New CoreXY 400x400x560mm Build in Progress
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I didn't see the XY stage in the CAD model, so it seems like you're working from the outside in. You may find that the XY mechanism that will fit in the space you've allowed for it won't reach you print envelope goal. When you have a print size goal, it's better to start by designing the mechanism, then build the enclosure around it.
If your goal to to minimize moving mass, using the F608 bearings I used may not be optimal. Those bearings are heavy, and have 8mm bore, so their axles are heavy, too. If you look around you might be able to find plastic or aluminum flanged pulleys that use smaller bearings and smaller axle hardware, while maintaining the relatively large diameter. A lot of printers use smaller diameter pulleys and seem to have adequate belt life and print quality.
Those tiny corner brackets don't really do much for rigidity compared to putting a sheet of plywood (ugh) or polycarbonate on the sides of the printer.
You might want to put leveling feet on the bottom of the machine. If the machine sits on an uneven surface the frame will twist to conform to that surface, especially if the machine is heavy. That twisting will distort the XY plane and could make it hard to tram the bed. UMMD usually sits on uneven concrete floors. When I move it to a new location I push on the frame and see if it rocks a little and if it does (almost always) I adjust the leveling feet to minimize the rocking.
UMMD's frame would have been a lot more rigid if I had screwed PC sheets for the side walls instead of fitting the dual layer PC into the frame's slots. I wasn't too concerned about rigidity (the 4040 extrusion is pretty good) and was more concerned with thermal insulation and appearance (I take it to makerfaires, etc).
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I'll toss in a few comments here based on my build of Black Beauty (which @mrehorstdmd gave me some ideas on as well)...
You will indeed need some sort of bracing on the frame but the standard corner brackets will not be enough considering the lengths of the extrusions.
An enclosure would be good but I found that having a permanent enclosure double as both thermal control and frame rigidity meant that you could only access the print surface from the front where you'd have a door. With a small bed, this isn't an issue but with a large bed it's pretty convenient to be able to reach in from any side or at least the left and right but then you'd then need side doors that have fixed frames to act as the brace.
You could do the diagonal braces as @Stephen6309 suggested but they'd need to create a triangle with at least 100mm on each side.
Another option is to use pieces of 20mmx40mm extrusion set a little ways up from the bottom and down from the top with the 40mm face being vertical. That will give you more mating surface and be less intrusive than diagonal bracing. You could even add another 3 pieces on the sides and back midway to get even more support.
With either the braces or the extra horizontal members you can do anything with the enclosure you want since it's not load bearing.
A big +1 on @Phaedrux 's recommendation of the Volcano.
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@mrehorstdmd said in New CoreXY 400x400x560mm Build in Progress:
I didn't see the XY stage in the CAD model, so it seems like you're working from the outside in. You may find that the XY mechanism that will fit in the space you've allowed for it won't reach you print envelope goal. When you have a print size goal, it's better to start by designing the mechanism, then build the enclosure around it.
If your goal to to minimize moving mass, using the F608 bearings I used may not be optimal. Those bearings are heavy, and have 8mm bore, so their axles are heavy, too. If you look around you might be able to find plastic or aluminum flanged pulleys that use smaller bearings and smaller axle hardware, while maintaining the relatively large diameter. A lot of printers use smaller diameter pulleys and seem to have adequate belt life and print quality.
Those tiny corner brackets don't really do much for rigidity compared to putting a sheet of plywood (ugh) or polycarbonate on the sides of the printer.
You might want to put leveling feet on the bottom of the machine. If the machine sits on an uneven surface the frame will twist to conform to that surface, especially if the machine is heavy. That twisting will distort the XY plane and could make it hard to tram the bed. UMMD usually sits on uneven concrete floors. When I move it to a new location I push on the frame and see if it rocks a little and if it does (almost always) I adjust the leveling feet to minimize the rocking.
UMMD's frame would have been a lot more rigid if I had screwed PC sheets for the side walls instead of fitting the dual layer PC into the frame's slots. I wasn't too concerned about rigidity (the 4040 extrusion is pretty good) and was more concerned with thermal insulation and appearance (I take it to makerfaires, etc).
Indeed the CoreXY is not in the model for the time being, but I do have a pretty good idea of what it will come out to be as for size and travel of the gantry. As for the corners I am still planning on either getting corner braces (aluminum or printing Carbon Fiber PC) as well as enclosing the printer once I have it up and running with PC as well. Just something not on the to-do list for the time being. Once I begin to dismantle the FT-5, I will have a decent supply of excess extrusions so as for reinforcing, that is when I will probably add them.
I am seeing now though this is really the first stab I have had at designing a printer from the ground up, and I really appreciate the input from everyone so please keep it coming
Seeing a few things I can improve on, and others I will just wait to see the outcome. -
Have you considered a zesty nimble for remote direct drive extruder to lower your carriage mass? You could add a duex board and then drive all 3 z screws independently for auto leveling.
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@mikebridge said in New CoreXY 400x400x560mm Build in Progress:
Have you considered a zesty nimble for remote direct drive extruder to lower your carriage mass? You could add a duex board and then drive all 3 z screws independently for auto leveling.
Mike,
I will say I am not entirely sure of what you're talking about, Ha!
Just looking around for it, I never new there was such a thing lol. I will try to stick with my direct drive for now as the gantry design is pretty much done. But I will definitely keep this unit in mind in case I have to move away.
As for auto leveling with each lead screw this is something I also thought about, but didn't deem it necessary. Plus I would lose roughly 50-60mm of usable z height.
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@fickert said in New CoreXY 400x400x560mm Build in Progress:
As for auto leveling with each lead screw this is something I also thought about, but didn't deem it necessary. Plus I would lose roughly 50-60mm of usable z height.
I haven't found need for auto-leveling on my XY machine. It only takes a minute or two to do it by hand and it doesn't need to be done again for quite some time.
Frederick
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@fcwilt said in New CoreXY 400x400x560mm Build in Progress:
@fickert said in New CoreXY 400x400x560mm Build in Progress:
As for auto leveling with each lead screw this is something I also thought about, but didn't deem it necessary. Plus I would lose roughly 50-60mm of usable z height.
I haven't found need for auto-leveling on my XY machine. It only takes a minute or two to do it by hand and it doesn't need to be done again for quite some time.
Frederick
I have 2 of the 3 leadscrews currently installed. While being guided by linear rails, there is very little slop, so I assume if I cannot get stall homing to work on the z-axis then I will not be that sad. I agree this will hopefully not need much leveling in general.
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@fickert said in New CoreXY 400x400x560mm Build in Progress:
@stephen6309 said in New CoreXY 400x400x560mm Build in Progress:
@fickert You may want to put some diagonal bracing on the side to keep the printer from twisting. On my corexy i made, I drilled access holes and tapped the extrusion ends to screw them together to not use any angle brackets.
I did think about this. Probably not a bad call at all. I was even thinking of doing some diagnal cable bracing as an alternative. Similar to pull barn structuring. Figure it's something I can add down the line.
I was wondering if you considered building an enclosure?
It would help for printing specific materials, strengthen your frame and keep it from bending and twisting. -
I apologize for anyone that has stumbled upon this and saw there was no conclusion.
This printer has been fully operational at the start of the 2019 year.
We bought a home and moved in late Dec. 2018.I attached a few photos of the full setup. Ignore the extra long shoulder screws on the carriages, I had these lying around and they work great!
I have been printing a bunch of poly-carbonate for a few projects from friends of mine (Porsche intake system, and mounting components)
Also the spine is 24 inches long
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One thing I still really would like to do is mill and tap the joints at the ends and cut 45 degree 100-150mm extrusions for the corners.
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@Fickert Looks good.
