Remixed the Anycubic Kossel Plus Heated Bed Clips by JamesWhite into a leveling clamp setup for the Kossel Plus.
These work like the other types of bed leveling clamps, the lower nut adjusts the level and the top one clamps it all together. The top nut needs to be thin to clear the autlo-leveling sensor that comes with the Plus. The top nuts can be further tightened down with a 13mm or 1/2" nut driver.
I used the following hardware:
- 3 x M5x30mm bolt (I used pan head, not sure if there is clearance for cap head screws).
- 6 x M5 nuts (regular, not locknuts)
- 3 x M5 locknuts
- 6 x M4x10mm bolts (used to hold the base to the 2020)
- 6 x M4 T-nuts
- 6 (or more) washers were used in the base on the M4 screws
- I used some 1/16" cork for the pads on the knob parts to insulate between the parts and the bed. Note that cork is not fireproof so use this design at your own risk.
The larger dials have some recessed dots and the bases have a small pip that can be filled with paint if that is desired.
Updated 8/6/2018 - There are 3 versions of the base now:
Bed-Level-Base.stl // this is the original short base, and will not allow clamping of the sides of the bed.
Bed-Level-V6-11mm-base.stl // new version for the heated bed only
Bed-Level-V6-15mm-base.stl // new version for the bed + 3mm glass plate
The taller 11mm and 15mm versions were designed to help corral the bed, which the original version does not do. I had used the original version without many problems for months, though it does need to be tightened down to keep the bed from moving around. The 11mm and 15mm versions are not tested for longevity or to know if being in contact with the bed will be a problem. I have however run about 1Kg through with the 15mm version (since I have a glass bed), and they are holding strong.
Originally I printed the parts in PLA (and was using Bed-Level-Base.stl), which worked OK, but as I have been printing more ABS I can see where PLA is not great for that. Since I was printing ABS anyway, I just printed these in ABS and I think they will do much better. I did noticed some warping on the PLA bottom knobs when I swapped everything with ABS so it was probably just in time. I am not sure if just running PLA would be a problem in the long run with these. Since the taller 11mm and 15mm bases are in direct contact with the bed, I printed it in ABS only (not PLA) - I am still testing the taller 15mm part with ABS, but after running several prints with ABS they are holding up fine so far.
Update 10-8-2018, I have been using the blue ABS clamps (15mm) in the pics for the past few months while running dozens of PLA and ABS prints, and they have been holding up well. I have had the bed off a few times, but have not otherwise adjusted them. They have stood up to getting very well stuck items off the PEI without messing with the leveling. So far I am pretty happy with these.
For the safety minded, or people who don't monitor their printers, please take note that Cork is not fireproof. I chose cork because I had it on hand, but other than that I'm not sure what the risk is for using cork with these. It is up to you to weigh and decide upon the risk of using these designs. If you know of a better material to use instead of cork please let me know.
One more thing to note about these, when using the stock Anycubic touch probe for leveling - if the bolt that is used on the left side is too long, it will probably hit the probe. To avoid this I make sure the bed is raised up enough so the screw does not protrude more than a mm or two from the top of the holding clamp. I also make sure the left side mount is pushed back away from the bed which gives a mm or two more clearance for the probe. If this is a problem you will hear the probe touch the screw when it is doing the auto-leveling or the z-height adjustment with the stock firmware. I would consider this a minor issue to be aware of, and is the only problem I have seen so far while using these.
If you use Marlin, I believe you can adjust the "#define DELTA_CALIBRATION_RADIUS" in configuration.h to reduce the circle size that is probed to avoid the screws (that's what I did), however if the scres are too tall they could still hit the head when printing.
I would print these with 40% infill or more next time (I used 20% before I realized I forgot to change it). I would also use 3 or more walls at least. I originally printed the short base and rest of the knobs in PLA and used them for months without major problems (aside from having to keep them tight which can require re-leveling). When I re-printed the new 15mm version, I used ABS which is stronger and should not warp as easily. I have printed these with and without supports, both worked fine.
Getting the bases to fit with the bed was tight. I had to removed the two washers from the M4 screws used on one of the bases to get it to get a tiny bit of extra clearance for it all to fit. I don't see it being a problem on mine and am not going to re-design it for that.
See the pics for more info on how to put them together. The locknut will be a tight fit, but I was able to slowly tighten it down into position without a problem.
Update 10/20/2018 - added STEP files for easy remixing.