Ion Systems - Build progress log

[adamclark]

you should try sponsorship from Oreo's

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[Limitaneus]

+1 for demented swirling murderbiscuit. =]

[TechAUmNu]

It looks like a demonic Oreo

You could make the teeth stronger and easier to mount with a small alteration to the ring:



If you add some ramps (light grey) around the teeth to form a flat bottomed pocket, the teeth will be easier to fit and weld to the ring and should be a little more resistant to tearing out.

For some reason i never thought to cut the ring with flats on it lol.

Are those ramps part of the cut ring i take it?

[overkill]

Yes, I just made them a different colour to make it more obvious the ring was thicker.

[typhoon_driver]

I'd really just dump the omni drive system and go conventional with 2wd. You've got enough of a pain in the arse building a ring spinner powered by brushless motors.

[TechAUmNu]

I'd really just dump the omni drive system and go conventional with 2wd. You've got enough of a pain in the arse building a ring spinner powered by brushless motors.

I don't think it's going to be that bad. I would rather try something completely off the wall now and if it doesn't work great then go to 2wd for the next series. (Also we need something academically interesting for the university to help fund it.)

[typhoon_driver]

Up to you guys of course. I'd say that going 2wd now with the proviso of an omni drive system down the line gives scope for the project to grow (something academic types all love). Trying to design a machine to survive 50kJ plus impacts and continue to dish them out is no trivial matter in itself.

[adamclark]

Omni mixer, job done - http://www.robotlogic.com/product_omx3.html

I use their standard mixer and its a doddle, plus invert at the flip of a switch

[supernova]

Adam, I'm trying to set up a IMX-1 and having a bit of trouble, did you get yours set up easily? I can get it to work roughly, but its not centred, so when the stick is centre, the wheels still spin.

[adamclark]

Yes, it worked right away, perhaps some trimming on your stick position to cure that dead band area ?

[TechAUmNu]

Found out the robot was almost 20kg overweight so had to ditch the Hardox top and bottom armor, reduce tooth thickness to 25mm and take out a lot of material from the skateboard wheel supports. We also are going to 3d print pretty much everything internal that isn't a motor or axle mount.

Spent about 15 hours on the CAD over the weekend, and ordered the VESCs, drive motors and OMX-3 mixer.

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[overkill]

I like the profile on the teeth, its a shame you had to thin them down. So the top & bottom armour rings are just screwed into the 8mm aluminium plates now? Given how easily I had 10mm ali bent in featherweights, its not going to last long. 3D printed internal parts can work well if they are thick and printed with 100% in-fill, but its risky to use them for anything structural. If possible, prototype parts with 3D printing and then mill them from HDPE, nylon or acetal for extra strength.

[TechAUmNu]

Its 15mm aluminium now, 25.6Kg for them both. I am quite worried about bending, so there will be lots of support pillars going between them, mostly in areas where things are attached to them.

We have some Nylon Alloy910 which is pretty ridiculous how strong it is. Should be fine at 100% as long as it doesn't suffer any major impacts.

We also have a major price problem, the current estimate is like £6500 for the whole thing. Which is just a tad more than we want to spend...

[TechAUmNu]

I wonder if adding a thin layer of HDPE would help at all, to act as a spoil plate for the aluminium underneath. Might help to absorb some of the impacts from axes.

[Gabe01]

I agree with Gary, keep it super simple. By all means use 3D printed parts, just remember that they break easily.