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The gate needs to be removed so this part can be used with an older part that does not accommodate the increased gate size of this part.

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SCH-I510
2/21/2013 5:57:52 PM

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This image shows the part after machining the gate away using a 3/32” endmill.

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SCH-I510
2/21/2013 5:49:53 PM

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Having 8,000 pieces to machine I decided to use vacuum to fixture the parts for machining. I have 3 vises installed on the machining center so I settled on 3 12 place fixtures, one for each vise. I wanted 3 separate vacuum pumps, one for each fixture.

I have a pressure regulator feeding 3 pneumatic venture style vacuum generators. There is a on / off control for each section and a vacuum gage for each section. I can easily pull 25" with this setup.

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This is the fixture plate which holds 12 parts. There is a foam cord that provides the seal in the bottom of the pocket. This fixture plate was designed in solid works and built using the FDM 3D printer. It works but isn’t accurate enough for the task at hand so the next project is to machine these pieces from delrin on the machining center.

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Here you can see the foam cord seal in the bottom of the pocket as well as the 1/32" hole providing the vacuum from the internal vacuum passages printed within the part.

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2/21/2013 6:25:17 PM

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This is the faceplate as designed in solidworks. I was planning on machining and engraving this panel but decided to print it on the FDM machine at the last minute. Probably would have been 10 minutes of machining but I was sleeping while the FDM printed it. Build time was almost 9 hours and the part is ¼” thick.

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2/21/2013 6:25:17 PM

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2/21/2013 6:25:17 PM

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2/21/2013 6:25:17 PM

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2/21/2013 6:25:17 PM

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2/21/2013 6:25:17 PM

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Here you can see the finished assembly. The mounts for the vacuum generators (the blue parts) and the T-Strainer filters are also printed in the FDM machine.

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SCH-I510
2/21/2013 4:27:41 PM

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SCH-I510
2/21/2013 4:27:52 PM

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SCH-I510
2/21/2013 4:28:15 PM

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SCH-I510
2/21/2013 4:28:32 PM

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SCH-I510
2/21/2013 4:28:54 PM

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SCH-I510
2/21/2013 4:29:14 PM

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SCH-I510
2/21/2013 4:29:31 PM

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SCH-I510
2/21/2013 4:29:47 PM

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I like to use electrical pull boxes / junction boxes for projects like these as they are inexpensive and robust.

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SCH-I510
2/21/2013 4:41:17 PM

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SCH-I510
2/21/2013 4:47:35 PM

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Errant pieces of fdm support material inside the letter a. Must be a bug in the FDM software!

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SCH-I510
2/21/2013 4:47:51 PM

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SCH-I510
2/21/2013 4:48:02 PM

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SCH-I510
2/21/2013 4:48:38 PM

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SCH-I510
2/21/2013 4:48:51 PM

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SCH-I510
2/21/2013 6:00:31 PM

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Close-up of the foam seal. Note the angled lap joint. This seems to seal well and doesn’t require the cord to be glued together.

Below you will see that I ended up having to machine the fixture plates instead of using the FDM versions as they just were not accurate enough.

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Parts sucked to the fixture with about 20” HG

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SCH-I510
2/21/2013 5:04:15 PM

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SCH-I510
2/21/2013 5:04:25 PM

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SCH-I510
2/21/2013 5:04:40 PM

2013-02-26 14.06.31

Here is the plumbing on the back side of the machined delrin fixtures. I rigid tapped the 1/8 NPT holes and installed instant tube t fittings and one elbow at the end.

2013-02-26 14.07.20

Installation of the 1/8 foam cord gasket material into the machined delrin fixtures

While not clear in this photo, there is a .08” spot drill with a 0.021" hole drilled through to the 1/8 NPT threaded hole on the back side. Having such a small hole providing the vacuum path allows the parts to stay sucked to the fixture even when all the parts are not installed on the fixture. This makes inserting the parts on the fixture easier as they stay sucked down during the loading and unloading process.

2013-02-26 17.05.32

Here you can see the 3 fixtures setup in the machining center. There is very little variation in the cuts across all 36 parts using the machined fixtures. The FDM fixtures had as much as a 0.015” variance between parts.

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Cycle time for all 36 parts is about 90 seconds. I can speed up the cutting if necessary, but compared to handling the parts the cutting time is negligble.

2013-02-26 17.06.51

SCH-I510
2/26/2013 5:06:50 PM

2013-02-26 17.07.07

Here is the vacuum control box on a cart under the machines control, this provides the operator with easy access to the controls and the 3 separate vacuum gauges let you know if you have proper vacuum pulled on each of the 3 fixtures.