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ksihota

MPMD adjustable magnetic bed clip

by ksihota Feb 8, 2019
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Bah, work only have 19mm binderclips in the stationary drawer.

If you print the latest version I believe 19mm binder clips will work. The bed clip will sit right back as far as it can. I think that it what I am using right now. The metal clip is about 30mm long.

Where did you source your magnets?
printing these up now

I just got mine set up using 1/2" neodymium magnets from https://www.homedepot.com/p/MASTER-MAGNETICS-1-2-in-Neodymium-Rare-Earth-Magnet-Discs-6-per-Pack-07046HD/202526367. Less than $5 for a set of 6, which is exactly the right number. They're the exact right diameter, but they don't fill the entire height of the clips. I'm still testing these out, but it looks like it's going to work perfectly.

Thanks, I found those will try them. How much did you have to scale up your print for them to fit? I scaled up 2% and think I might have to go bigger.
Also I found some 12mm at hobby lobby I’m gonna try.

If you need more, get them on AliExpress. Mine cost $8 CAD for 50 with free shipping. the only problem is you have to be willing to wait a month or so to get the stuff.

Thanks for the tip! I was impatient to get the printer tuned, so going to my local Home Depot scratched my itch.
Also, the magnets not taking up the whole height of the pocket doesn't appear to cause any problems. The ones I got are rated for 4lbs each, which is way more than enough to clamp the clip down.

I got mine 12mm and 10mm on AliExpress because they were way cheaper. I believe Amazon has them as well.

Thanks for the info, will likely use in the future. But, immediate gratification and all! I’m with Matt.
It’s excruciating watching shipping from China.

Did you by chance release the source? I'm wondering if it might be possible to remove the hole/clip part, and print that separate. That way the whole part is laid flat and the portion that can be glued/friction welded together (and honestly has no stress) is separate. A lip bushing or T bushing I think they're called.

Sorry for the delay. Thingiverse is having issues. I only just got this message.
I actually removed a version that was 2 part (requiring gluing) because it really didn't help. The single piece was easier and less cumbersome. The pin part is really there to allow a point for the screw to tighten down on the clip. It has to allow space below, in order to keep the head low enough, so I decided to position it over the existing hole. If you are willing to drill out the floor, you can position the clip farther back and just use a longer arm.
I am just looking at a slight change of design that does not require the use of hole. I'll upload it as soon as I have checked it for functionality.

Love the low profile clip - I only recently discovered that the effector was grazing one of the adjustment screws on the bolt-in binder bed clips and throwing off the calibration by that tower. The magnetic clip leaves lots of daylight between it and the effector so no more problem.

Just one question - what are you using to hold your glass?

My glass is fastened directly to the original sticker. I simply apply a thin layer of glue stick, spread it evenly with a wet paper towel and then apply the glass by turning it slightly as I press it down lightly.
I then heat the bed to allow the glue to dry. If I need to remove the glass I find that it will come off if I pry it carefully when the bed is hot. I have only removed it a couple of time in the last year. To remove prints I just let the bed cool and the prints pop off.
If you check on the Facebook group most others have removed the original sticker and then use thermal pads. They cut these from sheets and apply them to the aluminum bed. Since they are tacky the glass sticks to the pad. I do not recommend using clips to hold the glass on. They interfere with levelling.

Copy-Pasted from Dennis's Tutorial for the anti-Facebook users. Heat the bed up first before doing this.

BED CLIP ALIGNMENT:

1) Screw the 4-40 in until the clip just touches the bed on all 3 clips.

2) Power on the printer so the bed switches activate the single button light. It helps if the head is homed.

3) Slip a 0.24mm shim (110# index card stock), between the bed and one clip. Adjust the 4-40 screw until it is right at the point of actuating the switch then back it off a hair so the switch is off, but actuates if a not much more than a feather touches the bed. You may have to go back and forth a couple of times to get it just right. When adjusting the 4-40 screw with the hex key, you should not have to hold onto the bed clip to keep it from rotating. If it does, then either you did not get the clip tightened enough, or your 4-40 thread hole is too tight.

Also put the short end of the hex key into the screw so that you have the long arm to give more leverage and control over the angle, since it only takes a couple of degrees motion to make the final adjustment.

4) Do the alignment step on the other two clips one at a time, then go back around the bed double checking that none of the adjustments moved. Readjust as needed.

You now have a precision aligned bed/switch combination that will make it much easier to get repeatable first layers on your prints with G29 auto leveling.

Also note that the clip should be touching bare metal (no tape) and be close to the edge. I.E., not touching the bed post hex.

Why should they not be touching the hex? Mine are all touching the hex :)

I also just noticed I'm using the wrong sized binder clip, so they won't be touching the hex by this evening. Still I'd like to understand why it makes a difference.

I know I'm late to the party on this comment, but I overlooked it since it was posted during the most super busy/stressful part of my year so far.

I posted this comment update after I saw Brian (the MPMD 101) guy mention it on another user's troubleshooting post. In theory, if the bed switch light triggers whenever you barely touch the bed (with the index card shimmed in), that's all that really matters. However, I could also see how it might be easier for the binder clip to slip off of that slightly raised post over time. Better to have something more secure. Plus, there's what ksihota said. Consistency is always good.

I believe it is because the hex area may not be the same level as the actual bed. If you are trying to keep everything consistent it is best to make sure that each clip is securely resting on the top of the bed. Its a small diff but it might have some impact.