tool – 55o Diamond Insert (limit feed rate to 4 ipm)
T07 / Right hand parting tool - .085 wide (limit plunge feed rate to 1 ipm)

Note: Other tooling may be available – see instructor.

Your first three cuts will be partial facing cuts to obtain a smooth peg end of diameter .12” that is .15” long (to insert into the cribbage board holes).You will use T03 to make these cuts. The next three cuts will be roughing cuts to obtain the maximum diameter of 0.220”. These roughing cuts, and the finishing profile cut will use T01 – cutting from right to left. T07 will be used to cut the two v-shaped grooves, and then T03 will be used again to part the peg from the remaining work stock. The lab instructor will provide you with the initial and final CNC code sections for your part(s) on the Materials page of the course website. Each person on the team is responsible for helping to create the CNC program for the pegs. Your team’s codewill be standard for all individual programs within your team. Prepare your code using the provided drawing for your pegs manually, and save the text of your final program as a MS Notepad file with the extension .NC on your drive space. The program file must be verified before production.

Example Program for a Cribbage Peg.

Note that the workpiece origin is on the centerline of the workpiece (and not at the top, right corner of the part – where the touch-off is!).

N010 G90 G80 G40 F4 S1500 T01 M06

N011 G00 X.5 Z.15 M03

N012 T03 M06

N013 G00 X.3 Z-.05 F1

N014 G01 X.05

N015 G00 X.3

N730 G00 X.5

N740 G00 Z-1.85

N750 T01 M06 F4

N760 G00 X.2

N770 G01 Z-2.33

N780 G00 X.25 Z-1.85

N790 G00 X.15

N800 G01 Z-2.33

N805 G00 X.2 Z-1.85

N810 G00 X.125

N820 G01 Z-2.33

N830 G00 X.5 Z-1.85

N840 T03 M06

N850 G00 X.26 Z-2.25 F1

N860 G01 X-.1

N870 G00 X.5

N880 G00 Z.5 M05

N890 T01 M06

N900 G28

N910 M02 M30

Save your file to your disk space, and verify it with the TA / Instructor before cutting acetal!

III. Setup

This lab uses the Turning equipment located in located in CM 203. Access to the equipment on the following table may be required. Prepare this equipment prior to the start of the lab by making it generally accessible and cleaning any loose debris.

Equipment/Material Listing

Qty / Description / Location / Notes
(1) / Lathe Workstation / CM 203 / Power on controller, load software, home machine.
(1) / Shop Vacuum / CM 203 / Connect to power, set up by Milling station.
(2) / Flat Mill Files / CM 203 / One at Mill, and one at Lathe.
(2) / .5” x 3.5” Acetal Rods / CM 203 / One set of white & black rods per student.

IV. Safety Considerations

The primary personal hazard during this lab exercise results from inadvertent operation of the equipment. Secondary hazards result from tooling and debris left in the lab area. The following actions are recommended:

1.)Check all powered equipment and load software prior to lab. All persons within the lab production area must have approved safety glasses/goggles on during the entire laboratory period.

2.)All personnel should be instructed to visually check for and remove debris from the equipment and work benches.

3.)All personnel should remain standing during the lab. Lab instruction steps should be checked off on the clip boards some distance from any operating equipment.

4.)At the conclusion of the lab, the equipment should be inspected, returned to normal condition, and loose equipment and tooling returned to storage.

V. Lab Procedures

The lab instructor should avoid admitting students to the lab until the previous group has completed their clean up and exited with their materials. The lab team (approximately four to five people to a team) are run through at the same time, with sub-teams simultaneously operating both the computers for coding and the lathe (for verifications). This lab may take more than 1 hour 20 minutes in total.

Sequence of Activities for Each Lab:

1.)Introduce yourself, and the laboratory exercise. Distribute handouts, stock materials, and give any announcements. Students prepare their clip-boarded instructions and personal protective equipment. (2 min)

2.)The lab instructor guides the students through the general verification operation and safety on the Lathe. (10 min)

3.)Allow students to self-assign into two sub-teams of approximately equal size. Ask the student teams to take a minute or two to plan and organize themselves, then they should start their coding peg tasks on the computer equipment. Sub-teams rotate to the lathe to verify their code as they complete their tasks. (60 – 70 min)

4.)Encourage the team to assign one team member to compile a common program and verify it as the manual coding operations proceed.

5.)Ask students to wrap up their efforts and store their code in a couple of places for the team to access. Dismiss class. (7 min)

6.)Students complete their parts storage, 5S their station, replace safety equipment, gather materials, and exit the lab (5 min)

Students should feel free to ask questions before operating equipment as the work progresses. The lab instructor should observe and coach students as necessary to ensure their understanding.

At the conclusion of the lab, the lab instructor should return the lab materials, and report any items that need maintenance/replacement to the course instructor. If the lab will not be used in-between sections, the materials may be left neatly in place.

VI. Grading

This assignment will become part of the final project. There is NO lab write-up required for this lab, but the code will be listed in the project. The instructor will check for completion of each individuals workpieces by the due date. Solution code is listed below:

N010 G90 G80 G40 F4 S1500 T01 M06

N011 G00 X.5 Z.15 M03

N012 T03 M06

N013 G00 X.3 Z-.05 F1

N014 G01 X.05

N015 G00 X.3

N016 G00 Z-.08

N017 G01 X.05

N018 G00 X.3

N019 G00 Z-.15

N020 G01 X.05

N021 G00 X.5 Z.15

N022 T01 M06 F4

N023 G00 X.2 Z.15

N030 G01 Z-1

N040 G00 X.25 Z.15

N050 G00 X.15

N060 G01 Z-1

N070 G00 X.2 Z.15

N080 G00 X.12

N090 G01 Z-1

N100 G00 X.15 Z.15

N110 G00 X.1

N160 G01 Z-.2

N170 G01 X.1 Z-.44

N180 G01 Z-.54

N190 G03 X.10 Z-.66 I.18 K-.6

N200 G01 Z-.8

N210 G01 Z-1

N220 G00 X.5 Z-.5

N230 T07 M06

N240 G00 X.15 Z-.49 F1

N250 G01 X.08

N260 G00 X.15

N270 G00 Z-.80

N280 G01 X.08

N290 G00 X.5

N300 T03 M06

N310 G00 X.15 Z-1

N320 G01 X-.2

N330 G00 X.5

N340 G00 Z-.85

N342 T03 M06

N343 G00 X.3 Z-1.05 F1

N344 G01 X.05

N345 G00 X.3

N346 G00 Z-1.08

N347 G01 X.05

N348 G00 X.3

N349 G00 Z-1.15

N350 G01 X.05

N351 G00 X.5 Z-.85

N352 T01 M06 F4

N420 G00 X.2 Z-.85

N430 G01 Z-2

N440 G00 X.25 Z-.85

N450 G00 X.15

N460 G01 Z-2

N470 G00 X.2 Z-.85

N480 G00 X.12

N490 G01 Z-2

N500 G00 X.15 Z-.85

N510 G00 X.08

N560 G01 Z-1.2

N570 G01 X.1 Z-1.44

N580 G01 Z-1.54

N590 G03 X.10 Z-1.66 I.18 K-1.6

N600 G01 Z-1.8

N610 G01 Z-2

N620 G00 X.5 Z-1.5

N630 T07 M06

N640 G00 X.15 Z-1.49 F1

N650 G01 X.08

N660 G00 X.15

N670 G00 Z-1.80

N680 G01 X.08

N690 G00 X.5

N700 T03 M06

N710 G00 X.15 Z-2

N720 G01 X-.2