Cerberus (metric)

Projects
Participants	Ultratux
Skills	Electronics, Fine mechanics, Assembling, Construction
Status	Planning
Niche	Mechanics
Purpose	World domination

Workshop aiming to build a number of 3D printers of the "delta robot" principle. We will try to stick to the original design as much as possible, but with metric/EU parts.

First steps

• Waiting to see how many participants will join, to know in which numbers to order components
• Querying wishes of participants in regards to build volume, other details, etc.
• Compiling a bill of materials and defining correct order to purchase them in
• Making sure all parts can be acquired in a timely fashion (and for a fair price)
• Printing a few of the parts, noting time required and quality/checking tolerances
• Scheduling a first pre-purchase planning meeting?

I've built my first printer with 1 meter aluminum extrusions, but a bit higher or lower is also possible. Say minimum ~75cm, max ~1m20 maybe ? It would be good to hear everyone's preference to get the order of that under way.

I've emailed Steve Graber, waiting to hear back from him on availability and cost of the CNC'ed parts...

Yesterday I have printed three parts -see pic-. The two upper parts each took 3,5 hours to print. The lower one took 3 hours. The two upper parts are supposed to fit together, but it is extremely tight, I need to test if it fits or that printing adjustments need to be made (or machining...) Also, whether the lower part fits my extrusion profile which is hard to test without disassembling my printer..

Then, as each printer needs six pcs of each pictured part (not 100% identical but close enough) this means 40 hours of printing(!) for just the base building blocks for 1 printer. This means careful planning is in order to avoid disappointments, and perhaps an early start on printing objects.

Participants

• I, Ultratux, will probably build one as well, even though I have the earlier adapted variant.
• Damnlie has shown interest but had to cancel
• rad0 will very likely build one and volunteered to documment the whole process.
• caduceus has shown interest
• rep has shown interest / will participate

Proposed timeline

Without the parts from Grabercars, this project cannot take off. So first, I will wait for his reply and/or seek contact again by different means. Hopefully he'll reply with good news and we can order the parts.
Then, I plan to take the order for the aluminum extrusions, so I need to know the length everyone desires. Standard is 1000mm. I prefer ordering them cut, they can make much nicer cuts than we can, but mostly it helps with shipping; because 6 meter lenghts don't come by DHL...
In the mean time, a start should have been made with printing many of the base parts as shown in the pic. For 4 printers, we'd need 48 such parts, (plus a number of smaller parts)
Then to assemble and thread the towers, the only part(s) missing are the stepper motors. So by this time, we can either order the stepper motors, the stepper motors plus controller boards, or even ALL the remaining parts (extruder parts, hotends, heatbed etc.) So there is time until this step to choose hotend options, controller options, etc.

Testing the first printed parts

Today I printed a third arm, filed all three down a bit, removing debris and fit them together (a hammer and some careful use of it is required). It is a tiny bit too tight which is apparent by the somewhat wider gaps on the edges, but I think it still fits nice. It is very stiff and sturdy. Good.

Better implementation of bowden connection

For my current printer, I have made an intricate hinge to push the bowden into the hotend. However, today I found out that a pressfit adapter feeding the PTFE through exists, see [[1]] and [[2]]. This makes for a much stronger connection, which therefore permits the use of a stronger stepper motor, allowing higher feed rates thus feeding filament faster in a reliable way, which eventually will result in finally attaining the higher speeds these delta printers ought to be able to sustain (the platform being so lightweight). I hate it that I needed to severely limit my speed due to the extruder not being able to keep up. So I am very excited by this... I need me to order one ASAP!