Heated bed mount and slip ring

[ehegenberger]

I'm putting together an intermediate part that can be screwed to the existing bed mount below and a heated bed above, allowing for a slip ring down in the main body to power it. My thought is that this could be printed upside down and the print paused twice to position copper sleeves with wires soldered inside that pass through the slots and out the hole in the side. I haven't designed the brush holder yet, and every dimension is parameterized for easy adaptation. I've exported this as an f3d file, which I think anyone can open in Fusion and work on, including all the user-defined parameters. Maybe this can serve as a starting point in case anyone else has something similar in mind.
heated bed mount v5.zip

[xobes]

I love how fast this thing is evolving!

[TheOnlyMann]

Speaking of the bed, bed itself sourcing seems to be an issue- is the mk3 kossel extinct i imagine thats why they are in low supply
Siboor Aliexpress lists on the site but when i ask they say its out of stock(why do you list it then you psycho), REPRAP aliexpress store just wont budge with client answering(and from the example of the OP, a red herring) and on amazon it sells but seems like they're mostly out of stock too

[TheOnlyMann]

the hope isnt entirely lost since FLSUN sells their replacement beds, but their attachment methods are.... less than great, i think

[TheOnlyMann]

https://a.aliexpress.com/_on5ahUt

Pros. Quality looks fine
Cons. thing is a glass bed. it skips aluminium as the bed surface and idk how much that would weigh.

[TheOnlyMann]

OK, square bed it is then. I'll just put my circular one in a display case.

this is probably the way to go, since there are lot of premade products on it anyway... just dont use that part for print related activities and ignore the weight, i guess.

[TheOnlyMann]

https://a.aliexpress.com/_onL662l
if anyone wants to bother with glass beds i think flsun offers a decent product
its 215mm size and weighs ~500g though which is too hefty.

[xobes]

Did you order this? I didn't see dimensional information and opted for a different set of parts: alum 220 bed with corresponding 12V heater (will run with PWM and 24V, if that can't be maintained, I'll connect the two sides of the heater (parallel resistance is 3.2 ohms, connecting each of the 6.4 ohm branches in series will yield ~50watt (25V over 12.8 ohm) and that ought to work as a backup-plan) with magnetic 260mm pad and 260mm build plates.

[ehegenberger]

Another point worth considering is that physical bed size is not really an issue for many prints. Case in point tree. You could even just slap on a small square bed.

One of the things that makes multi-axis machining so accessible is the ability to securely clamp the workpiece. This is also the case for additive manufacturing in industry. While here in the hobby space we lose sleep worrying about our prints wobbling or even falling off the bed because it wasn't perfectly cleaned, sprayed, taped or whatever. So once Joshua's printer is properly up and running, I really think the next challenge is to design a 5th axis with a clamp that can securely hold any part during printing. Someone's going to make this happen sooner or later, so why not right here, right now? 😁

[TheOnlyMann]

imho the bottleneck is the slicer.
otherwise ill probably try to enclose this thing, its "footprint" is really big for a printer also compared to the "initial" buildplate

[TheOnlyMann]

possible idea to change the Bearing used in the bed

since the bearing is on a z axis position it is getting a axial force which is not supposed to be handled by regular deep groove bearings. a possible solution to this is by replacing them with angular contact bearings, and seems like bicycle bearings exist for these kinda things?
i'm also not that sure if such things are needed since ~1kg amount of bed and stuff isnt that much to a bearing, perhaps

[xobes]

I have a heated bed (not tested) with slipring (not tested) installed. The thermistor appears to be returning data.

I opted for a 6-wire, 10A (per wire) slip-ring, but dedicated two wires for thermistor and 2 wires to heat bed (less current through each ring).

Pictures later. See my fork for additional files like a riser and modifications to the c-axis-clamp part (screw holes).

[TheOnlyMann]

interesting method to deal with amps but idk if it'd solve anything. hope it works out though since 24V 144W DC Beds should only take around ~8 Amps

[xobes]

I agree that the bed ought not draw too many amps, but I wanted a safety factor and resiliency given I don't really know how durable this slip ring will be.