Wednesday, 5 March 2014

Clamshell grab for cranes

Grabs are fun. Here is a simple clamshell grab which uses the scoops from, e.g.,
42023 Construction Crew, or 8069 Backhoe Loader. It can be operated manually, or by a motor.

Here is a demonstration of the motorized version:

To build it, first make two scoops. They are identical, so lay out two times these parts:

I chose some coloured parts, just to make it easier to read the instructions. You should of course use parts in whatever colour you want.

Put the first tan 3-axle with stop into the cross-axle hole of the 2-length grey liftarm, and through the connectors of the scoop:

Having made both scoops in an identical way, bring out some more parts:

Connect the scoops offset by half a unit length:

Perhaps you dislike offsetting the scoops, but note that their teeth mesh better that way:

The 9-length yellow beams are for connecting the scoop to the crane, or whatever you are building:

Use the dark grey 4-axles to connect the yellow beams:

Get some more parts, note that you need three black 4-axles, not one:

Use the dark grey 4-axles to attach the black connectors to the yellow beams:

The grey 8t gear will be driven by the worm gear, eventually.

More connectors are needed to hold the worm gear:

And more:

Finally, the worm gear goes in with the 5-axle, and you're done!

If you want to motorize it, use this as a hint:

Another view of the motor driven mechanism:

Here is what the scoops look like when using less colourful pieces:

No comments:

Post a Comment