Is Polycarbonate a usable frame material?
I’m starting my first cartesian printer design and need to decide between Aluminium Composite (Dibond) and Polycarbonate (Makrolon) for the frame material.
Either way, for my prototype, I won’t be cutting the material myself. Not having access to a laser cutter or router I’ll be using a commercial supplier who can cut to shape given a sketch. Not the cheapest way but a solution.
I have learned that Acrylic (Perspex) has a number of drawbacks for use as a frame material e.g. cracks easily, thermal deformation etc. which Polycarbonate seems to address. The only downside? I see with Polycarbonate is that it is mostly a transparent material. For a prototype I don’t mind displaying the internal working of the printer so that might actually be a plus point.
I have experience of Aluminium Composite from my Mendel90 build and it seems quite serviceable. I think that price-wise Polycarbonate would work out cheaper than Aluminium Composite.
I also appreciate that Polycarbonate can yellow with extended exposure to UV from sunlight or other sources. I keep my printers away from windows anyhow so I don’t see this as a big problem.
Opinions and experiences of building in Polycarbonate would be welcomed.
Polycarbonate sheet can be bought in other colors, but black seems to be the main non-clear offering. I have been using PC clear doors on my enclosure and it’s been doing well for nearly a year now. The main other surface for my enclosure is aluminum composite and I’m finding the aluminum composite is more rigid. PC is pretty floppy, I think you want to go 50% thicker or more for PC vs. aluminum composite panel.
@Jeff_DeMaagd Thickness options were a primary concern. Dibond only seems to be available in 3mm and 5mm whereas Polycarbonate is available from 2mm to 12mm in 1mm increments.
Dibond exposes the aluminium component on its edges and shows its obvious sandwich construction.
I was also considering Polycarbonate for allowing wifi/bluetooth signal ingress to the buried electronics.
I think you’ll find 5mm dibond probably serves pretty welll, but if having a bigger variety is needed then PC is a better choice.
The metal in dibond certainly would make reception hard. Metal-based machines with WiFi use an extension to external antenna.
PC is likely going to brown when you cut it with a laser. I’ve had good cuts on the Shopbot. ACP cuts well and is more rigid though depending on where you are it’s likely going to be more expensive particularly if you have to get it shipped in. You could do something like Ultimaker and have an ACP structural frame and non structural acrylic panels.
Thanks @Jeff_DeMaagd , @dstevens_lv I might actually go with 5mm Aluminium Composite for my first prototype on the basis that it’s easy to work with manually.
Once I have a full CAD design with all the nooks and crannies worked-out I will re-evaluate whether I create a see-through model in Polycarbonate (I actually find that idea quite appealing but can’t imagine I could keep it scratch-free with manual machining).
@Neil_Darlow Leave the backing paper on while you cut and you should be good to go in terms of making sure you don’t scratch the material.