U225X PUBLIC-SAFE CONVERSATION NOTE

RECORD: CHAT-0049
TOPIC: 3D Printing Shock Bushings
IMPORTED: 2026.04.26

This note was generated from a matching conversation in the supplied ChatGPT export.
EXTRACTED REQUEST: Ehat would you make them out of on a lathe

RECOVERED CONVERSATION EXCERPTS
USER MESSAGES:
1. Do you think I can print this for them
2. What about tpu
3. Ehat would you make them out of on a lathe

ASSISTANT RESPONSES:
1. Short answer: you *can* 3D print it… but you probably *shouldn’t* for this application—at least not in standard PLA/PETG. Let’s break it down like a shop guy would:. ⚙️ What the part is doing You’re basically making a shock bushing sleeve: - Takes shear load + clamping force - Sees vibration + cyclic loading - Needs to hold tight tolerances (ID especially) - Likely gets compressed between brackets/bolts That’s a *mechanical part*, not just a spacer.. 🧱 If you print it (PLA / PETG) Problems you’ll hit: - Layer splitting under shock load (big one) - Creep over time (hole will loosen) - Ovalizing of the 16mm ID - Bolt clamp force can crush or deform it - Heat + outdoor use = faster failure 👉 It might work for a…
2. TPU is actually worse for this specific part—even though it sounds like a “rubber bushing,” it’s not what you want here.. ⚠️ Why TPU doesn’t fit this job You’re making a sleeve, not the rubber bushing itself. That sleeve needs to be: - Rigid - Dimensionally stable - Able to handle bolt clamp force TPU is: - 🟡 Flexible / compressible → it’ll squish when you tighten the bolt - 🟡 Low stiffness → your 16 mm ID won’t stay 16 mm under load - 🔴 Creep monster → it’ll deform over time and loosen up - 🔴 Will allow slop/play in the shock mount. 🧠 Think of it this way - Rubber bushing = absorbs vibration ✅ - Steel sleeve = keeps everything aligned + takes clamp load ✅ - TPU sleeve = tries to do both and does neither…
3. For that sleeve? Keep it simple and match the job—not overkill, not junk.. 🥇 Best all-around choice: Mild steel (1018 / 1020) This is what I’d actually use. - Easy to machine (you’ll fly through it) - Plenty strong for a shock sleeve - Holds tolerance well - Cheap and available everywhere 👉 For your application (adapting a shock bushing), this is the sweet spot. 🥈 Upgrade option: 4140 (pre-hard / HT) Use this if: - It’s a heavier vehicle - High shock loads / off-road abuse - You just want it bulletproof - Stronger, more wear resistant - Still machines decent (especially pre-hard) 👉 Slightly harder on tools, but nothing crazy. 🥉 Corrosion option: Stainless (304 or 303) Use if: - Outdoor / wet / road salt e…

EXTRACTED KNOWLEDGE / HOW-TO
- Let’s break it down like a shop guy would:
- --
- Takes shear load + clamping force
- Sees vibration + cyclic loading
- Needs to hold tight tolerances (ID especially)
- Likely gets compressed between brackets/bolts
- *Problems you’ll hit:
- Layer splitting under shock load (big one)
CONVERSATION SHAPE: 3 user turns / 3 assistant turns
ATTACHMENTS DETECTED: 8

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