Are the aluminum supports for extra stiffness? Did it make a difference? Count me in for that upgrade. Will the dual carriage upgrade require new frame parts? Thanks! Really excited.
Wow. This will teach me to stay away from the forum for a couple of days! My questions is: how would you characterise the performance benefits over the original dual? ;-)
I like the design, except 1 thing, WHY A MIRROR TITAN, I already have 3 of them, and seemingly I'll need to buy at least a new body to be able to upgrade. Can the design work with a normal titan? Please guys, check again Regards, T.
Yes it will of course work with a standard Titan. You will loose build volume doing so. That was done for testing. You should be able to leave the motor where it is. The aluminium upper supports will not be available as part of the upgrade. You can get them cut yourself of course! The frame has been altered to get the most out of the new design, so far three parts have been changed; the lower support, and the two upper supports. You can get away without changing them though but you will need to do some drilling for the extra dragchain on the left side.
That's what Greg has said and the pictures on Page 6 seem to confirm this. The loss of print volume may still push me to a single carriage with dual heads like Chase's.
What are the benefits of the new setup vs. 1.1 dual ? Here's to guessing: 1) negligible rod sag => bed appears MUCH flatter when mesh bed levelling? 2) print head lighter + centre of gravity of printhead between rods => allows higher acceleration and faster printing around corners for a given quality level? 3) problems of ooze from second nozzle eliminated? 4) improved cooling? Is that fair? Anything else?
One thing I'm interested in with this new design is how nozzle level adjustment works. I've had next to no success with dual printing with my 1.1 because I just cannot get the distance from the bed to each nozzle uniform across the whole width of the bed - if I get it perfectly level in the centre it's significantly out at the extremes. I've been contemplating switching to Chase's dual design because at least it's easier to get precise adjustment, although I'm not sure it will help or if the root cause of my problem lies elsewhere. I can't see how the nozzle height is adjusted on the 1.2 design as each hot end appears to be mounted directly in each titan.
I have no idea if that is possible with the firmware yet but if then you won't have to adjust the heights. You just have to level the bed for each carriage or better name it setting the Z offset from Z endstop trigger point for each nozzle. On a tool change you normally lift the head a bit in our case you lower Z a bit. Then change tools that's moving one tool away and move the new one into position maybe wipe or prime them... So neither head will interfere with the already printed material and upon the switch the new Z offset is applied so every head has the perfect distance to the bed...
Ah I see, so potentially each head would have its own Z offset? Looks like Greg says that's not possible at the moment though, but maybe we could hack it into the tool change script. The ideal I guess would be a mesh level per head.
Yeah that'll be the best... but that's not possible for the moment. We will have to level the bed with one nozzle and then assume that the sag and other things that influence the nozzle to bed distance are the same for the second head. Well we don't assume we just don't have an option to set it for the second head so the firmware just uses the same values for the second... I didn't look into that yet what is possible with Marlin now. But you might be right that we can set the Z offset for each head in the tool change script. Maybe we can just run the BCN Sigma firmware? Someone knows how they do the levelling for the two heads? Or we get some assistance from @Edward Patel regarding mesh levelling for two heads, or UBL might also fix that? But to be honest I am really looking forward how the Duet way develops. IMHO the time has come to make the next hardware step. There are a lot of great ideas but the current platforms get to their limits, take LIN_ADVANCE or what @Henry feldman mentiones every now and then that we are using a USB to serial interface to send commands to our box which is really old school... But for this to work with the dual carriage system we need the expansion board and the firmware addition... So maybe for at least half a year we have no other board option to achieve this other than the RUMBA or equal boards and Marlin...
My worry about the new design would be Y rod sag. Mesh levelling it's always been apparent that there's greater sag at the right side of the bed: now there will be two right sides! The new setup will merit some 12mm Y rods and so new bearings (how expensive could that be). And those new bearings might as well be in widely spaced spares.... The BCN Sigma has a nauseatingly clever system which you can just about figure out from this video / their documentation. It relies upon the fact that their extruders can move OUTSIDE the edge of the bed and so click on it with simple microswitches. Arguably we could do the same on the new system if BOTH extruders were equipped with IR sensors, working over the bed instead. (Video: ) How does it work? Each extruder clicks in 3 different places, two of which they share in common. That gives all the information on Z offset as well as all the information required to level their 3 point bed (with two adjustment screws). All of that is programmed in their custom version of Marlin.
Well maybe but as far as I can see Marlin fork for this board is dead for now. I have no experience with Repetier firmware and if a dual X carriage is possible with it... For all this dual stuff I am with Tom Sanladeres statement in one of his vids that getting reliable dual printing is the next major goal. And IMHO dual head is a good way for multi material. What Prusa does with the new system which look like a pimped version of what the Prometheus system does (4 vs. 2 materials) but one nozzle multi material is problematic. Cooling and heating on a tool change increases print time and remember on a support print you change tools every layer. For multi color printing with one material this is cool because you just retract a lot then feed the next material. But for printing with different materials I don't think this will work very well. Think of printing NinjaFlex with some rigid material for example... But has anyone an idea if Repetier supports dual X carriages?