Sunhokey 2015 Prusa I3 DIY Kit

This instructables are for guys who have purchased the Sunhokey 2015 Prusa i3 DIY Kit, and have the burning desire to get it working to the best possible state, without breaking the bank. I will be sharing some of the problems that I have encountered with this 3D Printer and how I have overcome them.

I have had some experience with Solidoodle 2, 3, 4, Press and Workbench and Dual-Feed Extruder Builder. This DIY printer caught my eye due to the fact that the nozzle fan came along with it (however I was dismayed to find that it DID NOT come with the nozzle fan), and that the price was 360 USD (pretty cheap then for the quality and now it is going for 299 USD, 4 months later), coming with free fedex shipping and 2kg of free filament of your material choice, PLA or ABS. It was also a bowden configuration, which I have not been exposed to and wanted to try it out. Another reason was that I found a youtuber, Hiboson, that was going to do a set up build of the Sunhokey, sadly I finished assembling before his video series even started and started working out the problems I faced myself, I have gone through his latest videos, and apparently the version he has is the older version, not the 2015 one, the one that COMES with the nozzle fan. His video series is a detailed step by step breakdown and his experiences in using the machine, do check his videos out if you're interested. https://www.youtube.com/user/HiBoson

Before my first test print, I was testing whether the hotend could extrude continuously, however I noticed no matter what, even at near max temperature of 280C (where the printer auto shut off due to extruder max temp reached), the printer wasn't able to extrude consistently. I then unplugged the cooling fan, thinking that the fan was preventing the nozzle from reaching the proper temperature, next thing I knew I had a clogged hotend. (DO NOT under any circumstances unplug the cooling fan for the hotend when it is heated and loaded with filament, the fan is for keeping the material in a solid state right before it reaches the heat break). Upon further pondering on why the nozzle was not able to extrude, I found that the culprit was my own poorly self-assembled hotend. The supplier's video showed that the hotend was pre-assembled, but mine wasn't, and I fixed it up without much thought. After thinking hard about it, unclogging the nozzle, fixing back the nozzle the way I think would be the best, I finally got it to work properly. If I had found this youtube video by Bruno M. then, would probably have made my life easier.

He actually took a different metal block to fix his hotend up, but his tips for how to unclog and reassemble are very sound.

In this video he shows how to assemble the hotend that was similar to the one provided by Sunhokey, except he included a improvement of changing the hotend throat to an all metal one. (instead of using the supplied one that uses a PTFE tubing inside the hotend throat)

I actually decided to make this guide as I brought this DIY 3D Printer thinking that the blower fan (Nozzle fan) was included (as shown in their demonstration video on, https://www.3dprintersonlinestore.com/diy-kit/full...). But it was not included, hence I went out of my way to design a holder for the blower (using CAD software and modifying from ZiegeOne version for the older Sunhokey model http://www.thingiverse.com/thing:714939), which can be fixed together with the leftover screws and nuts from Sunhokey. After sourcing a blower locally, printed out my design, revised it, printed it out again and finally got it fixed and tried printing with it.

After my first large print (a nerf dart gun, http://www.thingiverse.com/thing:7512), my main concern was that it really required a enclosure, as layer separations will occur randomly at the higher Z axis levels without it, severely weakening the strength between layers. My dart gun broke at the lowest surface area layer when I used too many rubber bands to propel my dart, I acetoned bathed it way too much and forgot to put the bolt carrier group back in before gluing the two halves back together, will have to design a two piece carrier for it in the future.

Searched around the web and found how other guys made their enclosure. After carefully searching IKEA's website for potential enclosures, went out to IKEA and got 3 items (Warning! These are pretty heavy to carry home by hand)

1. IKEA STUVA Frame 60x50x64cm (SGD35) Article Number : 201.651.70 (11.22kg)

2. IKEA SINDVIK Glass Door 60x64cm (SGD35) Article Number : 702.918.59 (4.85kg)

3. Two pieces of IKEA BESTÅ Soft closing/push-open hinge (SGD10 each) Article Number : 802.612.58 (0.26kg)

(For Item 3, you may want to only buy 1 set if you do not have a holesaw handy, as the front door for my enclosure requires some drilling of a 32mm diameter hole into the 3mm thick particleboard to mount the hinge)

I did not use the Fibreboard back panel, and placed the frame lying down on its back, with the glass door on top. I made the bottom panel into the front door.

Another problem occur due to my not putting on the heatsink onto the motor steppers chips, one of them died shortly after I finished printing my first test set for the nozzle fan holder. Please ensure you place the heatsinks on the motor stepper chips. After purchasing a replacement from ebay, and still concerned about overheating, I took one of my 80mm fan that were lying around (from previous desktops), took some chopsticks and twistee tie and created a standing 80mm fan to cool the electronics.

The way the LCD control panel was mounted and the lackluster design for it had me looking on thingiverse for a substitute. Found one http://www.thingiverse.com/thing:797839, but it was to be mounted on the front, so I edited it to be able to be mounted on top instead, due to the opaque nature of my chosen enclosure, the front door in this case. However, after printing this out, (sticking tape on the corners of the print while it was printing to prevent further warpage) I realized that using the supplied tape and glue-stick was not really going to cut it in the long term, especially for big surface area prints. Searched on the web, and I found this, http://www.buildtak.com/product/buildtak-3d-printi... . When I receive it, will update this instructables on how well it works. If it doesn't, may have to go back to the tried and tested glass bed and hairspray instead.

Please head to http://www.thingiverse.com/thing:891623 to download the .stl for the Sunhokey 2015 Prusa i3 Nozzle Fan Holder Set.

Print out at 40-100% infill, without support, there will be a total of 7 individual parts.

I used Sunhokey's supplied Cura settings to print.

Get ready the following from the leftover parts from the kit.

1. M3 x 12 (2pcs)

2. M3 x 16 (3pcs)

3. M3 x 25 (4pcs)

4. M3 x 30 (1pcs)

5. M3 Flange Nut (2pcs)

6. M3 Nut (6pcs)

Source a Blower 51 x 51 x 15mm 12V DC (with extension of at least 70cm, excluding the length of the original wiring, either get someone to do it or do it by yourself) http://sg.rs-online.com/web/p/blowers/7878967/

Once the Printed parts and leftover parts from kits are secured, start dismantling the current hotend assembly.

Fix up the piece that is similar to the supplied 3d printed fan holder part on the left side, with a M3 x12 screw and M3 Flanged Nut. Use the M3 allen key to hold the screw in place while turning the flanged nut clockwise to tighten it together.

Fix up the other piece which has a hole with a horizontal axis as shown in the second picture.

Fix up the extruder assembly with M3 x 16 screws and nuts.

Loosen and take off the nut on the right side of the assembly, and slide the cooling fan holder inbetween the metal plate and acrylic plate and fix it together with M3 x 16 screw and nut, tweezers usage is required. The fan can then be mounted onto the cooling fan holder with one M3 x 25 screw and nut.

The other corner of the cooling fan is then fixed onto the right Blower Fan Holder Adaptor with one M3 x25 screw and nut.

Twist the hotend until the heater cartridge and thermistor on the heater block is facing away from the cooling fan. This will ensure the cooling fan does not affect the hotend temperature drastically during printing.

Fix the small 3D printed clamp onto the cooling fan holder with a M3 x 16 screw. The 3D printed cooling fan holder needs some work by chamfering the hole that is joined by the small 3D printed clamp and then forcing the screw into the hole to create threads. The small 3D printed clamp may need its hole to be enlarge to allow the M3 x 16 screw to be secured to the cooling fan holder easily.

Add in a M3 nut into the hole of the cooling fan holder that is slightly blocked by the cooling fan.

Press fit the Blower Fan Adaptor into the flanged nuts. Insert a M3 x 30 screw and nut as shown.

Mount the Blower with a M3 x 25 screw with a 3D printed spacer into the top left corner, it will secure the blower to the flange nut.

Mount the last M3 x 25 screw into the bottom right corner, take note that you might have to lift the cooling fan holder to let the screw engage the cooling fan holder. Once engaged, push the cooling fan against the cooling fan holder to prevent the nut from falling out, and continuing using the allen key to tighten the screw in/all the way.

Slot the nozzle fan into the Nozzle fan holder/Blower fan adaptor, tighten the M3 x 30 screw and nut to grip the nozzle fan.

Insert the wire ends of the blower into the ports labelled FAN, take care to insert the negative (black) wire into the negative terminal and the positive (red) wire into the positive terminal, this allows the blower to be gcode controlled.

Get a 80mm fan, some chopsticks and twistee ties, create a rectangular scaffolding tie it to the fan to act as a base to support the 80mm fan from tipping over.

The sticker side is the side that the fan blows towards, make sure it is facing the electronics board and that no stray wires can get caught into it during operation.

Plug the 80mm fan into the same array of pins that the cooling fan is plugged into, refer to the documents that came with the DVD if unsure.

Choose from Back facing, or Front facing, mine is back facing (accidentally), as I realized that I needed free access to the bed from the other direction, to replace the tape after each print. But I had already printed out the wrong design, probably could use a coping saw to saw the correct slots later on. If you are still using the tape method for printing, apply some glue-stick on the area that would be used when the bed is hot, and get ready for some persistent lift off/warpage from the four corners. One thing which I think would help is to take some tape and while the print is on-going, as long as the first layer is complete, tape diagonally along each of the 4 corners, it should somewhat help, until you get a piece of glass and hairspray, or resort to kapton tape, blue painter's tape, or possibly a piece of Buildtak or whatever you can get your hands on for a reasonable price.

http://www.thingiverse.com/thing:891623

1. To add a proper surface for prints to adhere on, and report back on my endeavours.

2. To post what Cura settings I am using, Sunhokey's Cura Settings are pretty crazy slow (22 hours print for the LCD casing as compared to 9 hours for the default settings), but with the nozzle fan, the default Cura settings work pretty ok, but only on the Slowest setting, I would have to further experiment and tweak.

3. Ponder whether I should have just forked out twice the money in the first place to get a Solidoodle Press instead of a DIY kit, but heck, I've learnt quite a bit building and using this printer. As in our workplace we got a pre-ordered Press for 299 USD, which I treated as a wild card at the time before it finally arrived, and it had so many initial kinks to work out, but that was because we paid significantly lesser for it, it is actually quite a decent 3D printer, once you know what the heck you are doing, that is. (Reading forums everyday whenever there is free time) Entering M851 Z3.5 into Repetier Host to toggle the Z offset, pulling the cable sleeve out of the way before every print, adjusting the bed screws and frustratingly forcing the glass bed in, thus shattering the supplied bed and having to get another piece. Designing a Fan holder to mount a fan on the front of Press's Extruder, so that I could use temperatures above 230 degrees. Hearing the thump of death from the extruder and experiencing smoke from the burning insulation of the connector as I did layman troubleshooting (pushing the wires into the connectors or at an angle, causing sparks). Glad that they worked out all these problems, for those that paid more/brought later. But work is work, and this is a hobby, it has been quite an adventure I might add.