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Where are you selling from? How much postage to an Australian address for the minimum stepper order?
by
Greg Frost
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Australia - for sale
You might want to consider some 3 rail kits for peeps who want to build deltas.
by
Greg Frost
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General
With a request that vague I would suggest lobbing at your local hackerspace. They will be able to work out what you are actually asking.
by
Greg Frost
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General
You can specify the number of facets on the "circle" that makes the hole too (using the $fn=5 argument for example). If you have too many facets, the extruder may move slowly around the circle and ooze more plastic than intended making the hole smaller than intended. If you specify fewer facets, the hole will be smaller because the hole's vertices will be at the specified radius and the edges wil
by
Greg Frost
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General
Peek or all metal. People haven't been using ptfe for a structural component for a long time now because of the type of problems you are experiencing.
by
Greg Frost
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General Mendel Topics
Some parts need to be sting and should be printed almost solid. Z couplers, pulleys (if using printed ones) and extruder idler and small gear. Other parts can be printed as recommended above.
by
Greg Frost
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General
I assume you have a prusa? If so, have you checked that your z motors are screwed down firmly? Any slight movement in the motor position will badly affect your layer consistency.
by
Greg Frost
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General
Looks more like pulley slip. Do you have flats on your stepper shafts with set screws? If not, you clearly need them. With skipped steps there is generally more discrete stamps than a smooth slant.
by
Greg Frost
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General Mendel Topics
Very nice. You must be a skilled builder. Well done!
by
Greg Frost
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Mendel90
If you want to skip the autocad step you can generate gears directly in openscad using my parametric script.
by
Greg Frost
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General
Here is an animation I made from the model. The distance of the hinge from the smooth rods makes a difference to the achievable build area for a given strut length. The further from the rods the better, because you can use shorter struts which means you get greater build height, but this will put torsional loads on the bearings which may not be good. In the example, I had made that distance param
by
Greg Frost
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Delta Machines
I thought the twisting was because when moving the carriage in x, you need both motors pulling. One pulls one end of the x axis in + y and the other pulls the
end of the x axis in -y. Any play in the linear guides that mount the x axis will result in the axis moving slightly out of perpendicular.
I was trying to visualize a belt path that went the other way around the machine so that both ends
by
Greg Frost
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Developers
Those cable/hose guides look like they would add to the axis weight and limit the speed.
Water cooling is a good idea to make the heated chamber practical without causing a raft of other issues.
by
Greg Frost
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General
I think he is asking the tolerance on the length. +/- 2mm should be easy for them to achieve (I.e. not add any extra cost) and amply accurate for a reprap.
by
Greg Frost
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General
I did the work to the scad model to make rod lengths and frame size parametric and set the full model up so that it could be animated with the head moving in a circle. I think johann pulled the changes. I found that playing with the numbers using that gave a good feel for how to balance platform size, rod length and build height
by
Greg Frost
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Delta Machines
Your z rods are not perpendicular to your build platform. Adjust your frame.
by
Greg Frost
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Reprappers
Could the skewing affect that you have mentioned be fixed by running a second wire around the bot that travels in the opposite direction? Just attach the opposite wire that runs along the x axis to the carriage and wind it on the motors the opposite way.
by
Greg Frost
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Developers
The extrusion pressures needed for the pen would be well under what a reprap needs to print at speed. There would also be far less demand for well controlled extrusion rate. These two things probably make the job of designing the extruder easier.
by
Greg Frost
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General
I use a silicone washer instead of a spring. You can get good tension, but still with a bit of give to allow for filament tolerance. I have never found a good inexpensive source of springs with the appropriate properties, and you need longer bolts with springs.
by
Greg Frost
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General
If you turned he current down too much on your pololus, the motors may not be generating enough torque. Depending on your motors, it can be a fine balancing act to get enough torque without the motors or pololus getting too hot. If you have low resistance motors, you may need heats sinks on your pololus. Some people recommend setting the pololus by measuring the Vref signal. That should result i
by
Greg Frost
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General
You will get non-linear motion with your x belt setup. Also, the tension on your belt will vary with the position of your x carriage. The belt should be horizontal from the mounting point on the carriage to the idler and to the motor pulley to avoid these problems.
by
Greg Frost
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Look what I made!
Having the belts under tension in one direction like on a Rostock also means that any backlash due to belt/pulley mating imperfetions is minimised.
by
Greg Frost
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Delta Machines
I started out as a fan of thermocouples, because they are pretty much indestructible so you can bolt them directly to the hotend with a strong mechanical connection, but in the end, I gave up because it is more expense ( because of the additional electronics needed) and the thermistors do work pretty well. I do miss bolting them on though.
by
Greg Frost
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Reprappers
Slic3r produces poorer results for me because it does all the perimeters before any infill which makes for a lot of unnecessary perimeter traversals.
by
Greg Frost
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Reprappers
try something like this (subtracting the hollow part from a solid model):
difference()
{
for(i=[0:2])
rotate([0,120*i,0])
cylinder(r=50,h=70);
for(i=[0:2])
rotate([0,120*i,0])
translate([0,0,-1])
cylinder(r=40,h=72);
}
by
Greg Frost
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3D Design tools
Superglue works well, and I also find I can get some geometries to stick with a thin smear of acetone.
by
Greg Frost
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General
I used the one that came with the original techzone laser cut Mendel and was so frustrated with it that I designed the gregs wade. Not that it was bad because it was laser cut, it was just a design with flaws. The techzone oak insulator hotend was a massive pain in the ass too, so that was probably the main source of frustration. Now I have my own all metal hotend, many of the features I designed
by
Greg Frost
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General
If components can't be used outside their spec, then that would force the use of heat cartridges rather than resistor powered hotends, because we run the resistors at well above their current rating.
by
Greg Frost
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General
Not true! The z smooth rods need to be perpendicular to the plane of the print. You can tweak the frame nuts to get everything square but I don't know of an easy way to confirm it
by
Greg Frost
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General