core idex feedback

Hi All,

I've was inspired by digital dentist's UMMD build. I used a lot of the design methodology to build a core idex printer. I'm about 85% finished in fusion 360 and wanted some feedback. I'll be using Duet 3 in the XYU configuration. This is a 400x400x500 build. Here are some specific questions.

1. How difficult is it going to be to keep both hotends aligned to the heatbed assuming all the holes and alignments are accurate and exact?
2. I have belt cutouts in the hotend assemblies to manage the extra movement. There are 3 pulleys to keep it all aligned. Any issues with this?
3. I had to account for extra space on either side of the heatbed on the x axis. This way I can make use of the full 400mm bet assuming one hotend is inactive. Therefor the 40x40 tslot for the bed support won't reach either end. I can use 7x series aluminum corners brackets along with a flat milled 7x series aluminum support to go under the heatbed. Any issues with this?

I'd love feedback so I can get this started. Thanks in advance.

Why can't you use a longer piece of 4040 for the bed support?

I have found that there really isn't any need for the XY motors to go outside the printer enclosure, which would make it slightly easier to enclose the machine because you don't have to cut holes in panels for the belts. I suppose it depends on the enclosure temperature you use. I set it to 50C for printing ABS, which I don't do very often these days. The motors don't heat up much in operation, so being inside a 50C enclosure would be OK for them.

I'm considering building a new, smaller printer for a smaller nozzle to make more detailed prints than I can with the 1 mm nozzle on UMMD.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
the_digital_dentist
Why can't you use a longer piece of 4040 for the bed support?

How would I build in the springs to pull the bed down? It seems easier if the 4040 is flush with the bed ear.

It's good to know the motors can be inside. That would make things easier. However with this method, I'll need to make the footprint larger. How much offset is required for the motors in relation to the corner bearing supports? It looks like it would be nominal.

Edited 1 time(s). Last edit at 11/04/2024 02:02PM by mlaustin66.

You could anchor the bed hold-down springs with screws and t-nuts, or even just regular screws and nuts by drilling through the 4040.

The motor offsets relative to the corner pulleys are determined by the need to keep the belts parallel to the y axis rails.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

If you put the motors inside, it will be difficult to tension the motors because the 40x40 will interfere with screw placement. Good thing to visualize this in fusion.