Open Hardware robot - Rosmo - Looking for volunteer(s)

Have some feature requests, feedback, cool stuff to share, or want to know where FreeCAD is going? This is the place.
Forum rules
Be nice to others! Read the FreeCAD code of conduct!
Sam_uk
Posts: 39
Joined: Sat May 07, 2022 11:16 pm

Re: Open Hardware robot - Rosmo - Looking for volunteer(s)

Post by Sam_uk »

Nice, I love it :D

I can't seem to get images working here, but I added some here: https://github.com/rosmo-robot/Rosmo_3D ... /Readme.md

At first glance, the only part I think might need attention is the motor/encoder holders. I love the concept of what you've done, but it's unclear how the encoder board would be added/held in place?
Bance
Veteran
Posts: 2602
Joined: Wed Feb 11, 2015 3:00 pm
Location: London

Re: Open Hardware robot - Rosmo - Looking for volunteer(s)

Post by Bance »

Couldn't find any details of encoder, so made pocket the same as the example given, it's in the Motor bracket.

Does need a channel for wires, would need to know direction?

For images just drag and drop into text entry box.
ENC.png
ENC.png (37.73 KiB) Viewed 726 times
Sam_uk
Posts: 39
Joined: Sat May 07, 2022 11:16 pm

Re: Open Hardware robot - Rosmo - Looking for volunteer(s)

Post by Sam_uk »

Nice :)

The issue is that the encoder pocket needs to be _opposite_ the motor, on the same side as your mounting flange. We could cut the centre of the flange away I guess? Just need to make sure there is enough material to be structurally sound.

I think it could work if we lengthen the 'flanges' (is that what they're called?) between the motor mounts.This part:

Image

Lengthening them would make space for the encoders, we could then cut away enough of the 'flange' to make room for the encoder.

A nice side benefit of doing this would be that the central pin:
Image
would be wider and stronger too.

As we haven't done the wheels yet, maybe we can accommodate the extra width there? By just putting the motor further into the wheel?

These are the encoders: https://github.com/rosmo-robot/Magnetic ... SPI#readme

Image
Last edited by Sam_uk on Fri May 13, 2022 7:54 pm, edited 2 times in total.
Bance
Veteran
Posts: 2602
Joined: Wed Feb 11, 2015 3:00 pm
Location: London

Re: Open Hardware robot - Rosmo - Looking for volunteer(s)

Post by Bance »

Looks like I have to make a sandwich :lol: :lol: :lol:
Sam_uk
Posts: 39
Joined: Sat May 07, 2022 11:16 pm

Re: Open Hardware robot - Rosmo - Looking for volunteer(s)

Post by Sam_uk »

:)

Just found this photo of the encoder/motor holder

Image

https://github.com/rosmo-robot/Rosmo_3D ... coder.jpeg
Last edited by Sam_uk on Fri May 13, 2022 7:51 pm, edited 1 time in total.
User avatar
Kunda1
Veteran
Posts: 12561
Joined: Thu Jan 05, 2017 9:03 pm

Re: Open Hardware robot - Rosmo - Looking for volunteer(s)

Post by Kunda1 »

(You need to link directly to the image)

Code: Select all

https://raw.githubusercontent.com/rosmo-robot/Rosmo_3D/main/V2/images/encoder.jpeg
Alone you go faster. Together we go farther
Please mark thread [Solved]
Want to contribute back to FC? Checkout:
#lowhangingfruit | Use the Source, Luke. | How to Help FreeCAD | How to report FC bugs and features
freedman
Veteran
Posts: 2543
Joined: Thu Mar 22, 2018 3:02 am
Location: Washington State, USA

Re: Open Hardware robot - Rosmo - Looking for volunteer(s)

Post by freedman »

Just a thought about tracks; they are very inefficient for turning. How about making the idler/drive wheels with a couple grooves and use o-rings. Not sure what the environmental requirements are for the device, cat hair could be problem :) .

The o-rings placed around each wheel might also give a measure of traction from drive to track if that is a problem.
Bance
Veteran
Posts: 2602
Joined: Wed Feb 11, 2015 3:00 pm
Location: London

Re: Open Hardware robot - Rosmo - Looking for volunteer(s)

Post by Bance »

I'll need to see if I can get both encoders to be the same way up (for easier wiring,) but it's a start.....

I made it in two pieces for easier printing.The encoder board needs to be drilled?
rob.png
rob.png (158.95 KiB) Viewed 512 times
https://www.dropbox.com/s/0nn6jsv5yfklb ... FCStd?dl=0
Sam_uk
Posts: 39
Joined: Sat May 07, 2022 11:16 pm

Re: Open Hardware robot - Rosmo - Looking for volunteer(s)

Post by Sam_uk »

Looking great!

The encoders come with the mounting holes, they don't need drilling

Image

What's the best way to explode a model in FreeCAD? I've installed https://github.com/JMG1/ExplodedAssembly but can't work out how to use it.
Bance
Veteran
Posts: 2602
Joined: Wed Feb 11, 2015 3:00 pm
Location: London

Re: Open Hardware robot - Rosmo - Looking for volunteer(s)

Post by Bance »

Sam_uk wrote: Sat May 14, 2022 9:32 amThe encoders come with the mounting holes
But they don't align with anything useful.
Sam_uk wrote: Sat May 14, 2022 9:32 amWhat's the best way to explode a model in FreeCAD?
For checking parts is probably best to make everything invisible, then go back select the item for inspection and make it visible (Space-Bar)
Post Reply