[Kitt - Actuator project]

raess · February 3, 2022, 12:53pm

Since k3lso have moved away from home a few months. I had some extra time to start on smaller project.
here is overview of what I am temporarily working with.

raess · February 3, 2022, 12:54pm

Here is a Render next to Mini Cheetah´s actuators.

Here is a simple form factor print.

raess · February 11, 2022, 10:38pm

Spent a few hours tonight with adjusting symmetry for cut-outs and hole patterns. I love symmetrical designs where ever it is possible.

I also redesigned the carrier, planet gears, added space for optional bearing, new front cover. Adjusting the output slightly.

I also did some static load testing to see how the output will handle overhang (mounting) from the bearing since the magnet ring for the (AksIM-2) have a ~0.2mm “ride height” which means that this part needs to be rigid for the possible loads that may arise. Results ok.

Anyways with the new changes I was able to hit my 50mm goal (happy ~48mm) I name this version Rev3.

For the prototype I will also remove the housing fins.

In a few days I will also receive a full sets of mjf printed parts (Rev2) to play with (Formfactor print only).

I have worked with drawings and tolerances.

The gears for the planetary gearbox is now on milling order. I went with C45 and 25-30HRC heat treatment and black oxide! It should arrive in 14-days.

I did a small revison on the bearing width hole on the Planets. Incearings it slightly to 2.3mm to be able to fit the 682U-H from NSK.

The gear setup is:

Ring: 44T
Planets: 17T
Sun: 10T

Now lets finish the rest of the parts!

raess · February 14, 2022, 7:56pm

Allright, today I got my Nylon PA11 - MJF printed form factor parts (The rev2 version) and everything fitted like a glove.
The milling have started (The Rev4 version) for all parts except back - front cover in 7075 and will be ready in about two weeks. I chose to run 4 sets (4 - Actuators ) and 50% black oxide parts and 50% gold oxide parts, so I can mix and match with the color scheme.

I have also placed an order for more bearings from NSK & NTN and additional miscellaneous titanium screws that will be needed in later assembly.

Simple test:
Mjf printed prototype of rev 2 assembly. - YouTube

raess · February 15, 2022, 7:39pm

Had some time to finish the front and back cover on rev4.

raess · February 21, 2022, 10:20pm

Working on the rev6 tonight (future version ). Some redesign to skip the splitted output / carrier parts. Also increased the gear width by alot doing it this way (~66%). Some bearings needed to change to have the abilty to fit the new sun pattern diameter for the 6.85:1 reducation. The planets still remains 17T.