Looks like I need a new printer!
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To expand on @deckingman excellent advise, I use these from Motedis:
https://www.motedis.com/shop/Nutprofil-Zubehoer/Zubehoer-20-I-Typ-Nut-5/Verbinder-Winkel/Standardverbinder-20-I-Typ-Nut-5::570.html. It is the same principle as @deckingman uses but the plate will assure a straight connection between the 2 extrusions. Drilling holes in the extrusion is not hard to do with the right tools (and some cutting oil
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@whosrdaddy said in Looks like I need a new printer!:
To expand on @deckingman excellent advise, I use these from Motedis:
https://www.motedis.com/shop/Nutprofil-Zubehoer/Zubehoer-20-I-Typ-Nut-5/Verbinder-Winkel/Standardverbinder-20-I-Typ-Nut-5::570.html. It is the same principle as @deckingman uses but the plate will assure a straight connection between the 2 extrusions. Drilling holes in the extrusion is not hard to do with the right tools (and some cutting oil
)That's a good find - looks like they will give a bit more contact area than just the button head. I'll bear those in mind if I ever build another printer.
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@t3p3tony said in Looks like I need a new printer!:
... there is a tendency in 3d printer designs to repeat errors that have been well documented before (for example over constraining axis).
@t3p3tony, can you explain over constraining? For example, in the larger version of hypercube evo, the Z bed it supported by four vertical rods and moved by two lead screws. What are the over constrains in this example?
Also, the bed is supported and leveled by 4 screws. Is it also an over constrain?
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@zapta You would need one rod to fix the bed in X and Y, and another rod to keep the bed from rotating around the first rod. Anything more is technically over constrained. But in reality there are no perfectly rigid bodies and things do flex and sag, so adding more constraints can be used to overcome those problems, however it's not without its own problems, like binding when things aren't perfectly aligned. Or at least aligned to within tolerance.
For the bed leveling, 3 points define a plane, 4 points define a saddle parabola. If the bed is rigid enough to maintain a flat plane when supported at only 3 points leveling will be much easier. If the bed is too flexible to be adequately supported by 3 points, then 4 points can be used, and can still arrive at a flat plane, but it will take far more adjustment to take the twist out of the saddle.
If you're really interested in mechanical constraints in 3D printers I suggest this book: http://www.sublimepublications.com/store/p1/3D_Printer_Engineering_Volume_1%3A_Motion_Platform_Design.html
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@zapta said in Looks like I need a new printer!:
@t3p3tony said in Looks like I need a new printer!:
... there is a tendency in 3d printer designs to repeat errors that have been well documented before (for example over constraining axis).
@t3p3tony, can you explain over constraining? For example, in the larger version of hypercube evo, the Z bed it supported by four vertical rods and moved by two lead screws. What are the over constrains in this example?
Also, the bed is supported and leveled by 4 screws. Is it also an over constrain?
IMO that's a classic case of being over constrained. The vertical rods should not support the bed - that's the job of the lead screws. The vertical rods should only prevent the bed from moving in the X or Y directions and two rods, one at each opposite corner is enough to do that. Trying to accurately align two rods so that they are perfectly parallel is difficult enough, three is even worse and four is asking for trouble. But then lifting a bed with only two screws is also asking for trouble...........
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I do wish we could make getting a RailCore to the UK easier. Shipping and customs suck.
Co-Creator of the RailcoreII CoreXY printer
https://www.thingiverse.com/thing:2407174 -
@phaedrux said in Looks like I need a new printer!:
If you're really interested in mechanical constraints in 3D printers I suggest this book: http://www.sublimepublications.com/store/p1/3D_Printer_Engineering_Volume_1%3A_Motion_Platform_Design.html
I will take a look, thanks.
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@kraegar said in Looks like I need a new printer!:
I do wish we could make getting a RailCore to the UK easier. Shipping and customs suck.
Might be worth checking whether Ooznest stocks many of the parts already. If so then perhaps they could supply kits in this part of the world. They are already a Duet3D distributor.
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@PaulHew How are you getting along? Any enlightening moments (so long as they weren't sod this!
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@DocTrucker It is built!
mmmm Enlightening moments... Yes I nearly did have a "Why am I bothering and a F### it"-
Ordered the 8x2x2 leadscrews from reprapworld and 2 out of 3 were bent, enough so I could scratch my back with them!
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Misumi 15x15 extrusuions. In the UK / Eu, if you want to order them you have to have a company as in a Ltd with a VAT number. Anywhere else in the world you can order directly from Misumi. Self employed does not count!
Someone helped me out and ordered them for me. -
Customs charges - They do like to screw us!
I bought the Z yokes, magnum pulleys, pulley mounts, stepper mounts and some other bits from Mandala Rose Works. £80 customs.
713 Maker - Bed, Y carriage and hotend mounts, another £50 in customs. -
Linear Rails - was not going to mess around so found a supplier who gave me a price for all 6 rails and blocks for £380 in Hywin
Would I build another? Yes I probably would, but I would ask people in the UK to CNC some parts for me. Some parts have been designed by Mandala Rose and 713 so they would be harder to get made in the UK and I do not think that they would hand over the files that easily.
Stil some tweaking to do but it works and prints at an insane speed.
Without the help of the Railcore discord and Facebook pages, i would not of got there.
And as always, the Duet Forum has been brilliant too. -
