Piccolo Fabrication Guide
##Materials##
We suggest using a combination of MDF or Hardboard together with Acrylic for making Piccolos. We settled on this combination as we found MDF on Acrylic produced the least friction between moving parts. If using hardboard, use dry processed board that is smooth on both sides.
A 100% wood Piccolo also works, as does a 100% acrylic one, however acrylic tends to create more friction and is more brittle, so the parts will be more suspect to breakages. The cutting pattern is tailored to the tolerances below, so if making your piccolo entirely from acrylic, you may want to adjust the cutting pattern.
###Material Thickness###
The current Piccolo v1 cutting pattern is designed for 3mm material. Recommended thickness are:
- MDF parts: between 2.75 and 3.10mm
- Acrylic parts: between 2.90 and 3.20mm
- The gears: equal to or thinner than the other acrylic parts, but greater than 2mm.
(note, 1/8 inch material may work, but the slots will be a bit tight and may need adjusting. See Adjusting the Cutting Pattern.)
Whilst thicknesses in this range will work, it is important that the material thickness is consistent across the panel. MDF and Hardboard is generally pretty consistent, whilst Acrylic can vary in thickness across a single sheet. Extruded acrylic is recommended over cast acrylic as it will have a more consistent thickness, however it is more expensive.
Why different tolerances for the MDF vs the acrylic parts? On average we have found the acrylic sheets to be slightly thicker, so we've allowed for this in the design.
###Paper Spacers### In order to get a good fit for its moving parts, Piccolo uses paper spacers to adjust its tolerances. The paper spacers are generally needed if the acrylic is thicker or the same thickness as the MDF, if the Acrylic is thinner then the spacers may not be needed. Multiple layers can be used - the cutting pattern includes two sets of spacers. We have found that thin card, around 160gsm, provides a good amount of flexibility in adjusting the fit without being too finicky to work with. Thinner paper will also work fine, but more layers will be needed.
###Colours### We've used coloured gears and paper spacers to add flavour to our Piccolos. One thing to note about using coloured and clear acrylic together is that your coloured material could be slightly thicker - this is bad and will cause your gears to catch! Make sure the gear material is thinner than, or the same thickness as the surrounding parts.
We don't recommend painting or dying your MDF or Hardboard parts, as this will also affect your tolerances and can create friction. Rubbing a wood stain into your material can work though, and it is also possible to find coloured fibreboards (difficult however, to find in 3mm or 1/8in). We have a made a few Piccolos out of black MDF from Ventech in Australia.
##Laser Cutting##
Laser cutting leaves a kerf (gap in the material) when it cuts. The cutting pattern accounts for a kerf of about 0.2mm, however the exact kerf will vary between machines. If you are doing your own cutting and would like to adjust for the kerf, see Adjusting the Cutting Pattern. Laser cutting will also leave a draft angle on cut edges, and this is compensated for in the design by flipping any mating parts. That said, if the draft is too extreme, this will start to affect the tolerances in other areas.
A professional cutting service will likely give you a good quality cut with minimal kerf and draft, that should give you some decent working Piccolos. Dirty lenses or a lower quality machine will leave you with a wider kerf, greater draft and rougher edges, and your Piccolo is more likely to have a few issues.
For a prettier Piccolo, we suggest putting a protective paper coating on your MDF or Hardboard to remove scorch and flashback. If you are using a cutting service, just ask them if they offer this as well. You can also sand these marks off rather than use a paper backing, but this may affect your tolerances.
###Tabs and Labels###
All parts in the cutting pattern are tabbed into panels for each material, and the breaks in the lines are replaced with lines for etching, to help with breaking out the parts. If using a cutting service, make sure you tell the your fabricator about the tabs, to avoid confusion. We recommend a 50% depth etch for the tabs and labels.
##Adjusting the Cutting Pattern##
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