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Improved End Stop Switch Brackets
When I first built the i3v, the thing that annoyed me the most was the end stop switch brackets. The geometry of the Y stop seemed strange to me, with the bolt hitting the hinge side of the switch. I couldn't get the X end stop far enough to the right to use all of the bed and I never could get the Z switch to trigger, no matter how much I trimmed the wooden mount.
So, I designed a set of stop switch mounting brackets that solve these problems. The Y switch is reoriented so the ball end of the switch hits the screw. The X stop is turned vertically with a notch in the bracket to fit around the wheel bolt and the bracket has a place to zip-tie the wires. The Z switch is relocated around the side of the extrusion so it lines up with the X idler.
Downloadable files are here: http://www.thingiverse.com/thing:321810
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Micrometer Adjustable Z End Stop
This is a variant of my adjustable Z end stop that uses an inexpensive micrometer barrel instead of an adjustment screw. Micrometer barrels are available on eBay for less than $20 (USD).
The parts can be downloaded here: http://www.thingiverse.com/thing:356819
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Extruder Motor Fan Shroud
Like many other people, I had a lot of trouble with the extruder motor overheating. Mine got hot enough to soften the extruder block and the motor screws pulled through. There are many ways to solve this problem, but I built a fan shroud to mount a 40mm fan to keep the motor cool.
The shroud is designed to keep stray air from blowing on the bed, which I found caused problems with print adhesion. With this shroud, the motor peaks at around 45C, even with the current set as recommended by the MakerFarm instructions.
The parts can be downloaded here: http://www.thingiverse.com/thing:343026
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Sorbothane Vibration Isolator Feet
A lot of the noise generated while printing is actually being transmitted into the surface the printer is sitting on and from there into the room, the floor and the structure of the house. I have my printer in an upstairs room in my house, and I could even hear it downstairs, transmitted through the floor.
After doing a bunch of research, I happened on a vibration damping material called Sorbothane. We use it at work to damp vibrations in laser systems. It's readily available from Amazon and other sources in a variety of shapes.
I designed some round feet that clip to the bottom of the printer frame, allowing me to mount 3/4" hemispherical Sorbothane feet to the printer. Using six of these feet with the Durometer 70 Sorbothane, the sound is reduced substantially, and it no longer transmits through the walls and floor of my house.
You can download the parts here: http://www.thingiverse.com/thing:322915
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Improved Hexagon Cooling Fan System
I'm using the Hexagon all-metal hot end, and it requires a cooling fan blowing on the fins to maintain the temperature gradient. The fan shroud that comes with the hot end touches the hot end block, which melts it. It also directs the air back into an enclosed space, where it then blows down on the bed, interfering with adhesion.
I designed a replacement deck and a fan shroud that uses a 25mm fan to pull air across the hot end fins and vent it out the top, behind the extruder. This keeps all of the airflow away from the bed and also makes it easy to see what
s going on because the hot end isn't buried behind a fan.
The shroud is very close to the heat block because there isn't much space. I have found that wrapping the plastic in Kapton tape keeps it from melting. I went a step further and made a thin insulator pad out of fiberglass tape and Kapton because I am experimenting with higher temperature materials.
The parts and instructions are here: http://www.thingiverse.com/thing:335613
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Z Probe Servo Mount for Auto Bed Leveling
I added auto bed leveling to my printer so I don't have to mess around with the Z stop and bed leveling springs. I wasn't really happy with the aesthetics of any of the servo mounts I could find, so I designed my own.
This servo mount and switch arm tuck the switch up inside the X carriage when it's not in use, keeping it out of sight and out of the way. The arm is intended to mount a switch with a bare button (no lever arm) and has the switch element aligned vertically with the servo pivot to minimize the effect of servo position errors.
The mount is sized for a Hextronik HXT900 servo, which is available worldwide for less than $3 (USD).
https://www.youtube.com/watch?v=yazApS1ISxo
The parts can be downloaded here: http://www.thingiverse.com/thing:335632
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Install the Printer on a Travertine Tile
I have my printer sitting on a Travertine tile. The tile provides a flat surface so the printer is always square and doesn't twist when placed on different or flexible surfaces. The tile also adds mass to the surface, reducing the amount of sound and vibration transmitted to the surface. This works especially well with the Sorbothane isolator feet because it provides a vibration sink that improves the isolation.
You can get an 18" square tile at Lowes or Home Depot in the US, usually for less than $10. I put felt pads under the corners of the tile so it conforms to the table it's sitting on.
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Extra washers to solve clearance problems
I initially had problems with the M5 screws that mount the wheels contacting the extruder gear and the underside of the heat bed. For the heat bed, I added an extra M5 washer to each of the four wheels. For the wheels with spacers, the washer goes between the spacer and the bed. For the wheels with eccentrics, the washer goes between the eccentric and the wheel, since it has to cam into the bed. The extra washer reduces the amount of screw that sticks out of the nut. I also placed one extra M3 washer under the spacer in the back-right corner. The springs on the other corners take up the slack, or you can use an extra washer on each corner if you're using auto-leveling.
The top screws on the X carriage also were hitting the extruder gear. An extra M5 washer on each wheel solved this problem, as well.
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Insulate the heat bed from the Y platform
Many people find it useful to add insulation between the Y carriage platform and the heat bed. This allows the bed to heat up a little faster and retain heat better. It also reduces the thermal gradient in the wooden bed and reduces the warping. Without the insulation, the bed starts to warp as the top surface heats up, tightening the wheels on the extrusions. Then, as the heat soaks through the bed, it relaxes, loosening the fit of the wheels against the extrusions. With insulation, the heat flow rate is lower, and the gradient (hence the warping) is reduced.
I looked around for thin ceramic wool fabric, but ended up just cutting a piece of corrugated cardboard, and it's been working fine. The sheet has small holes in it to clear the various screw heads.
You may wish to keep an eye on it or use a more heat-resistant material, depending on how hot you run your bed.
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Adhesive Velcro strips to reduce belt slap
When printing, my X belt would often vibrate like a guitar string, slapping the extrusion and making an annoying noise. Changing the belt tension didn't really solve the problem. It just changed the resonant frequency so it slapped at a different speed.
I solved the problem by sticking four small pieces of soft adhesive Velcro to the inside of the extrusions. It barely touches the belt in operation, so it doesn't really add any drag, but it completely absorbs any vibration, preventing the belt slapping noise.
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