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Ross Crawford / projects / towercrane / preview

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Tower Crane with Luffing boom

Here’s my pre-project ideas:

It’ll use 2 RCXs - One to receive remote control signals and operate the turntable, boom & hook; the other (totally autonomous) will operate the balance weight.
It’ll be high. My initial plan is for a boom of at least 1m. This means the balance weight will need to be fairly heavy. I’ll probably include the 2 RCXs in the balance weight.

Links

Tower Ideas by Fredrik Glöckner
Some pics Look at Raimond cranes
Another Pic Products, Construction cranes, HC-L series

Preliminary info

Well, obviously, I’m not using the RCXs for the moveable counterweight. This was because of the difficulty of feeding all the 9V cables to something that’s moving (it’s total travel is about 25cm). So now they’re static ballast, and I’m currently using two battery boxes (not connected) for the moveable counterweight. 12 batteries aren’t really heavy enough, so I may have to change again...

The boom length is about 180cm, but is mounted about 10cm behind the turntable, thus making the maximum lift radius about 170cm. The platform extends about 30cm behind the turntable.

The tower is modular - the base section is different, but I can add as many other sections as I want. I’d like to build it higher, but I’m plum outta technic beams. Anybody wanna donate some????

The boom is sort of modular - I can add & remove sections fairly easily, in fact I’ll probably shorten it until I get all the other bits ‘n’ pieces finalised, and the programming done.

Currently, the counterweight RCX is running a LegOS program (because LegOS ignores the remote control), and the main RCX is just running the standard 1.5 firmware (no program yet). Although the RCX driving the counterweight is autonomous, the 2 RCXs do interact, as follows:

The counterweight limit sensors are connected to both RCXs, stopping all movement when activated.
The motor driving the counterweight drives one side of a differential, the other side driven by a motor from the main RCX. The output of the diff drives the main lifting cable. I came up with this arrangement, so that as a load is lifted off the ground, it won’t be raised very far until the counterweight has re-balanced the platform

Preliminary shots (sorry not much detail)

Site last modified November 4, 2004 Home

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