Baby steps must come before awesome big boy steps and today I took my first of most likely many. The quality of the parts are very poor which due to a mixture of poor calibration of the machine and an extruder that doesn’t work particularly well (due to a lamely implemented hack to the extruder in order to get it to work)
My first attempt was on a button stylized as an owl. As you can see from the pictures it is a very sad owl, and really a very sad button. The height the system raised the extrusion head for each layer was set too low so it smeared everything around.
The second attempt was on what is called the minimug. It is the standard RepRap test part and is intended to be used to toast your machine with an object that it printed. My glass wont be holding any liquids but it is heartening to see something that resembles an object!
I will be machining a proper gear driven extruder in the coming week and tweaking the settings of the machine to achieve highest possible print quality. Together those changes should give me much higher print quality. It will be interesting to see how it turns out!
I have had a few requests for the part drawings for the machined bits of my RepRap.
You can download them here
I have the RepRap completely wired up and everything – but I’m having loads of trouble getting the extruder to work. Since I am an extremely early adopter of the new RepRap design there appears to be an unfixed bug with the code/hardware that prevents the extruder stepper motor from getting the current that it requires. I hacked together a quick fix that *seems* to work (pictured below) but haven’t had time to really test it. Hopefully I’ll have some time over the thanksgiving holiday.
Mechanically the RepRap is done! Unfortunately I have to do some homework so I can’t wire it up and take it for a spin. I still have to figure out how to run the stepper motor on the extruder from the extruder controller board (via two H-Bridges), and put the nichrome wire and thermister on the barrel. I’m lovin it so far!
Last night I finished the rest of the mechanical components of the RepRap. As soon as I have time I will be assembling, taking photos, and finding out what I did wrong – and will post it all just as soon as I finish!
Today I machined the carriage for the extruder and most of the components of the extruder assembly (sans thermal barrier, nozzle, and the barrel).The bottom plate (with the two angled bearings) is located to the upper plates with two pins, and the compressed springs around the screws on the bottom apply a preload on the bearings so everything runs nice and tight. I left bearing/motor shaft that pinches the filament open to the air so I can enjoy watching it feed through. Hopefully I will be finished with the construction by next week!
This weekend I was able to make the majority of the frame components for the RepRap. As you can see in the pictures I am still waiting for most of the nuts, bolts and washers to arrive. (On a side note if you are buying more than 8 screws or bolts you might as well buy 100 offline because you can get a hundred for the same price as about 12 at the hardware store. Especially if you are buying metric – Home Depot wanted $.90 for four (4!) m4 16mm socket head cap screws, conversely mcmaster carr wanted like $2.80 for 100. Kind of insane really.)
Things are going well, as usual I have a test this week that is going to require a prodigious amount of studying but hopefully by next week I will have all of the components machined. Since I have a tested working set of electronics it should run once I get everything built. This will be VERY interesting.
What still needs done:
- Extruder Carriage/Extruder
- Z Axis Components (2 plates/timing pulleys)
- Y Axis bearings
- Printing Surface
Judging from the time it took to complete what I have so far it really is conceivable that I could have it all together sometime next week!
(keep in mind that the assembly you see is a test fit of all the components so nothing is properly aligned or bolted tightly, so if something looks crooked, it probably is – but it is not an indicator of the build quality)
Today I machined the 6 corner brackets for the RepRap, they were by far the most time consuming pieces (they took 8 hours total to make) they were time consuming because they were made out of scrap, and because of the strange angles it took a lot of setup to be able to machine them accurately (and repeatably).
More pictures after the link.
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The bearings arrived today. I test fit them on the busted linear bearing and they look good! The test that was keeping me from working on the RepRap is past, so tonight I am making drawings for many of the parts and tomorrow I will be machining as many parts as I can in the 8 hours I’ll be up at the shop. I may get some time in on Saturday as well. I have my fingers crossed that the dividing head will work so I can make my own gears. That would be fantastic!
Things are really starting to come together for the RepRap project, yesterday I received the motherboard, extruder controller, ABS plastic filament, etc. Basically everything I need for a working set of electronics. I wired them all up today, loaded a g-code file and watched as the motors slavishly rotated, performing their duties. It was thrilling. The only obstacle now is the mechanical construction.
I obtained the threaded rods and plated shafts for the linear bearing today, the actual bearings should arrive tomorrow, and as soon as I get past a big test coming up this week I will finish the design and get all hardcore about construction. Although the construction will easily be the longest step, seeing the electronics operating, I feel as if I am on the downhill now.
Z Azix Bearing Without Bearings
I couldn’t think of a better way to begin the construction phase of my RepRap than destroying the first part, so that’s exactly what I did! I decided to start with the 360 degree linear bearing for the Z axis because I had the perfect piece of material on hand and it wouldn’t take long to do. Everything looked great until I looked closely – the holes for the bearing were normal (that is perpendicular) to the wrong side of the slot so the bearings couldn’t be mounted. I did some quick redrills as a last resort to try to fix it, but I don’t think that it will hold, so I’ll probably end up remaking it.
The good news is that I am 95% done with the design so I’ll have lots of pretty parts to make over the coming weeks, as well as some drawings of all the parts for anyone else that wants to make one!
