Fit

Fit matters more than any setting. Use the included T10 driver. The fit video playlist shows each adjustment.

What moves:

Clusters move up and down on their towers, and roll left and right.
Towers move forward and back, yaw, and slide side to side in the baseplate track.
Palm rests move forward and back, side to side, and yaw.

Some users bend or reverse the steel towers so each cluster sits directly over its tower base.

Key width

Keys should sit as close around your fingers as possible without accidental presses. Print the sizer sheet and measure each fingertip, on both hands.

Finger clusters from above with Thick, Thin and Backset keys. Thick keys leave 15 mm at the bottom and 17 mm at the top, Thin 17 and 19 mm, Backset 19 and 21 mm. The matching sizer sheet sizes are Thick 16 mm, Semi 17 mm, Thin 18 mm and Backset 20 mm.

Key names give three numbers: height, thickness, offset.

Height: nominal key height in mm.
Thickness: where the key face sits relative to the front of the key base. +1 is “Thick”, +0.5 “Semi”, 0 “Thin”, −1 “Backset”, −2 “double Backset”. Thicker keys suit narrower fingertips.
Offset: magnet offset. A larger offset means a lighter press.

Example	Meaning
6 1 0.7	6 mm tall, Thick, 0.7 mm offset (default, about 20 g)
11 0 0.8	11 mm tall, flush, 0.8 mm offset (about 17 g)
8 −2 1.0	8 mm tall, set back 2 mm, 1.0 mm offset (about 12 g)

Standard clusters have 18 mm between key bases. Slim clusters have 16 mm and need a different circuit board. Your fit is the spacing minus both keys’ thickness:

Keys	Cluster	Fit
Two +1	18 mm	16 mm
Two +1	16 mm	14 mm
Two −1	18 mm	20 mm
Two −1	16 mm	18 mm

For reference, one user’s measurements and the fits he uses:

	L Pinky	L Ring	L Middle	L Index	R Index	R Middle	R Ring	R Pinky
Measured	14	17	16	15	16	16	17	14
Used	16	18	17	17	17	17	18	16

Include your measurements with your order.

Trackball size

The default trackball is 44 mm. A 52 mm ball is available for large hands, about 200 mm or more from wrist to middle fingertip. The 44 mm ball gives a more flexible fit even for large hands.

Size	Length (wrist to middle fingertip)	Width at knuckles
X-Small	under 170 mm
Small	170–180 mm	under 75 mm
Medium	180–190 mm	75–85 mm
Large	190–195 mm	over 85 mm
X-Large	over 195 mm

A hand measured from the wrist crease: 180 mm to the middle fingertip and 76 mm across the palm at the knuckles, with the differences between finger lengths marked.

Palm rests

Set the palm rests first. You need a steady hand position before you can fit the clusters.

Loosen both carrier screws until the carrier moves easily. Tighten until it holds, test, then tighten a little more. Don’t overtighten; it can damage the carrier and base plate.
With a relaxed hand, your fingers rest on the Center keys. Your base knuckles usually sit just in front of the palm rest’s front edge.
Hemispherical palm rests (default on orders after 2026-09-01): loosen the large center screw slightly with the 3 mm hex key to adjust pitch and roll, then tighten it firmly. They ship on 9 mm carriers; other heights are in the parts repository.
Tripod palm rests: newer ones have 5 mm shims installed. Remove them to lower the rest 5 mm, or use any shim up to about 6 mm.
PLA palm rests can be reshaped in hot water. Keep the rest attached to its carrier while you do it. Thermoforming demo. Palm rests are a consumable part; contact support@svalboard.com for replacements.

Finger clusters

Length, breadth and yaw: loosen the base screw just enough to move the tower with gentle pressure. Fingers should rest on the Center keys; many people like a slight bias toward South. If a cluster won’t reach, move the palm rest back.
Height and roll: loosen the cluster height screw slightly and slide the cluster. Each finger should rest with the same light pressure, without reaching or pulling back. Roll the cluster so you reach East and West easily. If you must favor one, favor the inward key (East on the left hand, West on the right).
Keep splay small: put clusters as close together as you can without neighboring East and West keys touching.
At very low heights, check that the cluster doesn’t hit the baseplate, especially on the pinky.
Tighten gently. Overtightening can damage the cluster or base plate.

Thumb clusters

Thumb clusters adjust the same ways as finger clusters. Thumb fit is personal. Aim for Knuckle keys that are easy to press on purpose and hard to bump by accident. If your thumb rest triggers the Down key, lower the cluster.