Lately, PLA filament ordered from a couple of different sources features quite an oval section (let's say, 3.01 x 2.78 mm), and of course this brings back some part of guesswork when dialing in the diameter in the slicer software. Two main options: - calculate an approximation of the equivalent round filament section by using the largest x smallest measured diameters - calculate volume by weighby Lanthan - Developers
I do not know how exactly the Prusa set of mods became so popular, but (after printing it and discovering some of its features the hard way like everybody else) I am concerned about how so much alpha & testing-level DNA went straight to the wiki's first page and was sort of officially endorsed by its popularity merits. Excessive enthusiasm? I do not think we should be excessively concerned aby Lanthan - Developers
So who and what could help improve quality assurance in a volunteer world? RUGS, indeed, but they do have dynamics of their own. I am under the impression that most often, RUGS are mostly one or two experienced users assuming leadership. Today, this model offers few definite advantages when compared to commited individual research plus the global network. Outside the particular case of inner ciby Lanthan - Developers
THX! I see very substantial speed improvements for some pieces (from 7 minutes to about 45 seconds). Circles: still seeing frequent artifacts going into thin air. But one simple piece that generated errors is coming out OK now. Is there a way to reduce temperature for bridges? (other than a small fan)by Lanthan - Slic3r
- Isn't the shaperbot lineage of very direct darwin ancestry? - nophead's mendel90 keeps many of the mendel choices and seems to be compatible with almost all of the hardware one has to purchase to build a mendel, minus threaded rods of course. Shouldn't it be attached to the mendel offspring?by Lanthan - General
Microswitches from eBay, without levers (supposed to be more precise). Cannot find the exact ones I bought, but much like those: You have the choice to connect them in activated-on or activated-off configurations. Activated-off is said to provide better protection against noisy lines. I have found no inconvenients when comparing to opto-endstops.by Lanthan - General
martinprice2004 Wrote: ------------------------------------------------------- > One shouldn't judge other peoples designs so > harshly. We can all see improvements in a design > its called "20/20 hindsight" Yes we all make errors but... it took nearly a year for this stuff to fully surface, and many people keep copying and reproducing parts with the initial flaws. One could attributeby Lanthan - General Mendel Topics
raldrich Wrote: ------------------------------------------------------- > @Lanthan: > > In the context of the original post, your stance > on bridges is an overreaction, although I agree > with you that not all of PrusaJr's changes to the > design were well advised. My point was that: to warn a gentle newcomer that bridging may not be the only (nor main) issue with this designby Lanthan - General Mendel Topics
OK I think I found a quick fix: as predicted, when the cylinders are generated with a large number of facets (in openscad, $fn = 100) the circle-finding routine is less prone to generate artifacts. Same piece as previously, re-exported and re-sliced: there is still a spiral artifact, always accompanied by an unusually large blob of plastic, but much smaller and manageable. Suggestion: Maybe yby Lanthan - Slic3r
martinprice2004 Wrote: > > The basic principle is shown here and should be > familiar to a lot of people. > > A simple bench setup could be made to test this, > perhaps clamping the base and pulling the top of > the machine with a known load in X. This is a very sound proposal. By just firmly pressing vertically with one finger on the end of a rod on the top, I can induceby Lanthan - General Mendel Topics
Note to self: at least when the openscad source file is available, try increasing the number of facets $fn to see if this decreases the error frequency... I do not remember having seen this happen on high $fn cylinders... BTW running standard current Ubuntu.by Lanthan - Slic3r
I can volunteer my skeinforge & slic3r config files... as well as Marlin settings, but it is for a stepper extruder... and RAMPS electronics This evening it printed very nice sim city pieces at 0.3 mm layer height and 70 mm/s speed (first layer and perimeters at half that value). I could not go over 40 mm/s with Sprinter. Marlin works real miracles. So with proper firmware & electronicsby Lanthan - General
slic3r 0.6beta from github, downloaded a couple of days ago. running it with the circles option since I use Marlin, and when it works it is awesome. In at least 3 very simple models, I got circles going nowhere. There might be an issue with the circle detection routine...by Lanthan - Slic3r
raldrich Wrote: ------------------------------------------------------- > martinprice2004 Wrote: > -------------------------------------------------- > ----- > > I think the part is supposed to be printed with > your bridging > > parameters adjusted correctly, so the printer > speeds up across the gap eliminating the sag. > > To adjust the bridging parameters, yoby Lanthan - General Mendel Topics
Yes, I had the same reaction. This part does print with a reasonably well tuned machine, but bridging especially at that scale has been reported to produce weak parts, and is a rather useless kludge. Bridging should be avoided to increase printability for all. Have a look at Adrian Bowyers build notes in the wiki, there are a couple of redesigned parts there, without the bridges as far as I rememby Lanthan - General Mendel Topics
martinprice2004 Wrote: ------------------------------------------------------- > Resonance? Try attaching a large mass somewhere > to change the natural frequency. Or better still a > large mass suspended in rubber attached to the > frame. As an added bonus it apparently works quite > well if your printing during an earthquake. Yeah. Tuning. But first we need to determine what thby Lanthan - General Mendel Topics
Time to kick in with more specialized tools. I choose seewave, an R module R seewave Sueur J., Aubin T., Simonis C. (2008). Seewave: a free modular tool for sound analysis and synthesis. Bioacoustics, 18: 213-226 I prepared a rough simulation of a 45 degrees fill at 25, 50, 100 and 120 mm/s G92 X0.0 Y0.0 Z10.0 G1 F1500.0 G1 X80.0 Y80.0 F1500.0 G1 X120.0 Y120.0 G1 X80.0 Y80.0 G1 X120.0 Yby Lanthan - General Mendel Topics
Indeed. For the majority committed to the Prusa Mendel frame (although coming upgrade options will permit a very hign rate of parts reuse) a couple of meters of threaded rod and three to six printed parts will allow stiffening the base and one of the sides. What I am seeing in the spectra (more coming soon) is that high freqency resonances in the rods themselves aren't that much of a problem asby Lanthan - General Mendel Topics
From my point of view, the cupcake it is not that bad of a machine, once it is fitted with real (salvaged printer) rods and brass bushings, a decent homemade wades extruder, a homegrown heated bed, a RAMPS brain and Marlin firmware . Once built and properly configured, it has proven less fiddly than the Mendel Prusa it printed. The real shortcomings are, from my point of view, the wimpy Y motorby Lanthan - General
Many industrial incinerators now "wash" the smoke by bubbling it through some liquid (usually water) in more or less sophisticated ways. Seems it helps a lot reducing the harmful emissions. Has anyone tried this method with laser cutter fumes?by Lanthan - Laser Cutter Working Group
I have been hunting for formulas and constants,it is not yet clear to me which one I should use. Here's one that seems to work. U = pi / L * sqroot( E / d ) and f = U / 2pi where U = natural frequency in radians per second E = Young's modulus of elasticity L = length d = material density f = frequency in cycles per second Given the values for steel: d = 7.8*10^3 (Kg*m^-3) E = 2.2by Lanthan - General Mendel Topics
Buback Wrote: ------------------------------------------------------- > All this is way over my head, but good work. > Something I've wondered before is how the belts > resonate, and if it has any impact? There is a basic primer on standing waves here, complete with nice videos. The case that most interests us is "both ends clamped". With our little experience, we can see clearly aby Lanthan - General Mendel Topics
nophead Wrote: ------------------------------------------------------- > The aluminium ones fro HK don't fit T5 belt, the > teeth are too thin so it gives loads of backlash. This is important data. THX for the tip! I am using the bulgarian ones, no problems so far (excepted an episode of loose X pullley because I hadn't secured the locking bolt with glue and the flat filed on the motor shby Lanthan - General Mendel Topics
@Buback. I am not excessively worried about crashes (yes they happen) because I made a two parts extruder carriage, with the upper part held down to the lower by magnets (horizontal plane play is prevented by tubular boltheads). So in case the hot end touches the bed with some force, it just pops up. Pictured here (IMHO this design is printable too, but I wanted plywood where melts happen) I hby Lanthan - General Mendel Topics
eBay is your friend. Mainly two sources, alminium sheet from HK and milled massive aluminium from Bulgaria (for some unknown reason searches in the .com domain provide many more interesting hits than searches in the localized versions)by Lanthan - General Mendel Topics
I think too a three point adjustment system is way easier to manage than a four point. The diameter of the supporting pieces (currently m3 blts and a spring over them) should probably be increased. Nophead eliminated the springs in his design, this certainly helps with rigidity I like the idea of a lever system - need to balance complexity and function, though. ...by Lanthan - General Mendel Topics
@Justblair: THX for the feedback and comments! Same findings here: it helps, but it is not the end of the road. Should I keep that frame, I'll crossbrace the lower side - or a couple of parallell bars supporting Z motors where they belong, at the base of the machine. I'd like to help getting the guesswork, hear-say and promotional snake oil out of the evaluation of machine frames (and other coby Lanthan - General Mendel Topics
Time for some science The aim is to set the bases for some experimentation on frames designs, vibrations & resonance. This may also provide a new way of evaluating and comparing different firmwares. I am no way an expert in sound analysis, but I hope this will get you experimenting as the experimental material is well within reach - I hope to see further analyses published here. Materialby Lanthan - General Mendel Topics
This one is not a 608 but you get the idea: tight tolerances and firmly shoved in (needed to stand up on the plate and give a "gentle" kick): no signs it is going to come free on the loose anytime soon.by Lanthan - Mechanics
- Pour les poulies imprimées il y a un truc avec un écrou M5 (plutôt que M6), une perceuse à colonne, et un taraud m2 ou m3. Cela ne résoud pas le probème des irrégularités - J'ai aussi des poulies alu de Bulgarie, elles vont très bien mais au bout d'un moment les vis de serrage ont tendance à se deserrer. Ne pas hésiter à 1) limer un méplat sur l'axe du moteur pas à pas à l'endroit, tout en prby Lanthan - RepRap Groupe d'Utilisateurs Francophone