Details and discussion on how to make your extruder head assembly easily removable. The big box is great but there's a problem. It doesn't matter if you have a single or dual at some point you're going to want to remove the extruder assembly or swap it completely for a volcano, chimera or something e3d haven't even thought of yet. While the extruder carriage has already been changed to allow it to be removed by undoing a few screws there's no way to disconnect all the wiring easily. Well, not yet anyway... Connectors One option for compact connectors is the molex micro fit range. Don't be concerned about the price of the crimping tool. A cheaper crimp tool can be found which works just fine. The Molex connectors are rated up to 5amps, come in a range of sizes and have a positive latch. You can also have them cable to cable or cable to panel mount. The panel connectors are handy because it means we can print a panel and attach it to the rear top edge of the bigbox and keep it as neat as possible. Part 2 - quick swap carriage Coming soon...
And it's not just me you know. Here's bigbox fanatic Livi's live stream of fitting molex connectors her to bigbox. Livi's using the cheaper molex crimp available on Amazon.
In case you're wondering, that's not someone playing minecraft, it's piano practice. Still relaxing though right?
How many pin connectors are you using, are you doing seperate connections for the various components or one big connector? Also if say you have a cartrage or something go bad can you remove the pins for that device (assuming your using one connector) and and recrimp with new pins?
-personal preference but I'd opt for separate plugs for fans, extruder and heater/sensor. You can remove pins, it's not easy but definitely possible. Once my bigbox arrives I'll post the details of how I arrange everything.
I use D-9 connectors on my current printer. One end is fixed to the frame with a printed box and the flying cable is plugged into this; pins are connected in parallel for the high current leads. I will wait to see what I can do on the BB when it arrives.
I was thinking that multiple connectors would be ideal, just less aesthetically pleasing maybe. I will have to pick some up, I would like to have the ability to switch to single from double extruders in case I ever need the extra print volume, without too terribly much hassle.
I know it's a bit off topic but I've had a bit of a think about fitting a filament detector. It uses a microswitch roller to trigger a pause if the filament runs out. I'm not great with CAD but I think this link should let you see it. http://a360.co/1StWPw0 Thats another 3 wires to plug in.
That looks OK and should work and it's not that "Off Topic". I am thinking about earlier detection so that a splice can be effected but have not put any ideas together yet. Mike
Yeah you might be right, I'm _fairly_ sure the pause will trigger before the filament runs out but I guess we'll have to wait and see. I have a simpler block made for the microswitch which could easily be mounted on the frame if needs be. If it's like the sailfish firmware I'm using on my current printer you can do a filament load while paused. I never got the knack of splicing reliably and she who must be obeyed was getting sick of me borrowing her hair straighteners Edit: if the switch was turned around so the roller was at the top that would be plenty of time to trigger a pause before the flow to the nozzle stops i bet.
Seemed to print fine and is a nice snug fit. I wonder if I need to model a collar on the top for the filament guide tube to fit in to? You gotta love it. Have an idea, do a basic model and have a copy in your hands a few hours later.
One question I have about the filament detector, which is based on the thread regarding nozzle cleaning, which is if this were to happen on an unattended print, wouldn't the PLA in your head turn into a gloppy mess as it sat there, or does the hot end turn off during this. Also what happens if you are printing an item in ABS or other plastic that needs a heated bed, do you let it cool and reheat it after your splice? Other question @mike01hu , is there some reason we don't want to put it on the back (those arrows look like a great place to mount this) where you would have lots of space to do a splice?
@Henry feldman Yes Henry, I agree that management of the hotend and bed would have to be part of the process but, for the hotend, that would be no more than needed for dual extruders when an extruder change is effected. I suspect that slicer scripts can be added but as I don't have experience with this I can only surmise and leave it to the experts of likes of Richard Horne to advise. Until I get my BB I can't envisage how this could be managed, but @Kanedias 's late detection is neat. You are right that the problem with splicing is that it takes time and a quick splice method has yet to be devised; I was thinking that it may be possible to design the whole of the feed mechanism to manage filament change by just simply feeding a new filament behind the old one by adding a second hob-bolt separated by a short tube so that continuous feed takes place, the hob-bolts could share the same drive. In this case early detection is needed to flag the need for attention. I might fire up Solidworks to look at this when I have more time. It's a rapidly changing world in 3D printing. Mike
After printing the second single print head parts for my realsoonnowhere BB, I sank in deep meditation looking at the bare parts populating my desk here - and yes, there is one more problem if you want to change the whole carriage - the belt. It's fixed on the hotend bracket, and solving that connection and re-connecting it on the next one is not really suited to become habit forming. I remember that Richard showed in one of his videos how he had solved that - iirc, he exchanged the printhead but let the carriage stay on its rails, so the carriage was what its name implies, like a truck that can be loaded with various different containers. Some quick lock turned, et voilà, new configuration ready to ooze. To be kept in mind... In the end, an automated tool change like in a CNC machine appears desirable for the heavy-duty-hardcore enthusiast.
@UlrichKliegis Ulli, you will see I've opened a discussion on G+ to see if Richard has any update on his quick change system, Mike
I did see that. It's good isn't it. If I didn't have to pay transatlantic shipping I'd find it hard to resist.
So I've done all I can without taking the irrevocable step of cutting cables. I modified the top cable bracket to add cutouts for the molex panel mount plugs. And this is the corresponding hot end assembly. It cost a little more to have a second complete hot end but it means changing them is siply loosening the 2 retaining screws and unplugging. Unfortunately this is something I wouldn't be able to do with a Titan because of the way it slides in the heat break. Nose for scale
I have a PT-100 question.... which 2 of the 3 cables are used? 2x red + 1x silver Oh and another question does someone know how the fans are switched? Like hot end 30mm and the side blowing thing? can they share a GND wire? and the end stop can all 3 share a GND?
My PT100 only has 2 wires, both of them blue so I can't help with that. The hot end fan is switched on the board so as long as the hot end is over 40 degrees it comes on. The cooling fan is controlled by Gcode from your slicing problem. I would guess you can share the fan grounds as they'll all be common in the end and are at the same voltage.
