Build

 

BOM

Printed Parts

I printed all of my parts in PETG, from a mixture  of  SUNLU and Polymaker filaments.
  • (1) Rotor - 184g
  • (1) StatorA - 287g
  • (1) StatorB - 252g
  • (3) Pins_Short - 20g (total)
  • (3) Pins_Long - 20g (total)
  • Optional
    • Planetary drive - 231g (total)
      • (1) PlanetaryHub
      • (3) Planet
      • (1) Sun
      • (1) Ring
    • Motor Mount -  119g

COTS

Build Steps

The first step was to get all of the parts printed.  Both stators and the rotor are pretty large parts. So they each took up a full build plate for me on my Mk3s.
 
hfpp_buildplate_c0602.jpeg
 
Unfortunately, they also require some supports. I used organic/tree supports, and they all popped off pretty easily. Main places to keep an eye on keeping reasonably smooth are 1) the bearing races and 2) the tube pass throughs in the housings.  The smoother the bearing race is, the better (and quieter) the bearing is going to run, and any stray bits of support left in the pass throughs is likely to snag the tubing when trying to feed it in, making it almost impossible...and enraging, or so I'd guess...
 
I added some brims on the  Pins, just to be safe, since they don't have huge contact patches relative to their height. 
 
Hmm, ok, I think that's the main stuff for printing, if you run into any questions, feel free to find me in the comment section of your liking :)
 
Once all of the parts were printed, I  put the motor mount heat sets into StatorA
 hfpp_ann_statora_d0921.jpeg
 
And since i had the iron hot, went ahead and put the M3s into the PlanetaryHub as well.
 
hfpp_ann_planrot_a89f1.jpeg
  
Next, I assembled the bearing sub assemblies with the large roller bearings and both the long and short pins.
 
hfpp_xsec_bearingsub_15bd0.jpeg
 
 I  assembled mine by putting the bearing into the Panavise, intentionally adding an angle to allow gravity to help me out with getting the nut started.
 
hfpp_bearing-in-vise_7dd02.jpeg
 
With the nut seated inside a small socket inserted into the Pin, and a hex driver preloading the M3 fastener into it's bore, I just brought the two together through the bearing and tightened up the fastener. To be honest, it went MUCH smoother than I expected :)
 
hfpp_bearingsub_tightening_c5960.jpeg
 
 With the bearing subs assembled, it was on to the fun part, aka trying not to make a mess with steel balls.  First filling the bearing race of one housing (it doesn't really matter which side you start with, it should be symmetrical.)
 
hfpp_mainbearing1_2e9e1.jpeg
 
 You want to err on the side of a missing ball vs having one too many if the count isn't exact around the race. A one ball gap won't hurt anything. Once the housing race is full, set the the rotor down on to the balls. It should spin freely and smoothly, but don't get too excited, it can be easily to get a little carried away spinnin and make a mess. 
 
hfpp_rotorinstall_4dedc.jpeg
 
 Install the rotor so that the side with the ledges for  securing the roller bearings is facing down (like shown above). That lip is also the reason there is a "long" and "short" set of pins. The longer pins go on the side with the lip. The extra length on those pins is to compensate for the thickness of the ledges.
 
But before I inserted the bearing sub assemblies, I added the steel balls for the other half of the main bearing.
 
hfpp_mainbearing2_a0179.jpeg
 
 The bearing assemblies then just slide into their pockets, and the other housing can be lowered and secured into place. 
 
If the bearing feels tight after tightening the housings together, you may want to add  some washers or other spacers to the gap between the housings. Having it tight will make it more resistant to heavy loading (for example if you wanted to run it with only a single tube installed, you'd want a good preload), but it will also make it harder to turn and could get interesting if run long or at high speed...although I can't help but wonder if this would just melt and shape the bearing smooth. I feel like it depends on if any melted plastic adhered to the balls. But anywho, I digress :)
 
Now just lace it up with some tubing!  And if using it with a drill or the like,  you're ready to go!
 
I need to grab some sleep, so the planetary gear  drive and notes  on the design will have to wait. If you have questions or comments, I'd love to hear em!
 
Cheers,
Bubs
 

No comments

Leave your comment

In reply to Some User