creating-a-dual-x-carriage-bukobot
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creating-a-dual-x-carriage-bukobot [2013/07/17 09:17] buildrob Added dual x-carriage design. |
creating-a-dual-x-carriage-bukobot [2013/07/30 21:05] (current) buildrob |
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| * 1 Synchromesh cable with crimped eyelet at one end. 1.25m | * 1 Synchromesh cable with crimped eyelet at one end. 1.25m | ||
| * 1 Syncromesh pulley | * 1 Syncromesh pulley | ||
| - | [The above stuff you can buy from Deezamaker.] | + | * [You can buy these from Deezmaker] |
| == Vitamins and Hardware: == | == Vitamins and Hardware: == | ||
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| * 2 Extruder cap arm (see Thingiverse) | * 2 Extruder cap arm (see Thingiverse) | ||
| * 2 Extruder cap arm bottom (see Thingiverse) | * 2 Extruder cap arm bottom (see Thingiverse) | ||
| + | |||
| + | === Other Stuff (Endstops) === | ||
| + | * 2 (or 3) Hall-effect precision endstops + trigger magnets | ||
| + | |||
| + | This dual-x carriage design requires that the distance between the two endstops is properly calibrated to ensure that the printing from the two extruders is aligned. I found that that the variability in triggering of the mechanical microswitches led to inconsistent alignment of the two materials (the X and Y endstops in a normal printer don't need to be very precise). I solved this by replacing the microswitch endstops with Hall-effect endstops ([[http://reprap.org/wiki/Hall-%CE%98]]). Search ebay for "Hall Endstops" - they are around $10 each. I used bigger trigger magnets than the ones supplied simply for easy of positioning. | ||
| + | | ||
| + | I also replaced the Z-axis endstop which is completely unrelated to dual x-carriage support but gives a nice improvement in first layer height consistency. [ I'm sure I could design a better Z-axis endstop holder but some [[https://en.wikipedia.org/wiki/Polycaprolactone|Polymorph/Plastimake/Polycaprolactone]](great stuff) and a cable tie is working fine for the moment. ] The endstop already includes a trimpot for fine adjustment of the trigger point. | ||
| + | |||
| + | Pictures of new endstops at bottom. | ||
| === Instructions: === | === Instructions: === | ||
| - Print all parts | - Print all parts | ||
| - | - Build stepper controller board. This can be done on a single piece of Veroboard. All parts should be readily available at your local electronics store. The circuit is constructed by using 2 x 8 pin header strips to seat the stepper driver. Then the stepper ENABLE, STEP, DIR pins are connected to a spare set of digital expansion header pins on the controller. The ENABLE pin should also have a 10K pullup resistor connected to VDD. SLEEP is connected to RESET. VDD, MS1, MS2, MS3 should all be connected to +5 volts (assuming you want the maximum level of microstepping). 1A/1B/2A/2B are connected to the motor header or terminals. VMOT is connected to +12V and the two GND pins are connected to Ground. Insulate the bottom of the board to avoid shorts [See stepper pinout here:http://www.panucatt.com/product_p/sd82b.htm ] See photos of board at the bottom of the page. | + | - Build stepper controller board. This can be done on a single piece of Veroboard. All parts should be readily available at your local electronics store. The circuit is constructed by using 2 x 8 pin header strips to seat the stepper driver. Then the stepper ENABLE, STEP, DIR pins are connected to a spare set of digital expansion header pins on the controller. The ENABLE pin should also have a 10K pullup resistor connected to VDD. SLEEP is connected to RESET. VDD, MS1, MS2, MS3 should all be connected to +5 volts (assuming you want the maximum level of microstepping). 1A/1B/2A/2B are connected to the motor header or terminals. VMOT is connected to +12V and the two GND pins are connected to Ground. Insulate the bottom of the board to avoid shorts [See stepper pinout here:http://www.panucatt.com/product_p/sd82b.htm ] If you can't get the SD82A/B, then get an SD8825 use it for your Y-axis stepper and then use your existing SD82A for the 2nd X-axis controller so that they are still a matched pair. Remember that the SD8825 uses different microstepping so you will need to change the jumpers for 16x microstepping or changes the steps per mm for 32x. Don't forget to check the stepper reference voltage trimpot has been calibrated (Vref should be 0.4V on SD82A). See photos of board at the bottom of the page. |
| - Remove synchromesh cable from the old x-carriage. | - Remove synchromesh cable from the old x-carriage. | ||
| - Disconnect wiring from the terminal block of each extruder. Undo extruder wiring, X-axis motor and endstop wiring so that the X-ends can be removed. | - Disconnect wiring from the terminal block of each extruder. Undo extruder wiring, X-axis motor and endstop wiring so that the X-ends can be removed. | ||
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| - The eyelet end of each synchromesh cable is attached to the cable riser blocks which is inserted into the extruder plate slit on the center-side (i.e., away from the frame). This is secured using a M2.5 16mm screw and washer + nut on the underside. | - The eyelet end of each synchromesh cable is attached to the cable riser blocks which is inserted into the extruder plate slit on the center-side (i.e., away from the frame). This is secured using a M2.5 16mm screw and washer + nut on the underside. | ||
| - The X-tensioner is attached to the slit on the outer-side of each extruder plate. Note that the orientation of the X-tensioner on the right extruder side is reversed to the left so that the off-center M3 10mm screw which locks tensioner is towards the front of the extruder plate. The center screw is a 16mm M2.5 or M3 screw. As this makes the X-tensioner fairly close to the edge of the extruder plate you may wish to use a washer on the underside of the plate to better spread the load. | - The X-tensioner is attached to the slit on the outer-side of each extruder plate. Note that the orientation of the X-tensioner on the right extruder side is reversed to the left so that the off-center M3 10mm screw which locks tensioner is towards the front of the extruder plate. The center screw is a 16mm M2.5 or M3 screw. As this makes the X-tensioner fairly close to the edge of the extruder plate you may wish to use a washer on the underside of the plate to better spread the load. | ||
| - | - Rewire extruders. | + | - Rewire extruders. [You can insert an extra length of wire into the middle of the two stepper motor cables to give the required length.] |
| - Tension synchromesh cables. | - Tension synchromesh cables. | ||
| - Reconnect all cables to the controller board & additional stepper driver board. | - Reconnect all cables to the controller board & additional stepper driver board. | ||
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| === Calibration of endstop distance. === | === Calibration of endstop distance. === | ||
| Unlike the normal Duo where you need to calibrate the fixed distance between the extruders, with the dual x-carriage design you instead need to calibrate the distance between the two endstops (as measured between the extruder nozzles). | Unlike the normal Duo where you need to calibrate the fixed distance between the extruders, with the dual x-carriage design you instead need to calibrate the distance between the two endstops (as measured between the extruder nozzles). | ||
| - | This distance is set as X2_MAX_POS initially but can be overridden with "M218 T1 X???" without reflashing the firmware (M218 then requires that the x-axis is rehomed to update the extruder position). | + | This distance is set as X2_MAX_POS initially but can be overridden with "M218 T1 X???" without reflashing the firmware (//M218 then requires that the x-axis is rehomed to update the extruder position//). |
| The calibration can be done in stages: | The calibration can be done in stages: | ||
| - A rough estimate is obtained by simply measuring the distance between the nozzles when they are both parked. | - A rough estimate is obtained by simply measuring the distance between the nozzles when they are both parked. | ||
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| === Slicer Configuration === | === Slicer Configuration === | ||
| Set the offset between the extruders to 0. | Set the offset between the extruders to 0. | ||
| - | If you are using the nozzle caps then you can also remove the extra extrusion after a tool change (in Printer Settings under Extruder). | + | If you are using the nozzle caps then you can also reduce the retraction on tool changes as well as remove the extra extrusion after a tool change (in Printer Settings under Extruder). |
| That's it. | That's it. | ||
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| {{:bukodualx-11.jpg?400}} {{:bukodualx-06.jpg?400}} | {{:bukodualx-11.jpg?400}} {{:bukodualx-06.jpg?400}} | ||
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| + | These are the new hall-effect endstops (on the x-axis they fit into the existing holders). The magnets were attached with a hot-glue gun. | ||
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| + | {{:bukodualx_endstop1.jpg?400}} {{:bukodualx_endstop2.jpg?400}} | ||
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creating-a-dual-x-carriage-bukobot.1374070662.txt.gz · Last modified: 2013/07/17 09:17 by buildrob
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