MicrobeHunter.com Microscopy Forum

Does anyone know any brands of circular compass cutters that have a measurement to their diameters. Similar to : https://www.amazon.ca/X-acto-Precision- ... B000KNNJ2I preferably ones that are in Canada? The compass cutter I currently have does not have any way to precisely measure its diameter and I want more precise alternatives so I can consistently cut the same size holes.

I feel your pain !!

Most of them seem to be 'badge-engineered' versions of the same thing.
I will be following this thread with interest ...

Meanwhile, I am pondering the possibilty of mounting a cutter on a 'gantry' above a slide-ringing table. It would probably be wasteful of filter material, but should do a much better job.

MichaelG.

Assuming you're cutting small circles, a sturdy draftsman's compass fitted with a tiny blade rather than a pencil lead or pen makes a very good cutter. It's finely adjustable and if of the center screw adjustment type will hold its position.

My own blades were bought quite a while back, when there were actually draftsman's supply places. Not sure where they'd be easily available today - but find one and it will be easy to sharpen for ages to come. You could also fairly quickly make one out of a piece of drill rod the appropriate diameter. Cut. Rough grind. Harden & temper with a butane or propane torch. Sharpen to heart's content. Carbide rod will also be available in small diameters and be easily sharpened on a cheap diamond wheel.

Something like this might fit: https://www.amazon.com/dp/B0758BSXNX/re ... il_1?psc=1

Determining diameter is a piece of cake. Get a good rule marked in .01" or .1mm. Put point in something like the 1" engraved line, adjust cutter to whatever radius you need.

We're working in the dark here. Please let us know the hole size, thickness and type of material you are cutting.

Material for stops is cardboard and size for holes are 32mm.

OK, great. So I will recommend neither a professional gasket-cutter nor a punch set.

Why not just compass draw them onto the cardboard and then just cut them out by hand (like you're probably already doing...)? I think the error from hand-cutting must be within the allowable tolerances for a stop. I mean, it's cardboard; think of all the fuzzy edges, and fibers sticking out!

When it comes to stop making, I am a perfectionist. There is nothing more pristine than seeing a circular cut with smooth edges that fits like a cozy glove to the filter holder.

I use a 3-50mm punch set from Mayhew that I like a great deal. Not cheap at all, but if you're a perfectionist, this is as good as I've seen. It will even cut concentric circles: https://www.amazon.com/Mayhew-66010-Met ... 82QRI?th=1

I have used a set like Tom suggests for years and it is great quality. Mine has to be from the same factory, but there is a different name on it. I think they are made in France. Here is a second link: https://www.axminster.co.uk/boehm-hollo ... ts-ax22429
For just 32mm you would only need the two chromed parts and the 32mm cutter. This are professional grade tools so parts will be available. These punch sets can make circles, but also rings with concentric inner and outer cuts.

Scales on compass cutters will bring you close, but in the end you will always need a test cut an measure the result. Why not use a pair of calipers to measure the distance between the points?

Bob

FWIW, a laser cutter will make stops (and annular rings) to any dimension you draw (in CAD). The melt edge on black delrin (etc.) might be a bit fuzzy, but about as good as a punch. Prices have dropped below $400. I suspect that's more than the OP really wants, though.

A 3D printer would also be worth a look. The print quality of simple round objects is really nice even with cheap printers.

MicroMan2 wrote:Does anyone know any brands of circular compass cutters that have a measurement to their diameters. Similar to : https://www.amazon.ca/X-acto-Precision- ... B000KNNJ2I preferably ones that are in Canada? The compass cutter I currently have does not have any way to precisely measure its diameter and I want more precise alternatives so I can consistently cut the same size holes.

I have used that model with good results....

BillT

I just found these on amazon and they don't make a pin hole in the center that can let light through.

https://www.amazon.com/Dispey-Circle-Cu ... 96&sr=8-20

https://www.amazon.com/DSPIAE-Stepless- ... 1653&psc=1

https://www.amazon.com/Fancyscale-Thinn ... =8-71&th=1

One of my discord members got something like this: https://www.amazon.com/Plastic-Mathemat ... B00VWSS5LU

and then scratched the outline of the circles in with a pin and cut them out with scissors. I bet a swiveling craft knife would also do the trick.

I got one of those adjustable circle cutters and it's pretty cool but struggles to cut thicker plastic sheets.