magnetic bed on mk2S  

RE: magnetic bed on mk2S

You could contact support via chat and ask for the BOM for the upgrade and order parts one by one.  

or make a list your self from:

https://help.prusa3d.com/en/guide/introduction_228813

RE: magnetic bed on mk2S

yeah i get that.. but I'm not interested in the filament sensor, nor the pinda upgrade just the magnetic bed, the question is are the sensor points in the same place so the mk2S firmware will detect them for the xy calibration and is the metal plate thickness then able to be compensated for manually, aka raising the pinda probe or something or is this something dealt with in the 2.5 firmware which presumably I couldn't use without the other upgrades? Or can the calibration xyz be done with the plate in place? I'm unsure how it later detects the sensor points with the bed in place before printing if the initial calibration must be done with the plate off? any suggestions or help welcome .

RE: magnetic bed on mk2S

@gizmatron

Someone might be able to answer that.  I would still ask the question of Support via chat before ordering.  

RE: magnetic bed on mk2S

yeah at €100+ I won't be winging it no

RE: magnetic bed on mk2S

OK spoke to support via livechat.. not hugely useful but they say first the bed is a straight swap but for reasons they can't remember the xyz calibration always fails. But if I don't redo that, keep same calibration I have currently ( which i haven't redone in over 2 years) and just re-calibrate Z with the spring sheet on I should be good to go.

So before I actually order this anyone chime in with why the xyz calibration would fail? I can only think either the calibration points aren't in the exact same place because of the magnet placement or the original pindaV1 is less sensitive and won't detect the points in the new bed for some reason. Can't see why it would fail otherwise. But if just redoing Z will work I'll order just be nice to hear from someone who's done it and had it work.

RE: magnetic bed on mk2S

one last question, just read the description of the replacement heat-bed and it says 28 magnets held with loctite. Are they just glued on the back or are they fitted into the actual bed surface? If the first whats stopping me just adding magnets to the back of my current bed to hold the metal sheet in place?

RE: magnetic bed on mk2S

@gizmatron

They are glued into CNC's holes in the back.  

RE: magnetic bed on mk2S

I also considered putting just the magnetic bed on my then MK2s. I ended up building a MK2.5S piecemeal as the kits were still being made but were not available at the time due to covid.  The kit would have been cheaper and better.  

Some considerations:

The old MK42 bed has more sense points than the new magnetic 12v MK52 bed. On the MK2s, the sense points are used for both the initial XYZ calibration and for the pre-print mesh bed leveling.  On the 2.5s, the sense points are only used for the initial XYZ calibration.  The pre-print mesh bed leveling is done by sensing the steel sheet.

This would make the initial XYZ calibration impossible without modifying the 2s firmware. However, if the XYZ calibration is already set with the MK42 bed, one could install the MK52  with the steel sheet attached and the pre-print mesh leveling  "should" (might?) assume that the steel bed surface are the sense points. The first layer calibration would probably be way off, but that is merely a PINDA height setting...

The filament sensor can  be disabled from the settings menu, so there is no great reason to avoid upgrading the firmware for this.  

However, the MK2.5  firmware will be expecting a fan speed signal from a 5v hotted fan, which means you will need the "V" cable adaptor and a 5v 3-wire hotend fan.  The "V" cable can be fabricated if necessary. The V cable is necessary only because the MiniRAMBO has no dedicated speed-sensed  fan ports, one is kludged from a repurposed 5v end stop port and uses the ground connection from the original 12v fan port. (a brilliant way of allowing old hardware to be upgraded) 

Also, the MK2.5s PINDA2 requires a "V" cable , or the PINDA2 cable modified to work on the MiniRAMBO. 

In short, it might be possible to partially upgrade your MK2s.  I found it far better and easier to scrounge together the parts for the full 2.5S  and like the results.  You could omit the filament sensor and disable filament sensing from the menu.   I recommend reading the MK2s > MK2.5s instructions before deciding on a course of action https://help.prusa3d.com/wp-content/uploads/2021/05/Original-Prusa-i3-MK2S-to-MK2.5-upgrade.pdf

Happy Printing!

RE: magnetic bed on mk2S

OK so some more accurate and useful info..thank you.already read the whole upgrade info several times..So is the 2.5 sensing just the steel sheet because the actual pinda sensor is different or will the V1 on the mk2S sense it too? I take it the pinda won't be able to sense the actual board sense points through the steel sheet. Are they just steel points set into the board then? or something special.

SO lets assume I have my perfectly calibrated Mk2S and i fit magnets under the existing mk42 bed and fit the steel sheet. Can i expect the pinda to detect the steel sheet as if it was the calibration points and just "allow" for the added thickness of it? Or will I find myself playing with either pinda height or a large live Z adjustment to allow for it? Either way I'll be testing with a bit of cheap galvanized sheet first, nozzle can crash into that as many times as it likes.

RE: magnetic bed on mk2S

for info the reason I don't want to change my print head etc is I'm using this design I collaborated on https://www.thingiverse.com/thing:2297721 I have a silent noctua fan already along with a high volume cooling fan that blows all round the part, the whole thing is on 4 bearings clamped not cable tied so is utterly rigid and precise. I haven't re-calibrated anything in over 2 years since a small nylon incident that destroyed the heater block and thermistor completely. (yeah i don't leave nylon un-watched for hours any more) I have printed every conceivable material with this , can leave it for weeks or months between prints or do dozens in a week and every single time it just prints perfect. The original pei sheet lasted years and i didn't replace it that long ago , aand I just gouged it again detaching a PETG print hence why I'm looking into the spring sheet option.

RE: magnetic bed on mk2S

I just bought an MK2s from Craigslist so I will be upgrading also.  Hopefully, it will be a new MK3S+ soon.  

RE: magnetic bed on mk2S

@gizmatron

The big difference between PINDA 1 and PINDA 2 is that PINDA 2 has a temperature sensor to increase accuracy.  Otherwise, it should detect the steel sheet.  An easy way to find out is to just clip your generic steel sheet to the bed and see what happens.  Probably, the first layer height will be quite high.  

RE: magnetic bed on mk2S

@chicago-keri

Bingo.  

RE: magnetic bed on mk2S

OK I have some magnets on order and I'm just waiting on a restock of the satin sheet to order so I'll give it a try.. I can't say as I've ever noticed any issues with temperature drift whatsoever , another reason the upgrade isn't top of my list,  and I print regularly with nylon and polycarbonate so I'll give it a try with the steel sheet soon as the magnets arrive and assuming that works I'll print with the satin sheet and report back with results. As it seems I can disable the filament sensor I could theoretically do the part upgrade but as I don't have any issues printing ,other than the detaching prints from a rigid bed, I'd be spending over €150 to get the pinda upgrade basically. Cause unless I'm reading it wrong the €100+ heatbed upgrade doesn't actually include a spring steel sheet of any flavour? So if I want to keep my current print head I'd need to work out a mod to locate the new pinda sensor in the exact position the firmware is expecting it to be in , although that wouldn't be impossible. The 3 wire 40mm noctua fan would be a straight bolt on but again not a massive gain over what I have already. So overall meh I don't think so. Be better putting the €150 away towards the mk4 🙂 I'll test and report.. watch this space.

RE: magnetic bed on mk2S

OK so after a wait for the satin sheet to come into stock I've added it to my mk2S , the auto levelling worked perfectly, pinda sensor sensed the steel sheet without issues, first print had to up the live z from 0.325 to 1.125 to allow for the original sensor points being lower inside the heatbed but other wise it prints 100% perfect. bed adhesion is perfect. prints detach as expected. Haven't done anything at all to the original bed so if I need to do the xyz calibration again for any reason will be as normal, just remove the metal sheet. Only thing I need to do is fix the magnets permanently to the underside of the heatbed so i don't have to reposition them when they fall off as I remove the steel sheet. Zero issues with the nozzle hitting the sheet on initial calibration etc.

So the answer to the original question, if you could just add the spring steel sheet to a mk2S with magnets and not bother with the no longer available full upgrade kit, is YES.