FEIN Cordless MultiMaster - Canadian Woodworking Magazine

The benchmark against which all other oscillating tools are measured. It's tough to match the MultiMaster's versatility, precision, and quality.

FEIN Cordless MultiMaster

FEIN Cordless MultiMaster

Ever since Fein's oscillating patent expired in 2008, a number of companies have brought oscillating tools to market. Some of them are quite good, but none has yet to match the versatility, precision, and quality of the groundbreaking Fein MultiMaster.

For those not familiar with the MultiMaster, it's a hand-held multi-tool that operates by high-speed oscillation rather than rotating or reciprocating motion. Rotating motion follows a circular path, reciprocating motion moves forwards and backwards or up and down, while oscillating motion moves in a side-to-side, arced motion, like a clock pendulum. 

The arbor on the MultiMaster has a small oscillating movement of only 3.2°, but it oscillates very fast - up to 18,000 times per minute. This narrow and fast angle of movement provides you with an unmatched degree of control. And, there are a wide range of accessories that enable you to carry out a host of cutting, sanding, grinding, scraping and polishing tasks.

The heart of the MultiMaster - oscillating motion 
A distinct advantage of oscillating motion is that it's very smooth running - there is very little vibration, virtually no possibility of kick-back, and no need to apply downward force on the tool, as you often do when using an angle grinder or random orbital sander. The MultiMaster does all the work.

This, of course, makes the MultiMaster ideal for precise work, such as sanding into tight corners or making intricate cuts. But, with the appropriate accessories you can also do aggressive work - removing grout, scraping paint, cutting door jambs and the like.

The new Fein Cordless MultiMaster (AFMM14) provides you with the same high level of quality found on the corded MultiMaster, but in a much more convenient format.

The AFMM14 Kit comes with a useful array of accessories  
The AFMM14 comes in a kit that consists of the MultiMaster tool, two 14.4-Volt lithium-ion batteries, fast battery charger, 7 accessories, 20 sheets of sandpaper, and a hard shell, lockable carry case.

Handle folds out of the way
Latches provide a tight, secure closure
The AFMM14 tool case is one of the best that I've seen, almost on par with the Festool Systainer. It's made of a durable high-impact ABS plastic and has a black comfortably rounded flat-folding handle, and a center lock. Because the handle lays flush with the top of the case it won't snag on anything, and it makes stacking the case that much easier.

Two chromed steel latches provide a tight, secure closure. Like the handle, these sit flush with the front of the case. You'll also notice that the corners of the case are rounded, which makes it less likely to sustain damage when transported to and from job sites.

Protrusions on the back of the case protect the hinge from damage
Six 'feet' protect the bottom of the case (felt pads added for additional protection)
Four protrusions on the back of the case protect the lid hinges from damage, while a series of six 'feet' on the bottom of the case protect it from damage. To keep the feet from getting overly scuffed I added felt pads on the four corners - they're inexpensive and easy to replace.

A high-density polystyrene insert makes tool storage 
On the inside of the case is a custom fitted high-density polystyrene molded insert that holds all the components neatly and securely. Fein has also included a removable box to store the accessories that come with the AFMM14 - in fact there is ample room to store twice the number of accessories in the box. There is also room to store the optional dust extractor.

Top quality Class A and B batteries
Intelligent charger
Fein uses top quality, Class A or B, high capacity batteries manufactured by Panasonic or Sanyo. These lithium-ion, 14.4-Volt, 3-Ah (amp hour) batteries generate an impressive 43.2-Wh (watt hours) of energy, made possible by the use of 8 individual battery cells. The higher amount of energy that can be stored in the 3-Ah batteries provides longer run-time, while the higher voltage yields greater motor efficiency. 

There is a convenient on-board fuel gauge that shows the charge level status. It provides a quick way of knowing when to recharge, and enables you to confirm that your batteries are 'good to go' before heading to a job site.

Electronics built into both the AFMM14 and the charger monitor each of the 8 battery cells to keep them from overloading, overheating, and deep discharge (where battery voltage drops lower than the final discharge voltage and reduces battery life). 

A full recharge takes 45 minutes, and these batteries will deliver up to 2,000 cycles. Still, you'll be happy that the AFMM14 comes with two lithium-ion batteries, as a replacement battery is priced at $195.

Superior construction with an all-metal gearbox and double ball bearing motor 
Looking inside the AFMM14 is akin to looking at the engine of a high performance car. The housing at the head of the AFMM14 is made of a durable aluminum alloy, which is corrosion resistant and has a better strength-to-weight ration than most other alloys, while the gearbox and accessory clamping system are all-metal, ensuring a long tool service life.

Electronic speed control delivers constant speed under load 
The motor and electronic controls are housed in an impact resistant Polyamide handle - the same stuff that's used to make Kevlar and glass-reinforced nylon. It provides high tensile strength and exceptional wear resistance. 

The motor delivers up to 18,000 oscillations per minute, and electronic speed control delivers constant speed even under load - which means the AFMM14 won't slow down with heavy usage.

Easy accessible controls
At 3 pounds 13-1/2 ounces (with battery installed) the AFMM14 is about the weight of a compact drill driver. I found the weight to be fairly evenly distributed between the front and rear of the tool, making it easy to balance and manoeuver. Two soft-grip strips provide some cushioning, but are more effective in affording a secure grip, particularly when your hands might be somewhat damp.

The on/off switch can be easily reached with your thumb without having to overly modify your grip on the tool. To reach the variable speed dial you need to shift your grip somewhat, which is a bit awkward when the tool is running, particularly if you're holding the tool on it's side.

Vibration and noise levels vary quite a bit, depending on the speed of the tool, the accessory you're using, and the material you're cutting. At low speeds using the sanding accessory I found the AFMM14 to be reasonably vibration-free, and certainly not as loud as a rotary tool. However, when cutting metal at top speed using a bi-metal blade, there is a noticeable increase in vibration and the noise level increases substantially. I recommend that you wear hearing protection at all times. (Unfortunately my noise meter is broke - once it's replaced I'll post the actual noise levels).

The air vents are placed on the sides of the handle. I found that when using the AFMM14 for more than about twenty minutes, there was enough heat coming from the vents to make my hands uncomfortable. When using the AFMM14 for extended periods of time you many want to wear a pair of work gloves.

Raise the locking lever and remove the fastening bolt from the drive shaft
Place an accessory over the 8-star arbor
Reinstall the fastening bolt and close the locking lever
When swapping blades or cutters I hate wasting time fiddling around, searching for an Allen key or wrench - invariably they get mislaid or lost. Which is why I love tool-less blade change overs. 

The AFMM14 has a unique accessory mounting system that is as practical and efficient as it is innovative. With the QuickIN mounting system changing accessories takes 10 to 15 seconds. Simply raise the lever that is located on the top of the tool, pull the accessory fastening bolt out of the drive shaft, place the accessory you want to use on the arbor, and then reinstall the fastening bolt and close the locking lever.

The only issue you might encounter is that the locking lever requires a fair amount of force to fully open. If you frequently change accessories then it can be somewhat annoying.

You can mount accessories in 45° increments (0°, 45°, 90° and 135° shown).
The arbor on the AFMM14, and the various accessories, have an 8-star hole pattern that allows you to position the accessories in 45° increments on the arbor. Most of the time you'll mount the accessories at 0°, 45° or 90°, on either side of the head. While this design only gives you 8 possible mounting positions, it does provide excellent torque transfer to the accessory, and once installed, accessories are held firmly in place.

Bottom row: sanding pad, rigid scraper, E-cut standard saw blade, E-cut universal saw blade
Middle row: carbide rasp blade, carbide segment blade, segment HSS saw blade
Top row: P60, P80, P120, and P180 sanding pads

The AFMM14 kit comes with 7 of the most commonly used accessories. However, there are dozens of other accessories.

As well, Fein has a number of useful attachments - a depth stop for use with the E-cut saw blades and the HSS wood saw blades; a holder that enables you to mount the AFMM14 on a workbench for hands free use, which is very convenient when you need to sand or cut very small items; a 4-1/2" sanding pad on which you can mount 4-1/2" hook & loop sanding discs; and, a dust extractor that will be of special interest to anyone who does a lot of sanding. There are two threaded holes just behind the drive shaft on which you mount these attachments.

The triangular sanding pad is unbeatable for just about any kind of detail sanding jobs, particularly in tight corners, on narrow edges, and in difficult-to-reach areas.
Fein sanding sheets are available in 13 sizes from P36 to P500. However, you don't have to use the Fein sheets, though I've found they wear just as well as generic brands. The AFMM14 comes with a non-perforated backing pad for use with hook & loop sheets - an optional perforated pad is also available.

When using the triangular pad it's important to remember that oscillation occurs towards the three tips of the sanding pads, and not in the center of the pad. For best results always keep the pad flush to your work surface and constantly moving to avoid heat buildup. Tilting the base of the pad to increase pressure on one of the three triangular tips will only serve to increase material loading, and possibly bend the backing pad.

Avoid tipping the sanding pad - applying pressure in this way won't speed up sanding
Keep the sanding pad flat to avoid overheating the tips and possibly bending pad
In general I found it best to sand at lower speeds (up to #3 on the speed dial), especially when removing varnish or paint - it helps to prevent the sanding sheet from loading. If you'll be sanding larger areas, then you'll want to get the optional 4-1/2" sanding pad, which enables you to cover a lot more surface area than the triangular pads. 8-hole hook and look sheets are available from P40 to P240 grit.

The rigid scraper makes short work of removing paint, adhesives, putty, caulking wallpaper, and other soft materials - in fact anywhere you would normally use a putty knife or paint scraper.

The leading edge is ground at a bevel and slightly radiused, while the corners are rounded. This helps to keep the scraper from digging into the work surface.

Eventually the leading edge will become dull, but you can easily resharpen it on a bench grinder. There is an optional flexible scraper which works better for removing softer materials like caulking.
Precision cutting is where the AFMM14 really proves its worth. There are a variety of saw blades available that can make a wide range of cuts that would be awkward, if not impossible, with any other tool. The AFMM14 kit comes with three blades - one for wood, the other two for wood or metal. 


As with any kind of cutting, it's important to prevent the blade from over heating, which can reduce blade life. Try to keep the blade moving in order to remove sawdust or metal filings from the kerf. When making deep cuts, occasionally pull the blade out of the cut to dislodge debris.

The E-cut Standard blade is a high-carbon steel wood blade. It's 2-9/16" wide and has 18 teeth per inch. Coupled with the minimal set on the teeth, it gives a very clean, smooth cut. This is the blade that is commonly used to undercut door frames.
I found that this blade worked best in hardwood, softwood, MDF, and plywood, and less so in OSB and composite panels. I find this blade too wide to make plunge cute - best to use the narrower 1-3/8" blade. I also find the standard wood blade a better choice for making cutouts in drywall, because it generates less dust.

The Segment high speed steel saw blade is 3-1/8" wide and has 20 TPI. There is no set on the teeth, which makes it ideal for flush cutting and straight (rip) cutting, particularly in hard wood, fiberglass, and 20 gauge sheet metal (up to .04"/1mm). 

You can make cuts at right angles, because the flat part of the blade doesn't have any teeth. And because there is no set on the teeth you can run it along an edge guide to get perfectly straight cuts. I find it helpful, particularly when cutting metal, to score a line for the tool to start in.

The E-cut Universal bi-metal blade is 1-3/4" wide and also has 18 TPI. The teeth have noticeably more set than the teeth on the E-cut Standard blade. It's good for making rough cuts in wood, drywall, plastic, copper and ABS piping, and sheet metal up to 1/16" (1.6mm) thick. A lot of renovators use these blades for cutting nails, and they do a reasonable job.


I was able to cut through 42 10D nails before the blade deteriorated to the point where cutting time increased substantially. Even so, the blade continued to make, straight quick cuts in wood, likely because only the teeth in the centre of the blade were damaged cutting the nails. A 1/1/8" blade is also available.

The carbide blades are suitable for coarse work - sanding and cutting grout, plaster, concrete and other building materials. The kit comes with two styles - a triangular blade and a segmented blade.

The blades are very stiff and don't flex in use. I found they work faster than course sandpaper for removing thick layers of dried paint, and they don't load up as much. They also work well in place of a wood rasp when you want to quickly shape wood. The segmented blade is great because you can remove grout in between tiles flush up to an adjourning wall.

To clean the carbide blades I use a soft wire brush. If you use it to remove thin-set under tiles you'll want to clean the blade frequently to avoid a build-up of crud on the blade.
Carpenters, renovators, flooring installers, tile setters, furniture makers - anyone who needs to do precision cutting, sanding, grinding, scraping and polishing will find a myriad of uses for the Fein AFMM14. It offers a unique, highly effective, quick blade changing feature; unmatched versatility for precision work; and high-quality mechanics that will provide years of trouble-free use. 

So if you're looking for a multi-tool that offers the best combination of performance, design, quality and value, then you can't go wrong with the Fein AFMM14.

  • Approximately 2 ¼” (W) x 2 3/8” (H) x 12 1/8” (L)
  • 3 lb 13 ½ oz weight (including battery) 
  • 14.4 V, 3 Ah lithium-ion power source 
  • 11,000 – 18,000 OPM 
  • QuickIN tool clamp system 
  • Amplitude: 2 x 1,6 degrees 
  • Soft-start motor 
  • Electronic speed setting 
  • 3 year warranty 
  • Backing sanding pad (#63806153022); 20-piece sanding sheets: 5 each of P-60, P-80, P-120, P-180; 
  • Universal E-Cut saw blade (#63502152010); 
  • Standard E-Cut saw blade (#63502134015); 
  • Segment HSS saw blade (#63502106015); 
  • Rigid scraper blade (#63903178017); 
  • Carbide triangular rasp blade (#63731001014); 
  • Carbide segment blade (#63502118016); 
  • 2 Lithium-ion batteries (#92605154020); 
  • Rapid charger (#ALG50); 
  • Hard shell storage case (#33901118030); 
  • Instruction manuals

MultiMaster Microsite: CA
AVAILABLE AT:Tool and equipment suppliers nationwide
Dealer Search
MADE IN:Germany (tool, accessories, case)
Poland (battery)

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