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Re: single z drive screw? - 14 years ago

Just a bit off topic, but: nophead Wrote: ------------------------------------------------------- > Not sure why we would want to move to > acme/trapezoid threaded rod or ballscrew/ballnut. > I attached a digital scale to my Prusa and found > the z-axis to be very linear and accurate using > cheap stainless steel studding and brass nuts. It just hit me that i'm using stainless nu

Re: 1.8 deg/step vs 0.9 deg/step - noticable difference? - 14 years ago

Nothing noticeable, but technically the .9 are better because of the nuances of micro-stepping. A very quick google:

Re: single z drive screw? - 14 years ago

That's a nice design! I assume you moved the drive screw in order to reduce size and maximize build space per volume, though I would think it's probably stiffer when all the bars are in the same plane. And i think the undriven side would benefit from a pair of lm8uu instead of the 624 (or whatever) in order to fully constrain that end. I like the idea of beefing up one of the rods.

Re: single z drive screw? - 14 years ago

Well there was a lot of talk 6 months to a year ago about ball screws and acme screws. ball screws are overkill for the z, but I've seen trapezoidal for about $12/ft which isn't too bad if you only need 1 foot of it. And there's a OpenScad module for printing lead screw nuts on thingiverse, so it might be a cheap future upgrade. I was also thinking it would be smoother, especially with all the we

Re: single z drive screw? - 14 years ago

I ordered some lm8uu's a week ago, and I'll try when they come in and I've printed appropriate parts. I have a Sells mendel, and for me the 2 lead screws easily get out of sync and i have to re-align every time i want to print. it's very tedious. As i understand it the prusa design is less susceptible to this issue. Even if it did sag a couple tenths of a mm, as long as it was consistent (espe

Re: single z drive screw? - 14 years ago

If it's properly constrained, it "can't" turn about the y axis, so it shouldn't be able to sag. The standard Sells design defiantly will not work with just one, but I think a VertX with lm8uu bearings might work ok.

single z drive screw? - 14 years ago

With a properly constrained z axis, is the second z drive screw and motor(for prusa) or belt(for sells) necessary? The community momentum is going towards lm8uu linear bearings, which, with a properly designed z carriage, should be very well constrained. Of course, the screw won't be at the center of gravity, so I can imagine some minor torquing about the y axis, but I don't know if it will be e

Re: T2.5 pulleys and belt - 14 years ago

The mendelmax webpage has some good info on choosing belts and pulleys. They're suggesting GT2 belts. edit: oops forgot the link

Re: T2.5 pulleys and belt - 14 years ago

And while we're asking for suggestions, how about pulleys for belt driven Z like the standard Mendel? Though i don't suppose you need the finer belt for the z axis, but better quality pulleys would help me.

Re: Cheap digital vernier calipers/micrometer, any good? - 14 years ago

I have one as well, from Harbor freight. was finicky when i first received it, but once i gave it the standard harbor freight once-over (disassembling, cleaning, reassembling) it works fine. uses a capacitive strip hidden under the ruler label, so maybe it was some grease or metal filings that were throwing off the readings.

Re: Vertical X-axis standard - 14 years ago

Re: 2.54mm connector pin crimper review - 14 years ago

do you think it would be possible to print a crimper?

Re: Does RepRap Assemble Itself? - 14 years ago

well you can make the argument that it doesn't replicate ad infinitum. Even if we were at the point where it printed it's own motors, does it make the alloys or plastics from constituent molecules? no? Then it's not self replicating. It's really a moot argument, and dwelling on a single word in the mission statement is a waste of time. Semantics have no place in engineering.

Re: Any Interest in an H-bot type Reprap? - 14 years ago

I think Forrest Higgs Sampo is similar, albeit Darwin based.

Re: crazy idea: shake weight camera stabilizer? - 14 years ago

This is the shakeweight. also, this:

Re: Mendel-parts Gen 6 'Marlin' firmware feedback - 14 years ago

hmm, i haven't gotten comm errors before, and am using the small gcode option in skeinforge, which should help a bit. Perhaps it's not a pause as much as a ponderously slow move.

Re: Does RepRap Assemble Itself? - 14 years ago

your absolutely right. anyway, back to important topics

Re: Vertical X-axis standard - 14 years ago

Lanthan Wrote: ------------------------------------------------------- > @brianandaimee: yes, indeed, if we are redesigning > the X ends we should also take into account the Z > rod to smooth bar distances given in those > pieces. > > May I suggest the following: > We should also take into account the possibility > of parametrically setting different (higher) > smooth

Sketchup Plugin roundup - 14 years ago

I've found a page where someone rounded up a bunch of great sketchup plugins. Check it out:

Re: Mendel-parts Gen 6 'Marlin' firmware feedback - 14 years ago

What are you looking for on your prints with different k values in order to tune it? I'm noticing some odd pauses at times. It seems to be only on infill moves at inconsistent times. it hasn't effected the print quality yet, so i'm not really concerned, but i thought i'd mention it. I think the default accel values are too high for me, and gives a lot of jerkiness. sprinter was smoother, and ma

Re: Thoughts on Z axis endstop, power control and tip cleaning. - 14 years ago

another benefit of mounting the z endstop above the hot end is that it would make bed mapping very easy: i.e. you wouldn't need another sensor and pins to do so. There's even a bed mapper application. it'd be really nice to get some feedback from the machine about how much i need to move each corner of the bed. full-bed prints are always a little scary for that first layer.

Re: Thoughts on Z axis endstop, power control and tip cleaning. - 14 years ago

with the mendelparts new v9 hot end and extruder (or the Carriage extruder), you could mount the hot end so that it was spring loaded, so that if the z collides, it pushes the hot end up. if you also mounted a flag on the top of the hot end, and an opto or switch above it, you can tune it so that when the z collides, it pushes the flag into the switch. the major problem is that Z0 will then be

Re: Digital micrometer for positioning - 14 years ago

the z axis doesn't move very fast so 3/second wouldn't be too bad. Here are some resources for the output signal: (at the bottom of the page)

Re: Mendel-parts Gen 6 'Marlin' firmware feedback - 14 years ago

Any instructions on the Advance settings? i uncommneted the one line to turn it on, and assume the obvious values for e steps per mm and filament diameter should match those of your machine. Not sure why the e_steps_per_mm aren't just pulled from the variable above. I also don't like that the filament D is hard coded in the firmware, instead of pulled from skeinforge, but i guess that'd requir

Re: Mendel-parts V9 extruder and hot end - 14 years ago

i suppose the lower PEEK piece is just a spacer, and the upper PEEK piece is larger for mounting purposes? and what's the clear plastic piece on the top? just a temp cover, or an integral part?

Re: SF Lash module - 14 years ago

The tension on the belt is like the tension on a guitar string. A tighter belt should move the natural resonance to highter frequencies. But can't we also move the resonance frequency up by forcing the belt into a harmonic mode? I'm thinking a ball bearing held at the right point on the belt should damp out most of the lower resonant modes.

Sculptures of Great Renown - 14 years ago

We really need a compilation of free 3d models of great sculptures. Here's my short list, if anybody has the equipment and access: The Thinker The Venus de Milo Michaelangleo's David (though not a very friendly liscense) it's probably easiest to get around restrictive liscenses by using pictures and trying to recreate the models with something like photosynth or another such program. if you

Re: Recycling plastics - 14 years ago

Most of the recycler designs are for horizontal extruders, like the plastic industry uses. How about a vertical, gravity fed design like for fiber optics? We can use plastic ooze to our advantage here. PLA oozes even with a tiny orifice, so it should ooze just fine with a larger orifice. Put plastic in a hopper, like a metal funnel with resistors, similar to heated beds. Hang the hopper from a n

Re: Mendel-parts Gen 6 'Marlin' firmware feedback - 14 years ago

I've had issues at high speeds with the hobbed bolt not having good grip. I think its just from my substandard hobbing job, though. the filament might not be melting fast enough either. I don't know whether you've printed at such high speeds before, but in my experience, doing so starts to expose printer flaws.

Re: Android Open Accessory Development Kit - 14 years ago

Prices seem to be getting more reasonable: is there any progress out in the community with this?