Delta Printer Build Questions / Advice

saffi

I have an ~8mm thick aluminum Mic-6 plate, should I be concerned about using more energy to heat it as a printer bed? It's extremely heavy and flat, so I thought it would make a nice print bed and I could add clamp screws to affix glass or just print on a PEI sheet attached to the aluminum. Will the heat transfer easily past the edges of the heat pad and into the printer frame if I'm not careful about attaching it to the printer?

Also, I don't want to run my extruder and effector wiring all the way through my towers - how well do the delta printers work where the wiring comes from under the printer and loops over to the effector? Will that cause problems during a print? I was thinking about making some sort of wire guide and attaching the wiring to a carriage so the carriage could help keep the wiring out of the way.

For 9 degree steppers, a 24V power supply is recommended for proper torque, correct? I have a mains powered heat bed and an SSR, so the heat bed voltage isn't dependent on the psu.

I have the new PCB effector and carriages, so the build is going to utilize that for auto-leveling.

Thanks

dc42

On my delta I have 3 metal M3 threaded standoff pillars attached to the lower triangle, then the bed plate sits on top of he pillars and is screwed into them. So the only heat transfer to the frame is through those 3 small pillars. I also have a sheet of cork insulation between the bed plate/heater and the lower triangle, held in place by the pillars. See
https://miscsolutions.wordpress.com/dc42s-large-kossel-build/ for more.

I have the extruder drive mounted about 1/4 to 1/3 way up one of the towers. The wiring to the effector goes up that tower to the extruder and is then twisted around the Bowden tube to the effector.

With 0.9deg motors you should definitely use 24V power. I use the -1684 motors, but for the generation 2 Duets the -2004 would be a better match.

HTH David

saffi

@dc42:

On my delta I have 3 metal M3 threaded standoff pillars attached to the lower triangle, then the bed plate sits on top of he pillars and is screwed into them. So the only heat transfer to the frame is through those 3 small pillars. I also have a sheet of cork insulation between the bed plate/heater and the lower triangle, held in place by the pillars. See
https://miscsolutions.wordpress.com/dc42s-large-kossel-build/ for more.

I have the extruder drive mounted about 1/4 to 1/3 way up one of the towers. The wiring to the effector goes up that tower to the extruder and is then twisted around the Bowden tube to the effector.

With 0.9deg motors you should definitely use 24V power. I use the -1684 motors, but for the generation 2 Duets the -2004 would be a better match.

HTH David

This is very helpful, thanks.

I checked my Stepper Online sourced motors, I believe they're part 17HM19-2004S - so I will be using those.

The biggest struggle I had last build was simply routing all the wiring through the aluminum extrusions, so a 1/4 way extruder makes a lot of sense for minimizing wiring (and it leaves the effector wiring completely accessible).

DjDemonD

Hi Saffi,

You can see images of my Kossel XL printer here:
http://forums.reprap.org/read.php?178,702599,page=3

That page has the bed mounts but if you go back 1 page, you can see the whole machine. My bed sits on mounts that straddle the horizontals, this makes it much more stable than just 3 point mounts as its supported around maybe 1/4 of its circumference, I also added clamps to hold it down, to resist teeter/totter when probing. The bed mounts have cork insulation on them, so little/no heat transfers to the frame (in fact the motors transfer more heat to the frame than the bed), they are also raised a little way off the horizontals, There is no direct metal to metal contact between the bed (6mm tooling plate) and the frame. There is now an aluminium plate separating the bed from the electronics compartment with a combination of cork and foil bubble wrap to keep the electronics cool.

The bed plate you have will work very well, but it will take time to heat up and for the heat to distrubute evenly, and it will take a fair bit of time to cool down after printing. Adhering the bed surface directly to the aluminium IMO is better, but then its easier to replace a surface on a removeable plate, especially if you cant get the adhesive off.

I bring my umbilical around 1/4 way up the z tower and then it is supported by a keychain retractor. I can move anywhere in the 330x460mm volume without any undue tension on the cabling, but the cabling is much shorter than if I took it to the top of a tower and back down.

saffi

Thanks for the ideas. I'm definitely going with the ~8mm plate and I have a Keenovo mains powered silicone heater, so it should work really nicely with the aluminum. The bed setup looks similar to your build.

The electronics are being mounted on a laser cut wood plate from Trick Laser and I can add some cork underneath the silicone heater to help insulation. It's mostly my last Delta build, except with some updates. The PCB effector and carriages will make it an easier build this time around.

Jarery

On my new build, I've turned the unit upside down, so the motors are in the upper triangle. This will allow me to put the Duet also in top, with short wires to the motors and the PanelDue.
The bottom triangle now only has the mains inlet, power supply and SSR wtih heatsink so not as susceptible to heat.

For the bottom triangle I used 2060 instead of the 2040 for the vertices, and printed a 20mm high version of the verticee so now both top and bottom use 2060 extrusions. I then mounted the bottom triangle on tennis ball feet giving me a fair amount of room underneath. https://www.thingiverse.com/thing:2158108

For the mains inlet, instead of using 2 pieces of 2020 on the one side, I have used https://www.thingiverse.com/thing:2313868 from James White who also did the feet. This way I do not need to drill or cut an access port into the side of the extrusion. The feet are tall enough to allow this mains inlet.

I'm having an aluminum plate cut that mounts into the top slot slot of the lower triangle. So the bed sits on standoffs, and the power and ssr mount to the underside of the aluminum plate. The now enclosed space between the bed and plate I can line with cork.

In the end I now have all electronics and wiring I can access without removing the bed, The Duet in the top, and the power/ssr on the underside.
I do really like the bed clamping technique in the earlier post which I may investigate also.

Pictures when i get it assembled further.

Gregc

How are you going to mount the carriages to your MaxMetal?