Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 21, 2015 04:48PM |
Registered: 9 years ago Posts: 1,035 |
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 23, 2015 12:29PM |
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Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 23, 2015 02:14PM |
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Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 23, 2015 02:57PM |
Registered: 9 years ago Posts: 1,035 |
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LarsK
I am concerned that play in the carriage bearings will allow your nozzle to move and thus you will not give very nice walls.
The bigger the distance from the linear bearing to the nozzle end, the bigger will the resulting movement from play in the linear bearing be. At the same time it seems you will only install one linear bearing so the play can be significant unless you buy very high end components.
Go look at other CoreXY printers and you will see that the nozzle is much closer to the center of the linear bearings
Rest looks fine. You should use bushings instead of ball linear bearings. It will be more silent and have smoother movement. I got some graphite inlaid from China and even though they cost 3 times the ball bearings they are still really low cost and even as I haven't installed them yet, they seem much better when running them with my hand.
How big will it be? Looking at the coffee table photo it looks like it will be huge.
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 23, 2015 06:32PM |
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Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 23, 2015 07:05PM |
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LarsK
Hey, looks nice. Good job.
I would maybe be a little worried about part stiffness. For example the vertical brazing from the wood plate to the steel structure and many of the carriage parts. Printed they might not be as strong as you hope for. Maybe reinforce and increase material thickness and surface contact area. It is my experience that with printed parts it is better to have a series of small bolts joining the parts together then one central bigger bolt. The force distribution gets better. So better to use 3 distributed M3 bolts then a single M5 for example.
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 24, 2015 07:03AM |
Registered: 9 years ago Posts: 346 |
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 24, 2015 08:02AM |
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LarsK
1) Your printer is too big for just 8mm linear rods.
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LarsK
2) An unsupported angle even in 5mm thickness will not have much strength. But at this point I think it is better if you make some test prints and try to feel it instead of listening to me trying to be smart based on picture
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LarsK
3) Don't spend hours and hours designing a part and then realize that the design won't work because it is overall not stiff enough or can't be printed to the tolerance needed.
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LarsK
4) Using M8 is way overkill unless you are forced by your table to do that- You will crack the plastic before you get any torque put into that kind of bolt.
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 24, 2015 08:41AM |
Registered: 9 years ago Posts: 346 |
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realthor
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LarsK
1) Your printer is too big for just 8mm linear rods.
the calculated linear rods are X=340mm, Y=360mm, Z=370mm.
Are you saying that I should have 10mm linear rods for X and Y and maybe 12 for Z (considering that I am planning to have only one shaft per side)?
Note: I could barely fit the 10mm Z linear shafts in the corners of the design, I couldn't fit the 12mm because the bearing above and the bearing case will get to a too big diameter that I couldn't fir because it will hit the XY belts. And if I fit the Z rods in between the steel pipes I would reduce the Z travel by more than 30mm.
I don't see too much effort on Z if the bed gets lifted from 2 opposite sides of the bed.
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realthor
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LarsK
2) An unsupported angle even in 5mm thickness will not have much strength. But at this point I think it is better if you make some test prints and try to feel it instead of listening to me trying to be smart based on picture
Are you referring to the fact that all the bolts are concentrated in the middle thus leaving the edges unsupported? I don't really understand what you want to say here...
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realthor
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LarsK
3) Don't spend hours and hours designing a part and then realize that the design won't work because it is overall not stiff enough or can't be printed to the tolerance needed.
Unfortunately I can only get some time here and there at the local library which is quite far in fact, so printing parts will be slow. That's why I am mostly dealing with design. I want to order the shafts/bearings/electronics/etc first and then, until they arrive, I'll have time to print bits and pieces.
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realthor
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LarsK
4) Using M8 is way overkill unless you are forced by your table to do that- You will crack the plastic before you get any torque put into that kind of bolt.
The holes in the metal frame are all 8.33mm ... strange for a metric value, maybe it's something imperial and I don't know but in those 8.33mm holes I plan to put M5 bolts to clamp the above and below plastic parts and the M8 is for the 608 belt-redirect bearings below. 608s take 8mm shaft...hence 8mm bolt. Do you know of a better choice of pulley for the 6mm GT2 belt?
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 24, 2015 09:54AM |
Registered: 9 years ago Posts: 1,035 |
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LarsK
2) An unsupported angle even in 5mm thickness will not have much strength. But at this point I think it is better if you make some test prints and try to feel it instead of listening to me trying to be smart based on picture
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 24, 2015 11:16AM |
Registered: 9 years ago Posts: 346 |
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realthor
Ok, now there is enough material here to send me to court . Bring it on
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 24, 2015 11:44AM |
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Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 24, 2015 12:26PM |
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Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 24, 2015 01:05PM |
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LarsK
Where is the motor and the part driving the filament? I know the smartrap-core is direct driven but I can't find the actual extruder in what you show above. Also earlier you showed two hotends in what seemed like a Bowden setup.
Kind reminder: The hot-end is the part that gets hot (the one you showed a screenshot of above) and the extruder is the parts with the motor with a hubbed bolt which drives the filament. Sometimes the hotend and extruder is made in the same assembly (like SmartRapCore) and sometimes it is not, then it is called a bowden setup. If the motor shaft is driving the hubbed bolt directly it is called a direct drive, if there is a gear (like Wades infamous extruder) then it is not
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 25, 2015 09:00AM |
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Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 25, 2015 12:52PM |
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realthor
I haven't sketched the actual extruder but I'm planning to use a direct drive extruder like this one.
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realthor
@LarsK: if you are still watching the thread, what bushing did you use? Should i consider bushings for X and Y only and Bearings for Z - noise on Z is not that bothering because of the little movement?
For ont of the previous unanswered questions I haven't found a preper answer yet:
- 10 vs 20 teeth GT2 pulleys. I plan to use the 16 tooth; any disadvantage?
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 25, 2015 08:21PM |
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Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 26, 2015 12:53PM |
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Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 26, 2015 01:51PM |
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Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 26, 2015 02:17PM |
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Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 26, 2015 03:44PM |
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Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 26, 2015 06:26PM |
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Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 27, 2015 04:16AM |
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Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 27, 2015 09:05AM |
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Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 27, 2015 09:13AM |
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J-Max
Hi guys,
That's so true. the Duet have many features and is expandable.
Actualy, the price of the Duet is the major restraint for purchase.
If it was Smoothieboard vs Duet, I'll go for the second one, definitely.
But even if you add a screen, a Pi, another screen for the Pi, you're still ways under the price of the Duet with the Sbase.
Otherhand, if you plan to manage several printers, Octoprint/Pi is not a bad idea.
The Sbase, as the AZSMZ, represents a first price 32 bits board.
Obviously it do not offers all the features of the best boards.
But It's ways better than any 16 bits board which does not offers much features too.
This for a third of the price of a genuine Ramps.
You want to take the Sbase just for what it is.
It's personal, but I can't imagine investing 100€ or more in a control board.
I didn't even for my 650lbs CNC mill.
++JM
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 27, 2015 09:38AM |
Registered: 9 years ago Posts: 233 |
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 27, 2015 09:56AM |
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patrickrio
There is some interesting work using the ESP8266 chip to run the Duet style web interface on MANY boards and adding WiFi into the mix too. That could change the balance toward SBASE if ESP8266 ever gets the bugs worked out of it. I have a bunch of the ESP8266 chips lying around, so I may play with this too if I get a chance.
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 27, 2015 11:42AM |
Registered: 9 years ago Posts: 346 |
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 27, 2015 12:34PM |
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LarsK
about ESP8266 see this, it is truly great work!
On subject; Why don't you just start out with a RAMPS and the boring 8bit? A lot of people (me included) is still running this antique way and it is fine. Once you get a better feel for where you wanna go and how much money you want to sink into this, you can upgrade.
Yes, in the future you may end up having an unused RAMPS and Arduino Mega - And so what? It is a nice platform to have for experiments, 3d printer or no. The little money you sink into that now, will give you much more time to evaluate what you need - Plus - and not to forget, this is your first printer, and everyone makes mistakes the first time (and 2nd, and 3rd... etc.) - You will cry a lot less if you burn out an Arduino Mega board then a Duet(!).
Finally - Ramps + Arduino just works... It is one less unknown for your build because you can be 99% sure that whatever problem you encounter, someone else will have experienced it before...
Re: Coffeetable CoreXY:: new build :: small apartment rep-strap solutions November 27, 2015 12:34PM |
Registered: 10 years ago Posts: 14,672 |
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LarsK
...
Finally - Ramps + Arduino just works... It is one less unknown for your build because you can be 99% sure that whatever problem you encounter, someone else will have experienced it before...