Talk:SpoolHead
I propose that in a multiple spool/pinch wheel design-> in order to facilitate "multi-head" printing: the "new" wire could be adhered to the "current" wire by means of an adhesive such as superglue and a crimping clamp. The "current" wire would then feed both wires past the adhesive crimping clamp, grab the "old" wire, and cut it at a point past the grabber, but prior to the bond.
The "new" wire can be then towed to the pinch rollers by the "current wire."
In practice: it is most likely more practical to have multiple "spool heads" which contain pinch rollers and the spool of wire as a complete independent assembly, separate from the stepper driver, and which can be changed out by the means of a "tool changer."
>> There are three proposed methods for this as well: Using superglue, using UV-curing resin, or using heat.
A fourth option may exist as a viable alternative - use mechanical means to secure the wire.
Print a layer or two with a linear recess with a small complete or segmented overhang, then press the wire into the recess, snapping it past the overhangs. The recess should be as close or slightly larger than the wire diameter, and the overhangs just slightly less... in cross sectional ASCII art:
O <- mechanical pressure forcing the wire past the overhangs. __ __ (_) <- surface created with a small recess allowing the wire to snap into it.
- Interesting method! This could work well for larger diameter wires than what we're considering at the moment (<0.5mm), but I don't think our resolution or accuracy are good enough for doing that on the small scales we're starting out with.
We are planning to use similar mechanical methods to help position the wire though; for example, we'll print guides on the inner radius of corners and such, so that the wire's tension doesn't pull it out of place.
By the way, can I ask who wrote the above idea? :)
--Jbayless 19:31, 28 January 2010 (UTC)
I also mentioned in the forum the idea of 'zigzagging' thru pre-printed small overhangs. new ASCII art image:
< <-. | \ > <-+-- tiny overhangs to prevent the wire from moving laterally | < | <- wire
I'm not sure how you would secure the initial bit of wire.. perhaps wrapping a small amount around a post that would be snipped by the operator when attaching external wiring. The idea would be that you would advance the wire enough, then switch to printing plastic on top of that wire to firmly secure it. With two print heads, one wire head, and one plastic extruder, and the ability to retake up slack given from the wire tool, you could possibly calculate points that would allow you to more firmly secure wiring by wrapping it around a temporary post, extruding extra plastic on top of the just layed wire, then returning to the wire wrap tool which unwraps the temporary end back off the post.
