Delta printer advice
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@bartolomeus that is some great information. Thank you, that helps me a lot.
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You may wish to look at my Kossel variant described at miscsolutions.wordpress.com.
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@bartolomeus said in Delta printer advice:
I believe for a Delta the best route is to build your own with a Duet+Smart Effector+Hadyn Huntley arms+Linear rails, add a Bondtech extruder, and you are already in the 500$ range. Add the rest of the electronics (24v, 0.9 steppers and so on) and the frame, and you're cruising towards $1000.
@bartolomeus pretty much nailed it.
- Duet
- Optional PanelDue (may not fit the budget).
- Smart Effector (VERY important to easy, reliable, operation of the printer)
- Hadyn arms (length depends on size of frame and print bed, see below)
- Linear rails (not v-slot & roller)
- Bondtech extruder.
- 24V Power for sure
- 0.9 degree steppers. I used 42BYGHM809 a couple of years back. There may be better choices now.
For a 600mm bed, I chose to use RobotDigg 2040 corners. This worked very well, and should work fine for a 300mm bed. https://www.robotdigg.com/product/555/2040-or-3030-Alu-Vertex-for-Kossel-XXL-or-XXXL
I put the motors on top.
I used a glass table top for the bed, with the heater stuck directly on the bottom. No aluminum layer at all. Works great.
Delta / Kossel printer fanatic
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Oh, and if you do use the robotdigg corners, this will tell you a lot about sizing of the bed vs. the smart effector/haydn arm combo:
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Thank you everyone for the advice. I now have a better idea for a plan.
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@Danal said in Delta printer advice:
I used a glass table top for the bed, with the heater stuck directly on the bottom. No aluminum layer at all. Works great.
@Danal That's interesting. I would like to upgrade my heated bed. Glass/mirror with a heater stuck directly sure saves some cost. No downsides at all?
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@bartolomeus said in Delta printer advice:
@Danal said in Delta printer advice:
I used a glass table top for the bed, with the heater stuck directly on the bottom. No aluminum layer at all. Works great.
@Danal That's interesting. I would like to upgrade my heated bed. Glass/mirror with a heater stuck directly sure saves some cost. No downsides at all?
Some drawbacks:
- A glass table top is almost certainly be toughened glass, and the toughening process tends to warp the glass.
- The glass will be thick, probably 6mm, which means heat will take longer to reach the top surface from the heater, and the temperature drop will be even larger than for the usual 3mm or 4mm thick glass beds
- With no heat spreader, the uniformity of heating will depend very much on how uniformly the heater heats it
- There is nowhere you can fit a separate temperature sensor to get a more accurate temperature reading, so you will be have to rely on the reading thermistor in the heater.
- The main benefit of using glass beds IMO is that you can remove and exchange them, e.g. to start a new print immediately the previous one is finished without having to wait for the previous one to cool down so you can remove it, or to try different surfaces on top of the glass (PEI, PrintBite or just plain glass), or to replace the bed if you scratch it or break it. With the heater glued to the underside, you lose this advantage.
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............and if the heater isn't uniform, there is real danger that uneven heating will cause thermal stresses which can crack or shatter the glass in an alarming way.
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@dc42 said in Delta printer advice:
replace the bed if you scratch it or break it
That's the main reason I chose to do this. 600mm borosilicate and 600mm aluminum are not cheap. In fact, 600mm borosilicate is extremely hard to find. My tabletop was ordered from Amazon for about $40 USD. Very replaceable.
As it turns out, I've been using it for two or three years with nothing that would motivate a replacement.
Flatness? Reflecting light off the surface and looking at straight lines in the background, it seems to be very flat. Mesh grids bear this out. So does the bottom of quite a few large prints. Maybe I got lucky. Slow heat? Maybe. It is slower than some of my other printers and faster than others, due to its relatively high power density (right at 0.5 watt / sq cm). It is about 6mm thick, just like dc42 predicted. That does make it somewhat slow to cool. Temperature accuracy? Ha ha ha. IR any bed you have that has a thermistor on the bottom. Very, very few printers bed surface are anywhere near the reading the firmware gets (where most printers have one sensor on the bottom). Temperature evenness? Again, IR any bed you have. Like most printers, this one is not perfect; like most printers, it has never been uneven enough to cause any detectable problems.
Shatter? Not so far.
In short, I agree with the reasoning behind all the drawbacks above. In physical reality, none of them have manifested to a level I can even detect, much less worry about it affecting printing in any way. With the one notable exception of slow cooling.
Were I to build a 200 or 300mm dia delta, I'd probably use "off the shelf" heater + aluminum + PEI, or similar. Once you get larger than parts you can buy, a custom heater stuck directly to a glass tabletop has served me very well.
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@Danal said in Delta printer advice:
That's the main reason I chose to do this. 600mm borosilicate and 600mm aluminum are not cheap. In fact, 600mm borosilicate is extremely hard to find. My tabletop was ordered from Amazon for about $40 USD. Very replaceable.
You don't need borosilicate. Ordinary float glass is fine if it is on top of a heat spreader (some people even use it directly on top of a PCB bed heater).
