- April 3, 2016 at 10:55 am #10168
First off, I have to have I am really intrigued by the design of the carriage. I think I might have shot myself in the foot with the middle joiner assembly. I was trying to figure out how to put the assembly together and I wound up snapping middle joiners. I thought I could get aways with a crazy glue repair seemed like a good idea at the time. I think this locked in angular misalignment in the x-y axis.
The failure occurred where the bolts put the too halves together. I think there where a couple of things I could have done to have improved the quality of the print. For one thing, I didn’t use support. Next try… I will add support. The other issue that I had was that I had printed these parts one at a time. One issue that happened where the failure occurred, I don’t think the plastic had enough time to cool between layer. I think I could have addressed that by printing out more than one part at once and this would have made the small cross section prints stronger. (Have my cooling fan directed a little better probably wouldn’t hurt either)
One thing I’m curious about. It seems to me that it’s going to be hard to keep all the axes orthogonal because of stack up errors on the assembled printed parts . It seems to me that if you add a square reference, say a extruded aluminum square tube and build off that, the errors wouldn’t accumulate as much. Have you ever considered this?April 3, 2016 at 3:37 pm #10191
The updated parts are a bit different. 1 piece in the middle vs 2, so far. Printing up the new design tonight.
I hoped there would not be a stack up error. The rollers should lock the conduit in square. Then the middle assembly should actually be tightened down while the rollers hold it all square. The machine I built last week has been running on hand tightened parts in the middle assembly and it is actually the most square machine I have put together yet. I am getting the feeling people are severely over tightening this thing. I am using large bolt because they fit the bearing diameters. Most people are seeing these big bolts and getting out there ratchets and cracking parts, miss-aligning things by actually crushing them out of square.April 3, 2016 at 8:50 pm #10201
So on the next iteration, is the only change to the middle joiner only? I need to reprint the part. if you think this a part worth trying I’ll guinea pig it for you.April 4, 2016 at 6:56 am #10212
No, unfortunately it is everything in the middle, except maybe the nut traps (for now).
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