Working on my first Delta build, first design revision of the effector. I am hopping there is enough clearance at the heater to print this in PLA without any warping issues. I might duct some of the air down through the effector at the nozzle as well. What do you all think? Any problems I missed? First delta build after all, might be a few…
Thermal barrier (tin foil) with a slight breeze should contain radiating heat mostly. Or alternatives like ceramic cloth.
You are using the Deltaprintr mini hotend?
I wouldn’t put a hot end that close to PLA. Asking for trouble.
Plus, there’s a pretty good argument that the ideal location for the nozzle in terms of stiffness/deflections is at the virtual intersection of the arms, which would suggest you should drop your nozzle lower. Draw an imaginary line down the middle of each arm (between the pair of rods) and extend those three lines to where they intersect below the effector. That’s the “center of stiffness” for the printer.
@Ryan_Carlyle interesting I will consider these things.
My MK10 hotend has a fan duct completely encircling it about 5mm away and though there is slight warping its not an issue printing at 200c. It has been in use for a few hundred hours of printing and survives. It is way closer to the hotend than this effector design so I will probably have to just try this anyway.
This is 5mm carbon fiber rods for arms I sort of doubt the concept of even thinking of them as ‘stiff’ versus centering the load between the ball joints on the effector and trying to lower the amount of off center inertia in that. I am not sure i buy ‘virtual center of stiffness’ as that only exists at 0,0 center, anywhere else on the print area and its moved. As the effector moves that point moves so I think I may ignore that virtual point and go for balance center of gravity.
@Ryan_Carlyle thanks for the info though if it doesn’t work perfectly (which I expect being a first revision) I will have some info to troubleshoot the design. Thanks again!
Keep in mind, the mk10 in your i3 won’t get anywhere near as hot as the mini hotend here if the firmware or a hardware problem sticks the heater on. It’s a safety issue as much as a warping issue.
Consider an aquarium air pump for PLA layer and hotend cooling
@Ryan_Carlyle Yes overall fire safety is a concern. I will be running it on a Duet not a knock of clone MKS base. But I do prefer a nearly all metal set up within the print area like my i3. I will definitely be considering this.
@Jason_McMullan I looked into it, air pumps for aqua culture and large aquariums might do but the small ones don’t seem to put out enough airflow. 40mm Scythe Kaze 12v DC electronics fan moves 36 gallons per minute (4.8cfm converted to the air pump standard of measure). A small aquarium air pump does about 1 gallon a minute. Also torque on the effector from the air lines would seem to be an issue that would negate any weight savings. For the price ranges of a 40mm fan moving 36 gallons a minute at $2-9 depending on quality and shipping, versus air pumps moving around 15 gallons per minute starting at near $40, I must stick with a small fan.
You also need to consider backpressure through a nozzle.
The air pump will continue to deliver 1 gallon/minute through even small orifices (which is what is designed to do).
The fan will rapidly drop in total flow as the orifice size decreases
I have my airline zip tied to my filament Bowden tube, by the way.
And you should try going to a local (non-national chain) aquarium or pet store, or a friend who has aquariums .
Ask if they have any broken or worn out air pumps from their displays you can get cheaply, as they are very simple devices, and can be easily repaired with spares from the same model family.
@Jason_McMullan I will consider it further, since you say it works for you. Filament and temp you print at and layer height? whats your pumps actual rating in Gph? or Lph, anything I can convert.
Is that a Mini Hotend I spot? 
Let us know how it works for you!
Duet arrives tomorrow supposedly, hope to have calibration going by next weekend I will definitely post more as the build moves along. It looks beautiful, really well made, it’s making me speed up on getting the build done because the MiniHotend looks like it wants to print something!
@Shai_Schechter Hey I have a noob question, do I need a 100k resistor with the Mini Hotend, like a J-head? Edit: never mind I researched a bit and figured out the difference between a heater coil and a resistor based heater. 