Small brass parts work holding ideas & suggestions

[swood1]

Hi all,

I like to work on small brass parts mainly for clocks so they can be quite small parts. The parts I work on usually have a thickness of 3.0mm but they can be 1.0mm if I want to machine some clock wheels. Generally I am machining right through the material. My question is can anyone give me some ideas on fixturing as currently I am really struggling. I use bits of wood, usually my project fails because of poor fixturing so I end up making with hand tools.


Regards

Steven

[JohnHaine]

Two approaches. One, prepare your gcode with CAM that can insert holding tabs in non critical areas so you can screw the blank down to a wood base. I use Cambam. Second, a layer of blue masking tape on both the stock and the spoil board, then superglue the stock down. Prise the work off when cut and boil in water to release the glue. I used to use this mainly but now tabs most often.

[swood1]

Is blue masking tape double sided tape? Never tried this method.

[m_c]

Sounds like the kind of parts I'd do on a vacuum table, but the parts I do I'm happy to not fully machine through, and then finish with a sharp knife and deburring tool.

Tabs and/or gluing the parts down are all workable options, but you'll likely need a mix of options depending on the part.

[pippin88]

Is blue masking tape double sided tape? Never tried this method.

No, double sided tape usually has too much "give" / movement because it is thick and soft.

Blue tape method:
Layer of blue painters tape (masking tape) on flat machine surface
Layer of tape on flat workpiece / sheet of brass
Superglue one side and hold down firmly until glue dry

Many videos on it available

[Robin Hewitt]

I thought the makers of clocks had switched from shellac to super glue. Either way you heat it up when you want it to let go

[phill05]

I am cutting clock parts and I use a thin double sided tape used and sold for hold down small engraving parts, it works really well.
http://www.pantograph.co.uk/pdfs/accesories.pdf there is low tack and high tack depending on what you need to hold down, far quicker and easy clean than using super glue and blue tape.

When I design a sheet of clock wheels to cut out I put a strip of D/S under and also cut out the centre holes first and drop a screw in to hold each in place whist all the crossing cut outs are done then follow up cutting the disk out I only use tabs for parts with no screw holes.