Showing posts with label 3D printing. Show all posts
Showing posts with label 3D printing. Show all posts

Tuesday, November 20, 2018

Anycubic Photon review


Today I’m very happy to review this amazing printer. I’ve been looking for this print quality for a long time! I mainly print miniatures and models, so my FDM printers were pretty good, but not good enough. I made impressive miniatures, but they all needed rework like epoxy resin finish and smoothing with soldering iron. I was dreaming about resin printers for years until the Anycubic Photon was released. The first models had blue windows, not good to protect the UV sensitive resin. The latest models have proper orange windows. I bought one from the official Australian importer on Ebay for $465 AUD including a 500g resin bottle which is $50 alone. It’s usually around $550-600 AUD without resin but I was lucky at the auction.

The kit with all the accessories

The test print

SPECS

DLP (digital light processing) is a pretty new technology similar to SLA, but instead of moving lasers it uses a fixed UV led projector and a masking LCD screen. The LCD stands between the UV light and the resin tub to create a shadow, letting light pass only where it’s needed. The UV light that hits the bottom of the resin tub hardens the resin. The only moving part is the Z axis and it’s very precise (1.25um or 0.00125mm steps). The layer height can be set between 0.01 and 0.05 mm (10 to 50 microns). I always use 25 microns, it’s good enough for my miniatures, once painted you can’t see layers. But it’s good to know that I can get an even better definition if needed. The horizontal resolution is good too (47um against 400um of a standard FDM 0.4mm nozzle). The horizontal resolution is due to the masking LCD screen resolution (2560x1440 pixels).
One of the best “side effect” of this technology is that every layer takes the same time to print (set by you), no matter how big it is. It’s the time the resin takes to cure. Curing a dot or a large area takes the same time. So the best efficiency is achieved when printing multiple models. I usually print about 6 miniatures at the same time. And I rotate them to be as low as possible on the Z axis to reduce the number of layers and print time. This way I print 6 28mm miniatures in 4 to 5 hours.

THE KIT

The printer comes with all the tools you will ever need plus a spare resin vat film and a 250g resin bottle. There are clear instructions and the packaging is very secure. Straight out of the box, you need to align the platform, zero the Z axis and you are ready to print. Make sure the LCD screen and the bottom of the tub are always clean. You can leave the resin in the tub when not in use but it’s recommended that you pour it back in the bottle. You might want to filter it when you do that, there are filters in the kit.

SOFTWARE

The printer comes with a slicing software, very easy to use. You can scale, rotate, move multiple models and adjust the print settings like layer thickness, curing time per layer, first layer (to make sure it sticks on the platform). Like FDM printers it needs supports for overhang parts. You should rotate the models to minimize the parts that need support. Then you can add supports automatically or manually.
One of the downside of the software it’s that it doesn’t save your project. You can only save the sliced file or the stl file. But I know there are other software you can use to create the model with support and save your project, then use the Photon software just for the final slicing of the stl file.
After you slice the model, you can see the preview. Make sure the raft is printed from the first layer or it won’t stick on the platform. I failed a print because of that. Then I moved the model down 0.1 mm so the raft was actually lower than the platform and it started printing the raft from the first layer.
It’s pretty easy to use, you’ll figure it out in two or three prints.

PRINTING

The printer has a touch screen with a simple menu to test screen, adjust basic settings and print from USB (even the USB memory is provided!). During the print you won’t be able to see the first 20mm of the printed part because it’s still in the vat, so for 2-3 hours you won’t know how your print is going.
Finished print of two models
Finished print of six models (it takes the same time as printing two)

AFTER PRINTING

After the print finished, you remove the platform, then remove the printed part from the platform using a spatula. If you use a metal one, try not to scratch the platform as I did.

The model will be wet of resin, so it needs to be cleaned with isopropyl alcohol for few seconds by immersion or with a brush. It’s also soft, so it needs to be hardened with UV. After removing supports I leave them in the sun for an hour or two. Australian sun is rich of UV. But you can use a UV nail dryer or something like that.
Then you clean the platform. I use a lot of paper towel and alcohol after every print.

CONCLUSIONS

I was really impressed by this printer since unboxing it. It looks very professional, user friendly, it comes with tools, instructions and spare parts. It prints straight out of the box with amazing definition. The details on the printed models exceeded my expectations. Like all resin printers it requires lots of cleaning after print and you can’t use it in a normal room of your house due to the toxic nature of resin and bad smell. I use it in the garage. I highly recommend this printer if you print miniatures or small object that requires high precision in details and you are not scared of a bit of cleaning after every print.

Primed with gray

 "Washed" with black wash


Finished with metal dry brushing


Thursday, June 30, 2016

CTC 3D Printer


I bought a CTC 3D printer on Ebay for 550AUD and I've been working on it for a while. It's a cheap printer, but easy to modify and make it as good as the expensive ones. It comes with heated bed and dual extruder, the build volume is 220mm x 150mm x 147mm. The hardware is driven by a Mightyboard. It's basically a cheap copy of the Fleshforge Creator.
Straight out of the box, one of the Y-axis ball bearings was broken (very noisy), so I had to replace it. The 40 mm fan at the bottom (to cool the board) was broken too, it's not really needed but I replaced it.
After some time researching the internet and working on it I achieved a level of quality I never seen before in FFF 3d printers. Here I summarize what I found and the results of my experience. I rated all the modifications by "effort" (how difficult or expensive) and "improvement" (results in the printer quality).


FIRMWARE UPDATE: SAILFISH (Effort 3 Improvement 7)
Everyone suggest to do it. I've seen an improvement in the print quality just doing this update. Plus, Sailfish add new and very useful tools and features to your CTC. Here is the process explained to update the firmware to Sailfish. It's a bit messy but it works and it's definitely worth it. One of my favorite functions is the ditto printing: it uses both extruders to print 2 of the same object at the same time, but the object can't be larger than the distance between the extruders (36mm).

Ditto printing with Sailfish firmware


SPOOL HOLDERS (Effort 2 Improvement 4)
The kit usually comes with one of them to attach on the back of the printer, but it doesn't fit the spools with smaller holes, so I printed two of this thinner ones.


The back of my CTC with the filament spools in place


PILLOW BLOCKS (Effort 7 Improvement 6)
One of the first thing I noticed is the y-axis bars bent and moving up and down when they rotate. To fix this you can print a pillow block in each corner (4) and insert a ball bearing to hold the bars. There are many designs on Thingiverse, I used this one (find the assembly instruction on the same page). The ball bearings are cheaper on Aliexpress than Ebay but it takes a couple of weeks for delivery from China to Australia. The rod is 5mm, I used 5x4x10mm ball bearings (no flange). Installing them is a precision job and require the disassemble of the frame. You also have to drill 2 holes per pillow block in the wooden panels to hold them in place with bolts and nuts. I don't know if this mod improved my print quality but definitely it looks more stable and the y-axis rod are kept straight.


The pillow blocks on the Y-axis bars with ball bearing


Z-SHAFT PRELOADER (Effor1 Improvement 6)
Another thing you will notice straight away is that the build platform moves a little bit because the vertical rods are not completely fixed on the frame. To fix that, you just need to print a very simple piece that push the bars forward and keep them in place. Very small effort but a big improvement in print quality because the platform doesn't move around anymore.

Z-axis preloader (left from thingiverse, right from my CTC)


DRIVE BLOCKS (Effort 5 Improvement 7)
The original drive blocks are fixed, which means they are not adjusted to the small changes in filament diameter. A spring loaded drive block compensates for these small changes and it's easy to remove and replace the filament, just pressing the lever to release the pressure. This design also make possible printing Ninjaflex and other flexible filaments, which would clog in the original drive block. I suggest to reuse the ball bearing of the original drive block (concave), but if you want to print flexible filament, a plain ball bearing might be better. If you don't want to print them yourself, you can buy them from Ebay and Aliexpress (some as cheap as 5$).



                     The driveblock, printed, assembled and mounted on the extruder


BUILDTAK (Effort 3 Improvement 6)
I always had problems with ABS non sticking on the build platform, I tried many materials including blue tape and ABS juice but I've never been very successful. I tried a Buildtak and I solved all the problems at once. It actually sticks too much now. You have to find the right settings with your slicer to print the first layer so it sticks but it's not difficult to remove after print. You might ruin the first BuildTak with your experiments before you find the right settings. I bought it from Aurarum, it's the right size for CTC and decent price. Just stick it on the aluminium plate.

My CTC with BuildTak from Aurarum


ACTIVE COOLING (Effort 8 Improvement 7)
If you want to print PLA properly you need a cooling system. This make sure the layers solidify before printing on top of them. Without it, the print quality with PLA was really messy.
You have to connect another fan (or blower) on the extruders and print a duct to guide the air to the printed part. You can wire the fan to the power supply and add a switch to the circuit, but this way you don't have software control over the active cooling, you have to switch it on and off manually. Or you can connect it to the Mightyboard, so you can control it by software. This is useful because you can adjust the power and the time on and off (usually print first layers without cooling to improve adhesion to the bed). To do that you need to add a component to the board. A MOSFET (PSMN7R0-30YL). It's not an easy soldering job, and it's easy to damage the MOSFET with heat or even just touching it (electrostatic discharge). Also if the pins are shorted (soldered together) it's possible to damage the whole board. So I suggest you to do it only if you are confident with it.

What you need:
-24V fan or blower (better)
-wires
-duct to guide the air to the printed parts.
-MOSFET and board connector or manual switch

Because I had to buy few extra, I'm selling them on Ebay as a complete kit. There's everything you need to make your active cooling, except the duct that you can print (better in ABS).
The complete kit as I'm selling it on Ebay

For the duct I used this design because it's mounted on the back, it can't be seen, it doesn't hide the nozzles and it blows air equally on both extrusions.

The active cooling blower and duct mounted on the back of the extruders


ENCLOSURE (Effort 8 Improvement 4)
To achieve the best results printing ABS, you have to keep the printing volume warm. If the printed part cools down, it will warp up. The active cooling must be switched off with ABS. To build my enclosure I used perspex (acrylic), I bought cheap left over from building companies. For the front door I used magnets, so I can remove it completely. The top hood can be removed quickly too, the back of the hood is fixed to the printer.
The measure I used are:
 
To join the sides of the hood i designed those joints (there's no hole, I drilled them after):
I didn't notice any improvement in printing ABS (it was sticking pretty well on the BuildTak anyway, and I manly print PLA), but the enclosure protect the printer from dust and attenuate the noise when printing. The front door is held by magnets, so it can be completely removed.

The hood can be removed quickly but the back remains in place

Angle joints (the angle was calculated on the measures in the picture above) 


Small magnets inserted in the frame and front window

To close the corners I printed 4 of these pieces, they fit very well.

My CTC with corner fillers


DUST FILTERS AND CONDUCT (Effort 5 Improvement 4)
Dust filters make sure no dust or dirt on the filament enter the extruders, risking to get stuck in the nozzle. I used this design, it make it easy to remove and replace filaments. You need to buy PTFE (teflon) tubes 6mm. They have very low friction. To fix them on the back of the printer I printed this part . Note that this will add some twist tension on your filament. If your PLA is too brittle (or cold room) the PLA filament will snap after few hours when the printer is not used. I still didn't solve this problem, but I'm not the only one. It definitely didn't happen in summer.

The dust filters block mounted on top of the extruders

The PTFE tubes holder (left from thingiverse, right from my CTC)


LIGHTS (Effort 4 Improvement 4)

Having a light you can turn off and on anytime you want inside the case is very useful. I bought these LED from Ebay, I designed a frame to hold them in place and point them to the middle of the build plate. I wired them in parallel with each other and in series with a switch and a potentiometer (if you don't add a resistance you will burn them), and straight to the 24V rail of the power supply. It requires some basic soldering and drilling the frame to fit the LED holders, switch and potentiometer.

LEDs and their holder



Lights switch and potentiometer


LUBRICANT (Effort 1 Improvement 4)
I've read many sources on internet and the best lubricant for 3D printers is dry PTFE. It creates a slippery and protective film on the rails and components, and it doesn't collect dust and dirt. I bought this in Bunnings for 13.5$. There are many others around.
Dry PTFE lubricant


BRONZE BUSHING (Effort 6 improvement 2)
Many people prefer bronze bushings because they are not as noisy as the linear ball bearings (on the x and y axis). I left the original ball bearings because noise is not an issue for me. Bronze bearing also provide automatic lubrication (they are impregnated with graphite).

Bronze bushing with graphite (picture from AliExpress)


ARM STIFFENERS (Effort 4 Improvement 3)
I didn't get those yet because they cost at least 40 AUD, but I'm thinking about it. Sometimes you have to put pressure on the platform to clean it and the plastic arms are not very robust. These on Aliexpress are the cheapest I found.

Arm stiffeners for platform (from www.p3-d.com)


SIMPLIFY 3D (Effort 6 Improvement 10)
I don't usually buy software, but this is worth every cent. It gives you total control, but you can start with basic features and learn new one once you need them. It's also very quick in slicing (nearly instantaneous) and the preview shows you exactly what your printer will do. I tried a cracked version at first and I decided to buy it. The support provides profiles for all printers. In AUD it's about 200$. Go to Simplify3D website.


CONCLUSION
The CTC printer is cheap, and it's not a good printer straight out of the box (you get what you pay!). If you have time and passion it can become a very good printer, very versatile and capable of amazing quality. I hope this post was useful for you, looking forward to hear your feedback.

Wednesday, June 1, 2016

PC-TPE



I bought a spool of PC-TPE from my favorite local shop, it wasn't easy to find and a bit expensive (55$ for 1Lb = 0.45Kg) but I've read very good reviews.

I always wanted to print a flexible filament, but I couldn't use TPU/Ninjaflex because my Kossel XL has a Bowden extruder. A flexible filament compresses and gets stuck in the hose between the extruder motor and the hot end. This PC-TPE, produced by Taulman3D looks solid like ABS in the spool but it's flexible once printed. This means that it can be printed with a Bowden extruder. I'm very happy with the results. The printed part is not elastic like rubber, but it's flexible and it can be designed to be elastic, like this bracelet.

The bond between layers is very strong, the part keeps the original shape and goes back to it after it's been stretched or squeezed. I printed it using the same settings of ABS.
It would be perfect to make tracks for a tank or robot.
You can buy it here: www.3dprintergear.com.au