Print failure / adhesion problems

I’m attempting to print some pulleys directly on the platform.
The prints have failed twice today.

Attached is the .form file.

It seems only the inner and outer lips are printing or a few layers on top of them (so I’m essentially getting the flanges) before failure.

After the first failed print, I did sand the platform with 120 grit on a machined marble sanding block, but no progress was made.

I also cleaned the platform with 91% alcohol (and then heat dried it so as to not prevent adhesion).

Thoughts? Is this maybe where I start considering the “fine tuning” settings to adjust height down or?

GT20_Pulleys_20150601.form (562.5 KB)

David,
I would not print the pulleys this way. Looking at the first few layers, there is not enough material making contact with the build platform to properly secure them. I assume that your part is not designed to compensate for the initial few layers that are compressed to promote adhesion as well as after looking at the parts the overall shape is not optimal for printing them this way.

I would let preform angle the parts for better printability and this way the raft and supports will be appropriate for the parts being printed. If you really have to have them print with no supports, you will need to thicken and flatten the part of the pulley that is touching the build platform.

There may be other ways to get them to print properly without supports and raft but someone with more experience with raft less printing then I have will need to chime in.

Good luck.

1 Like

Thanks, @DavidRosenfeld.

I agree. I changed the flange to be flat to solve that issue. I thought the flat base would solve the issue, but I printed them again, and alas it failed.

I have printed similar parts in the past on a different platform with white resin (instead of grey as I’m printing now), and in a v1 vat (now v2 relatively now), with no problem so I’m wondering if the “fine-tuning” might help or if there’s something else I could do to coerce a successful print.

Any other thoughts/suggestions?
David

GT20_v2_Pulleys_20150601.form (475.1 KB)

Looking at this I do not think it will work if you do not tip them you have a large surface area plus you are creating a vacuum at each pulley by not tilting the parts this is a lot of added stress that could be avoided. If anything you may do a great deal of damage to your PDMS layer in you resin tray.

I would either only print one at a time if you absolutely need this orientation with out supports or I would do a slight tilt and add supports manually to print multiple.

@Thomas_Judy, thanks for the heads up on the vacuum issue.

I’m still a bit perplexed. I’ve printed similar parts before (see image + .form file)
Laser_Cutter_Bearings.form (414.1 KB)

These are the parts I mentioned in my previous post that printed fine. Same machine, white resin, different vat (older), and different build platform.

They are approximately the same size so the vacuum shouldn’t have been the cause.

Suggestions? I’m still stumped.

seems like fine tuning the build platform lower is in order.

@ChristopherBarr Any recommendations for a starting place for a first z-offset? I read the Fine Tuning article and it doesn’t give any suggestions.

Dear David Miller,
Do you have the failure print picture to share with? So that we can analysis your fail print.
Case 1) The parts do not stick to the build platform?
Case 2)Or they stick to the platform, but the “top-part” is missing?
For Case 1: If your detail level is set to 0.025mm, you can try to lower it with 0.3mm. (Please test print with one single item first for quick test print)
For Case2: I agree with Thomas_Judy’s opinion about vaccum. Printing with support can help.
Hope this help.

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