Roland digital pianos, particularly models from the mid-90s to the early 2000s, are known for their unique feel and sound. However, many owners face a common issue: the failure of the infamous plastic weighted hammers!
The Issue with Original Roland Hammers
The original hammers were constructed by surrounding a lead weight in a very thin layer of plastic. Cracks form around the encased lead weight, and once these cracks form, the hammers inevitably break. Often the shrapnel from the broken hammers causes other problems inside the cabinet.
I’ve talked to quite a few people about this, including G&G Products in Kennebunk Maine who specializes in injection molding. There’s reason to believe that both the design and the manufacturing process were not optimal. They can’t be easily repaired, and Roland stopped manufacturing these hammers in 2020.
This is a bit of a travesty, as the internet is filled (reddit.com) with accounts of people (pianoworld.com) with otherwise beautiful Rolands who are now unable to play them. And even worse, Roland appears to be uninterested in this issue.
Previous solutions have included multiple designs of 3D printed blanks. You can print these using a 3D printer and then add weights from the old hammers. This has the advantage of being very inexpensive, but also very time and labor-intensive.
Some technicians have used steel-infused epoxy, but the fix is difficult to apply, and the thin plastic provides very little surface area for the repair. Epoxy usually fails. For years, I’ve replaced them using “old new stock” hammers, although I worry these will have the same problems decades hence.
Fortunately, we’ve been rescued by Syntaur, who now manufactures replacement sets! See below. The price is considerable, but the quality is very good, and at least the option now exists!
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The Roland hammers circled have been coated in some kind of adhesive by a previous technician, trying to stave off breakage. (It didn't work.) Syntaur replacements are seen alongside originals."
List of Models Impacted
This is a partial list of Roland keyboards I know use these hammers. If you’re happening upon this article because you’re considering purchasing one of these models, have caution! This problem will occur, and you will need to replace broken hammers at some expense:
Models: RD-500, RD-600, A-90, HP145, KR370, KR570, XV88, A-90, A-90EX, FP-1, FP-8, FP-9, HP-145, HP-147, HP-236, HP-237, HP-237E, HP-245, HP-2800, HP-2800G, HP-2880, HP-330, HP-330E, HP-335, HP-3800, HP-3800G, HP-530, HP-530E, HP-535, HP-550G, HP-555G, HP-5700, HP-730, HP-7700, KR-1070, KR-370, KR-375, KR-4300, KR-570, KR-570W, KR-575, KR-575P, KR-770, RD-500, RD-600, XV-88
The part numbers are PA-4B N-KEY HAMMER 04671289 and Roland PA-4B S-KEY HAMMER #04671290.
The Syntaur Replacement Hammers
Syntaur has stepped in to provide a much-needed solution. Their replacement hammers are designed to be more durable and are available in various quantities: octave sets, complete sets of 88, or individual hammers for white and black keys. The new hammers are color-coded, which makes them easier to identify and install. They’re priced at around $160 per octave, so they’re not inexpensive, but they’re a considerably better option.
Opening the Cabinet
The first step is opening the cabinet. How this is done varies from between models. Below is one relatively common design. Many Roland digital pianos open in a sort of clamshell design. If you’re luck enough to have one of these, remove the screws pictured (or their equivalents), and the keyboard will open up easily.


Now unscrew the keyboard. The keyboard is held in by a rank of screws at the back, and a rank underneath the front. Undo both rows of screws. You only need to move the keyboard back an inch, but it must be unscrewed to do this.


Once the keyboard is unscrewed, move it back about an inch. You’re now ready to remove the hammer! If you’re never done it before, this feels challenging. But with a pair of needle-nosed pliers, they pop out easily:
Other Guides and Videos
All of the above looks similar for different keyboards, but the exact manner of opening up the case will vary. The most important part is gaining enough access to scoot the keyboard back about one inch. Here’s another video by another person repairing their hammers. There are numerous other videos of repairs.
I also encountered this very detailed photo gallery of a hammer replacement by Anachostic.