I'm browsing the Misumi site, and just learned that there are lots of options when shopping for linear shafts: Material, surface treatment, and dimensional tolerance. The following page spells out which materials/treatements are available for which tolerances (from one of the 'material' buttons on the above Misumi page). From this site, , I gather that the tolerance codes for 8mm shaft areby mkeveney - Mechanics
I'm considering a something like the Portabee, but without a heated bed. ...I'll use PLA exclusively. I'd like to use the smallest power supply I can get away with. How many watts to I need? Is there a chart somewhere with various hot-end power requirements? How much extra for the electronics and 5 steppers? -Mattby mkeveney - Controllers
Still thinking that I must be missing something, I asked the same question of the Makerbot support staff. They gave me permission to copy the exchange to this forum (below). Bottom line seems to be as nophead has suggested: there's no _electronic_ magic in the circuit boards; they're merely for convenience of mounting and managing the switches. -Matt ------------------------------------------by mkeveney - Controllers
nophead Wrote: ------------------------------------------------------- > Switch bounce isn't really a problem with an > endstop. The first time it changes state the end > has been reached. It doesn't matter if it then > bounces a few times. Okay, then what's the point of the circuit on the board-mounted switches? I found this: ...which mentions an LED for debugging. The circuiby mkeveney - Controllers
In my research, I've seen two styles of mechanical endstop switch: Some designs have the switch mounted on a small circuit board; others mount bare microswitches wired directly to the controller board. I thought the purpose of the small boards was to eliminate 'bounce' in the switch signal. Correct? If so, how do the other designs get away with simple switches? -Mattby mkeveney - Controllers
Good job on the video series; I just made it through step 12... but it doesn't seem to be complete. I presume more are on the way? -Mattby mkeveney - For Sale
I just found out about this. The challenge is to create an inexpensive machine that produces filament from pellets. I searched this forum, and only found two passing references to it; one in French, another in German. I just thought the wider RepRap community might be interested. -Mattby mkeveney - General
How 'bout bead-chain? If you need a continuous loop, gets harder to find, more expensive, and probably doesn't compete with flat belt prices. But otherwise, you can get it cut to length at a well-stocked hardware store, and I've seen light-duty drive systems that use it. I have no idea about accuracy, backlash, or whether an effective bead-chain pulley could be printed. ..just food for thoby mkeveney - General
John, Now that I've read your build notes more carefully, I'm curious about something. I note that you reoriented the X-axis belt, to avoid issues with the belt slipping and rubbing against the guide washers... but the Z-axis belt is oriented the same way as the old x-axis belt. Why doesn't it have the same problem? For that matter, I wonder if it wouldn't be simpler to just use two steppersby mkeveney - General Mendel Topics
I'm learning about RepRap, and just discovered your design. I'd like to thank you for submitting such an outstanding series of build documents! I'm sure that must have taken a lot of time. The care you put into it certainly sets it apart from the (well intended but sometimes spotty) instructions elsewhere on the wiki. And, I'll be keeping your enumerated summary handy as I learn more. Pointsby mkeveney - General Mendel Topics