Rotary Tool Techniques
by Puglsey and Mswi
A while back TR101AL asked me to write an article on my techniques for using a Dremel. I was a bit reluctant but after being asked again by another person, I thought well maybe there is a need. However, I recognize a talent greater than my own when it comes to using a Dremel and that talent belongs to mswi (also known as Heretic), so I have asked him to help me with this little write up.
Materials you will need
- Dremel (or other brand of rotary tool, mine is a craftsman)
- Drum sander mandrel bit (I prefer 240 grit)
- Cone shaped grinding stone
- Engraving/Burr bit
- 120, 200, and 400 grit sandpaper or sanding sponge
- X-acto Knife
So this article came about due to the thread where I showed some alterations I had done to improve the jaw line of the ROC Cover Girl figure.
Some people worry that their mods made with a Dremel always end up with a rough finish. A way to help prevent this is to not go overboard with the coarseness of your sanding drum grit. I use 240 grit, which although is not very coarse, when you put it on a machine making several thousand revolutions per minute it will take off some serious plastic! So the first rule of thumb is, Using a finer grit will produce a smoother finish.
The most important thing to remember when shaping with a Dremel is to use a very light touch. You want to take off very thin amounts at a time. Remove the burrs with your X-acto knife or by sanding them off. Check your progress and remove more as needed, layer by very thin layer. If you start to feel it "dig in" back off! You don't wanna try to take off 1/8" at a time. As a hairstylist once told me, you can take off small amounts at a time, but if you accidentally take off too much you can't put it back.
Another thing I do, in particular to dremelling vintage armor is, as I remove all the material to the point where there’s a small amount left, I angle the sanding bit inward at a 45 degree angle, which results in a smoother outer line with a lot less sanding. Use a burr bit for smaller areas, at 1/4 speed.
Mswi definitely hit on something I totally forgot, it's best to use a slower speed no matter which bit you're using. It will help to keep from over-doing it.
When it comes to smoothing out your modifications, the key to achieving a smooth finish when sanding any plastic is to make use of several different grits of sandpaper throughout the course of sanding. You'll want to start with a coarser grit and slowly increase to finer and finer grits as you go. Anything that I've dremeled that I plan to paint, I go over it with a 120 grit sanding sponge, then a 200 grit sanding pad, and finally a 400 grit pad. You may choose to go with an even finer grit, especially if you use an airbrush to paint your customs.