I am in the market for a new sander, I am currently weighing up whether to get a 5mm stroke sander or if I can do with a 3mm stroke. I have a Festool rotex 150mm so part of me thinks I could be fine with just a 3mm sander but at the same time I think a 5mm will be very convenient.
Be glad of thoughts of those with a similar set up.
Your question is somewhat INCOMPLETE...!, Let's see:
There are TWO main categories of rotary sanders as of today:
ONE: the "standard", ubiquitous, and "plain" ones with the following characteristics:
a) A 125mm platter;
b) A Free wheeling bearing that allows that platter to rotate thanks to the sanding disc presenting a drag, and an Excentric shaft that carries that bearing, so that the excentric rotation makes a given sanding grain to describe a "kind of" epicycloidal motion, so that the sanding disc leaves a miriad of scratches that blend together, thus the other name: "Random Orbit Sander" or ROS;
c) A Bearing Excentricity of around 3 mm or 1/8", loosely called "orbit";
d) A motor of approximately 300 to 400 Watts of input power, a little less or a little more...
Examples of commercial models are numerous, like DeWalt, Milwaukee, Ryobi, and too many others.
TWO: The
SERIOUS ONES.... With the following differences:
1) A
GEARED, forced rotation plus circular oscillation swichable option, in addition to the free-wheeling bearing guided platter.
2) The larger (150 mm) platter;
3) A larger Excentricity or "orbit" of about 5.5 to 6 mm or 1/4";
4) A noticeably more powerful motor, above the 800 or more input watts.
These characteristics make the
SERIOUS ones a way more versatile tool, because those can perform in a more useful manner the task commonly asigned to medium power, medium size Belt Sanders (say 3" X 21" belt), while at the same time providing the capability of producing very fine Sanding and Polishing tasks... And the capability of taming down their power thanks to ample range of variable speeds.
While more expensive, they can easily sand much larger surfaces than the run-of-the-mill 125 mm-400 W sanders, like a large dining table, a large wooden desk, a long wood stair between floors, or a large Concert Grand piano, which will take many more hours for sanding with lesser sanders.
In my country, we have only three such models available; from Festool, Bosch and Makita. In my case (and limited budget), the Festool is way too expensive (more than A THOUSAND US Dollars!), the Bosch has been pointed to have weak gears, thus I bought the Makita BO6050 at about 25% of the outreageous price of the Festool...
This sander is much more than a sander; I have polished two car windshields, one automotive paint job, a lot of wood, several fiberglass parts and even a Marble top. I bought it after years of using my older Bosch PE12 AE 125mm sander, which was desperately slow, weak and only for for small jobs, I would say up to a small desk size. Anything larger just took too much valuable time. Compared to the "standard size", 125mm, less than 500 watts, 3mm orbit, non-geared Random Orbit sanders, it is like light day and night! Now my old Bosch is seldom used at all. The only CAVEAT these larger sanders have: They do demand a Learning-Curve... They need to be handled with aplomb, FIRMLY planted on the floor, held with BOTH hands, always using the lateral handle (like an angle grinder!), and taking care and observation of the selected speed. Their dust creation flow needs one to use a vacuum and hose, as well as a well fitting sanding disk hole pattern. The Makita has some more vibration than the Rotex, but using gloves and replacing the lateral handle with the better grade Vibration absorbing one (not expensive) gets it perfectly under control at a net value.
