Smooth roller design to solve 2 problems encountered when using food dehydrator upgraded filament dryer:
设计这个适配的滑顺滚动轴为了解决果干烘干供料机使用中遇到的两个问题

First Problem：In the original design by AP Engineering  two filaments roll together when either one of them is pulled. Normally, it's ok. However this makes using both filaments at the same time impossible. Sometimes it's necessary to pull both filaments at the sametime. For instance, using the filaments as supply for multicolor system like 3D chamelion, ercf etc.
第一个问题：在大神AP Engineering 的原始设计中滚动中轴是一个粗杆，在烘干打印的使用过程中当任意一卷料被推动使用，两卷料是一起滚动的。通常来说没有问题而且还可以通过使用的料拖动未使用的料盘滚动从而更充分烘干，但是这样让同时使用两卷料很困难。有时候是需要同时使用两卷料的，比如使用外挂的多色打印系统或者给两台不同的单色打印机供料（比如我自己的P1放在一层，供料二层，A1放在第三层）

Second Probelm：I have modified the middle part of the dryer (to be released) so that the filament can be pulled from just under the lid. The original roller is just not rolling smooth enough and the filament will end up tipped or misplaced (only if pulled from above).
第二个问题：我把果干烘干供料机的中框进行了改造（未发布，稍后发布）这样可以直接在盖子下方就可以出料。原始设计的中轴转动不够顺滑导致顶部拉料的时候料盘会被拖动倾倒（只在顶部出料的时候发生，当然原始设计出料是底部出料）

Now this roller is smooth enough and most importantly compartible to the original slot design. Swich whichever one you like
现在这个中轴设计滚动得非常顺滑，而且重点是这个设计和原始设计的凹槽完美匹配，可以自行替换

BOM:
- 2 x Rod 8mm (diameter) 202-204mm (length)
- 4 x M3*4 screw (optional, to lock the rod)
- 4 x 608zz bearings

材料表：
- 2根8mm直径光轴，切割202-204mm长度，只可以短不可以长，有些定制会预留长度务必了解清楚
- 4颗 M3*4 螺丝（可选, 拧入缩进光轴)
- 4颗 608zz 轴承

PRINT:
Rod Secure x 4
Roller limiter mid x 2; side x 4
Roller 80mm x 4
TPU roller cover (optional)

Just put everything together like kebab (refer to the image above) and place the rod on the original slot, enjoy!
就这些东西全部打印，然后看图像串烧烤一样串起来，最后小心放入槽内，搞定！