3D shaft model with a keyway: smooth, stepped or splined, STL and 3MF
Pick a smooth, stepped or splined shaft, set the diameters and lengths and get a 3D model for STL or 3MF. The keyway width and depth come from a table by diameter, and the tool warns about a slender shaft.
Opens without an account 3 times a day. A free account removes the limit.
- 3 shaft typesand a custom mode
- DIN 6885keyway size by diameter
- L/D above 15slender shaft warning
- STL and 3MFfor 3D printing
What a shaft keyway is and what the 3D model gives you
The 3D shaft model is a free online tool from EduFacturing that builds a shaft with the dimensions you set: smooth, stepped or splined. You add chamfers, a DIN 6885 keyway and a groove for an external circlip to DIN 471, and download the model as STL or 3MF.
A keyway is the slot in a shaft where the key sits, the small part that locks a wheel to the shaft. The check panel shows L/D and the torsion formula.
A 3D shaft model with a keyway, chamfers and splines
A 3D model of a smooth, stepped or splined shaft
The smooth shaft is a cylinder with chamfered ends, the stepped one has up to three diameters with shoulders, and the splined one has 4 to 24 longitudinal teeth. Custom puts the type and the dimensions in one panel.
A keyway by diameter and a circlip groove
The keyway width b and depth t1 come from the DIN 6885 table by diameter, on the smooth and stepped shafts and in Custom. The DIN 471 circlip groove is a checkbox on the smooth shaft and in Custom.
A check that the shaft is not too slender
On the stepped shaft it reminds you that the transition needs a radius, and above L/D 15 it warns about sag and vibration.
Download for 3D printing as STL and 3MF
On the smooth shaft the diameter runs from 5 to 80 mm, the length from 20 to 500 mm and the chamfer up to 4 mm.
Who needs a 3D shaft model: lessons, prototypes, fits
A shaft carries the gear, the bearing and the key, so its dimensions have to agree.
A lesson on machine elements
A student adds a keyway to a Ø17 and a Ø30 shaft and sees b × t1 grow from 5 × 3.0 to 8 × 4.0 mm.
A test shaft for checking an assembly
A printed shaft with chamfers and a keyway goes into a bearing and a hub and shows the fit before turning.
A shaft for bearings and gears
The shoulders are stops, and the diameters Ø1, Ø2 and Ø3 are set separately.
A splined joint instead of a key
Teeth around the circumference replace the key and let the hub slide.
Keyway size by diameter and the slender shaft check
The model is built from cylinders and cuts; the check calculates only L/D, and the keyway comes from a table.
Body
The smooth shaft is one cylinder, the stepped shaft is up to three cylinders in a row, and the chamfers are cones at the ends.
Features
The splines are N rectangular teeth along the first section, the keyway is a slot with rounded ends, and the circlip groove is a ring-shaped cut.
Table
The keyway width b and depth t1 are looked up in the DIN 6885 table by the first diameter.
Check
L/D is the length divided by the diameter, on a stepped shaft for the first section. Above 15 a warning appears.
| Applies to | Formula | Meaning |
|---|---|---|
| Keyway, b × t1 in mm | Ø up to 8: 2 × 1.2 · to 10: 3 × 1.8 · to 12: 4 × 2.5 · to 17: 5 × 3.0 · to 22: 6 × 3.5 · to 30: 8 × 4.0 · to 38: 10 × 5.0 · to 44: 12 × 5.0 · to 50: 14 × 5.5 · to 58: 16 × 6.0 · to 65: 18 × 7.0 · over 65: 20 × 7.5 | the DIN 6885 table in the tool |
| Slenderness | L / D > 15 | warning for sag and vibration |
| Torsion, bending, critical speed | τ = 16·T / (π·d³), σ = 32·M / (π·d³), n ∝ 1/L² | text on the card, not calculated |
What is different: a keyway from a table, an L/D check
The keyway comes from a table
Its size comes from the DIN 6885 table by diameter and is not typed in by hand.
The check is on the screen
L/D shows as a number, and a warning appears above 15.
A splined shaft and a custom mode
Besides smooth and stepped shafts there is a splined one with 4 to 24 teeth, and a mode where you choose the type and the dimensions.
The tool does not size a shaft for a load: the formulas are text on the card, torque and the strength of the material are not entered, and the choice of material changes only the colour and the note. The splined shaft's teeth are plain rectangles, not a DIN 5480 or ISO 14 profile, and the circlip groove follows a formula (width the larger of 1.1 mm and 0.03·D, depth the larger of 0.8 mm and 0.05·D), not the DIN 471 table.
The transition on a stepped shaft has a sharp corner, not a radius, although the check recommends one. A printed shaft is a mock-up for fit and teaching, and a load-bearing shaft is steel.
Questions about keyway size and shafts
What is the keyway size for a 20 mm shaft?
6 mm wide and 3.5 mm deep (t1), so b × t1 = 6 × 3.5 mm. That is the DIN 6885 table entry for diameters over 17 up to 22 mm.
How to calculate keyway size for a shaft diameter?
You look it up in the DIN 6885 table: the diameter gives the width b and depth t1, for example 8 × 4.0 mm over 22 up to 30 mm. The tool does it once you tick the keyway box.
What is a shaft keyway?
A keyway is the slot in a shaft where the key sits, the small part that locks a wheel to the shaft.
What is a spline shaft?
A splined shaft has longitudinal teeth that replace the key and let the hub slide. A smooth shaft is a cylinder with chamfers; a stepped shaft has up to three diameters.
What does the L/D warning above 15 mean?
The shaft is long and thin: it can sag, and its critical speed drops. Check the deflection and the critical speed.
Can a 3D printed shaft carry a load?
No. An FDM or resin shaft is a mock-up for checking an assembly and teaching, and a load-bearing shaft is steel.
Is the 3D shaft model tool free?
Yes. Without an account the tool opens 3 times a day, and a free account removes the limit.
3D shaft models is free. Pro opens the rest
Pro costs 15 EUR a month and opens 45 Pro tools.
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Build your shaft
Opens without an account 3 times a day. A free account removes the limit.