some calculations

13 Jul 2007 After doing a lot of reading on the subject, I finally started doing some calculations regarding sizes. It's not much, but it's a start.

Because I'm lazy and I don't want to drill a zillion holes in the platen, I will go with a single-hole design. This also happens to be the best way to work with differently sized plastic sheets.

The polystyrene sheets sold at the hardware store are 100cmx200cm. The 100cmx100cm sheets are cheaper, so I will be buying those. This means my machine needs to be able to work with 100cmx100cm sheets MAX.

One of the applications I want to use vacuforming for, is to create a cover for my lawnmower robot. I estimate it will be pretty big (because I'm an amateur ;)

So, I will design my vacuform machine to have a 100cmx100cm platen.

Because of this size, I'll also create an over/under model. This means that all the components are aligned vertically. The oven on top, the platen right below it. Total surface area for this machine will be 1m^2, which is OK for me.

So, I'm basically building a giant closet with 3 levels: 1 for the oven, 1 for the platen, and 1 below the platen where I can place my vacuum cleaner or vacuum pump and tank. I won't consider the oven at this point, because it needs to be constructed from a heat-resistant material and I don't have a clue about that yet.

The local hardwarestore sells MDF panels of 244cmx122cm big (both 12 and 18mm thick).
This is how to plan to cut them up: 2 big panels of 102cmx102cm, and 8 102cmx10cm pieces. I'll have a 20cmx40cm piece leftover (in white).
[G2:11432]

I'll get 4 metal L-profiles of 2m long to use as corners. The 8 MDF pieces will fit between those metal profiles, making 2 squares: 1 for the platen, 1 for the shelf below. The bigger 102cmx102cm pieces will rest on top of those squares (just like shelves).

The reason that all pieces are 102cm long and not 100cm, is because I want some room to maneuver with the holding frame for the plastic. 1cm on each side should be enough room to maneuver.

Hopefully, I will get all this stuff from the hardware store and start putting it together tomorrow.

Also, I've been wondering if my vacuum cleaner is powerful enough to pull plastic with this thing. On the TK560 forums, the power of a vacuumcleaner is measured with inches of mercury. Now my vacuum cleaner doesn't mention anything like that in it's manual ;)

Here is an online convertor between pressure units:
http://www.vacuum-guide.com/english/equipment/calculatorpressure.htm

I haven't checked if my vacuumcleaner is powerful enough yet...