Endpin Button

What it is

The endpin button is the small tapered peg set into the bottom edge of the violin, at the centre. The anatomy section collects the related terms.

The tailgut loops around it, anchoring the tailpiece and, through it, all four strings.

On violin it is a fixed button. On cello and bass the equivalent is an adjustable spike that supports the instrument on the floor, which is a different component with the same name.

What it does

It takes the entire string load.

The strings pull the tailpiece toward the neck. The tailpiece is held by the tailgut. The tailgut is held by the endpin button. Everything ends here.

That is roughly 25 kilograms of tension resolved onto one small tapered peg in a hole bored through the ribs and the end block.

How it is fitted

The button is tapered, like a tuning peg, and fitted into a matching reamed hole through the bottom rib and into the end block behind it. The chromatic tuner on this site is worth having open while you practise this.

The end block is a piece of wood glued inside the instrument at the bottom, providing the material for the hole to bite into. Without it, the thin ribs alone could not hold.

Fit matters. A loose button works and eventually pulls. A button forced into too small a hole splits the ribs.

The saddle

Just above the endpin button sits the saddle, a small piece of ebony set into the edge of the top plate.

The tailgut passes over it, and the saddle takes the downward bearing pressure, protecting the softer spruce edge underneath.

Without a saddle, the tailgut would cut into the top edge.

The saddle sits in a shallow mortise and, on some instruments, is deliberately fitted with a small gap at each end to allow the top to expand and contract with humidity. A saddle fitted tight can cause a crack when the top moves.

What can go wrong

Cracks from the endpin hole. The most common problem. The hole is under constant tension and cracks propagate from it along the grain.

Causes include a badly fitted button, humidity change, and impact to the bottom of the instrument.

Loose button, which pulls out gradually under tension. If it releases entirely, the tailpiece drops, the bridge falls, and the soundpost usually goes with it.

Saddle cracks. A saddle fitted too tightly cracks the top when the wood moves. This is a well-known cause of a specific crack running from the saddle upward.

Worn hole, from repeated removal and refitting.

What to watch for

Any visible line running from the endpin button toward the edge or upward into the ribs.

A button that looks like it is sitting proud of the ribs, or that has visibly moved.

A crack running from either end of the saddle.

None of these are emergencies but all of them should be looked at rather than watched.

Care

Very little to do. Do not knock the bottom of the instrument, which is easy to do when setting it down.

When the instrument is in the case, the bottom edge is where it rests, so a case with adequate padding at that end matters more than most players consider.

If the button ever feels loose, stop and see a luthier before the tailgut releases.

Where it comes up in playing

Never directly.

Its only appearance in a player's experience is as a source of cracks, and as the thing that fails catastrophically if neglected.

How it is taught

Rarely mentioned at all, which is arguably a gap.

The useful point for students is where the string load actually goes. Most players never think about the fact that everything holding their instrument together resolves onto one small peg at the bottom, and knowing it encourages the kind of care that prevents the crack.

Where the load actually goes

Worth picturing, because it explains why several apparently unrelated problems happen at the bottom of the instrument.

Four strings pull with roughly 25 kilograms of tension toward the scroll. That pull is resisted at two points and two points only.

At the top, the neck heel glued into the top block, which is why neck joints fail and necks need resetting.

At the bottom, the tailgut around the endpin button, seated in the bottom block, which is why cracks radiate from that hole.

Everything between those two points is comparatively unstressed. The top, the back, the ribs and the bridge deal with downward force rather than lengthwise pull.

Setting the instrument down

The bottom edge is where the violin rests in a case and where it contacts a surface if put down.

It is also where the endpin button sits, in a hole already under continuous tension.

A knock there is more consequential than a knock almost anywhere else on the ribs, which is worth knowing when putting an instrument down in a hurry.

We teach private and group violin lessons across Johns Creek, Suwanee, Peachtree Corners and Woodstock. Bring how the instrument is built to a first lesson and we will build the plan around it. book a no-commitment evaluation lesson or call 470-789-2422.