If I understand your idea correctly, it seems the granules would jam in the tube, or at least require a lot of force to keep them moving.by Dale Dunn - Plastic Extruder Working Group
Woot! Baby steps! As opposed to micro-steps... On to the next hurdle!by Dale Dunn - Reprappers
brupje Wrote: ------------------------------------------------------- ... > I can't imagine messing up the soldering twice, so > what might be the problem? ... I can. This suggests to me that you're not troubleshooting methodically. Be meticulous. Isolate variables. Test individual components. Never think you know something is good unless it's been tested.by Dale Dunn - Reprappers
You can load the plate .stl file into FreeCAD. I don't know how or if FreeCAD will report the volume on that. I do know that you can use FreeCAD to convert the .stl to .stp, which Inventor will open. Inventor can give you a volume if everything translated cleanly. To use FreeCAD to convert .stl to .stp: Open the .stl in FreeCAD and select it in the list on the left. Find the tool in the menus toby Dale Dunn - General Mendel Topics
It sounds like you accidentally got hold of the source code files instead of compiled code in an installer. Here's a page with and .msi file. It's not current with the latest version, but it's good enough for what we want. Give in? No, this is just part of getting used to open source. Especially something so early in development as open source CAD. More mature projects are much easier to deal wby Dale Dunn - Reprappers
True enough about the auditing. I'm looking forward to hearing what the fundamental problems might be. The only thing that makes me nervous about it is using three rods instead of a single profile with a larger polar moment. It seems like it should work, but intuition is notoriously unreliable.by Dale Dunn - Plastic Extruder Working Group
syknyc Wrote: ------------------------------------------------------- > Greetings everybody! > > ... > My yearlong goal is to build my first printer and > then use that to build a second machine.. > > Thank you all for your time and for your amazing > community! My program is similar, but I'm starting with a MakerGear Prusa Mendel. I know I'm spending more than buildingby Dale Dunn - General
It is unfortunately non-obvious, but I just worked through a part in FreeCAD, from .stl to .stp, then successfully into SolidWorks. It even merged co-planar facets into faces for me. In FreeCAD, go to File, Open, with "Supported Formats" as the file type. It can see the .stl files when I do that. Once it opens the .stl, select it in the "Combo View" thing on the left, go to the Part menu and selby Dale Dunn - Reprappers
At least one of the open source CAD programs can open .stl and export STEP. HeeksCAD or FreeCAD, or maybe both or neither. I know I saw it though. A free trial of Alibre might do it for you too.by Dale Dunn - Reprappers
The SKF data sheet should be describing the generic properties of ABEC bearings. Any SKF-specific features or qualities will be noted as special. So, any Chinese (or whetever) bearing that meets an ABEC tolerance class should be just as good as an SKF bearing of the same class (except as noted by SKF). In other words, I wouldn't hesitate to load a generic class 3 bearing from anywhere the same asby Dale Dunn - Plastic Extruder Working Group
I've read elsewhere that the software can handle machines much larger than a standard Mendel. I don't have a printer up an running yet, but I'll answer the other questions from my own machine design experience. For steps/mm, I'd start out near the default of the Mendel. Once you get that up and running and successfully making parts, you can start work on running faster, or more precisely than aby Dale Dunn - General
Call it ... Temporary? A beautiful example of how it doesn't have to be pretty if it works.by Dale Dunn - General Mendel Topics
OK, Here is one of the six vertices. I also put a STEP file in the .zip. I don't anticipate a problem importing such a simple IGES, but I figured it wouldn't hurt to include the STEP file too. I forgot: SolidWorks can export some Pro/E formats. I don't think it will include features, but it should import cleanly. Let us know how it goes. Have fun!by Dale Dunn - Developers
Rhino has an excellent reputation as an industrial design tool (freeform surfaces). For mechanical design, not so much. I'm sure you could pinch hit with it. For mechanical design, start with the $100 Alibre at the bottom, and move up through the options listed by andysuth. If you have access to educational licenses of anything above Alibre, go with that. It's what you'll be using in industry, anby Dale Dunn - 3D Design tools
The best models I know of are listed here. Unfortunately, you'll need to be able import SolidEdge or SolidWorks models to use them. That won't be much better than importing IGES or STEP, but still better than .stl. If you can't work with any of those (or don't want to), let me know. I can export IGES or STEP from the SolidWorks models. Hopefully the resulting file will be small enough to attachby Dale Dunn - Developers
Hmmm. Some Teflon inside the pinion might reduce friction some, if experimentation shows it to be problematic. I was thinking about the multiple extruder possibilities too. Is anybody running multiple physical extruders yet?by Dale Dunn - General Mendel Topics
Technically, both are cap screws. Button head cap screws, they're called. The only downside is that, since the head is half the height of the regular socket head cap screw, the socket depth is also half as deep. It's easier to strip them out. The head diameter is pretty much the same, so they will clamp plastic in the same way. I usually find them to be fully threaded too, instead of about 3.5 diby Dale Dunn - General
Andysuth, This sounds like an idea I had and then shot down in another thread. It might be more appropriate here, though. For all the torque it will carry, a piece of aluminum square tubing should work for your "shaft of uniform cross section". (Look up "spline shaft" for a commercial equivalent). For the square tubing "shaft", the pinion would have a (probably) printable matching square holeby Dale Dunn - Plastic Extruder Working Group
Instead of the flex shaft, you could use something like a spline shaft to move the motor to the end of the X axis. The spline shaft would lie parallel to the X axis, and the pinion gear would slide along it to maintain contact with the main gear on the extruder. Of course, you don't need a proper spline shaft for this application. You could maybe use a small rectangular aluminum extrusion for theby Dale Dunn - General Mendel Topics
Looking at the pencil-plot, my experience with machining is screaming "backlash!" The belts are tight, but something else could be loose. A sloppy bearing on one of the axes, perhaps? Does the X axis carriage have any wiggle room in the Y direction, and vice versa? Can the Z axis carriage be wiggled? Can the carriage be wiggled in any direction with the stepper holding position? From old motorcyby Dale Dunn - General Mendel Topics
Those more experienced than me may ask what kind of machine you're working with. I think there have been several variations on the Z axis pulleys.by Dale Dunn - General
Hmmm. It is true that the RP processes are not as precise as the geometry generated in CAD. But the inaccuracies in the CAD models will be added to the inaccuracy of the printers. So it seems to me that it would be good practice to keep things precise as far along the tool chain as we can, in order to achieve the best possible prints. Having to make sure the model is in the positive octant seemsby Dale Dunn - General
Mendel kits are in the rough neighborhood of US$1000. If the cost of the printed parts was reduced to $50, you've only lowered the total cost to around $850. If your source the hardware yourself, scavenge steppers, and get unassembled electronics, you can lower the cost more, but it's still a few hundred. The cost of the plastics doesn't seem that prohibitive to me in comparison. Commercial prinby Dale Dunn - General
This seems to be a supply/demand thing. It's about what people were paying for printed parts on eBay a few months ago. It has been noted that eBay prices are falling lately, theoretically because of increased availability and more people printing them. Fixed prices at the stores will probably lag any changes on eBay by a matter of months. The actual cost in plastic and electricity isn't that mucby Dale Dunn - General
Signed up! OpenScad is an interesting little platform. I can see why programmers take to it. Painful from my perspective. At first I thought I would just patch up the .stl files, but the .scad files contain formulas that document what we in the SolidWorks community call "design intent". I'll translate that too, but it's going to take a while to catch up to this moving target. A long while if Maby Dale Dunn - General
nophead Wrote: ------------------------------------------------------- > Anybody tried something like this? > > ep.html > > Even if you take openscad, convert to STL and then > to STEP and then edit it in a GUI, you can't go > back to openscad again, so you can't collaborate > on Prusa Mendel, only fork it. Murrayd pointed out that TurboCAD has a similar function (thougby Dale Dunn - General
nophead Wrote: ... > You want everybody to use STEP, but very few open > source programs support it. None of the ones > commonly used by the reprap do. ... That's what I'm finding out. I can see that if I want to contribute design work to the community, I'll pretty much need to work in these formats. That's the way it works in other mechanical design realms too. You use what's compatiblby Dale Dunn - General
SebastienBailard Wrote: ------------------------------------------------------- > copy-and-paste from parallel discussion in > reprap-dev (which you guys should be in, since you > are devs ): ... > > > Andrew, one issue though is that an exported > STEP is a simi dead format. > > > The native formats of the open source CAD > programs are the most workable. &gby Dale Dunn - General
murrayd Wrote: ------------------------------------------------------- > All I can say to you is that standing about > stamping your foot because you don't like the > format isn't likely to change anything. The > people who got there before you made it work. Well, maybe I need to examine my tone, but my intention is not to whine about my favorite CAD system. I don't expect people tby Dale Dunn - General
Yes, .stl files are manifold bodies, but that's about where the similarity with BREP models ends. Even if the only considerable difference is curved surface definition, that's a big difference! I've been exploring these functions for converting between meshes and BREP. They still run afoul of the fact that the .stl mesh is an approximation of the original model. Curved face definition is lost,by Dale Dunn - General