CoreXY vs Quadrap mechanism November 26, 2015 06:35PM |
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Re: CoreXY vs Quadrap mechanism November 26, 2015 07:04PM |
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Re: CoreXY vs Quadrap mechanism November 26, 2015 07:24PM |
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Re: CoreXY vs Quadrap mechanism November 26, 2015 08:35PM |
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Re: CoreXY vs Quadrap mechanism November 26, 2015 09:23PM |
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LarsK
Hey,
How come you are not looking at a Delta? It seems to me that it is the perfect solution for the geometry you want (300x300 x1000)
Re: CoreXY vs Quadrap mechanism November 26, 2015 11:43PM |
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Re: CoreXY vs Quadrap mechanism November 27, 2015 06:11AM |
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grat
Delta's scale poorly, even more so when you're talking 1m Z axis-- My delta is 720mm tall, and has a build height of 280mm.
dc42's delta is 300mm diameter, 480-540mm print height, and is 1m tall. Best case, you're looking at 1.5-2.0 meter tall printer, and you're going to have to make the frame out of 2060 or something similar to get it to work. Even then, the bowden length would be pretty crazy (800-1000mm?).
Re: CoreXY vs Quadrap mechanism November 27, 2015 06:38AM |
Registered: 11 years ago Posts: 14,686 |
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LarsK
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grat
Delta's scale poorly, even more so when you're talking 1m Z axis-- My delta is 720mm tall, and has a build height of 280mm.
dc42's delta is 300mm diameter, 480-540mm print height, and is 1m tall. Best case, you're looking at 1.5-2.0 meter tall printer, and you're going to have to make the frame out of 2060 or something similar to get it to work. Even then, the bowden length would be pretty crazy (800-1000mm?).
This is not correct. If DC42's does 500mm at 1m tall then to do another 500mm he just makes it 1.5m tall. In height it scales 1:1. You are thinking about the bed diameter which scales different. You are correct that normal bowden would not be optimal but there are many work arounds for this. See this also
I wanted to mention that there is / was a printer on kickstarter not so long ago that came at least close to the specs (470x435x690) - This one maybe it can serve as an inspiration in parts.
Re: CoreXY vs Quadrap mechanism November 27, 2015 09:39AM |
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Re: CoreXY vs Quadrap mechanism November 27, 2015 10:33AM |
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LarsK
This is not correct. If DC42's does 500mm at 1m tall then to do another 500mm he just makes it 1.5m tall.
Re: CoreXY vs Quadrap mechanism November 27, 2015 11:24AM |
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Re: CoreXY vs Quadrap mechanism November 27, 2015 03:10PM |
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Re: CoreXY vs Quadrap mechanism November 29, 2015 04:24PM |
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Re: CoreXY vs Quadrap mechanism November 29, 2015 05:07PM |
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the_digital_dentist
With a delta, it seems the only tricky/critical alignment is setting the guide rails parallel.
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the_digital_dentist
...But then there's the loooong belts...
Re: CoreXY vs Quadrap mechanism November 30, 2015 03:31AM |
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Re: CoreXY vs Quadrap mechanism November 30, 2015 07:48AM |
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Re: CoreXY vs Quadrap mechanism November 30, 2015 08:26AM |
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Re: CoreXY vs Quadrap mechanism November 30, 2015 10:51AM |
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Re: CoreXY vs Quadrap mechanism November 30, 2015 12:00PM |
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patrickrio
I was also concerned with belt length and also bowden tube length. I therefore really concentrated on keeping my movements tight to the printbed, and the carriage small. Every mm you can shave from either X or Y axis length means 4mm less belts used. You could mount the bowden tube vertically above the printer bed center to shorten the bowden tube for a large printer.
Re: CoreXY vs Quadrap mechanism November 30, 2015 02:33PM |
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Re: CoreXY vs Quadrap mechanism December 01, 2015 12:15PM |
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patrickrio
When I was researching my printer, I talked to almost every major linear guide manufacturer (around 10 manufacturers). One very important feature in the CoreXY design when used with linear guides is to keep the Y axis guides perfectly parallel. And they really mean perfectly parallel!!! The most common failure for linear guides in all machinery is apparently not getting guides parallel. Hard linked linear guides (like what we do when clamping the X axis to the Y axis...) have no tolerance for variation in parallel at all. The best guides have an even LOWER tolerance for variation in parallel than the cheaper guides. Several of the manufacturers recommended that you machine perfectly parallel lips on the mounting plate at the inner edge of the two guides. Then you actually clamp the guides against the lips before screwing them into place. Apparently it is almost IMPOSSIBLE to drill holes in your plate accurately enough to keep parallel spec on the best guides. Since I did not use parallel lips, or even a mounting plate, I used cheap Chinese guides that have more forgiving tolerances and are more disposable. I suspect that YOU will be using sealed linear guides which have VERY tight tolerances and will probably require the lips.
Re: CoreXY vs Quadrap mechanism December 02, 2015 05:42PM |
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Re: CoreXY vs Quadrap mechanism December 03, 2015 03:11AM |
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Re: CoreXY vs Quadrap mechanism December 05, 2015 07:17AM |
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Re: CoreXY vs Quadrap mechanism December 05, 2015 07:45AM |
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Re: CoreXY vs Quadrap mechanism December 05, 2015 07:59AM |
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Re: CoreXY vs Quadrap mechanism December 05, 2015 08:05AM |
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Re: CoreXY vs Quadrap mechanism December 05, 2015 08:10AM |
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J-Max
And a good link about the 6 degrees of freedom and accuracy measurement : Ensuring Linear Motion Devices Meet the Needs of the Application
They uses a granite block as reference plate. I guess sadly none of us own one.
But reference can be one stile (or rail) of your structure. But you need to always reference to... that reference.
You should not reference from another element until that element is perfectly referenced with your initial reference.
(Uh... I wonder if I'm understandable...)
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J-Max
Here Spectra line is expensive. (about 16€/roll) I guess anywhere over the world you want Spectra line to save money.
First, even if you can get a cheap Specta spool, you're only saving fiew bucks.
Belts are accurate and pulleys are machined. Printed Spectra pulleys are probably not as accurate.
If quality comes first and price comes seccond, you want belts and pulleys or better.
Re: CoreXY vs Quadrap mechanism December 05, 2015 10:26AM |
Registered: 12 years ago Posts: 5,797 |
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patrickrio
Yes, that is the procedure for getting parallel.... however, some of the manufacturers feel pretty strongly that this is not enough to meet spec. a few of the manufacturers, IKO for example, will not even honor the warranty on their smaller sealed guides if you do not have a mounting lip. I believe this is up to their 12mm rail miniature sealed guides.
I did not have a lip on my design either, and did exactly as you did to get them parallel.
Re: CoreXY vs Quadrap mechanism December 05, 2015 11:10AM |
Registered: 10 years ago Posts: 233 |