I did a cube design out of 2 inch .120 wall steel square tubing. TIG welded. Recirculating ball screws. Standard Gen 2 electronics and steppers. Doesn't move particularly fast--doesn't print right at the moment either--but it is sturdy as hell! And weighs in at about 140 lbs. Not dainty. Haven't hooked anything up to do any milling yet. Made it for school. They wanted it beefy. Take a look at itby Demented Chihuahua - Controllers
Many good ideas. Have eliminated some of them as you say but others I will try. A note on the heater problem...I can run the extruder exerciser and get it up to temp in a fairly timely manner so it isn't open circuit or anything. The more I think about it, the more I'm leaning to your original idea that this is a power issue. I'm gonna clear this up by trying to run the print without the heateby Demented Chihuahua - Controllers
Have done extensive tests on the power before this and somewhat limited tests on this now. Doesn't seem to be any problems with a power drop. I'm only seeing a fractional dip in voltage when I turn on a stepper and then only for a fraction of a second. Plus, the line test works fine in the stepper exerciser and that's two steppers working at the same time. The weird thing about this is that justby Demented Chihuahua - Controllers
Hi all! Here with another problem... Running a print on the OIT RepStrap and ran into a snag again. I recently replaced the x-axis stepper driver board because I burned out the last one due to improper cooling. Those driver chips get really hot really quick. Anywho... When I run the stepper exerciser the system works fine. Run the extruder exerciser and things go without a hitch. Nothing to comby Demented Chihuahua - Controllers
certainly does. just crumbles. dementedby Demented Chihuahua - Plastic Extruder Working Group
hmm, good to know. I'll have to hook up more fan and heat sink power! Dementedby Demented Chihuahua - Reprappers
Had the same problem. Others are having the same problem. I don't know what it is about the hardware that causes this but it is annoying. I'm doing the same thing you are. Setting up to cool things down even more. Fans, larger heat sinks, thermal pastes, etc... Dementedby Demented Chihuahua - Mechanics
I use MDF and put the print head so it rather smooshes the extrudate into the bed. Causes a good mechanical bond. Then they normal layer height step evens things out and I get a good build. Also, had to up the temp a bit too. Dementedby Demented Chihuahua - Mechanics
I have this problem also with the OIT RepRap. Boards heat up and then they start jittering. Not really moving anywhere. They look like they take a step forward and then a step back at like one seacond intervals. Ended up replacing the X-axis stepper driver board. Tried turning down the trimpot that adjusts the amperage. Helped a little but not overly much. What I really need is a bigger heat sinkby Demented Chihuahua - Reprappers
Ah, thank you very much. I've been seeding continuously since I got it. Also seeding the other LiveCDs. Dementedby Demented Chihuahua - RepRap Host
Forest, You have a bright 12 year-old sitting around waiting for your experimentation? Should the rest of us start looking for this mythical and rare bright 12 year-old for future testing purposes? I'd just settle for anyone who is bright and does not have a background in electronics, software, or mechanical engineering. Dementedby Demented Chihuahua - General
wow...thanks forest. :-) You've been such a help to me here. Zach!!! Where are you!? Help me! Forest is picking on me! Dementedby Demented Chihuahua - Controllers
are you kidding me? No answer in a couple of days? Does no one know!? Dementedby Demented Chihuahua - Controllers
Previously I had my Gen 2 stepper drivers wired up to yous the Sync Enable pins on the boards. The wiring diagram used to say these were to be used. Now I look at the Arduino code and it doesn't use them and the wiring diagram doesn't have them included anymore either. Are these used at all in any versions of the software/firmware? Can I get conflicts by having different versions of the host runby Demented Chihuahua - Controllers
Just tried to torrent the .7 LiveCD with uTorrent. Says there are no seeders. We should keep someone on this at all times. If someone will seed till I get it downloaded, I'll seed for a couple weeks. Thanks Dementedby Demented Chihuahua - RepRap Host
@Forest and Viktor We need to get all you older guy's houses in the same place so we can visit them like a hi-tech tourist mecca for nerds! Make the Haj young one, MAKE THE HAJ! Dementedby Demented Chihuahua - Paste Extrusion Working Group
Viktor, is this all stuff you have in your house! Dementedby Demented Chihuahua - Paste Extrusion Working Group
hmm, I'd just borrow a lathe or a milling machine...if you have one. ;-) Dementedby Demented Chihuahua - Reprappers
Yeah, but how long does it take to set up an injection mold? How much time, manpower, technical ability? I believe they are talking about commercial machines here using Laser Sintering so the print speeds are much faster than our RepRaps right now. Obviously you can deduct some from that number to account for this. Even if you reduce it by a power of 10, you still have quite a respectable numberby Demented Chihuahua - General
Tanex Polyester strapping comes in 9mm wide strap and is what is used on medium weight strapping applications for pallatizing products for shipping. It is exactly the stuff I saw in the warehouse using the strap binder. It is rated at a strength of 1,890 N or 425 lbs. The stuff is made to not stretch because you are putting it under constant tension and load and if it stretches the load falls oveby Demented Chihuahua - General
Sid, sounds like you could use a Fonly drill press! Enjoy that one! Dementedby Demented Chihuahua - Reprappers
The act of making the end product is called Rapid Prototyping. The act of making molds, jigs, or other things associated with product production is called Rapid Tooling. Either way, it saves a siginifcant amount of time and money over conventional methods as long as production runs are less than a given amount. From "Rapid Prototyping-Laser-based and Other Technologies" by Venuvinod and Ma 2004by Demented Chihuahua - General
Sure on the modulos of elasticity but I think we are getting carried away with how much stiffness this machine will need. It isn't undergoing any crazy forces. It just needs to stand up to gravity and the slight vibrations from itself. I think this strap idea will do just that. Dementedby Demented Chihuahua - General
Wow, that cruises through there. Now if only my cartesian bot could keep up with it! Dementedby Demented Chihuahua - Mechanics
You have a four bar linkage here. It tends to swivel about it's corner brackets--they would crack in real life--and we want to cause them to resist this linkage action. Since the bars cannot slip through the corner blocks--screws and bolts and such--adding a force to them that pulls diagonally through the center of the square constrains that motion. That member through the center--in our case theby Demented Chihuahua - General
Agreed, tension and stiffness are different. However, I don't think we need stiffness here, only tension. We are basically making strong little triangles. A good triangle can certainly be made from two sticks and a string as long as There is a force tending to push the vertice where the two sticks meat toward its string hypotenuse and thus forcing the two sticks into a straight line. We have thatby Demented Chihuahua - General
I like it. Dementedby Demented Chihuahua - General
Here is the idea for the diagonal support with a bit more explanation since I really do suck at explaining things. :-) An overview of how the pieces go together generally. Diagonal corners being strapped together. Strap in Red. Strap Binder in Blue. Now, a detail of the intersection of the blue and the red--the strap and the binder. There is text there so pay special attention. Hope thatby Demented Chihuahua - General