Tool changer questions for those that have them
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I am gradually thinking that a new printer is in order. I am not exactly sure about tool changer setups so I would like to ask some rather basic questions if I may:
- How are different tools (the selecting/mounting and storing) dealt with in software? Is it a matter of selecting a different extruder as if I was running a multi nozzle printhead and then just putting the steps for picking up and storing the tools into the appropriate macros?
- How does software deal with fundamentally different tools - or does it? Let's say I have a standard hot end and then I have a small drilling/milling tool. Do I run one piece of software for the additive process and then another piece for subtractive/milling?
I suspect if I want to combine the gcode files it's all manual work? - .... and the really BIG question in my mind - how repeatable is the Z height between tool changes. Let's say I have dialed in the z offset for both heads and then repeatedly switch back and forth between tool heads. If I would measure the difference between the configured Z offset and the actual offset, what would I see in real life. How repeatable is the Z position ?
- what is your opinion on tool changers - have they gone past the tinkering and babying phases and can they be considered for production technology? Once dialed in, can I just load a model and print or will it be a situation of watching what it does and then tweaking things to work ?
Bonus question - if you wanted a tool changer with a 500x500 build plate, what commercial duet based unit (or complete kit) under $5k would you purchase or would you be forced to design your own?
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i dont have one but ive think about maybe at some point building one , i would definitively go with a duet 3 .
what surprised me is that nobody has made a tool changer using a system similar of a cnc machine , were the head move up and go down and clamp on one head using a cone
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@jens55 Also, check out the Jubilee project. IIRC, E3D fell fowl of a patent when they came up with their tool changer so had to alter their concept. My memory is hazy on this but I think it is to do with using pogo pins or such like so that tools can be completely disconnected electrically. So E3D had to run wires to every tool. The Jubilee project does not have that constraint but it means machines can only be made for personal use and cannot be sold (because of the patent).
I think that's the reason why you won't find an "off the shelf" solution (but I could be wrong).
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Something else to think about. If you want to print different materials, you'll likely want to use a heated chamber. Which means, you'd likely need to use liquid cooling or pipe in chilled air from outside the chamber. That's relatively easy to do with a single tool but becomes much more complex with multiple tools.
And then, if one or more of those tools is a subtractive cutter, you need to think about how to remove the resultant swarf and dust if you want to print onto that surface. Oh and generating the gcode for such a part would be a whole lot more "fun".
That's Just a few more of the random thoughts that have been going through my head recently. -
I'm no expert, these are just my thoughts...
1 - This depends on your "tool changer" of choice. If we are focused on E3D/Jubilee style it's handled by simply moving an empty carriage to the alignment of the tool then locking it into place. The G-Code for this can be set in the tpost<#>, tfree<#> system files.
2 - This is a broad question. First, you need a program that can handle both additive and subtractive processes. Most slicers only handle one or the other... Possibly Fusion360?
3 - E3D/Jubilee is typically made of metal and standard ball connectors that fit in a special (forget the name) socket. Very repeatable for more than I know how to count. Of course, misalignment of the print head or some sort of bump offsetting your machine can cause a crash and change everything... This is the nature of the beast...
4 - Tool changer is and has been production-ready. The only thing holding anyone back is tuning and hitting print. There is little magic, but you do need a slicer to handle the multiple "processes". Cura and S3D are two popular ones. I'm sure Fusion360 probably can handle things too.I don't believe there is a 500x500 Duet-based commercial system, definitely, nothing with ToolChanger already included.
I started my journey with a TronXY X5SA-400 (400x400x400). They have a 500 version and the $400 currently costs about $300 (Walmart), but I purchased mine several years ago at about $500. I've since upgraded to Railcore-II motion system, along with my own sourced Duet 2 Wifi / Duex5, now integrating E3D Toolchanger. I've spent less than $5K on mine.
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As there is only information about CoreXY printers in this topic I will leave a link to my D-PATCH which is a Delta Printer with Automatic Tool Changing. https://forum.duet3d.com/topic/16082/d-patch?_=1615034280593
About your Questions:
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As already stated the commands for picking up and droping the tool are all in the macros. The slicer is just calling T0, T1, ..., Tn.
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As for now I only tested with different additive heads but plan on adding a subtractive tool head. There is a add-on for Fusion360 which allows the combination of additive and subtractive but there is a long way to go.
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As I am mating cone to cone I have almost no issues with repeatability once the offset is dialed in.
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Toolchangers are not jet at a stage of normal 3D-Printers because of a little bit more complexity but nothing that can not be handled.
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I guess depends on the number of tools you want, because a printer with a second head can be called a tool changer as well
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Thank you for all replies!
I am still having doubts about the repeatability of Z in the E3D tool changer system. Can anyone post actual figures on the amount that Z is off for a few tool changes ?
