Pet Mobility Frame

←Pet Mobility FramePrototype a measured two or four-wheel mobility support frame.

Fit the mobility frameMeasure the animal while standing

♿

Measured mobility prototypeChoose rear support or a four-wheel layout. The ZIP includes a separate frame, every wheel and spacer, a fit coupon, and assembly instructions.

Assembly & fit guide

For your current 2-wheel setup. Hardware sizes update when you change dimensions.

1. Parts & hardware to prepare

Print: 1 frame, 2 wheels, 2 spacers and 1 two-hole test coupon. Print each numbered STL once.

2 × bolts: M6 × 45 mm, standard 1 mm thread pitch; length measured under the head.
2 × locknuts: M6 nylon-insert locknuts, matching the bolt thread.
4 × flat washers: 6.4 mm hole × 12 mm outer diameter × 1.6 mm thick. Two per axle.
2 × metal sleeves: 10 mm outer diameter × 6.5 mm inner diameter × 14.6 mm long. Smooth tube, cut square and deburred.

Buy the metal hardware separately. The sleeve is the stationary surface the wheel turns on. This connection needs a bolt; it does not snap together.

The bolt length assumes a 6 mm thick locknut and the washers listed above. With different hardware, recheck the length and leave at least two full threads beyond the locknut.

2. What is the two-hole rectangle?

It is a fit test coupon, not a mounting part. The file is fit-coupon.stl. You do not attach it to the frame.

Small hole — Ø6.40 mm: check that your M6 bolt passes through without forcing it. This represents the frame and spacer bore.
Large hole — Ø10.50 mm: insert the Ø10 mm metal sleeve. It should slide in and turn freely. This represents the wheel bore.

Print this first using the same material and settings as the final parts. If the small hole binds, increase “M6 frame / spacer bore”. If the large hole binds, increase “Wheel bore diametral clearance”. Reprint the coupon before printing the full set.

The coupon checks hole fit only. Also check the finished frame holes: their print orientation can affect the result.

3. Assemble each wheel, step by step

Inside → outside
Bolt head → washer → frame → spacer → wheel with metal sleeve → washer → locknut

Put one washer on the bolt and insert it through the frame axle hole from the inner side. Repeat in the mirrored direction on the other side; both wheels go outside the frame.
Slide the printed 3 mm spacer onto the bolt, against the frame. The small round printed parts are spacers, not replacements for the metal washers.
Insert the metal sleeve into the wheel, then slide this assembly onto the bolt. The sleeve’s inner end must contact the spacer.
Add the outer washer and locknut. The washer must contact the sleeve’s outer end. Hold the bolt head with a suitable tool while tightening the nut.
Check that the sleeve is clamped securely and the wheel still turns. Repeat for all 2 wheels.

Why the wheel can rotate: the 14.6 mm sleeve is 0.6 mm longer than the 14 mm wheel. Clamping the sleeve leaves 0.6 mm total axial play. The wheel bore has 0.50 mm diametral clearance around the sleeve.

4. Rotation check & troubleshooting

After tightening, turn every wheel through 360°. It must rotate freely, have slight axial movement and stay clear of the frame.
If it binds on the sleeve, inspect burrs and printed bore size; adjust running clearance and reprint as needed.
If it turns before tightening but jams afterward, measure sleeve length and wheel thickness. Ensure the washers clamp the sleeve. Do not solve binding by leaving the nut loose.
If the wheel wobbles excessively, recheck the bore fit, sleeve dimensions and clamp security.

Inspect supports for the frame’s horizontal holes in the slicer. Measure finished parts and check rotation under the intended load before use. Recheck nuts and printed spacers for loosening or compression. This prototype has no validated load rating.

Fit and safety check requiredConfirm posture, body clearance, wheel height, and harness placement with a veterinarian or animal rehabilitation professional. Use only under supervision and inspect every part before use.

Adjust dimensionsValues are in millimeters

Internal hip width

Body-side length

Frame profile heightmmGround-to-frame heightmmFrame profile widthmmWheel flare for stabilitymm

M6 bolt + metal sleeve + locknutAxle height: 45 mm (wheel radius). Each wheel uses a Ø10 / ID 6.5 × 14.6 mm metal sleeve and an M6 × 45 mm bolt. Two 1.6 mm washers per axle. The sleeve takes the clamp force; the wheel has 0.6 mm axial play.

M6 frame / spacer boremmFront harness holemmStrap slots per sideStrap slot lengthmmEnd safety marginmmWheel diametermmWheel thicknessmmWheel bore diametral clearancemmWheel side clearancemm

LIVE 3D PREVIEW

↕20.0 mmframe profile height

Left drag: rotate · Right drag: move · Wheel: zoom

MODEL SIZE266.8 × 202.5 × 170.0 mm

ESTIMATED PRINT≈ 45 hr 49 min

GEOMETRY● Frame + 2 separate wheels + spacers