Print anomalies on left and right side

Hi, I have been using my 1+ “keenlambkin” to make very small odometer gears. The prints are wonderful with beautiful fully functional gears that operate at low RPM with low load. But there is an obstacle that I am constantly working around to get everything to print correctly. Maybe somebody has an answer to what I am encountering?

I have what I call “sweet spots” on the print platform. That is a tiny precision part can be printed without any distortions. A distorted gear will have one side of its teeth saw toothed shaped (or filled in) instead of a regular sharp “V” shaped tooth if not in a sweet spot. I found 5 locations on the print platform where gears come out perfect. The anomaly seems to occur to the left and right side of a defective printed gear when looking at the machine straight on.

Here is a more easy to see example. I am printing out a cylinder. You can clearly see the “ribbing” on the left and right sides. Any ideas what causes this? I believe this phenomenon is what restricts me to 5 ideal print locations and prevents the machine from making gears in batches greater than 5 at a time. It also wears out the resin tank as I am forced to print in the same locations.

Mirror and optics are super clean. The printer is working great for my application (making odometer gears) as it stands, but being able to print more than five tiny 7mm gears at a time would be nice. This “ribbing” effect is what I see on the sides of the ruined gears aka the teeth are filled in by a horizontal rib and/or saw tooth shaped in the microphotograph of a failed gear itself. You can see the “ribbed” band that has completely filled in the gear teeth. Yet look how crisp and perfect the pinion teeth are! I have 5 locations that produce perfect gears, rest have the ribbing where the teeth are filled/saw tooth shaped



Any ideas or suggestions what is causing this? Notice the rib (or band) that has filled in the outer gear teeth? The teeth also lack definition compared to the pinion teeth that are perfect.


Some Form1+ users reported issues with laser “spot” distortion that introduced problems in their prints. If you do some searching in the forum you ought to be able to find the posts. It was a while ago, though. The blame was placed on the lens inside the laser, which was said to be shifted off center. I don’t think I ever saw quite enough hard data to be convinced of the issue. And my Form1+ developed a suspiciously similar problem that was remedied with mirror cleaning. The front aperture of the laser probably needs to be cleaned eventually, too. But I remember one guy who was sure everything was clean and removed his laser and add his own “collimator” to clean up the laser spot, which fixed his problem…

I know this doesn’t explain why it comes out in some locations and not others but have you tried orientating your piece differently? I think if you tilt the gear a little bit you will have better luck printing everywhere.

Indeed I have. I have 100’s of trials and found that I can only get gears to print properly in the horizontal position. I am pretty certain I have a laser flare issue as Randy brought to my attention. The beam looks nasty. Don’t know what kind of tolerance is allowed. It wouldn’t even make a suitable laser for a pointer giving a lecture. Going to look deeper into galvo mirrors and the laser emitter itself.

I just tried printing with the high strength resin from a brand new bottle and tank. All details are filled in. The resin is curing well beyond the perimeter of the part itself. The mirror is perfectly clean.

HPCreations, I think you nailed it. My laser beam looks more like a cheap flashlight beam than a laser at the test spot. I just bought high strength resin and a brand new tank. The print comes out with no details. The resin is curing beyond the laser path. But why some areas are more defined would tell me I have dirty mirrors somewhere. But from what I can see everything is spotless. Going to check deeper.

But I tell you, that formlabs high strength resin is pretty impressive stuff. A guy can hurt himself trying to break it to test its strength.

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