Cut my ball

February 4, 2016 1:14 AM

I have a large acrylic hamster ball I would like to cut in half. I can remove the lid to rest the sphere on a flat surface, but I would like to my cut to be parallel to the flat side, not perpendicular (like this). What's the best way to do this? The cut doesn't have to be super-precise, but the cleaner the better.

Assume I have access to most common and some not-so-common tools. I've never really worked with acrylic before and I only have one of these hamster balls, so I'd like some tips before I start hacking away!

posted by btfreek to Grab Bag (13 answers total)

I bet a hot wire styrofoam cutter would do the job. It might be overkill but if you built a wall at the right height as your cut to secure the ball you could use it as a guide for the cut as well, or build an arm to attach the cutter to and keep it at the exact right height, while moving the ball into it. I'm just spitballing here though, I have no applicable experience except watching that Tested short where they take apart a BB8 toy.
posted by Mizu at 1:44 AM on February 4, 2016

Do you know someone with a woodworking shop? This should be a job for a bandsaw (IF wielded by a safety-savvy person!).
posted by Namlit at 2:43 AM on February 4, 2016 [1 favorite]

I'd mark the cut with masking tape to give me a line, then use an appropriate cutting instrument along that line, and use sandpaper to neaten up. Masking tape will also reduce the chance of splinters. But the bandsaw idea sounds good, if you have access to one.
posted by Joe in Australia at 2:48 AM on February 4, 2016

dremel tool with a cutting disc.
posted by 5_13_23_42_69_666 at 3:25 AM on February 4, 2016 [4 favorites]

Fine-toothed hand saw, going slowly.
posted by Too-Ticky at 4:01 AM on February 4, 2016 [1 favorite]

My main concern with this project would be the plastic shattering. Second would be the edges melting when using power tools. This can be minimized by using low speeds.

I would probably start with a hacksaw, get aggravated with the time it was taking and then move to a bandsaw. Some type of jig or support would be needed to prevent wobbling.
posted by Talia Devane at 4:02 AM on February 4, 2016

I think using a bandsaw would be asking for trouble. You'd need to make a pretty involved jig to hold it safely.

I'd mark it out with a thin sharpie, elevated on some books or something to get a straight line. I might run an exacto knife over the line to make it less likely that the surface plastic will flake off. Then I'd use a dremel and a disk. If you put a sheet of sandpaper on something flat, you could get a pretty clean edge. In school, I remeber using successive grades of wet dry sandpaper and then buffing compound on a felt wheel to polish.
posted by bonobothegreat at 4:10 AM on February 4, 2016 [2 favorites]

After you draw a line using a sharpie or masking tape and a pen, you could try using a mini-hack with a fine-toothed blade. It will take a while, but it will avoid the melting problem you may have with just about any powered solution(and it's cheap).
posted by H21 at 5:31 AM on February 4, 2016

I'd use a Zona razor saw, which is an inexpensive, thin-bladed, fine-toothed backsaw. Rather than trying to eyeball it, I think I'd clamp the saw to a table, elevated on a block of wood (or whatever) at the correct height relative to the flat bottom with the edge sticking out, and then draw the hamster ball sideways across it. Easy-peasy.

(Agreeing with bonobothegreat above, the bandsaw idea is not good).
posted by jon1270 at 5:39 AM on February 4, 2016

Whatever you choose, please wear goggles when you’re doing the cutting.
posted by blueberry at 6:17 AM on February 4, 2016 [1 favorite]

I am pretty sure your "cut" will end up following the original glue joint/seam between the two halves of the ball when it was originally assembled, judging by the product you linked plus your diagram. So I would think your best bet is to start with a sharp knife (but relatively blunt - think more of a utility knife than an Exacto #11) -- first to start to open up the seam, and then as you work the blade down into the seam, I think you will be able at a certain point to just pop the glue joint open.

Yes, definitely please wear eye protection.
posted by misterbrandt at 7:59 AM on February 4, 2016

Agreeing with the above and synthesizing: rig a fine sharpie up to be the right height, then with the ball on its flat part spin it against the sharpie tip to draw the cut line, then cut along the line with a fine toothed hacksaw, then clean up with sandpaper.
posted by Capn at 8:16 AM on February 4, 2016

Like Mizu, my first thought was to put it on my bandsaw with a high vertical fence, but if it's a relatively brittle plastic I'm liking the idea of building a jig that holds a hacksaw blade or similar parallel to a table at the appropriate height, so you can put the flat side down on the table and spin the ball against the jig holding the blade.

If you'll pardon my refrigerator art: a flat block, screw two verticals to it, and then screw the hacksaw blade to those verticals..
posted by straw at 9:18 AM on February 4, 2016