3D Printing · Maker Select V2 · Ep 4

My first Benchy and first mod: taming the wobble

Time to benchmark and upgrade. Episode four prints the famous 3DBenchy to measure quality, then installs a Z-axis brace to kill the gantry wobble that was hurting tall prints.

Maker Select V2 Episode 4 First Benchy First Mod video thumbnail
▶ Watch the full episode · 14:12

Editor's note (July 2026): Part of my 2017 3D-printing journey on the now-discontinued Maker Select V2. The 3DBenchy is still the universal calibration print, and gantry braces are still a common upgrade for open-frame printers of this style. Modern machines are far more rigid out of the box, though. If you are starting today, see the current-printer link at the end.

The short version

Before modding a printer, print a 3DBenchy so you can measure any improvement. Mine showed the printer's weakness: the tall gantry wobbles when the bed and head move fast, which softens detail on tall prints. The fix is a Z-axis brace: printed mounts and two threaded rods that triangulate the gantry to the base. It is a long print and a fiddly install, but the after Benchy came out visibly cleaner.

Benchmark first. Then brace the gantry.
The benchmark

What a 3DBenchy is and why you print one

With my first custom parts printed in episode 3, it was time to start upgrading the machine itself. But you cannot tell if a mod helped without a before and after, so first I printed a benchmark. The 3DBenchy, a little tugboat, is the most popular calibration print there is, deliberately full of tricky geometry (overhangs, bridges, fine text, smooth curves) that exposes any weakness in your setup. Grab it from 3dbenchy.com or Thingiverse and print it at normal quality, 20% infill, no supports. Mine took about two hours.

A happy accident made my first Benchy extra informative: I ran out of generic PLA partway up and switched to Worksteel high-precision PLA, leaving a visible quality line across the hull. The generic filament showed artifacts and stringing; the Worksteel section printed clean deck lips with no stringing in the cockpit. Only the bridges over the doorway and windows stayed a little rough. A good reminder that filament quality matters as much as the machine.

The problem

The wobble problem and the Z-brace mod

Watch this printer work and you notice the tall gantry visibly sways when the bed and extruder change direction quickly, and it gets worse with a full, heavy spool sitting up top. That wobble blurs detail, especially on anything tall. The classic fix is a Z-axis brace: a diagonal support running from the top of the gantry down to the base, which triangulates the frame and stops it rocking.

All the printed parts come as a single Thingiverse package, seven pieces in all (top mounts, bottom mounts for the fasteners, back feet, and the ridged thumb-fasteners the design calls BallsMk2). They are honestly over-engineered, taking around 16 hours and 44 meters of filament to print at normal quality and 20% infill. Worth it for a permanent stability upgrade.

The printed Z-brace mod pieces including the top mount for the Maker Select V2
The printed brace pieces: top mounts, bottom mounts, feet, and the thumb-fasteners.
The build

Printing and installing the brace

Cleanup is minimal: snap the support pillars out of the thumb-fasteners with a small screwdriver or pliers, and lightly file the screw holes on the bottom brackets with a round needle file. Then gather the hardware:

  • 2 x 410mm (16 inch) lengths of 8mm (5/16 inch) threaded rod.
  • 20 x M3 x 10mm screws (longer if you have clearance).
  • 6 x 8mm (5/16 inch) nuts, plus 2 x 8mm locking nuts.
  • Rubber or felt pads for under the mounts. Anything works, no need to spend much.

Threaded rod usually comes in 3-foot lengths, so one rod cut in two does the job; most hardware stores will cut it for you, or an angle grinder makes a cleaner cut than a hacksaw. A pre-cut hardware kit was also sold by 3D-printing stores if you would rather not source it all yourself.

  1. Attach the bottom mounts: remove the original base screws, align each front and back mount, and fasten with three M3 screws. Leave them slightly loose for now.
  2. Attach the top mounts: mind that the left and right pieces differ. Remove and replace only one screw at a time so the gantry never shifts out of alignment.
  3. Fit the rods: slide a nut and two thumb-fasteners onto each rod, feed it up through the top mount, add another fastener and nut, then settle the rod into the bottom mount. Lock it with a locking nut from underneath the front mount.
  4. Square it up: snug the bottom fasteners first, then fine-tune with the top ones. Leaning toward you? Raise the bottom fasteners. Leaning away? Lower the top ones. Check square, then tighten everything.
  5. Add the pads under each mount to soak up vibration, and you are done.
The Z-brace mod installed on the Maker Select V2 with the diagonal threaded rods supporting the gantry
Installed: the two diagonal rods triangulate the gantry to the base and kill the sway.
The proof

Before and after: did the brace help?

Straight away the gantry feels far more solid to the touch. For a fair comparison I printed a second Benchy from a single roll of filament, so there were no mid-print material changes to muddy the result. It came out cleaner than the first: a slightly smoother roof, sharper deck-lip definition, with the top arcs and bridges roughly the same. This is one of the most worthwhile upgrades you can make to a printer of this class.

A side-by-side comparison of two 3DBenchy prints before and after installing the Z-brace mod
Before and after: the braced print (from a single roll) shows cleaner top surfaces.
Common questions

Frequently Asked Questions

What is a 3DBenchy and why print one?

The 3DBenchy is a small tugboat model designed as a calibration print. It packs in overhangs, bridges, fine text, and smooth curves, so how well it prints tells you a lot about your printer's tuning. It is the standard before-and-after test when you change something.

What does a Z-axis brace do on a 3D printer?

It adds a diagonal support from the top of the gantry down to the base, triangulating the frame so it stops swaying when the bed and head move quickly. Less wobble means sharper detail, especially on tall prints.

Does filament brand really affect print quality?

Yes. On one Benchy I switched brands mid-print and the difference was obvious: the cheaper generic PLA left artifacts and stringing, while a higher-precision PLA printed clean deck lips with none. A good machine still benefits from good filament.

How long does the Z-brace take to print?

About 16 hours for all the parts, using roughly 44 meters of filament at normal quality and 20% infill. The pieces are over-engineered, but that is fine for a permanent structural upgrade you print once.

What hardware do you need for the brace mod?

Two 410mm lengths of 8mm threaded rod, twenty M3 x 10mm screws, six 8mm nuts, two 8mm locking nuts, and some rubber or felt pads. Threaded rod comes in 3-foot lengths, so one rod cut in half is enough.

Wrapping up

Benchmarked and braced

Two lessons this episode. Always benchmark before and after a change so you actually know it helped, and a Z-brace is one of the highest-value upgrades for a wobbly open-frame printer. Between better filament and a stiffer frame, my prints took a clear step up.

Next, a quick side project I had wanted to do since day one: filming the printer at work without shaky footage. Episode 4.5 designs a camera mount that rides along with the bed.

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