First time 3D printer user - strange issues with first 3D print

[plasticbasher]

Hi All,

 

I have just got a Geeetech Alkaid 3D printer (the $99 / £99 3D resin printer of YouTube fame).  I am using Geeetech 405nm UV resin.

 

My first print was a failure and I cannot work out why.

 

It was one of the pre-loaded "demo models" - a fantasy snake's body with a dragon's head, curled up a bit like a pretzel.  In general I was pretty impressed with the print, but there are two whopping great flaws and one smaller, but obvious flaw:

• A significant section of body / neck behind the head came out flat and thin, like only one surface printed.  Probably about twice the heads length.
• The last 10-15mm of tail didn't print at all.
• A section of the head by one of the eyes looks recessed (it's all there, but it's like someone cut it out and glued it back in 1 mm lower than the surrounding surface).

 

I also have a Geeetech washer & UV hardener and the upper surface of the print was perfectly hard after 20 mins; I flipped the print over and despite having a further 25 mins under UV lights, it is still tacky to the touch.

 

I suspect that I did not shake the resin anywhere near thoroughly enough.  Does anyone think anything else might be going wrong?

 

Cheers,

plasticbasher

[SteveM666]

I can't comment on the failure to cure although your supposition regarding mixing may be a factor.

The flat surface failure could be down to insufficient supports causing that layer to fail and peel away. All layers after that one will have nothing to stick to. They will still print but will be stuck to the bottom of the resin reservoir. 

Follow your printers cleaning instructions to get rid of that or your next print could crack the LCD screen.

[njee20]

Clean your model more thoroughly, then let it dry prior to curing. You shouldn’t need anything like 25 minutes (or even 10) to cure. 4-5 minutes is likely plenty. 
 

Shaking the resin may be a factor, did you warm it? That’s more likely to be a cause IMO. Don’t need to do anything special. Put the bottle in hot water, use a heat gun on the vat (my preferred method), all sorts of options. 

[PhilH]

Obvious but I take it you've done the build plate level and removed any protective transit film from the LCD screen?

Edited March 17 by PhilH

[ikcdab]

i really struiggled with my 3d printer when i first got it - a elegoo saturn. I had failure after failure. after much heart rending and almost throwing the thing out of the window, I can now get reliable prints every time. My learning points are:

1. use decent resin. I started with water-washable which was rubbish. Now i am using standard resin, things have massively improved.

2. as said above, make sure things are warm. I heat the room to 20C before printing, and switch the machine on 15mins before i use it.

3. shake the resin bottle or stir whats in the vat.

4. make sure the build plate is exactly level. Take your time, this is critical.

5. check the settings in the slicer software. Mine came with chitubox and the default settings were not appropriate. I had to joggle the exposure time, lift speed and dwell time to get reliable results.

6. supports are critical. i always use "medium" in chitubox as i found that "light" snapped. go through the model layer by layer in the slicer and check the supports are adequate in chitubox.  There are various check models you can download to test the settings.

7. accept that it is not "plug and play". it takes loads of fiddling to get it working right.

8. make sure the models are washed very well. I saw no need for a washer and i use a plastic tub and a soft brush to clean the pieces. I find it very effective. Do it very well as any residual liquid resin will result in stickiness. i sometimes think that the UV curers are quite aggressive. If the weather is at all decent I prefer to lay out my models in the conservatory and let the sun do the job, turning from time to time. Its imprecise, but sun-cured do seem to be less brittle than those cured under UV lights.

perserve, as once its working well, its brilliant.

[Pete the Elaner]

Do you level it before each print?

I levelled mine when it was new, but not after the first print. Subsequent prints were disappointing, so I now do it every time. I assume that taking off the print plate to remove the previous print will move it a little?

When you think about how the print process works, it makes sense that levelling it is crucial. It should be an easy process too (It is with my Anycubic).

[bradfordbuffer]

Even as spring is nearly hear a warm printer and walm resin is a must

Pre warm your resin in bottle couple of good shakes as it's more fluid easier to mix. Fix a reptile heater to inside of  uv hood of printer..

My mono x has 3 so I can disconnect to get different heat settings

I use to get loads of failures now failures down to my stupidity with supports...or stl file pants

 

Go for 2 stage wash!

Ist dunk in ipa give a good wash then into 2nd ipa bath in a separate tub or a dedicated wash and cure allow to dry then blast it with air to remove any last ipa

Then cure! Don't cook your model a few mins on each side should be sufficient 

Don't let your 2nd wash station ipa get too contaminated with resin....decant and recycle. check out yt to find the 101 ways. I save up 10lts of dirty resin ipa in a big adblue tub and clean it using the distiller method losses are about ⅓ to ¼ of ipa but other ways you lose ipa too just a fact of life the ipa is a consumable that needs replacing/toppling up.

Make your own mind up on ipa cleaning some methods are easier than others

 

Failures are part of home 3d printing.....you learn by failure and success

 

 

[plasticbasher]

Thank you all very much for the suggestions.

 

I've only quickly skimmed them, but will look properly before attempt No. 2 next weekend:

• Yes, I did level the build plate (all films were removed including the one on the LCD screen).  Will read the instructions again.
• My resin shaking was probably nothing like enough and I certainly didn't then wait for the bubbles to dissipate.
• I have just bought a 5 litre container of IPA so I can clean things more effectively (I probably only had 150 -200ml to use last night).  Thanks for the filtering advice!
• Temperature definitely wasn't something I'd paid much attention to (windows were open because of the resin smell and it wasn't exactly warm and dry yesterday.
• The print was a demo, so I would have hoped the supports were good enough....I will have a good look though.  Mine also came with Chitubox and I'll check the support settings there.

I would also like to find a source of the pre-cut FEP sheets as the one on my resin contain has a thumb nail scratch (guilty) and took a bit of a hammering in my amateur clean-up efforts.

 

Yes, I recognise this is a bit of a learning process; the need for absolute cleanliness has been my first lesson..!

 

Cheers,

plasticbasher

[bradfordbuffer]

Don't bother with pre cut fep sheets you have to trim them anyway!...I ordered some for my mono x from anycubic when they arrived they are twice the size of vat so I get two out of every sheet...

[PhilH]

One other thing before you do a lot more printing. Make sure you order and fit a protective screen over your LCD. They're like the house insurance of 3-D printing.... considered expensive and unnecessary until you need them. They can save your LCD screen from resin spills and leakage from holes in your fep, screens don't take kindly to having resin on them.

Edited March 18 by PhilH

[F2Andy]

If stuff fails to print on one section of the build plate, but okay on another, it is probably a levelling issue.

 

I doubt it is mixing. I leave mine to stand in the vat for days and before printing, and it is fine. When filling from the bottle, I turn the bottle upside down a few times; I avoid vigorous shaking because of the bubbles. I use Elegoo 2.0 resin, but I guess that is pretty close to what you are using. 

[njee20]

Given the build plate squashes virtually all of the resin out of the way i can’t believe bubbles are a factor. They will definitely all get popped.