Dremel - Cutting a hole for a 120mm fan

[Organized]

Hi guys,

 

I want to cut a hole for a 120mm fan into my side panel. The only tool I got for this is my dremel. Circular saws are just way too expensive for just one hole, that's why I'm not going for it.

 

I have a circle cutter for my Dremel, but as it's supposed to be used with a simple drill, I don't know if I can use it for metal. Does anyone know that?

 

If it's not possible, I have to do it by hand - right?

 

Greets,

Andy

[SCHISCHKA]

A dremel might not cut a nice round hole. A pair of tin snips will make a nicer hole

[historicalpoultry]

I'm going to say that it is possible to get a round enough hole with a dremel. I've used one for cutting a window in my front panel. While not round, the process should be the same. Mask the panel with painters tape and draw your circle with a marker. Then go ahead and cut one or two milimeters inside your mark (gives you room for mistakes), you'll probably have to make cuts one by one. When done, use a file to true the hole up to your mark and finish up with several grits of sandpaper. Of course, working carefully will get the best results, again, I only used a dremel to cut straight lines freehand. But the lines came out very nicely, unless you get fairly close and look for mistakes, you can't notice it on my front panel.

[Organized]

Thanks!
 

I found a piece of metal and will use that for doing a test cut. The guy on this Amazon review used the circle cutter for a sidepanel aswell.

 

If my test cut will fail, I will do it by hand - there will be a dust filter on it, which will hide a possibly bad looking result. 

[historicalpoultry]

Also, if your circle cutter doesn't work, I used these cutting disks. Worked pretty nicely. 

[it_dont_work]

Might be a silly question, but what's wrong with just using a carbide hole saw?

 

Or just a center punch drill bit and a half round bastard file.

[Organized]

2 hours ago, it_dont_work said:

Might be a silly question, but what's wrong with just using a carbide hole saw?

 

Or just a center punch drill bit and a half round bastard file.

A hole saw with this size would cost at least 50€ and that would make that hole really expensive.

 

I didn't get the second part, do you mean that I should drill a hole in the middle and then use a file to remove the rest?  You don't want me to be online for the next 2 months? 

[sl06bhytmar]

Cutting circular hole is easy with dremel when you watch the guide here

 

 

[it_dont_work]

7 hours ago, Organized said:

A hole saw with this size would cost at least 50€ and that would make that hole really expensive.

 

I didn't get the second part, do you mean that I should drill a hole in the middle and then use a file to remove the rest?  You don't want me to be online for the next 2 months? 

No that's just silly, you drill around the circumference of the circle and file it round, only takes about an hour with a small hole like that. As for the hole saws sorry I forget sometimes how much tools cost now, I've had a set for over a decade and they come in handy, like my plasma cutter but I don't think you need to buy one of those for a one time circle.

[Organized]

I already asked a local company that does laser cutting jobs, but unfortunately it's not possible to cut painted metals with lasers. That would be the best and cleanest solution 

 

I think I will do it tomorrow, at almost midnight my neighbors would become kinda angry I think. And also, my slim fan will arrive tomorrow, so I can build everything together 

[Organized]

Okay, doing this with a dremel will not be as easy and clean as I thought it would be. My test hole is pretty messy and I don't want my side panel to look like this  I'll try to borrow a hole saw from somewhere. Maybe a jigsaw would do the job, too?

[W-L]

On 2016-12-13 at 7:43 AM, Organized said:

Okay, doing this with a dremel will not be as easy and clean as I thought it would be. My test hole is pretty messy and I don't want my side panel to look like this  I'll try to borrow a hole saw from somewhere. Maybe a jigsaw would do the job, too?

Your going to need to clean up your cuts using a metal file if you want perfectly circular cuts with clean edges. A hole saw would help a bit and lessen the amount of filing required but not eliminate it, if you go for a hole saw be sure to get a bimetal one. 

[Mick Naughty]

They have an attachment for cutting circles with a dremel. They also have the cheaper plastic jig that works just as well. Just need a metal bit and regular drill or bit to get the pilot hole started. 

Used a jig saw for mine but I was cutting a hole for a 360 rad.