Rotary Stage: Updated

UPDATE: 3/1/2024 - ver. 1.1

I added additional pictures and explanation, below, to try and clarify the assembly process.

UPDATE: 5/12/2023 - ver. 1.1

I have added a worm and worm gear set for finer rotation control.  The FINE version of the worm and worm gear have a ratio of 1:68.  The gears are interchangeable so you just need to print the new worm and worm gear if you want the higher ratio.  

The FINE gear set is the set on the far left in the picture showing three sets of gears.   The far right set is the original set.  The middle set was an attempt for a higher ratio while maintaining a standard worm tooth profile.  The FINE set on the left is an M16-2 tooth profile.  

(I subsequently learned the ISO standard has M16-2 as Coarse and M16-1.5 as Fine.  Oh well.)

ORIGINAL DESCRIPTION

This is a small (80x80x22.5) worm gear rotary stage with a ratio of 1:32.  It is sized to match the other stages I have uploaded separately.  

The only mounting holes in this model are for stacking other stages.  Some of the photos show the rotary stage stacked on a linear stage.  There is a separate universal mounting plate that can be attached to the top of the rotary stage.

Linear Stage

https://www.printables.com/model/453719-linear-stage

Angle Stage

https://www.printables.com/model/464120-angle-stage-10-degrees

Mounting Plates

https://www.printables.com/model/470451-stage-mounting-plates

Printing Issue:

The Worm:  Print the worm by itself with a layer height of 0.15mm (or less) with no supports.  Printing the worm with a 0.20mm layer height will require support on the bottom side of the thread faces.  The supports will leave artifacts on the thread face that interfaces with the worm gear and those artifacts will prevent smooth operation between the worm and worm gear.

Bottom: The bottom pieces are printed with supports.  You may be able to print Bottom1 upside down without supports, but I haven't tried it myself.  

Post Processing:

This model requires some post processing in order to work.  The holes in the model are sized for tapping.  I used the following tools to complete the model:

M3 Tap (2.5mm holes)

4 x M3 socket head cap screws to assemble Bottom1 and Bottom2

2 x M3 socket head cap screws to connect Top1, WormGear, and Top2

Assembly Notes:

Note 1:  The first step should be to tap the M3 holes in Top1 and Bottom2.

Note 2:  My photos show the Top pieces printed in Grey and the Bottom pieces printed in Green.

Note 3 UPDATED:  The assembly order is WormShaft, Bottom, then Top.  The different part groups are based on fastened connections to one another.  The Bottom parts sandwich around the Worm group and M3 screws are used to fasten Bottom1 and Bottom2 together.  The Top parts then the Worm-Bottom and M3 screws are used to fasten Top 1 and Top2 together.  

UPDATED Note 4:  I have added some assembly renderings.  (Colored arrows is as fancy as I know how to do.)  BLUE ARROWS show M3 holes for fastened connections between parts.  YELLOW ARROWS show holes that allow M3 screws to pass through to connect the rotary stage to another stage or or some other base.  RED ARROWS show holes that need to be tapped and are for attaching something to the top of the rotary stage.  

     WormShaft:  The WormShaftTool is used to determine how much of the WormShaft should be sticking out the end of the Worm.  I placed the WormShaftTool on a table with the opening facing up, set the Worm over the opening on the WormShaftTool, and then pressed the WormShaft down into the Worm and WormShaftTool.

     Bottom:  The WormGear and assembled WormShaft must be placed in between Bottom1 and Bottom2 before screwing Bottom1 and Bottom2 together.  Make sure the square notch in the WormGear is facing UP.  

     Top:  I discovered it was difficult to get even pressure with the 4 M3 screws used to assemble the Top.  If one of the screws is too tight it will cause the WormGear to try and move out of alignment with the Top causing it to bind and making it hard to turn the WormShaft.  I found that using just two opposing screws was sufficient and was easier to tighten equally.