K8200 Success!

K8200 3D Printer K8200 - Your printer, creations, and ideas for imp
1

Add me to the list of very satisfied owners of the K8200. I just made my first few successful prints this evening.

I am very impressed with this kit. The design is very good and the quality of the hardware is excellent.

I did make a few customizations while I was building it, mostly based on suggestions I read in this forum. I made a correct-gauge wiring harness rather than using the supplied ribbon cable, and I mounted the controller in an enclosure to give it some protection. I only used 4 of the 8 thumbwheels under the table but added compression springs to make leveling easier. I also replaced the z-axis limit switch trigger because there was too much play in the screw in the stock design. For this, I used some hardware from a MakeBlock robotics kit. The new actuator is more rigid and makes contact near the switch button instead of further down the lever.

I splurged and got the Velleman glass plate for the bed which made a HUGE difference in how flat the table was, but also lengthened the bed heating time. The Velleman bed is a substantial sheet of tempered glass with a nicely ground edge and I am much happier with it than I would have been with the thin pane of window glass that I got from the hardware store. I’ve been printing straight onto the clean glass without any glue, tape, or hairspray needed.

I leveled the bed by placing a sheet of paper on the table and adjusting the height at each corner so that it wouldn’t pinch the paper. I think this actually got me too close to the table, so I backed off the limit screw a bit from there. This was a really easy way to find level.

I was able to build the firmware using the 1.6.4 Arduino IDE/SDK and it seems to be working reliably. But (as I mentioned in another post) I had to drop the baud rate from 250000 down to 115200 before my Mac could talk to the printer. Other than that I am using default settings for everything and it is working very well already.

Next I am going to add the stand-alone controller and I will probably print a stronger z-axis motor mount, as I can see the side-to-side motion of the motor when it turns.

Note to Velleman: This is a great kit, and the instructions were almost perfect. If I could make just one suggestion, it would be to ask you to please include a small bag of spare hardware for the common nuts and bolts. The extra brackets and plastic parts were a very welcome surprise, but I was derailed any time I dropped a simple lock washer on the floor. Just a few spares for these tiny parts would have been wonderful.

2

hi man
I want to ask you for some help cause i set my new printer and it start to print the first layer good then it goes crasy do you have some tips
thanks in advance…

3

Scor,

You posted your problem before so keep this at one place.

4

Please see the suggestions in your other post.

5

[quote=“Dr. Vegetable”]Add me to the list of very satisfied owners of the K8200. I just made my first few successful prints this evening.

I am very impressed with this kit. The design is very good and the quality of the hardware is excellent.

I did make a few customizations while I was building it, mostly based on suggestions I read in this forum. I made a correct-gauge wiring harness rather than using the supplied ribbon cable, and I mounted the controller in an enclosure to give it some protection. I only used 4 of the 8 thumbwheels under the table but added compression springs to make leveling easier. I also replaced the z-axis limit switch trigger because there was too much play in the screw in the stock design. For this, I used some hardware from a MakeBlock robotics kit. The new actuator is more rigid and makes contact near the switch button instead of further down the lever.

I splurged and got the Velleman glass plate for the bed which made a HUGE difference in how flat the table was, but also lengthened the bed heating time. The Velleman bed is a substantial sheet of tempered glass with a nicely ground edge and I am much happier with it than I would have been with the thin pane of window glass that I got from the hardware store. I’ve been printing straight onto the clean glass without any glue, tape, or hairspray needed.

I leveled the bed by placing a sheet of paper on the table and adjusting the height at each corner so that it wouldn’t pinch the paper. I think this actually got me too close to the table, so I backed off the limit screw a bit from there. This was a really easy way to find level.

I was able to build the firmware using the 1.6.4 Arduino IDE/SDK and it seems to be working reliably. But (as I mentioned in another post) I had to drop the baud rate from 250000 down to 115200 before my Mac could talk to the printer. Other than that I am using default settings for everything and it is working very well already.

Next I am going to add the stand-alone controller and I will probably print a stronger z-axis motor mount, as I can see the side-to-side motion of the motor when it turns.

Note to Velleman: This is a great kit, and the instructions were almost perfect. If I could make just one suggestion, it would be to ask you to please include a small bag of spare hardware for the common nuts and bolts. The extra brackets and plastic parts were a very welcome surprise, but I was derailed any time I dropped a simple lock washer on the floor. Just a few spares for these tiny parts would have been wonderful.[/quote]

Hi, Cool! Sounds like you’re on your way!
I have had great results, and great learning of basics with my 8200, but finally melted down the bed wiring ribbon cable. Would you mind posting pics or some details as to how you wired to get to the bed and have keep it movable, good for back and forth constant movements and not too thin? Mine was great over a bridge I printed from Thingiverse but then it wore out on the actual aluminum bed carriage (I’m sure alot due to the fact that I upgraded to 24v…)

Also, I love your idea of the compression springs too on the bed!
I’ve never had trouble leveling, but this would make it SO much easier!! Did you just use whatever spring from a store or get online?

Do you have pics of your bed wiring and springs? I’d appreciate very much!

I did all of the typical upgrades and the z-axis rod and 1.75mm direct drive extruder were awesome as well! I’m currently working between different slicing softwares as I once love simplify3d, it doesn’t work at all well compared to Cura or Slic3r moreso for quality on another printer I have!

6

Sorry to hear about your meltdown.

Personally, I did not trust my own skills as an electronics tech to use the ribbon cable supplied with the kit. I knew from the outset that I would break wires and have issues unless I used “real” wire in the harness. I used a mix of either 18 awg or (predominantly) 24 awg stranded wire for all wiring. I also used different colors of shrink tubing to color code the connectors by axis. (ie: the y motor, y limit switch, bed heater, and bed thermistor are all color coded with green shrink tubing.)

For the moving parts of the harness, I wrapped the wires in a plastic spiral material - “SpiraFlex” is what I think it is called. I used multiple tie wraps at each end to secure the spiraflex to the frame. You want to make sure the wires do not move or rub when the carriages move. You also have to “bias” the twists of cable so they curl out of the way when the carriages move. You can see in this picture how the cable is dangerously close to the y-axis limit switch, but it fortunately does not interfere:

The springs on the bed leveling mechanism work very well. I got them out of an inexpensive package that contained a variety of small springs. I think the whole package of springs was about $4 at Harbor Freight. I just used four identical springs that were maybe 20mm in length:

I also replaced the z-axis limit switch actuator with a better design, to reduce wobble and inaccuracy in the homing mechanism. The key ingredient is the teflon PC board spacer that has good friction against the zero adjust screw:

I hope this answers your questions. Good luck with your repairs!

7

I should point out one other deviation from the standard design. IIRC, the K8200 instructions have you run the bed heater and thermistor wires down to the x carriage before running out to the controller board. As you can see from the picture, above, I ran the four wires from the heated bed directly to the back corner of the frame. This makes it a little bit more complicated to test for free cable movement at all x-y positions of the table, but also simplifies the run of these four wires, and allows them to be a little shorter.