Manufacturer of Thin Walled Parts CHALLENGE:
- Tall Stainless Steel Part
- Thin Walls
- Tight Tolerances
- Vibration
- Long Process Time
THE ENGINEERING TECHNOLOGIES SOLUTION:
- New Fixtures for Rigid Part Holding
- New Process & Tools
- Increase depth of cut
- 4 axis machining
- New Set-up Station for Offline Setup
RESULT:
- 300% Increase in Productivity
- 80% Reduction in Setup Time
- OD Tolerance < 0.010"
- Surface Finish Ra 125 micro-inch
Quantum Leap...
In Productivity and Set-Up Time Reduction
Machining parts a meter or larger in size is a difficult task. Part handling, fixturing and tooling all present unique problems. Given the task of reducing a customer's production time by 75% is also a significant challenge. And, when the part is 1-1/2 meters height by 1 meter in diameter and made out of a rolled piece of stainless steel, the job is even more daunting. This is what faced Engineering Technologies in its latest turnkey project.
To solve the machining capability size requirements a Model V80 vertical turning lathe with a 80" diameter table was built by Engineering Technologies in its Toronto facility. Two ram heads were mounted to the machine cross rail to allow the part to be machined by two cutting tools simultaneously. To reduce tool vibration and dampen machine harmonics, the machine was also designed with a polymer base construction.
The specifications for manufacture called for the 6-8 mm stainless steel part to be machined to a thickness of 2mm and maintain an OD tolerance of less than 0.010" with a surface finish of 64 RMS. The challenge was to fixture the part cylinder in such a way to prevent part distortion while machining as well as not apply too much fixture pressure that would allow the part to release itself into an out of round condition after machining was completed and the part removed from the fixture.
To solve this problem, Engineering Technologies designated a portable fixture that had 32 curved locating pads, each covered with a piece of soft rubber on the exterior. The part is lowered over the fixture as only the OD requires machining. Then the part and fixture are mounted to a set-up station that is a rotary table mounted near the operator workstation. This allows fixturing to be done while another part is being machined.
Each fixture pad has its own leadscrew adjustment that allows the pad to be expanded individually in increments of less than .001". As the part and fixture rotate slowly, an indicator shows where the adjustments are required to provide the proper diameter dimensions and roundness.
Prior to Engineering Technologies unique engineering solution, set-up and machining for this part used to require the customer to spend over 12-14 hours to get a finished part. The customer needed to reduce production time by more than 50% to address an order backlog and initially did not believe Engineering Technologies time study and production guarantees. They asked Engineering Technologies for a penalty/bonus clause in the purchase order and Engineering Technologies engineering team delivered more than the customer expected by providing a machine and fixturing system that produces one part in less than 4 hours. This dramatic solution to the customer's productivity problem earned Engineering Technologies a $30,000 bonus payment.