Some time ago I bought the K8400 with the second extruder kit and the led kit. Overall I am impressed with the whole kit, but it would be nice if the manuals would be integrated or at least have some pointers on how to prevent first putting things together and then taking it apart again to add something else. I also ran into an issue where the wire colors of the led kit were wrong.
Suggestions for the K8400 manual:
- At the end of chapter 11 add a link to the second nozzle manual to assemble the extruder. It is a lot easier to do if the print bed it mounted yet.
- At the start of chapter 12, strongly suggest to solder on the header for the led assembly kit before mounting it if the user has this kit.
- At the start of chapter 12, suggest to attach the mainboard to a computer with only the usb cable (no separate power supply needed) and update the firmware from your computer. Makes life a lot easier and it works perfectly.
- At chapter 13, suggest to route the cable for the led kit if the user has it.
- In chapter 15, suggest to insert a piece of filament in the PTFE tube before cutting it. The tube will stay more in shape with a piece of filament inside when cutting.
- At the end of chapter 15 add a link to the second nozzle manual to assemble it and add it to the head before mounting the print head.
- In chapter 19, note the direction of the bolts+nuts for mounting the bed arm K8400-BA to the bearing clamps K8400-HQP-ZBC. I did one in the wrong direction making it close to impossible to disassemble because I cannot insert the allen key in the bolt from the inside. Stupid me.
Design issues:
- The hot end is almost impossible to disassemble. This is a major problem when you have issues with it like a clogged nozzle. The isolator guide HE1.75MM-IG is completely round; there is no way to grip this element while trying to unscrew the nozzle NOZ8400. Also, there is no point to wedge to nozzle out of the heater block HE1.75MM-HB. I have had the nozzle cloged and it took over half an hour to carefully extract the nozzle.
- Everything is screwed together, except the 50mm fan DC501512SM? Why? There is a certain elegance to the design I can appreciate, but the 50x50 fan on top seems like an afterthought.
- The 50x50 fan on top blocks access to the bolts for the hot end assembly
- It would be nice if the bolts and/or nuts that hold the print head assembly were of non-magnetic material. This would make using magnets in prints easier.
- There should be a better way to mount 24mm fan BSV1225 and gain another usable centimeter on the print bed. Maybe even replace both the 25mm and 50mm by one fan.
- Why no bearing no the top of the z-axis / threaded rod? I printed a design and bought another bearing and the print bed seems to move up and down more smoothly.
Led kit K8403
After just one day the led strips came loose from the double sided tape. Glue did not help. So I designed small clips to hold them in place, see thingiverse.com/thing:1825374. I think something similar should be included by default. Or maybe provide a better design and refer to it in the manual instead of tape and/or glue.
The real issue I had with the led kit was with the wire scheme. On page 15 it indicates what color cable should be connected to what wire with symbol. I soldered them together as instructed, but got nowhere trying to get them to work. I am furtunate enough to have some tools and figured it out. I have the following colored cables connected at the symbols:
Blue wire: +
Red wire: G
Green wire: R
Black wire: B
Question:
Any suggestions on how to make sure both nozzles are at exactly the same height?