Malte flipped his Y-axis dragchain to be the "conventional" orientation, and I copied that on my build.
Recently I've figured out how to flip the X-axis dragchain as well, although it's a bit of a tight fit.
First you have to take the uppermost pair of v-wheels on both the front and back gantry plate (total of four wheels) and replace the screws with low-head screws, and also flip their orientation around so the nut is outward. I used these, which fit perfectly and are super-cheap ($15 for a bag of 100).
This will create just barely enough room for a 10x15 dragchain underneath the z-motor. I used this one. It's a bit of a tight fit, and the heads of the screws do make a very soft "clacking" noise as they brush by the dragchain, but there's no real friction. If anybody knows where to get a dragchain that is just 1-2mm narrower, please let me know.
The 10x15 dragchain can fit a pneumatic hose, USB cable, and two shielded-Cat5 cables easily. I put the A+Z motors (four wires each) on a single Cat5 cable and it works fine since those are low-current motors, but I would never attempt something like that with the high-power X+Y motors. The other Cat5 carries all the data wires (limit switches, ADC, etc). But it certainly isn't as "roomy" as the dragchains that come with the liteplacer. I recommend moving the X-limit switches off of the backplate and onto the horizontal beam so those wires don't have to pass through the X-axis dragchain. I'm using nonmechanical inductive proximity sensors, you can see the one for x-max in the photo; I'm going to move them to the back side of the horizontal beam for a cleaner appearance once I'm done fiddling with them. Their wires still go through the Y-axis dragchain, but that's still a big fat one.
The final revision of my headplate PCB (which I will post GERBERS for when it is ready for the public) has only two wires in the dragchain: one for the motor wires and a USB-3 cable serving only USB-2 devices so the four additional superspeed conductors can be recycled for other purposes. My limit switches are daisy-chained and I'm putting a second (USB-native) AVR on the headplate so the ADC readings and solenoid commands are sent as USB packets. The limit switch is still a dedicated wire and I don't plan on changing that, it's important enough to deserve its own wire using simple electrical signals rather than something as complex as USB. Hopefully the extra four conductors will be used only for one limit-hit conductor and solenoid power supply (+12v/+24v) leaving two of them free for future use, although I still have some work to do there.
Photos below show both dragchains, I've been running this way for a while to make sure the new dragchain doesn't cause mechanical problems. Now that I'm satisfied with that I'll move the wires and take out the old dragchain.
- DSCF1203 copy.JPG (88.84 KiB) Viewed 5200 times
- DSCF1204 copy.JPG (69.65 KiB) Viewed 5200 times
- DSCF1204.JPG (3.04 MiB) Viewed 5200 times
- DSCF1203.JPG (3.03 MiB) Viewed 5200 times
