Made to order plate configurations are available. Call toll free 877-462-BOLT for further information.

 

Lean Manufacturing & Modular Fixturing

Invert-A-Bolt™ products are routinely used to implement lean manufacturing initiatives in the work environment. By eliminating dedicated fixturing and the related costs (tool design, manufacture, maintenance & storage) and creating standardized tooling & work practices, it is possible to become significantly more efficient & productive. See the Cessna Aircraft Continuous Improvement Newsletter describing the benefits of using an Elijah Tooling Common Modular Fixture.

A Universal Common Modular Fixture (UCMF) consists of a flat plate tooling fixture with Invert-A-Bolt™ fasteners set on standard centers and used in conjunction with locating pins on diagonals. Additional versatility is realized by using multi-purpose holes at the pin up locations making it possible to screw other tooling components into the fixture as well. The manufacturer is able to realize the benefits of using both Invert-A-Bolt™ fasteners (for hog-outs) and off-the-shelf modular tooling components (for castings, forgings, etc.). These fixtures are available turn-key, customized to fit your specific application!

 

View Full Universal Common Modular Fixture Video Playlist

Typical usage of a UCMF consists of setting up a part in a picture-frame , using the fasteners at the tab locations for hold down while simultaneously locating at the bushed hole in the fixture. The picture framing concept is ideal for many parts since hard location against datums is not required.

 

Typical machining sequence for over-the-top tabbing in picture frame machining configuration using Invert-A-Bolt™ fasteners:

1. Prep the stock to accept the back bolt fasteners and locator pins. Prep for the fasteners consists of drilling a through hole and tapping (or thread-milling) a thread for about 1/2" deep. Prep for the locators would be a drill/ream operation for whatever size locating pin is to be used.

2. Load the stock into the fixture. Rough side 1 of the part. No clamps are used. Nothing is in the way of the machining. No clamp changes or avoidance of clamps is required. This looks like a pocketing operation. It's best to leave the excess on the flange top to keep the setup as rigid as possible. At the captive fastener locations, tap the thread about 1/2" deep.

3. Flip the part over, locating on the outer "frame" which should be at the height of most of the internal ribs. Shim as required, and rough/finish side 2. Locate as much as possible of the stock material on the base plate. This adds stability to the process versus having it up in the air while machining. Again, no provision for clamps is made. Side 2 is completed including the outside mold line.

4. Flip the part over. Finish Side 1 except the tops of the flanges.

5. Last operation - thin the tabs to approx. .02"-.03". Part is complete.

6. Snap the tabs and perform minimal handwork to top of flange to clean up.

Elijah Tooling UCMFs are used to implement Six Sigma Initiatives to eliminate variations by creating standardized workholding: Design for Six Sigma (DFSS) - Workholding

Define: The number of setups & the associated setup time is hurting our ability to be competitive. Creating a mill fixture for every part is capital intensive and adds to our non-recurring costs. Non-recurring costs are too high, especially since we generally don't get paid for those costs up front, rather they must be amortized over the run of production parts.

Measure: Moving clamps around and stopping the machine to do it costs too much. Counter-bored bolts are always in the way of the process and require more setups to get around them, especially in multi-axis machining. Manufacturing a fixture plate for every new part requires design, program and fab time.

Analyze: By using picture frame machining concepts and tabbing schemes it was possible to eliminate the use of clamps. By establishing a standardized mill fixture plate, it was possible to eliminate design, program and fab time. It was also possible to eliminate the need to produce a mill fixture for every new part.

Improve: Implement standardized workholding techniques and eliminate duplicate milling fixtures by incorporating standardized fixturing. Convert tooling to Elijah Tooling Universal Common Modular Fixtures for horizontal machining cells. Use Invert-A-Bolt™ fasteners to replace bolts and clamps for vertical machining.

Control: Establish standardized workholding procedures. Train operators, CNC programmers and tool designers to "think Lean" and maximize the benefits of using Invert-A-Bolt™ fasteners for workholding. 

High-Speed Machining and Throughput

Define: The efficiency of our high-speed machines is reduced due to vibration and un-stable setups. 

Measure: We are running our spindles at 60% of max due to vibration in the setup. 

Analyze: By getting the holding power of our clamps closer to the fixture plate we can improve the stability of the setup. The taller the clamp setup, the more vibration we encounter.

Improve: Replace clamps with Invert-A-Bolt™ fasteners which are contained in the fixture plate and hold the part as close to the base as possible. 

Control: Establish standardized workholding procedures. Train operators, CNC programmers and tool designers to maximize the benefits, wherever possible, of using Invert-A-Bolt™ fasteners to create stability in the setup.