Tool Changer: Dual DW660

Switching pens is cool as a proof of concept, but for real work we need to change cutting bits.

I am also wanting to someday be able to make wood inlays that are arbitrarily complex. Just because. In this video you can see I still have a ways to go on that front. The quality of the part is poor because I don’t yet have a good method to carve out complex detail.

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I wouldn’t say Jamie is an evil genius…

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Have you tried the carving tool is estlcam? With a flat bit as the pocket tool and cutout tool, it would work well.

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Well, that was freaking cool. Made my day and I still have my first cup of coffee in hand. Thank you!

I will need to explore the carve feature some more. I’m using Estlcam carve for the perimeter, but I had manually separated the pocket for the endmill because I didn’t realize it had support for that. It was complaining about stepover for the v-bit which sent me looking for a workaround. I am going to have to look at what it can do for the narrow gaps that are not reachable with the endmill.

Also I think I might prefer the term ‘Supervillian’ or you can just call me Mister Foil Head… :slight_smile:

Ok. wow. That is… I like it. I like it a lot.

What are you doing talking all nonchalantly about the inlay question! I’m still trying to comprehend that tool change!

Ohmygod. Just wow. And…how? What are we not seeing? Have you set up router control as well or are you secretly wrestling a snake nest of plugs and extension cords behind the scenes? (I’m pretty sure I know that’s not the case).

Incredible.Would love to know more.

At the moment I am wrestling cords and manually switching the routers on and off. But I have a plan for automatic turning on and off, and I’ve tested it once or twice. It’s just not yet ready for everyday use.

I mentioned in the other thread my desire to get six-pin electrical connection working. I have almost finished a group of six “pogo pins” (not actually pogo pins but the same concept of spring-loaded pins) on the tool mount, and I ordered some simple PCBs to connect on the tool side. These custom PCBs are so cheap it’s staggering.

I actually had it working but it was using a 3-D printed spring which I found was quickly losing its springiness, leading to intermittent connections. This part needs a redesign, so until then I am without automatic on/off of the router and also without probing.

The way it works is this: the extruder “E0” pins for Step, Dir, and Enable are wired to the tool mount. Then the +5 and Enable pins are connected to a solid state relay. This is the small tan wire that snakes along each power cord. Enable is active low, so when Marlin tries to turn the extruder stepper on or off, there is voltage or no voltage between +5 and Enable. If you look closely in the first video, you can see that the power switch also has a solid state relay. These are wired in parallel, so the tool can turn on from the physical switch or the solid state relay. To turn on the enable pin, I used “G92 E0” and “G1 E1” to force an extruder movement to enable what would be the extruder stepper driver. Then to turn off the tool is “M84 E”. As I said, I had this working but right now I am needing to repair the pogo pins.

As for wrestling cords, the power cords do not have much room and during tool change I feel like I need to hold them to make sure they don’t get caught or pinched. This puts a damper on the “automatic” tool change and I don’t yet have a good solution in mind. I might move the parking fixtures so they are not so cramped, but this eats up working space. I am also considering drag chains to keep the cords within limited areas.

 

This project is so amazing, I’m sure you’ll end up with a great solution. But reading it I though about a simple solution :

What if the tool mount acts as a switch ? When the router is parked, it cuts power supply. As soon as the MPCNC holds it and goes up, the swith goes ON and the router starts. No need for extra gcode or relay, just mechanical switches.

This would be possible, the main concern I would have is sending high current through the contacts. It would definitely simplify the routing of the wires, which is one of the factors that limits scaling to an infinite number of tools.

I might revisit this after I get the six low-voltage, low-current signals working. Safety is another consideration that might make it difficult.

Put a wall switch by the router with a rubber flap on the router mount. When the router goes up, the flap flips the switch to on, when the router goes back into the mount, the flap flips the switch to off.

I’d leave the routers power alone.

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Use a low voltage switch to control a larger relay (or IOT power strip) for the router.

There is a critical choice in how the switching/wiring happens, which to me falls into these cases:

  1. Power goes through the tool mount so it also acts as a switch
  2. Power does not go through the tool mount and the switching occurs another way
    a. Separate control line from the board and a relay for each tool
    b. Single control line multiplexed through the tool mount to control a relay for each tool
    c. No control lines and a physical switch for each tool, switched ‘automatically’ or via programmed motion

Option 1 seems risky to me, due to high current through contacts.
Option 2a doesn’t scale nicely to a large number of tools because you use up digital pins and you have to keep it straight to make sure the right pin is enabled for the right tool.
Option 2b was my plan and 2c seems okay. I’m not sure if there is a safety or reliability difference. I’ve had a solid state relay hooked up the whole time and finally a couple weeks ago I got around to enabling M3/M5 to actually use it.