Resin printing problems, what am I doing wrong?

[njee20]

I think the ‘good’ resins have been around for a while, but they’ve become more accessible recently. I find Sunlu ABS-Like good as my ‘normal’, with Siraya Fast now reaching more sensible prices in the UK (<£30/litre for the last few I bought) I use that quite regularly, with Siraya Tenacious used to make softer bits like bogies and NEM pockets where the ABS-like isn’t quite enough on its own. 
 

I used to use Anycubic grey and actually found it fine, but they changed the formula about a year ago, and it became awful!

[stevel]

my personal preference is the Siraya Tech products, I have tried the Elegoo and Anycubic and had too many issues. The Elegoo was too brittle, and the Anycubic always seemed to give very soft edges, which i tried to cure with more supports, to no avail. after four failures of the Anycubic. with the only change being supports I switched to Siraya tech and got a perfect print on the first try. If you join their Discord group you can download, tried and tested printer settings, which can speed up the testing process. 

[monkeysarefun]

Siraya tech just seem so expensive here. I bought 6 litres of Elegoo ABS 2 for a total of $210 from Amazon (£112 or so equiv) on Black Friday or whatever its called back in November, which was a sale price but that kind of offer comes up more often than I go through resin so I've never had to pay much more.

 

  In contrast Siraya always seems to be stuck  in the $70 - $80   (£37 to £42 equiv)  per litre range. 

[tom s]

Phrozen Aqua has worked for me since i started printing, probably on the brittler side but it is easy to work with. Apparently the smell is quite low, the IPA is probably the stronger smell involved. My only regret is not waiting for the grey resin to restock when I purchased it, bright blue prints can be a bit of a hindrance... good for spotting small dropped prints though!

[njee20]

1 hour ago, monkeysarefun said:

Siraya tech just seem so expensive here. I bought 6 litres of Elegoo ABS 2 for a total of $210 from Amazon (£112 or so equiv) on Black Friday or whatever its called back in November, which was a sale price but that kind of offer comes up more often than I go through resin so I've never had to pay much more.

 

  In contrast Siraya always seems to be stuck  in the $70 - $80   (£37 to £42 equiv)  per litre range. 

Yes, Siraya is expensive here too. I paid £90 for a litre of Tenacious back in 2020, and that’s now down to £56 when I bought some earlier this year. Fast has stuck resolutely around £40/litre, and whilst it’s good I struggle to justify that for ‘regular’ use. However as I said, literally in the last couple of months I’ve picked some up for less than £30/litre, which makes it far more viable. 

[billbedford]

11 hours ago, monkeysarefun said:

The only thing that marks it down for me is that it is quite viscous so models have a fairly thick coating of excess resin on them, even if I leave them in the printer on the build plate  to drain for 24 hours or more, It just doesn't seem to run off.

 

I don't seem to have that problem. The temperature strip on the tank reads a fairly constant 26ºC, so the heater seems to work. 

 

11 hours ago, monkeysarefun said:

 

The other thing is a fairly nasty allergic reaction I have acquired, even though I've always been diligent with gloves etc but still inadvertently it does got on me sometimes, for example on my wrists above the gloves if I brush the buildplate on them trying to release prints. There is no visible rash or anything, but it gets unbelievably itchy for ages even if I wash the skin straight away. I do have an identical reaction to spray-on insect repellant (roll-on is fine) and one or two brands of deodorant though, so its possibly me rather than the resin.. (Not that I'd want it on me either way!)

 

 

My understanding is that raw resin is quite viscous and the suppliers dilute it with various solvents. It sounds like you have a reaction to one of these solvents rather than the actual resin. Changing the resin brand you use may help. 

[monkeysarefun]

10 hours ago, billbedford said:

Changing the resin brand you use may help. 

Hmmmm,  good- quality prints VS  physical discomfort.... What a choice to have to make!

[billbedford]

We all suffer for our art...

[MJI]

OK I am planning on moving to ABS like resins Elegoo ABS 2.0 seems recommended.

 

What would be a good start point for exposures?

 

Using the basic Elegoo grey resin, the really brittle stuff.

 

Mars 2 Pro

 

Currently 0.05mm layers

2.5 second per layer

35 seconds base layer

 

I do know I need slightly slower lift speeds.

 

Should I try similar, or longer?

 

Thanks

 

Martin

 

 

 

[billbedford]

It's no good guessing your settings, each printer is different. 

 

I suggest using UVTools to get the basic settings:

 

https://www.youtube.com/watch?v=lRbZw6GbGCI

 

and Cones of Calibration to check they will work. 

 

https://www.thingiverse.com/thing:5416700

[PhilH]

https://www.elegoo.com/en-gb/blogs/3d-printer-user-guide/elegoo-printers-resin-setting-sheet

 

you can download basic settings for different resins on this page

[GWR57xx]

I also now use Elegoo ABS-like v2 grey, exclusively for now. I don’t see any reason to change at the moment. It gives me very good results.
When I was having problems finding satisfactory settings another RMWebber (sorry, can’t remember who) suggested trying a much longer time than I had previously used (and twice the supposed recommended time).

I’ve printed dozens of different exposure test pieces at different settings, and am now happy with the ones I use.

The test piece I prefer is the 3DRS Starship. It has very useful sections such as the filament columns and holes on the wings, the letters at the front and the barrels supported on thin poles and the arches over them. There are also many tiny, almost invisible, features which if they all print out shows you’re pretty close to the right settings. It’s also a bit of fun.

I also use UVTools to set a pause after descent, which I think helps.

I use 5s normal exposure and 10s for the bottom layers.

I have fairly slow lift and retract speeds at 60mm/s normal and 30mm/s bottom.

These might give me longer print times, but I think that’s a worthwhile trade for not having loads of failures.

Good luck!

edit: should have said, this is on a Mars 3 Pro.

Edited March 29 by GWR57xx

[MJI]

Very good first print, but too soft.

 

3.5 second too short even though recommended, going for 5

[ikcdab]

So after all of the advice on here I am now getting good results.

I now need to print some track bases today need to be perfectly flat on the bottom.

Supports always give me little lumps that need sanding off. 

Would it be ok to print these bases directly on the build plate? 

I will have a go later and see, but wanted any input you guys had. 

Ian

[GWR57xx]

I print a lot of stuff flat on the build plate without problems.

Depending on your bottom layer exposure time you might get a bit of “elephants foot” but probably not a problem for track bases.

[monkeysarefun]

38 minutes ago, ikcdab said:

So after all of the advice on here I am now getting good results.

I now need to print some track bases today need to be perfectly flat on the bottom.

Supports always give me little lumps that need sanding off. 

Would it be ok to print these bases directly on the build plate? 

I will have a go later and see, but wanted any input you guys had. 

Ian

 

 

 

The little lumps feature is something I never encountered in my original printer, the first Anycubic Photon of 2017. Perhaps because the vat was so small, assuming that its caused by the FEP stretching in the larger printers ( I think thats the latest theory for what its all about) which wasn't such an issue with the small printers.  I definitely get it with my Saturn3 Ultra , and it is a quite annoying and unwelcome enhancement, though fixed by angling the print.

 

Regarding  printing directly on the plate - as @GWR57xx said, you'll most certainly  get a splayed elephants foot effect out of it, but you can hide that with ballast.

Edited April 6 by monkeysarefun

[Siberian Snooper]

Martin Wynne of Templot fame prints track bases directly on the build plate for fdm prints, but emphasis that it it needs to be flat and level. He uses a glass build plate.  Hayfield of this parish, has some experience of 3d printing.

 

 

[tom s]

While adding the webbing I bevel the sleepers in blender to combat the elephant footing and give the spatula something to slip under.

[njee20]

1 hour ago, Siberian Snooper said:

Martin Wynne of Templot fame prints track bases directly on the build plate for fdm prints, but emphasis that it it needs to be flat and level. He uses a glass build plate.  Hayfield of this parish, has some experience of 3d printing.

 

 

FDM is totally different in this respect. You don’t get elephants foot with FDM. 

 

I printed track bases at an angle, use lots of light supports with a 0.15mm contact patch and depth, minimises the marks. 

[tom s]

Only issue I have had with the flat on the plate approach is chairs in the centre of the FEP not forming correctly, and the frequent irritation of having the whole piece scrapped when they snap off when trying to thread rail though, even when the outside chairs accepted rail correctly.

Admittedly this was in the colder part of the year and it was so annoying I shelved the project for a bit, I am meaning to do a proper clean and relevelling, and try again now temps are back up in the 20s.

[njee20]

That was my other concern, by printing flat you’re compromising the shear strength of the chairs, as the layers run ‘through’ them. 
 

Personally I’ve shelved rhe printed track at the mo, as lots of stock bumps on the chairs and the running is poor! Adjustment takes longer than building with copper clad! One to return to in future…  

[tom s]

Indeed, I have found a spare wheel needs to be used to feel out the chair collisions and a needle file needs running along the inside of the rail to knock them down a fraction.

[billbedford]

21 hours ago, njee20 said:

That was my other concern, by printing flat you’re compromising the shear strength of the chairs, as the layers run ‘through’ them. 

 

Curing will polymerise the resin across the layer boundaries. I use 60ºC for 60 minutes for an ABS-type resin. These values were inherited from a similar Fromlabs resin. 

 

This video has more information:

 

https://www.youtube.com/watch?v=886X2geCRrA&pp=ygULY25jIGtpdGNoZW4%3D

 

[MJI]

10 minutes ago, billbedford said:

 

Curing will polymerise the resin across the layer boundaries. I use 60ºC for 60 minutes for an ABS-type resin. These values were inherited from a similar Fromlabs resin. 

 

This video has more information:

 

https://www.youtube.com/watch?v=886X2geCRrA&pp=ygULY25jIGtpdGNoZW4%3D

 

I thought curing was uv light machine?

[billbedford]

Yup, but that's what njee20 has.