Modular Working for NASA Ames

At the September 2014 IMTS show, Emmett Quigley, the Manager of the Airborne Instrument Development Lab at NASA Ames Research Center, was looking for a modular workholding system that would help him to quickly change over the fixturing on his table to meet the lab's demands of rapid prototyping and development.

According to Quigley, 

"R&D prototype researchers, scientists and engineers can can come into our lab at anytime.  

If an instrument is down that a scientist needs data from, we stop what we're doing and get it back up. If an instrument is going to be deploying we need to eliminate any machining bottlenecks... anything that would impede deployment." 

"Set up time is productivity killer for our needs"

Demanding design requirements for future development

Quigley had several initial requirements:

1. Has to change over ASAP - immediately!
2. Has to mount two Kurt 5 axis self centering vises in a repeatable location time and again
3. Has to be able to to utilize some of the subplates designs that the lab was already utilizing.
4. Interchangeability across the machine inventory a must utilizing common hole grids and hardware

Emmett looked at a couple of systems but post IMTS only mPower had followed up with the information he needed to start the design.  He found that the Modern Industries mPower modular tombstones and fixturing systems would meet his needs, but would need some customization to truly get the maximum use of his machines table space and travels. The mPower system was to be implemented on two machines to begin with.  The first would be the labs workhorse, a Deckel MAHO DMU70V.  The next machine would be a Deckel Maho MH600C Universal Milling Machine.  The MAHO is unique in that it has both a horizontal and vertical spindle as well as a full fourth axis capability.

After several email exchanges and design discussions with regional manager Chris Savolainen and Ron Bemis, the Application Engineer at Modern Industries the team spent from from October 15th through 17th reviewing the various part shapes and size requirements to define the subplate hole locations that would provide the very best versatility to meet the needs of the lab.

• The Deckel Maho MH600C required around table sub-plate with center hole (2.700" diameter). 19.700" round diameter (500 mm).
• Deckel Maho DMU70V required a "football shaped" table sub-plate with center hole and end hole for zero fixture 20" wide x 27" long. 
• The Y center line 11" needed a 2" diameter hole and they also needed to fit quick change fixture plates for Two 6" Kurt Vises with base and without to be mounted without interfering with the grid plate locations. 
• An  L- shape Tombstone fixture also had to have the ability to mount within the machines without exceeding the internal travels

It was decided  to go with 2" x 2",  1/2 -13 bolt hole pattern in 1.5 “ thick aluminum plates.  However they needed to modify the DMU plate by adding the through hole so they can reach the table with their tool setter.  Quigley then need to duplicate the plates in steel.

The final requirement was that the lab needed to have the locating/clamping features below the surface as these plates will need to be surfaced from time to time. 

Due to budget constraints the system had to be developed with consideration for the longer term lab requirements so that it could eventually expand for upcoming new projects.  Preparing for the unknown problem has always been part of the mission at NASA so long term contingency planning is the norm.

In June of 2015, phase one of the project was implemented on the Deckel Maho DMU70V machine. 

Quigley's thoughts on the implementation thus far:
“One of the great results of the system is the lack of visible clamping devices making cleaning the table a snap.  People come into the lab and ask how the vises are held down! 

The mPower system has paid benefits since its deployment on the DMU.  Cleaning the chips off of the working surface takes longer than switching over from one configuration to another.  The addition of the 1.5 inch thick aluminum subplate with a ½-13 2x2 threaded hole pattern has made doing oversize/plate work considerably quicker and repeatable than our previous method.

The acquisition of a KURT self centering vise has made the switchover to do 3+2 work routine.  Being able to know that the vise is in an repeatable position each time makes setting the work coordinates easy.  The same holds true for our dovetail device.
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This year we plan on expanding the fixturing capability to the MH 600 as well as working on designs to adapt the main subplate had points to our CNC Tree mill as well as our Bridgeport and Deckel FP4m manual mills."

According to Savolainen "NASA's Airborne Instrument Development Lab at Ames really considers both current needs and future needs when they look at workholding systems.  The machines and equipment have to be versatile enough to handle current projects but also new research projects that might not even exist until 10 or 15 years from now. They really put a great deal of thought into products before they get them and it's actually a real pleasure to work with engineers who plan and think so far into the future!"