Cerberus (metric)

From Technologia Incognita
Revision as of 02:34, 12 October 2013 by Ultratux (talk | contribs) (Testing the first printed parts)
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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..
20131010 024607.jpg

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
  • rad0 has shown interest
  • caduceus has shown interest

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 fir them together (a hammer is required). It is a tiny bit too tight, but I think it still fits nice. It is very stiff and sturdy. 20131011 232157.jpg

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 enables the use of a stronger stepper motor, thus feeding more filament faster is a reliable way, which eventually results in finally attaining the higher speeds these delta printer ought to be able to sustain. I am very excited by this... I need me to order one ASAP!