Creality LD 002R LCD Resin 3D Printer (Howard)

Howard, the new Creality Resin Printer!

The eagle-eyed amongst the DoES community will have noticed a new resin printer in the workshop area.

My own experience (@ajlennon) is that resin printing gives far higher quality prints than filament printing and is easier to do, although the cleaning stage isn't great fun. Also resin can be an irritant so be careful when working with it. Make sure to use gloves, preferably a mask too, and clean up after yourself.

Specs for the Creality printer.

• Build Volume: 120 x 65 x 165 mm.
• Layer Height: 20 – 50 microns.
• Resolution: 2560 x 1600 pixels.
• XY-axis positioning accuracy: 0.075 mm.
• Z-axis positioning accuracy: n/a.
• Printing Speed: 50 – 70 mm height/h.
• Bed-Leveling: Manual.
• Display: 3.5 in touchscreen.

A quick note on consumables

Resin for the printer is relatively expensive at circa £40 for a 1l bottle

It's also not an easy job for people to remove resin from the vat and replace it with different resin, e.g. their own. There is inevitably some waste and feels a bit pointless unless you really need a particular colour or type of resin.

Currently all the resin we have was bought by me (@ajlennon) and whilst I'm very keen for people to use the printer I can't underwrite the cost of the resin in the future

My hope is that as a community we can agree a plan to pay for the resin similar to what is done for PLA filament.

Important points

1. The vat holding the resin can be unscrewed from the main body of the printer. If you do this you will see the bottom of the vat is clear plastic. This can easily be damaged or holed with a sharp tool in which case the resin will run through and may destroy the printer. Be very careful not to damage the plastic sheet.

2. The hard plastic base above the display in the body of the main machine needs to be completely clean for the printing to be optimal. You shouldn't need to unscrew the vat for cleaning but if you do make sure to use a cloth and materials that do not scratch or otherwise damage the transparent area.

3. The flexible plastic at the base of the vat needs replacing periodically. We should have spares somewhere. I suggest you don't try this yourself but contact me or an organiser if this an issue (Alex, @ajlennon).

4. Failed prints can result in cured fragments of resin in the vat or on the surface of the plastic at the base of the vat. From time to time it can be worth straining out the resin from the vat to remove any fragments that would damage the print. Also if a failed print results in resin sticking to the plastic at the base it is probably best to go through the machine cleaning process in the first instance. This basically exposes a rectangle to cure it which can then be easily removed from the plastic. Be gentle and do not use sharp tools to try to remove resin from the flexible plastic as you will damage it.

Resin printers work differently from filament printers. They work on a UV curing process. The process is this

The print itself

• Fill vat at bottom of printer with UV curable resin
• Start printing
• The metal plate is lowered into the vat to just above the display which faces upward through a transparent sheet at the bottom of the vat.
• A horizontal slice of the object to be created appears on the display and cures the relevant areas of the resin closest to the display
• The metal plate raises (with the cured parts stuck to it) and lowers again slightly higher so the cured layer is now closest to the display
• The next slice of the object is displayed and the next layer of resin cures, sticking to the layer of resin above it
• The process repeats. In this way the object appears to "lift" out of the resin vat.

When printed there are two more stages which can be a little messy

Washing and UV curing

• All of this is best done with latex gloves on!
• The metal plate is unscrewed from the machine with the knob at the top (make sure the plate doesn't drop off)
• The resin object is stuck to the plate and needs to be removed without causing damage to the metal plate. A sharp knife or stylus gently applied is sufficient
• The resin object then needs to be washed in isopropyl alcohol (IPA) to remove the uncured resin. You can leave it soaking for 5 minutes and gently wash off the resin. A toothbrush may help. An ultrasonic cleaner will greatly improve the cleanness of your final model and is a less messy option for general cleaning.

Alternative from Andy Goodwin: "There are some environmentally friendly/low odour/reusable options for cleaning your model. I use Simply Green cleaner which actually results in a cleaner model."

• Snip off any support material that you added to the print.

• The object is still quite flexible. It then needs to be "cured" further under a UV light such as a nail hardening lightbox or in the sun. Also for curing (Andy Goodwin) uses a bin with a UV led strip on a timer in it. It’s cheap and effective. I (@ajlennon) am building a similar thing but the UV LEDs I am using at present in a plastic box don't seem to work very well. They may be emitting at the wrong frequency.

• You're good to go!

Slicing with ChituBox

There are probably other alternatives but Creality recommend using ChituBox to do your object slicing. This is the resin printer equivalent of something like Cura for filament printing.

You can download ChituBox here

If you've used Cura you've probably got the basic ideas down. If not you might want to go get an organiser to give you a run through.

First off load up ChitBox and then load in your STL file of choice (this is is a standard 3D modelling object format)

Important

1. Remember that the resin printer exposes a complete 2D plane all in one go. So orienting an object to be as small as possible in the vertical plane will lead to faster prints.

2. Also remember the object will be lifted out of the vat so gravity will pull on the parts. You may need to add structural supports to help with this so your object does not deform or get pulled off the metal plate. ChitBox has tools for this.

Printing Notes

1. Because the resin printer exposes an entire 2D image in one go if you want to print multiple small items, can fit them all on the metal XY base and the Z height doesn't change then the time taken for the print will be the same as just for the one item.

2. If possible placing two holes in your print (near the top and bottom) will allow the resin inside to drain. This saves resin and will result in a quicker cure time. This will obviously depend on the model but it is highly recommended for larger prints.

3. If you have a very detailed model then printing at a 45 degree angle with supports can result in better prints. This is offset by the need to remove all the supports which can be tricky if you have equally detailed sides of your model. See https://all3dp.com/2/sla-printing-5-tips-and-tricks-for-great-resin-prints/ for examples.

Here's an example of an "O2 Port" STL file that I loaded in. You can see the representation. You can then orient, scale and move this around using the icons on the left hand side.

Then if you right click the "support" icon over on the top right hand side you can add supports if you feel they might be needed. There is an automatic option or you can draw them in yourself. Alternatively you might use the automatic option then remove any support you feel isn't needed

There are a number of print settings. I find these work and in the first instance I wouldn't change them but you can play with optimising print speed and quality

Then do the slicing and save the resulting file in the .CTB format (not .CTBDLP or other)

Copy the resulting file to a USB stick which should then be inserted into the resin printer (left hand side near the base).

Power on the printer and you should be able to use the "print" option and see renderings of the files on the USB stick...

Have fun !!!