Obviously credit should go where credit is due...Richard Horne (RichRap) for his design of the original 3DR from which my design began, Johann Rocholl for his development work on delta printers in general, and of course SeeMeCNC and the members here for getting me into deltas and 3D printing. I will be uploading all STL's, STEP files, and BOM to GitHub whenever everything is complete.
Here is the link to RichRap's blog where he released and outlined his 3DR printer... http://richrap.blogspot.com/2013/07/3dr ... lease.html
So lets start with why I like the 3DR design...
1) Small form factor with a decent print area. The original 3DR is designed around a 170mm build plate (so 160mm diameter build area) and fits inside a of 9.5" x 8.5" square space on your desk. Just to give a sense of scale that means the entire printer will fit on the build platform of the Rostock Max.
[img]https://farm8.staticflickr.com/7506/16041795151_1fc1fca005_h.jpg[/img]
2) Design allows for use of tension line or belts/pulleys for carriage movement. The carriages would need redesign to used belts, but the clearances and top and bottom plates are already designed to accept both.
3) Stays true the the RepRap mentality that all parts used for this printer can be printed by this printer. It does require a lot of plastic, but that's okay for a machine in this size class in my opinion.
Now how about the things that I felt could be improved upon and why I decided to go ahead and redesign the entire printer from the ground up.
1) Precision shafting for linear bearings is expensive (the title of the thread pretty much gives away what I'm doing to remedy this). Using v-slot extrusions and mini wheels from OpenBuilds saves just under $70 on the cost of the printer. Changing to this style design does require the printer be a bit larger however.
2) The top spool mount will not accept the standard 8" diameter spools used here in the United States. This one I didn't expect (or think about) with the original 3DR design.
3) Design not modular in terms of electronics. The top mounts are designed specifically to mount the RUMBA controller and hall-effect end stop sensors. I wanted to be able to use mechanical end-stops since they are MUCH cheaper and other controllers...specifically RAMPS 1.4 and the Panucatt Azteeg X5mini. Other devices will also be compatible with provided adapter plates.
4) No provisions for a heated bed. Even though this is meant to be an inexpensive PLA printer, designing in the option to use a heated bed for either better PLA prints or ABS was one of my goals.
5) Many of the STL files for the 3DR have several errors which have caused me slicing problems. They also use an extremely course mesh so round features are very polygonal. This is me being more a perfectionist than anything else, but if I'm doing everything else then I might as well make this more to my liking as well.
6) Lots of other small improvements/changes that I will go into more detail with as I start printing parts and assembling the machine.
Anyway...here are a couple of rendering of the printer as it is right now. Definitely not complete yet, but I was itching to show off the work so far.
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