# Need ideas for how to make the cases for projects...

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#### digitalox

##### New Member
I've pretty much got the electonics, soldering. etc. down.

I've seen the plastic cases for projects out there, but I do not know what to cut the various holes with for the power switch, LEDs, etc. Any tips or pointers to some how-tos on the net greatly appreciated.

Thanks,
digitalox

#### ElectroTech2002

##### New Member
I make lots of these special weather proof boxes and I typically use calipers to measure o.d. of switch, l.e.d., connector, etc.. then use a dremmel or drill bit to center hole, then find chassis punch of closest diameter. If you need weatherproofing (weather preventing) I always use R.T.V. silicone. From my experience nothing is ever weatherproof. :lol:

#### psilikon

##### New Member
project boxes

I put together a little projects today in a radio shack project box as a matter of fact. I Don't have a dremel yet so what I did to make holes for my switched and LED's is grip a penny nail with some pliers and then heat that mug up on the stove and just started slowly making holes of the required dimensions. Then i went back with a razor blade and cleaned up the openings....

#### Klaus

##### New Member
For plastic boxes, one of the best tools (after the drill for making round holes) is a special file called 'abrafile'. The one I have and use most is round, about 1/8" in diameter and 5" long (3.5mmx125mm), with a plastic handle. Its different from conventional files in that the teeth are very coarse and the file shaft is flexible enough so it won't break if one tries to bend it - it actually bends.
There are larger diameter and also square abrafiles available but the smallest is most useful for the above.

I first drill a hole, slightly in from each corner, and then use the file like a saw to cut the square or rectangular opening. Its quite quick and if one files (saws?) carefully only a little smoothing with a conventional file is required for a professional looking cut out.

These abrafiles also work in aluminium but the cutting is a little slower of course. Sometimes I use my hand 'nibbler' to cut holes into metal boxes. This requires a larger pilot hole of 3/8" (10mm) and the cut is 1/4" (6.5mm) wide. This also does not cut close to the corners of boxes.

Another trick is to drill a close spaced row of small (2 - 3mm) holes all round the opening and file the parts between the holes with a needle file.
this requires careful drilling on a bench drill to be successful. One could also, for straight lines, drill just a few holes in a row at each corner, enlarge them into a slot and then use a hacksaw blade (there are special handles available to hold the blade) to cut along the rest of the marked line of the opening. Try to cut with a 'pulling' motion or the blade is likely to jam and snap.

I do have a few chassis punches but these are expensive for just the odd hole - more useful in a workshop where lots of holes need to be made.

One 'could' also use a hole saw, again expensive, for a quality one (the cheap, multi set- split barrel, variety are a waste of money, IMO, and can be downright dangerous) and holesaws leave a rather rough finish.

There are tools like a 'flying cutter' that do very neat round holes into plastic, this is an adjustable tool, but it only works on a bench drill safely and requires to clamp the box firmly to the drill table which is not possible with small boxes.

When drilling holes with a power drill into plastic be careful as the drill often 'bites' and drags the box out of one's grasp. Countersinking holes is especially tricky and they are easily ruined by a 'runaway' drill bit. The cure is to very carefully sharpen the drill bit but that requires a grinder and the knowledge how to sharpen drills.

I don't have a Dremel tool either and got by with the above suggestions for 40 years, cutting all sorts of openings into project boxes. Mind you, if Santa were to bring me a Dremel...

I hope this gives you some ideas, the burning the hole suggestion is a bit crude, IMO :wink: and bound to be inaccurate, not to speak of the toxic fumes created by this process. But, if you are desperate....

#### jsdriscky

##### New Member
just use a forstner drill bit, the produce a chip free round hole no worries

#### seeker

##### New Member
Hi digitalox,

For the smaller holes(1/8-3/16) I usually just use a good,sharp drill bit and go slow. I know with thin-walled plastic cases if you try to drill a much bigger hole the bit will grab and crack the plastic or even worse tear out a big-a hole

One solution I use to avoid the cracking/splitting problem is to use a cheap ratshack soldering iron to melt the hole out to the right size for whatever you need. I then take a drill bit that is a little bigger than the hole and twist it by hand to remove the plastic ridge that forms around the melted-out hole.

This is a bit tedious but is very effective if you don't have access to hole punches and stuff .

(I have a 7 or 8 dollar radioshack soldering iron that I use ONLY for this purpose....stinky, yet effective :lol:

#### Optikon

##### New Member
digitalox said:
I've pretty much got the electonics, soldering. etc. down.

I've seen the plastic cases for projects out there, but I do not know what to cut the various holes with for the power switch, LEDs, etc. Any tips or pointers to some how-tos on the net greatly appreciated.

Thanks,
digitalox
Small holes = drill/dremel with drill bits or hand-held punch.
Big holes = hole-saw bits or multi-hole bits (cone shaped with increasing diameters)

All these can be found at local hardware store and they are relatively cheap.

Tips: Cutting metal boxes? use oil on the bits (they stay sharper longer)
Titanium coated bits are worth the extra few bucks.

#### Agent 009

##### New Member
There are cases that just have 'ready-made' holes. You have to choose which one you wanna use. But they aren't as professional-looking as a home-made one, are they :wink: ?

#### stevez

##### Active Member
I've got some brad point twist drills - essentially twist drills from 1/8" up to 3/8" that have a sharp point ground in the center and points or cutters ground at the end of each cutting surface. I've not used these on plastic but I'll have to give it a try. They work very well for smaller holes in wood - much cleaner than just using a standard twist drill. The set I have is a low cost ($6 or$7 here in US) but I am quite satisfied with how well they work. The downside is that you'd need special tooling to sharpen them - so for me they are throw-away.

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