Draft reference · October 2026

Printing

Draft. These settings and hole sizes are for the prototype being built now. They have not been validated by a load test. The print files are released with the verified CAD after the prototype is tested.

The bolted 6061 aluminum frame, the drum and the rack side carry the rope load. The printed parts bolt to that frame: the two end pieces, the level-wind, the exit, the screw-end tower, the gears, the brackets and the covers. Every part fits a 256 x 256 mm bed. The print files come in the assembly's orientation: turn each part in the slicer as listed below.

Materials

Material	Parts
PAHT-CF, dried before printing	load-path parts: the 81T drum gear and the 45T screw gear, the traveller frame, the fixed roller bracket, the top tie, the far-end screw stand, the screw-end tower, the rope clamp ring, the exit bearing housing, the exit carrier, its retainers and rail caps
PA-CF (or PAHT-CF), dried	the motor-end and battery-end pieces, the ODrive bracket, the latch finger bar and the service lid
PETG-CF (or PA-CF)	the two covers (each with its end cap printed in) and the rear I/O panel
PETG	the screen frame, the front board plate and its standoffs, the WAGO bracket, the fan duct, and the battery spacer for the TP2700 pair
PETG or PLA	the drill guides (see below)
TPU 95A (optional)	the three battery pads, flat, 15-20 % gyroid; or cut them from 1 mm and 2 mm EVA foam sheet

The carbon-fiber filaments wear brass nozzles: use a hardened nozzle.

Settings

Suggested for the structural parts (PAHT-CF and PA-CF), not yet validated by a load test:

0.2 mm layers;
5-6 walls;
6 top and 6 bottom layers;
40-50 % gyroid infill.

Orientation

Part	Face on the bed
Screw-end tower	on its side, web flat on the bed. Its bending then runs along the layers. Never print it upright.
Top tie	on its side, so the layers run along the bar
End pieces	underside down
Covers	top down (the wire loops bridge; no supports)
Rope clamp ring	outer face down (grooves and knot pocket up)
81T drum gear	gear face down
45T screw gear	hub face up
Fixed roller bracket	flange face down
Traveller frame	carriage plate down
Far-end screw stand	foot down
Front board plate	back face down
Rear I/O panel	outer face down
Battery pads	flat
TP2700 battery spacer	side plate down

The bearing seats, the nut bore and the screw holes in the level-wind parts run horizontally. A hole printed on its side can droop at the top: check each against its fit coupon before assembly.

Heat-set inserts

The pockets are cut for the 3DZWMAN 380-piece insert kit. Other brands' inserts have other sizes and may not grip.

Thread	Insert (length x outer Ø)	Pocket hole
M2	3 x 3.2 mm	2.9 mm
M2.5	4 x 4.0 mm	3.6 mm
M3	4 x 4.2 mm	4.0 mm
M4	5 x 5.0 mm	4.6 mm
M5	5 x 7.0 mm	6.4 mm

Pockets are one millimeter deeper than the insert, with a 0.5 mm lead-in. Press each insert in square to the face with a soldering iron and an insert tip, and let it cool before loading it.

Other printed holes: clearance M2.5 2.9 / M3 3.6 / M4 4.7 mm; self-tapping pilots M2.5 2.2 / M3 2.6 mm.

Drill guides

The frame is bolted together, and a few of its holes go into the edge of a plate or the end of the drum tube, where a laser cutter cannot reach. Printed drill guides make them accurate by hand. Each guide is a cap that slips over the edge, with an end stop that locates the holes, and guide bores 20 mm long sized for the tap drill (drill + 0.15 mm).

Guide	Holes	Drill	Located by
Rear plate, bottom edge	6	3.3 mm (M4)	an end stop on the plate's motor end
Motor face plate, back edge	2	2.5 mm (M3)	an end stop on the plate's bottom edge
Rack cheek, front edge (one guide per cheek)	3	3.3 mm (M4)	an end stop on the cheek's bottom edge
Drum tube end (use it on both ends)	4	2.5 mm (M3)	a boss that centers it in the bore

Print them in PETG or PLA, cap face down so the bores print vertical, with 100 % infill round the bores.
Clamp the part in a vise edge up, push the guide against its end stop, drill through the bores, then tap by hand. The depths are in the build instructions.
A worn guide is reprinted.

Fit coupons first

Print the fit coupons in the same material and on the same printer before the large parts. Each one tests a few sizes around the design value:

Insert pockets M2.5 / M3 / M4 at -0.15 / nominal / +0.15 mm. Press an insert into each and use the size that goes in straight and holds a tightened screw.
Clearance holes M2.5 / M3 / M4 at -0.2 / nominal / +0.2 mm. The screw should slide through the nominal hole without forcing.
Battery slice: a 10 mm slice of the battery cradle (44.0 mm opening: the TP3300's 43 mm plus 0.5 mm a side). Slide a real pack through it both ways. A TP2700 pack goes in on its printed spacer.
688 bearing seat: slices of the screw-end tower wall with 15.90 to 16.20 mm bores (the design uses 16.10). Use the tightest that seats the bearing flush by hand or in a vise without splitting the ring.
Roller shoulder holes: 6.0 to 6.3 mm (the design uses 6.2) with the 10.4 mm head counterbore. The shoulder should slide in without wobble and the head should sit below the face.
M5 and M4 inserts: M5 pockets at 6.25 / 6.40 / 6.55 mm and M4 pockets at -0.15 / nominal / +0.15 mm.
T8 nut seat: bores of 10.4 to 10.8 mm (the design uses 10.8) for the brass nut's 10.2 mm body, with the flange's M3 insert pockets. Check that the bore stays round with the inserts set: only 0.6-0.75 mm is left between them.
Lead-screw clearance: 8.6 / 8.9 / 9.2 mm (the design uses 9.2). The screw must turn freely: the nut is the only contact.

If a different size works best in your material, note it. Hole sizes are easy to change in the editable CAD, which is released with the verified build files.

A draft reference: the prototype is being built and tested, and the CAD, build files and software are released after testing.

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