Printing RepWalker Mutation RA04

[jmccartney]

(05-08-2014 11:29 PM)steamboat Wrote:  

(05-08-2014 11:21 PM)jmccartney Wrote:  Are you going to publish the meshes or make people reverse engineer them

I do not have any SketchUp files. But I thought about to give the main dimensions of the coupling points to make it easy to adapt things.

Thats great. I would publish the sketchup files myself, but I worry on things like this that we have "perfected" to this extent whether its a great idea or not. I am not against mods, I mean this is one, but I think there should be a slight barrier to prevent people from "over modding" something. It becomes confusing to the consumer when there is 10 versions of the rep-walker with 1 or two builds of each. Its much better if additional mods for this exact design (and thus improvement efforts are directed towards..) at least keep the chassis the same i.e. all the parts except for the legs and the brain and front and back bumpers I am calling the chassis.

[steamboat]

Hello Team,

I edited all files according to your helpful hints:

- changed all M3 holes from Ø 3 mm to Ø 3.2 mm now.
- changed the M3 hex cut out from 6.1 to 6.0 height.
- the Ø 5 mm bores for the axis from Ø 5 mm to Ø 5.4 mm
- moved the position of the servo mount bores in #1-muscle-torso 1 mm higher.
- changed the bores in #2 and #3 accordingly

Additional I tried to make it easier to assemble RepWalker without an instruction - for kids or other nervous human beings...
Changed the hip-axis from nominal Ø 5 mm to Ø 6 mm so you will recognize it if you are doing something wrong.

The hind-leg has the longer axis so the change from Ø 5 to Ø 6 mm makes it even safer to print.

The c-rings are the same for the Ø 5 and Ø 6 mm axis...

Have printed all new parts except the legs already. Want to go to bed now.

You can download all new files with the ending 4.1 from my webpage.
http://shellmo.radow.org/repwalker-ra04/...#stl-files

Tomorrow I will publish it at Thingiverse also. Is there any other interesting platform where I should publish it?

[steamboat]

Changed the hip-joint axis back to it's original Ø 5 mm. Files are still named 4.1

It was a stupid idea because changing the hip-joint axis from 5 mm to 6 mm also required a new tendon with a 6 mm bore - realized that during final assembly. So it would not make the model easier to build that way...

[steamboat]

Quote:Hello Rainer.

I'm assembling RW_RA04, but I found a very simple but important error at
"FrameA".
Please see the picture. I put my FrameA on yours. There are about 4mm
lag with the position of nut holder.
From this lag, the Frame C also move 4mm to outside direction and can't
attach core.
Can you understand what I mean ?

I think it's easy to repair 3Dmodel, but I don't sure you can put
circuit here because the circuit attachment space will be 4mm smaller...

BestRegards.
Sho

Hello Sho,

I thought about this issue again...

Do you think I should make a new FrameA to be compatible? Or are we in a stage where this is not that important because everthing is changing and we don't have to many "customers" and other that build/print with us and combine modules - in the moment?

The next step for me will be the centipede. I will make it a "Macropede" because my printing abilities don't allow a Micropede ;-) This also will have other outer dimensions.

I think because this is all work in progress, it is more important to get first results and learn what and how we can print it at home than to have it standardized at the first step - on other hand as a German Engineer I like standards ;-)

I am open for all kind of discussions!

[sho]

"Do you think I should make a new FrameA to be compatible?"
Yes ! If you have a time, please modify a little.

I want to print FrameA for connecting core module by 5/16.
I will put all circuits to core when release RepWalker_RA as official module.
So, honestly, I don't mind that we can put circuits and battery to RepWalker or not very much.

[steamboat]

Changing my hip and shoulder to meet your frame A
don't automatically will make the core shell match the holes on top of your frame C because of the battery position. Your 156.5 are about 163 in my actual design.



For me this 70 x 156.5 with a flat bottom would be the module boundary. By the way 156. 5 is a funny number - why not 160?

But this is only half the story! We should describe the full building volumes to make modules interchangeable. This includes:

- max core width - to fit between the legs
- max core length in relation to the mounting holes - to avoid wrong bumper positions etc.
- max weight - maybe to early but a rough estimation would help Especially the centipede plastic legs might have a problem with to high load.
- center of gravity
- and so on...

[jmccartney]

Build update. Modified two hk servos like Rainer demonstrated. Very easy. Printed eye parts today, began assembly tonight.

My bolts to connect to the the eyeballs to the tie rod are too long. I only have 16mm m3 screws at the moment, so have to wait/figure out something here.

Rainer how did you fit a nut at the bottom of these anyways? They seem to not have enough clearance at the bottom?

   

[steamboat]

(05-15-2014 11:22 AM)jmccartney Wrote:  Rainer how did you fit a nut at the bottom of these anyways? They seem to not have enough clearance at the bottom?

This design is without any nuts! The bolts will be screwed into the plastic only! Have to add this in the description.

Is this possible with your plastic and high printer accuracy or do I have to make the holes a little smaler? They should be Ø2.8 mm in the actual stl-file