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http://reprap.org/wiki/Prusa_i3
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Re: 3 Point Bed Leveling Mounting Locations - 7 years ago
It's a matter of lever arms. Imagine that the printer bed is not just a flat plate between the leveling screws, but maybe four times as big in any direction as the distance between any two leveling screws, and all that pesky frame and other stuff is mysteriously gone, but the leveling screws still work as they would otherwise. When you adjust one leveling screw up or down, where does the bed tiby R.G. - General
Re: Setting Up 3 Point Leveling - 7 years ago
I had new Y-carriage and heated bed support lasered in acrylic for mine. I put tabs just outside the heater outline so the adjusters could be placed on the top/accessible side of the bed, and use locking nuts on all three. Two of the adjusters are along the Y axis, the third in the middle of the opposite side, largely as described above. It's proved very handy. Locknuts are especially good. I fouby R.G. - General
Re: FLSUN I3 kit review - 7 years ago
Yep, been there. The Exp 2 connector has all the icsp pins except reset. I soldered a pin onto the reset switch to connect to that. I flashed in the bootloader and then I started getting good IDE updates. Apparently there are several 'waves' of the controller board, some with, some without.by R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
I'm fairly new to all this myself, so this may or may not help. When you say that the version that came with the printer compiles and works fine, have you actually done the step of compiling the code that comes with the printer, and then loading that into the printer? I tried that, and found that the firmware image in my printer did not include the bootloader code that actually lets the code loby R.G. - Extruded Aluminum Frames
Re: talk about the thermal fuse? Some ideas and help needed. - 7 years ago
There is a fundamental idea in engineering - if you can't make it work forever, make it easy to fix. Yes, that adds cost and perhaps adds the need for preventive maintenance, but it also sidesteps possible catastrophic failure. It's why air, water, and oil filters are replaceable. I like the idea that a replacement thermal fuse can be removed and a new one inserted quickly. If the design is goby R.G. - Safety & Best Practices
Re: FLSUN I3 kit review - 7 years ago
The theory says to clamp one Z-guide solidly, and let the other have a bit of compliance. So modifying the Z bearing holder for one side would make sense. I have the Z-guides converted into FreeCAD. You want me to send you an STL with one side a little looser for a rubber insert so you could try it?by R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
I read an article on applications of linear bearings from one of the major US bearing makers. It had some interesting comments. One was that for good linear motion, no binding and long life, one of any group of guides should be rigidly fixed in position, and the other(s) fixed with a little compliance. The compliance let the one fixed guide be the thing that set the actual line of motion, the oby R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
Well OK, then. It may also be that "shorter life" is hundreds of hours instead of tens of thousands. That might well be enough.by R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
Very nice. I did have one question though. In the reading I did on linear bearings, I got that linear bearings should have substantially zero rotation of the shaft they slide on because the bearings are constrained to roll along the shaft, not across/around it. Something about dramatically reduced life if they did both rotation and linear motion. If the idea is to just constrain the tops, wouldby R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
Here's a pic of some aluminum stiffening mods. The four legs are 2.5" lengths of 2x2 aluminum architectural angle, as is the angle in the upper corner of the Z-frame. The motor mounts are green, and the Y-axis mounts are ... um, pomegranite? The five pieces in front of the frame are the size of the flat mounts, and can be cut from one 6" x 9" pieces of aluminum sheet. I used 20x20mm cubesby R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
Did some speculative thinking while messing with the 3d cad drawing of the FLSun in FreeCAD. For stiffening and rigid-izing, the obvious points to start are the corners of the frame, the motor mounts, and the Y-axis rod mounts. The motor mounts and Y-axis mounts are fairly easy to replace with aluminum sheet in 1/8"/3.5mm or thicker. The simple way is to remove the old mount, lay it on a bit ofby R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
The hardware could be a contributor, I guess. You mention hex nuts. Mine were supplied with M4 square stainless nuts, not hex nuts. They are smaller than the recommended hardware, all right. But they did seem to seat in pretty well. Time will tell. I wish I had "blueprinted" the acrylic parts as I assembled the printer. Some time spent measuring would have resulted in drawings to replicate the aby R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
You know, it might work to make some triangular feet. Imagine taking an equilateral triangle of, say 1/8" aluminum, and bending it 90 degrees on a line perpendicular to a side at the center, leading to the opposite point. Make 4. Mount them in the outside channel of the extrusion with one point down, on all 4 corners. This ought to stiffen the corners. A lot. With a gusset to stiffen the frame frby R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
QuoteDuckmang Looking into the causes I noted that the Y axis rests on the front and rear extrusions. I also noted that depending on which corner you're looking at that these two extrusions could be flush, proud, or below the mating extrusion. It became obvious that this is a source of Z dimension error in the Y axis. I tried to loosen the angle brackets and tighten them with a clamp holding tby R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
Got the conversion to FreeCAD done for the Y-axis belt tightener.by R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
I just finished putting the Z-axis top caps with the Z-guide rod holders into Freecad. I got STLs of two different ones, a shallow one only 12mm deep, and a deep one that's 40mm deep and could be used to capture the Z lead screws too. The holes are 10mm diameter. However, I can now change that in the CAD model and produce STLs with 8mm pockets. However, while I was doing that it occurred to meby R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
QuoteDuckmang [...] some red RTV [...] holding the cartridge and the set screw both.[...] holding up well. Very worthwhile tidbit. Quote >20$ on ebay will buy a 33A 400 watt unit >pair of 45mm linear bearings to replace the 24mm units on the Z axis >3mm set screw on the upper rod [...] to final tension an already snug X belt by spreading the carriages and locking the rod in the left cby R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
I really wish I had a pretty good metal fab shop in my home!! There are self-setting silicone rubbers good to over 500F available at auto parts stores. That's probably what you were talking about as "red RTV". They're used for gasketing in car engines. None of the RTVs are good heat transfer materials. Well, better than air, but not good in general. What thermal paste were you using? I'm familby R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
My experience with anything that gets noticeably hot is that it's going to have to be replaced at some point. Household irons and car engines are exceptions, but I suspect that their lifetimes are just longer. I suspect that hot end blocks are in the same category. That being said, the bare aluminum block design for hot ends is a minimal "design" that hardly qualifies for the term in the sense oby R.G. - Extruded Aluminum Frames
Re: Mounting dc42's Mini height sensor board - 7 years ago
Quotedc42 I recommend aiming for 1.5mm. Below 1mm there is a risk of the sensor contacting blobs or curl-up on the print, and above 2mm there is a risk that the sensor will not trigger. I have one of these, from Filastruder, and like it very much. I'm curious - is the height of "make" on the diffIR a function of just beam aim from the LEDs, or is intensity wrapped up in that too?by R.G. - Ormerod
Re: Help me improve rigidity of frame - 7 years ago
Look up the term "gusset". That frame can be made incredibly rigid by adding triangular gussets to each right-angle intersection. In the case of the intersection of two 2020 frame members, a gusset bolted to the outside of each intersection will add a huge amount of stiffness. These can be as simple as triangles of aluminum, bolted into the outside slots of the frame members. This leaves the insby R.G. - Extruded Aluminum Frames
Re: AC mains safety - how to not let your 3d printer electrocute you - 7 years ago
AC Mains Control Concept The idea is to run a low power uC from a transformerless power supply directly on the AC mains. This controller can turn a big triac switch on and off through a zero crossing opto triac driver (MOC3063, for example). It runs all the time that there is AC attached to the power in cord. It senses two momentary switches on the mains/hot side of the power line, "power on" anby R.G. - Safety & Best Practices
Re: AC mains safety - how to not let your 3d printer electrocute you - 7 years ago
OK, 'bout got that nailed down. Transformerless power supply with 5V/50ma running from the AC line, powering a low-power 8-pin uC. The uC drives a Triac to switch the AC line through a zero crossing opto-triac isolator, and can turn the AC to the power supply on and off based on how long it's been on and on some pin conditions. The pin conditions are read from the DC side of the main DC powerby R.G. - Safety & Best Practices
Re: AC mains safety - how to not let your 3d printer electrocute you - 7 years ago
Yes - those are a couple of good ways. And the printed "nose" for the nominal LED supply is a good one for the members of the group. Tucking the power supply somewhere that is inaccessible is another. Here's a thought for the safety end cover - it's really handy to be able to have a real front-panel power switch remote from the power supply. The end cover makes me think I ought to design a cirby R.G. - Safety & Best Practices
Re: talk about the thermal fuse? Some ideas and help needed. - 7 years ago
There are some thermal fuses rated for 280C - I have some coming in the mail. My first thought is to remanufacture the aluminum heater block to be a bit bigger with two 4mm holes in it. The 4mm holes will snugly hold two 280C thermal fuses. 240C is about as hot as most plastics need, so there is some headroom up to the 280C trip. It's unlikely that normal operation will cause trips or fatigue fby R.G. - Safety & Best Practices
AC mains safety - how to not let your 3d printer electrocute you - 7 years ago
I worked for some years designing power supplies for a major computer manufacturer, and had electrical safety beaten into me. What I have seen for electrical safety on the pictures of DIY 3d printers and the kits I received leaves me shaken. If you power your machine from a metal-encased power supply with an integral IEC power socket for connecting a wall cord, that might seem to be safe. Somethby R.G. - Safety & Best Practices
Re: FLSUN I3 kit review - 7 years ago
I posted my updated commentary on the FLSun instructions at the link below. It's a translation from the originals to text that I thought was more appropriate. Enhanced FLSun instruction comments I once tried to learn a little Mandarin as my job required working with Chinese businessmen. I thought it only polite to share some of the burden of the language differences. It led me to a huge apprecby R.G. - Extruded Aluminum Frames
Re: Help finding firmware source - 7 years ago
I'd like to add a beeper.by R.G. - Prusa i3 and variants
Re: FLSUN I3 kit review - 7 years ago
As a preface to what I'm about to say, the idea that Chinese-made goods are low quality because they're Chinese is a misconception caused by Western businessmen. In my day job I have worked directly with Chinese manufacturers for nearly two decades. They are as concerned about producing high-quality goods as any manufacturer. They were limited by their low technological base back in the 80s and 9by R.G. - Extruded Aluminum Frames
Re: FLSUN I3 kit review - 7 years ago
Quotemarkshur Re the 8mm/10mm issue, the printed parts supplied are for 8mm rods, but the print quality is so poor they might as well be designed for 9mm. Yes, there is that much excessive clearance - my comment about the bottom X rod falling out is not exaggerated. The STL files are all for 10mm rods, so you cannot simply reprint the parts with the files supplied, and if I'm going to have to Cby R.G. - Extruded Aluminum Frames
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