Assembling a TrussLab frame

What export gives you#

After export, you have three kinds of parts: printed joints and attachments, stock tubes to cut to the listed lengths, and whatever fasteners the chosen attachments expect. This page explains how those pieces go together.

The important thing to understand up front: every printed attachment in the catalogue belongs to one of a few fastening systems, and each system has its own small assembly routine. None of them are difficult, but the fits and clearances in the printed parts are designed for a specific method, so knowing which system a joint uses tells you exactly what to do with it and what a correct fit should feel like.

Cut the stock#

Cut the tubes to the lengths from the export manifest. The generated lengths already account for how far each tube seats inside its joints, so cut what the manifest says, not what looks right against the model.

A square, deburred cut is all the precision work the frame asks of you. A pipe cutter or a fine-tooth saw with a simple miter guide is enough; chamfer the cut edge lightly so the tube slides into printed sockets without shaving material off the socket wall.

For steel and aluminum tube, a simple tube cutter deserves a special mention: it scores and parts the tube with a clean, square cut, makes essentially no noise, and leaves no chips or dust behind. You can cut the stock for an entire frame at a desk. This is one of the quietly remarkable properties of the whole system: a 3D printer, a tube cutter, and a solvent-free epoxy are office-compatible tools, and they are enough to build structures all the way up to two-meter-tall machine frames. No other construction system offers comparable stiffness-to-weight, scale, and mounting modularity from tools you could use in a shared office.

Bonded sleeve joints#

Slip-on sleeves, including the plain tube sleeve, flanged sleeves, and the joints generated from them, slide over the tube end and are bonded in place with a structural adhesive. Two-part epoxy and MMA (methyl methacrylate) adhesives both work well; this is the same class of adhesive used to bond metal and composite tube assemblies.

The sliding fit is designed, not a printing error. The clearance between tube and sleeve is where the adhesive lives, so a sleeve that slips on without force is correct. Degrease the tube end, abrade it lightly, apply adhesive to both surfaces, seat the tube fully, and leave the joint unloaded for the adhesive's stated cure time.

Bonded joints are the lightest and stiffest option, and the right default for frames that do not need to come apart.

End-bolted sleeves#

The end-bolted sleeve fastens to the end of a tube with a single central bolt, so the tube end needs to carry a centered thread, typically a threaded end insert fixed in the tube. The sleeve's central clearance is sized for the bolt to pass through and clamp the sleeve against the tube end.

This system keeps the joint mechanical and removable at the cost of preparing the tube end. Prepare the insert first, dry-fit the sleeve, then bolt it home.

Bolted and snap-on clamps#

Clamps are the no-preparation system: nothing is done to the tube at all. The two-piece bolted clamp and the single-bolt clamp close around the tube and are tightened with bolts; their bolt bosses are sized for heat-set threaded inserts, which you install into the printed part with a soldering iron before first use. The snap-on clamp needs no hardware; it snaps over the tube through its wedge opening.

Because the tube stays untouched, clamps can be added, removed, and repositioned on an assembled frame: any position along the tube, at any rotation angle. They are the system to reach for when a mount needs to move, or when you are attaching things to a frame that is already bonded together.

Dry-fit first#

Assemble the whole frame dry before any adhesive comes out. Check that every tube seats fully in its socket, that the frame closes without forcing members, and that you have an assembly order where every joint stays reachable. On a closed, fully triangulated frame the order matters, since the last members must still have room to slide into their sleeves.

Adhesive is the one step in the whole workflow you cannot undo, so it comes last, after the dry-fitted frame has already proven the geometry.

The strength a finished frame actually achieves depends on your printing and bonding process. The load testing guide describes a canonical fixture for measuring it with your own parts.

Design your own fastening#

Bonded sleeves, end-bolted sleeves, and clamps are the fastening systems currently built into the attachment catalogue, not the boundary of what the tool supports. Attachments are ordinary authorable parts: the attachment editor gives your designs the same parent-link awareness the built-in catalogue uses, so a custom fastening idea like a different insert standard, a printed thread, a pinned joint, or a bayonet fitting becomes a reusable attachment like any other.

If you develop a fastening approach that works well, that is exactly the kind of thing the catalogue is meant to grow around. Tell us about it by writing to info@trusslab.ai or joining the Discord, and we will gladly help promote good community fastening systems into catalogue presets so other builders can use them too.