Last May (2015) I found the deal too good to be true on a Prusa i3 3D printer so I had to get one. I had always said when 3D printers got under $300 I'd get one, that i3 cost $265 delivered. Of course, it was a kit and required about a week to build it, and then about 2 more weeks to get the calibration down. I have since wished that I had documented the entire process to get the printer to where it is today, a true workhorse that requires nearly no maintenance and rare calibration.
I had since heard good things about the Kossel Delta printers, this week (Jan 18, 2016) I saw the deal I could not pass by, $226 delivered, so, this time, I will document in this blog the entire purchase, build, calibration and user experience. As with my Prusa, I found this kit on AliExpress. I had a very good experience last time, hopefully this will be as well. So far, looks good, today(Jan 22nd)I got a message that the printer had shipped.
This printer did not come with a heated bed, so I ordered one to add to it at some point. I'm hoping the supplied controller board will support a heated bed, and hopefully also a cooling fan. Unfortunately, the listing does not give very good details on the microcontroller, power supply or stepper motors. Looking at other printer by same seller, it looks like I could have gotten one with auto bed leveling for a bit more money... oh well, but do I really need that? It seems to me that once I calibrate, it should keep its settings.
STAY TUNED FOR OUR NEXT EPISODE!
Oh my! Tracking says the new kit will be here by Weds! So I am getting a spot ready for it. One thing I found with my Prusa that the biggest help in getting good prints was a solid FLAT and level base for the printer. I'm sure for the Kossel it will be no different. Yeah, I thought the thick wood table I was using was flat, but in reality there is no such thing as a flat, straight piece of wood. Temperature and humidity changes, so does the wood. Once I mounted my Prusa to a piece of ground stone tile (18" x 18" for $4 at the Home Depot) everything changed, and calibration stuck, and has not changed since. So for this printer, same thing. Also, the table it is on must be stable, and not wiggle from walking past it, etc. The Kossel is very tall, so stability is very important. I attached the back of my table to the wall.
I built my Prusa on the kitchen table, and I'm planning the same for this one. Being single, I can do this. You will need a large area for building, and one that can be left undisturbed for a number of days. Don't rush the build, in the long run you will appreciate it.
Many of the Prusa build instructions showed wiring things before the printer was completely assembled, I ignored that and was glad I did, as I found routing the wires on a completed frame was better for both the components, and made for better routing.
STAY TUNED FOR OUR NEXT EPISODE!
Quick update! too busy fooling around with this thing for a complete post, but wanted to say, its working very nicely, after a bit of a learning curve, which I will share with you all soon.
I'm posting a video of it running for today, and hopefully will have more time to post tonight or tomorrow. In the mean time, check out the video
Time to give my report on this printer build. The kit is great, albeit with some Pros and Cons. I'll start there. Keep in mind that his printer was under $230 delivered in less than 8 days from China. For the Cons that I had to modify, I'll be posting those changes.
Would I buy again? Yes! already ordered one for my brother. I absolutely love this printer.
* Not advertised on the link, this has the Auto Leveling feature, and set up correctly works rather nice
* All the plastic parts were made nicely, and none were defective.
* an extra set of plastic parts for the extruder drive were supplied
* The screws supplied, most had ample extras. I did have a couple of defective screws, but was able to use them
* The extruder motor and the drive motors are nice quality
* 1 extra length of belt
* The LCD control panel is nice
* The instructions are really good, both for build, configuration and use.
* They sent a power cord for Europe (not a big problem, same as most 2 pin power supply and stereos)
* The hotend is not real good, and needed some modifications to make it useable
* The supplied MKS Mini controller board works nice, but cannot support a heated bed. This is a non-issue if printing PLA. If you want heated bed, they have it available for about $60 more, or as I am doing, can add yourself for around $25 (not including an extra power supply)
* I did have one of the spherical rod ends with excessive play, but they are sending 2 new rods
* The Bowden extruder tube is too short!
* The wire wrap was about 1/2 as long as needed (cheap to remedy, but jeez...)
* It came with no spool holder. I made one from a piece of tube I had laying around
* Came with 40 meters of filament. don't use it. It is dirty.
There it is, non of the Cons are show stoppers for a DIY person.
Its important to look through the instructions before starting the build. Assembling the triangle frames is interesting, much like a Chinese jigsaw puzzle, you build 3 sub-assemblies, then slide all 3 together at once. For the top triangle, make sure all the pieces are facing the same way up versus down.
Wire routing for the limit switches and the extruder motor takes some care and thought, see my detail pictures for ideas and make sure to take a metal file to the sharp edges that the wires would run over. Double stick foam tape is handy here too.
The hotend mount bracket, be careful here, the small part looks like it has flash on it and you'll be tempted to cut it off, don't, its not flash (I almost did). Also make sure the hotend hinge mount can move freely, but not sloppy, a small file or emery board comes in handy here. This is part of the Auto Leveling system.
DO NOT put the hotend into its mounts until after assembling the frame, it's just in the way.
Once you have the long frame pieces into the base, set the micro-switches to all be the exact same height.
It's important to follow the configuration steps for setup in the manual closely. You will need to make some minor changes to the Arduino Marlin firmware and flash it a few times.
I had never done cold bed printing before, I soon found that the Blue Painters tape with a coating of Gorilla Wood glue works nicely. I understand AquaNet hairspray or a glue stick work also. I'll be adding a hotbed soon.
This printer was giving me excellent prints pretty much right away. A bit of fine tuning and it really is sweet. The Auto Bed Leveling is really nice. Tinker with its micro switch fine tune screw to get your first layer height optimized.
Do yourself a favor and make a shroud even before you use it that directs air from the fan around the upper portion of the extruder, and set the fan to be always on (or wire direct to a 12 volt power like I did) or you will soon find out how extruders plug up. I used some thin aluminum and double stick tape for a starter shield, then designed a nicer one and printed it.
I also modified the hotend by drilling out the narrow passage so a piece of the 4mm OD PTFE tube could be run through it right to the lower part of the hotend.
Initially you will want to do your prints while connected to a PC, so you have some extra control, but one I had things working nicely I disconnected the PC and used the LCD SD card for printing gcode. That is really a nice feature, fun to use.
My brother was over and somehow static zapped the printer. The MKS mini controller board lost its extruder motor controller. Sadness.... But, not the end of the world, just an opportunity to yet modify and improve this thing some more.
I found a Ramps 1.4 set for $37 including the larger graphic LCD, and it fully supports a heated bed (the MKS mini would need an extra board ($5) to handle power for a heated bed). I'll need to rewire the steppers as the pins are not matches. I'll also be adding a 30 amp power supply along with an MK3 200mm heated bed, and building a base to hold everything.