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jit-s-build [2012/11/05 15:22]
jit
jit-s-build [2012/11/05 17:58] (current)
jit
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 Some photos show printed parts lists. ​ These are based on an early version of the Bill of Materials (BOM), and may not exactly match your kit. Some photos show printed parts lists. ​ These are based on an early version of the Bill of Materials (BOM), and may not exactly match your kit.
  
-The background grid in some photos is a 1 cm grid. +The background grid seen in some photos is a 1 cm grid.
-   +
-{{wiki:​jitsbuild:​x_left_kit.png}}+
  
-The printed plastic part shown in this image has a significant overhang in the large circular opening. ​ The printing technique used to make this part cannot produce a sharp clean profile with this kind of overhang, so the part must be trimmed before you attach parts to it.  See [[Cleaning up printed parts]]. +[[jitsbuild-x-carriage|X carriage]]
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-Sometimes you will find that a screw will not easily fit into a hole in the printed part.  This printing technology cannot produce holes of a precise size, so parts designers adjust the size of holes to minimize problems for builders. ​ If a screw is intended to be self-tapped into a hole (with no nut on the other side) it is important that the hole not be too wide, so the designer will specify a smaller hole than really needed for that screw. ​ If you have a lot of trouble turning a screw into a hole, widen the hole, but not too much. +
- +
-On the other hand, if a nut is to be used on the screw, the hole can be widened until the screw easily passes through. ​ Be very careful to determine which holes use nuts and which don't, as it can be a big hassle if you remove too much plastic from a hole that needs it to hold threads. +
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-Sometimes a designer will indicate which holes need nuts by printing a nut-shaped depression at one end of the hole.  In some cases you can press the nut into this depression and it will stick there. ​ But if this depression is printed on the bottom of a part, its shape will not be very accurate and the nut may not fit into it.  In this case, you may not have to adjust the size of that depression to actually fit the nut;  add the screw and nut to the part, then check to see if the protruding nut will interfere with anything. ​ Often there is no potential interference,​ and no need to do anything else.  Consider the nut-shaped depression to be just a hint that a nut goes on that side of the part, and not an actual required feature of the part. +
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-Note that there are generally no lock-washers. ​ Vibration during operation may cause nuts to unscrew. ​ You can use a dab of threadlocker (the blue removeable type) to hold nuts in place. ​ Many nuts and screws are left loose throughout much of the build process, so that the position of various parts can be adjusted in later steps; ​ don't apply threadlocker until these adjustments are made.  If you are worried about nuts working loose during the build, apply a small dab of threadlocker near the end of the screw, far from the nut;  the nut may work itself toward the end of the screw, but it won't leave. +
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-We add one stepper motor and one synchromesh pulley: +
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-{{wiki:jitsbuild:x-leftend_assembled_bottomview.png}} +
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-Note that the two nuts near the bottom of this image are sitting on top of nut-shaped depressions,​ but don't fit precisely into them.  They don't need to.  There is room on the bottom of this part for the nuts to protrude from the surface. ​ Threadlocker will be used later to keep these nuts from wandering. +
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-Top view: +
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-{{wiki:​jitsbuild:​x-leftend_assembled_topview.png}} +
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-The nuts with fender washers on them should be quite loose. ​ The long steel rods will be inserted under the fender washers later. +
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-The wires for the stepper motor have been threaded through the oval hole near the motor.+
  
 +[[jitsbuild-x-leftend|X left end]]
 + 
  
  
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jit-s-build.1352150523.txt.gz · Last modified: 2012/11/05 15:22 by jit