Hobbed bolt alternative for geared extruder?

I am looking to print a new extruder preferably geared one like those based on Wade's design instead of direct drive because I am printing 3mm ABS.

Most if not all requires a hobbed bolt or some what if I am not mistaken. My problem is I don't own a lathe, mill or dremel. Drill + HSS drill bits, hand tap, jigsaw, hammer is all the tool I have.
As I live in China, there is plenty cheap supply of standard parts - like T2 pulley or M4 insert. Although asking a workshop to machine just one hobbed bolt is not ridiculously expensive, it's not the cheapest way either and the turn around time is very long.

I would like to know if there is any extruder variations or anyone have the experience of building one using standard parts, without the need of machining but simply assembling for the driving chain? Be it the pulley, inserts or any unknown component I couldn't name. Thanks.

I tried google and thingiverse for a while but the derived designs info are so spreaded out that I might have missed the gem.

See the RepRap wiki for "How to make the hobbed bolt" using a hand drill, a file and M3 tap. Most people now use an M4 tap or they use the new dremel tool method but since you don't have a dremel tool...

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Frankly I don't even have a vase, and not exactly comfortable working with power tools - drilling aluminium would get me nervous already.
The room I am working with the reprap is also my bedroom so I don't exactly like having all the dust and bits flying around. =)

Okay, perhaps I should walk out my comfort zone a bit and try that out, but I am still pursuing a no-power-tool method. Leaving the hot end the only thing that I needed from the workshop, with all other components I could buy, assemble, DIY myself.

Side note: Electronics wise there are so many cheap TB6560 drivers and Arduino clone selling around so I could get away with hot-oven or plate soldering as I don't have such things either. The microwave oven I have doesn't quite work well with SMD I bet =P

In the interest of making this topic informative… There are a couple of extruder designs that use an M5 bolt and an MK7 filament drive gear. You mount a printed gear on the M5 bolt, flatten a part of the bolt and put the MK7 gear on the bolt, tightening the grub screw on the flat. Then align the gear with the small gear on the motor, and you're good to go. [www.thingiverse.com]

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Does anyone have a link to the new dremel method? This is the first I have heard of it

Just an idea.. if you'd use a simple screw as shaft and glue a structured insert on this... threaded inserts are available for furnitures - not aproved - just as an inspiration

This is a typical one

alibaba.com/photo/630547504/metal_barrel_insert_nut_for_wooden_furniture.jpg

[img.alibaba.com]

or any other knurled nut til down to the ventile fitting ring on a bicycles tire ( I heared that China is the land of bicycles)


Good luck on searching


[www.google.de]

Edited 2 time(s). Last edit at 07/31/2013 03:44AM by Optimist.