Dancing gnomes, OpenSCAD and 3D printing

For the gnomes workshop at the weekend I wanted to create a dancing gnomes display using one of the motors. The stepper motor was smallest so fitted the requirement the best. I found an example of a planetary gear arrangement in OpenSCAD and based my models on that.

I designed a stepper motor mounting plate based on the 28BYJ-48 data sheet and added a cross beam to support that. I also added a base which was a simple ring. The gears were modified with a top hat based on the washers and pins design I used for the Enchanted Cottage. These screw into a cross beam, again based on the designs from the Enchanted Cottage. I added some supports on the gears so that the gnomes could be slotted in place.

Mechanism

I printed these out and discovered that the design for the clips was quite weak. So I redesigned these with a side support. These have also proved to be fragile at the top so have a further redesign as per the final picture. I also experimented printing the gears with and without a brim. The brim does ensure that the teeth don’t curl up but means there’s a clean up to be done afterwards. With out the brim I had one curled tooth but it was not sufficient to stop me using the gear.

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I printed out the motor mounting plate so that I could check that it fitted the motor correct. It was fine so I went ahead to print out the main gear/chassis. I looked at the time it would take to print and slimmed down the design a little with small cross supports and a thinner ring around the outside. The first print of the cross beam also had an issue with the hole sizes and the hole for the stepper motor pin was too small, that was due to the allowance being subtracted rather than added to the hole.

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When fitting the top hats the round top caused a problem for getting a screw in place so I’ve redesigned those with a hex head. Finally the brackets were re-enforced a bit more thanks to some suggestions from Dave Sawyer. However, I may just go with the version I’ve got printed depending on how much time I have spare before Friday.

R3

Workshop Preparation

Workshop Preparation

In preparation for the Raspberry Pi workshop at the end of the month I’ve been experimenting with the Raspberry Pi and simple hardware. So far I’ve had success with: LED Micro switch Tilt switch Servo Motor via H-Bridge I’ve also

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Thinking about animatronics

Thinking about animatronics

I’ve been invited to a play workshop in Leeds at the end of the month and that in turn has got me thinking about animatronics. Basically we plan to make some gnomes and make them move. Two key factors here

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You are my density

You are my density

It can be a bit tricky to determine the nature of a mystery metal, and in the home workshop it can be even harder to tell the purity of a metal. So I looked up the density of Aluminium and

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Bird table

Bird table

Back in the summer of 2014 I completed a gate modification extending the height of the back garden gate. One component of that was some bamboo screening at the top. Unfortunately as various cats, foxes and squirrels had used this

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A new industry TV channel and competition

A new industry TV channel and competition

The newly formed Department of Industry Commerce and Services is launching a new TV channel. The channel will showcase British Industry and trade as well as news, parliamentary reports and documentaries. It is believed that it will also include reruns

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Casting a flywheel – Melting metal

Casting a flywheel - Melting metal

Prepare furnace There’s not a lot of preparation to the furnace other than plugging in the fan and connecting the pipe to the side of the flowerpot furnace. However, one key piece of preparation is to ensure is the layout.

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How to get the best results with a bandsaw

How to get the best results with a bandsaw

Doing your own repairs, construction or crafting projects can involve a lot of tricky steps. But one that’s often handled in a relatively crude manner even by experienced handymen and DIY practitioners is sawing. Simply put, with a hand saw

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