Lathe chuck spider in metal and plastic

With some of the small bits I've been needing to grasp in my sherline 2 1/2 inch three jaw chuck, I decided to make some chuck spiders. I have been wondering if plastic spiders would work well but was concerned about making the thinnest spider out of plastic as it would be likely to flex under any significant backwards pressure. I decided to try making both! The thicker design would be plastic to try out its effectiveness and the thinner design I'd make in bronze infused stainless for strength and durability.

Because I wanted the inter-jaw webbing to be as thin as possible I knew I'd need to extend the webbing into the throat of the chuck to get a better beam. No problem there and it has the added benefit that it sure makes it align beautifully when installing it quickly.

Here's the thinnest metal version first. It really performs fabulously and is as rigid as I had hoped. there's a small amount of clearance around the chuck jaws so the spider has almost no place to move. I made this one without magnets and it doesn't seem to need them. It was a simple matter to take a light clean up pass on the front of the spider to remove the low profile casting texture. I left it on the rest of the part.

Metal chuck spider for sherline chuck

As with many of the metal parts for upgrades I design, I created this in CAD and sent it out to Shapeways to print it. (sorry about the smudges on the chuck surface. bought it second hand with a bit of wear on it).

Rapid prototyped metal chuck spider for Sherline 3 jaw chuck

Rear of chuck spider showing deep center for rigidity

Installing metal chuck spider on sherline chuck

Mowrer chuck spider in use on Sherline chuck

The plastic part came back functioning equally well. Its rigidity was very good and dimensionally it was very accurate. For future prints of this part, I think I will do it in black plastic as any oil on the chuck quickly leaves its mark on the white part.

Plastic printed chuck spider for Sherline 3 jaw chuck

Installing plastic printed chuck spider on Sherline Chuck

Back of plastic printed chuck spider

Plastic printed chuck spider in place on Sherline 3 jaw chuck