M38 model : turning double slider crank

thingiverse

You'll need two M3x3 bolts or a strong adhesive to assemble the spline shaft and boss. https://www.facebook.com/cybbiggu/posts/2633595906722672 https://www.facebook.com/groups/koreamakers/1635595236579207 <<3d printing and assembly precautions v.1a2>> 1. To improve print quality (dimensional accuracy, etc.), follow these steps: 1) Print different types of parts separately. 2) Reduce the number of parts printed at once. 2. If the nozzle and bed distance (Z-axis setting value) is too close, the bottom surface will be compressed like an elephant's foot, resulting in a rough finish. This is particularly true for parts with round holes or spline holes on the bottom surface. 3. When assembling two parts, they may fit loosely, correctly, or tightly. However, if it feels tight during the first assembly after printing, try removing and reassembling several times to loosen it up. If it still doesn't budge, there might be a problem with print quality. 4. If the spline shaft and gear or spline shaft and boss are difficult to assemble, try reducing the XY scale of the spline shaft by 5% and reassemble them. This should improve fitment. 5. When using pins, they may become loose after repeated insertion and removal. To prevent this, avoid disassembling parts after initial assembly. If it does become loose, you can reprint the part or use a strong adhesive. Filament material may also affect the tightness of the pin. 6. To secure the boss to the spline shaft, you'll need M3x3mm socket head cap screws and 1.5mm hex keys. Be careful not to overtighten the screws, as this can cause the threaded holes to become misshapen and loose. 7. If you're having trouble finding socket head cap screws, you can use a blue-colored strong adhesive (available at most hardware stores) to fill the M3 hole in the boss. However, be aware that disassembly may be challenging. 8. If you accidentally damage a part during assembly, you can use a strong adhesive for partial repair. 9. Make sure there's a small gap (about 0.5mm) between moving parts to ensure smooth operation. You may need to perform some post-processing using tools like pliers, wire, sandpaper, or deburring tools. If these methods don't resolve the issue, feel free to let me know and I'll be happy to help.