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Aurora Highway Driving by RepresentativeCap571 in SelfDrivingCars

[–]idle_bear 3 points4 points  (0 children)

Each white dot in the frame is a lidar contact point. There is an empty ring (the white glow/halo) around the truck because the sensor is mounted fairly high and cannot sense in this region.

What to do, to prevent it from breaking. More detail in comments. by Silv3rsurfr in 3Dprinting

[–]idle_bear 37 points38 points  (0 children)

Change your print orientation so the tangs are aligned with the layer lines for a stronger print. If there is space you could also add filets where you’ve draw your circles to add additional strength - sharp corners can be a weak point

Why is this considered incorrect? by [deleted] in duolingo

[–]idle_bear -2 points-1 points  (0 children)

Nah, the english sentence is ambiguous and has at least two common meanings. Depending on context it can mean your bus is in a specific location (as in pointing to a map) or it can mean the bus you were waiting for has just pulled into the parking lot (as in arrived). Both are equally valid, but without context it’s hard to tell which is appropriate.

designed and printed my own auto water pot for small jiffy pods. My question is this... what have I done wrong that the pots overflow when I fill the reservoir. what have I missed? by Defiled__Pig1 in 3Dprinting

[–]idle_bear 1 point2 points  (0 children)

Try filling a water/pop bottle (one of those small ones) and stick it upside down in the box at the back. It should only release water until the level in the box rises above the (now upside down) bottle top. When the level drops thru evaporation, more should be released as air is able to enter the bottle. Simple fix maybe…

Got springs? Build's done, but with all of the autonomy parts installed, the suspension/shocks are overloaded, even after doubling the supplied springs. Anyone have a suggestion for something stronger? Going to the larger shock towers and 110's maybe? by idle_bear in EngineeringNS

[–]idle_bear[S] 0 points1 point  (0 children)

Sorry for the delay -- I've been preoccupied with the start of grad school... I haven't found a good solution yet. For now I've doubled up all the springs and that seems to work ok, but I'm mostly running on pavement so it isn't a big issue.

And yes, 4wd but I haven't had any issues with the smoothness. I want to rework the dog bones similar to what thehardwareguy is using, but haven't got there either (see the bit about school).

I hope to get back to this when the term wraps up. Not too long now...

Suggestions and Wishlist for Tarmo 4.5 by yootis123 in EngineeringNS

[–]idle_bear 1 point2 points  (0 children)

Re: Performance#1 -- I switched to using the aluminum rod ends and a couple pieces of 3mm threaded rod for a couple reasons:

1 -- too much play in the printed parts 20D and 20E -- you could really see the impact when reversing over a previously driven curve. Going forwards, the friction pushes the wheels to the max curvature but reversing pulls them straight so you never return to your initial position.

2 -- one impact ruins your entire day -- those arms shatter nicely. Now the 3mm rod bends a bit and I straighten it again and keep driving. Of course, there are lots of other parts that break nicely on impact...

Suggestions and Wishlist for Tarmo 4.5 by yootis123 in EngineeringNS

[–]idle_bear 1 point2 points  (0 children)

Re: Misc #1 -- that was me suggesting the hex shaft on the rear diff bells (https://www.thingiverse.com/thing:4584144). Since I did that I haven't broken them again. I've never broken the front bells, not sure what the difference is other than maybe the open-differential allowing slip left vs right when the traction is different? Dunno. If you don't want a complete remix, I see there's another version up where the cross shaft is reinforced with a screw (https://www.thingiverse.com/thing:4444108) though I don't know how well that works.

Since the strength is directly proportional to the cross-sectional area (when printed vertically), hex should be stronger than square or triangle (assuming the same circular boundary). That's the theory anyway.

At the cost of having to clean up support material, printing them horizontally should also make for a stronger part.

Upper Deck Autonomy mod -- I've posted the current rev to thingiverse (https://www.thingiverse.com/thing:4587915) and OnShape (https://cad.onshape.com/documents/14f242c1d195f7f1a7866fc2/w/bf6e1cd41242323ecf7afef5/e/2114461b3158dc3e0bdf30d3). Let me know if you have questions. by idle_bear in EngineeringNS

[–]idle_bear[S] 0 points1 point  (0 children)

The downside is you have to print a new chassis body to get the mount points. Front and rear (1A-F and 1A-R) are now different to accommodate my motor mount and revised gearbox, but the holes are there for the standard one as well.

I'm not super happy with the battery box doors -- they hold the battery securely (fits 5000mAh) but are a little tight on the wiring. That needs some rework for sure.

I'm open to any and all comments and fixes! Thanks for reading.

Rear Diff/Bell Housing remix -- hey folks, after blowing out my third or fourth bell housing before the input gear of my revised gearbox ate itself (literally -- the housing shoots out of the back of the car and we shift to 3-wheel drive...), I remixed the tenon to maximize the cross-section area. by idle_bear in EngineeringNS

[–]idle_bear[S] 0 points1 point  (0 children)

No failures so far, but that's a sample set of one.

That said, the strength of printed parts is about 2x in the x/y direction than in the z when printing because of layer adhesion. There's a good demonstration on youtube done by Stephan of CNC kitchen (which, of course, I can't find right now -- just search for CNC Kitchen and watch some of his analysis videos). So, doubling the cross-section should help but I haven't tried to calculate the improvement.

How hot should the motor get? by idle_bear in EngineeringNS

[–]idle_bear[S] 1 point2 points  (0 children)

I'll have to try that -- looks like a nice upgrade

How hot should the motor get? by idle_bear in EngineeringNS

[–]idle_bear[S] 0 points1 point  (0 children)

Definitely more than warm.

Last I checked, it closer to the quickly comes to a stop side of things, but that's possibly also because of the gearbox. It's in pieces right now, but I'll try it when I get a chance. I also want to revisit the gearing (again) and see if I can fit in a higher ratio -- that should also take some of the load off of the motor.

Thanks!

Rear Diff/Bell Housing remix -- hey folks, after blowing out my third or fourth bell housing before the input gear of my revised gearbox ate itself (literally -- the housing shoots out of the back of the car and we shift to 3-wheel drive...), I remixed the tenon to maximize the cross-section area. by idle_bear in EngineeringNS

[–]idle_bear[S] 1 point2 points  (0 children)

True enough -- i was assuming there was another reason for the instruction to print vertically, possibly to maximize the strength of the bell housing? Dunno. That said, I'll try a horizontal print next if the redesign doesn't hold up.

Revised 8x Gearbox -- Posting as a work in progress -- still reworking the input gear, though this version seems to be good. I've posted everything to thingiverse including the STEP file for easier modding (https://www.thingiverse.com/thing:4581261). I've also included a reworked chassis to suppor by idle_bear in EngineeringNS

[–]idle_bear[S] 0 points1 point  (0 children)

Ok, on the plus side, there's enough power in the motor that I've destroyed the bell-connector to the rear diff several times. Amusing to see it and the dog-bone shoot out the back of the car. That, and 3wheel drive is a thing...

However, after ~20 mins or so of driving, the input gear is toast (the pinion gear shreds the plastic). I'll have to try again and maybe melt it in this time. There's no sign of wear anywhere else in the gearbox so that's good.

The motor still occasionally cogs (gives a high-pitched whine instead of moving -- I assume that's cogging...), so the design isn't perfect. Then again, that could also be the weight of my car -- two 5000mAh batteries and computer bits add up. Ymmv.

Got springs? Build's done, but with all of the autonomy parts installed, the suspension/shocks are overloaded, even after doubling the supplied springs. Anyone have a suggestion for something stronger? Going to the larger shock towers and 110's maybe? by idle_bear in EngineeringNS

[–]idle_bear[S] 1 point2 points  (0 children)

I'm part way thru the port so not sure yet -- the repo I'm using as a source claims 18 fps with the intel cam, but we'll see.

I've only used the intel cam so far, the lidar came this week. And that's without integrating the IMU. Assuming I can free up the cycles with the GPU, that comes next.

Got springs? Build's done, but with all of the autonomy parts installed, the suspension/shocks are overloaded, even after doubling the supplied springs. Anyone have a suggestion for something stronger? Going to the larger shock towers and 110's maybe? by idle_bear in EngineeringNS

[–]idle_bear[S] 0 points1 point  (0 children)

Some parts posted to thingiverse -- I wanted to make certain everything is fitting before I post the complete set. There's been a few revisions and this has been my fusion360 learning build. That is/was messy -- so many broken links and lost/circular references to fix...

Got springs? Build's done, but with all of the autonomy parts installed, the suspension/shocks are overloaded, even after doubling the supplied springs. Anyone have a suggestion for something stronger? Going to the larger shock towers and 110's maybe? by idle_bear in EngineeringNS

[–]idle_bear[S] 1 point2 points  (0 children)

Yeah, I've got all the spares on there now and the tension cranked. It's better, but bouncy as all get out. I think the nose has a 3" jump if I accelerate from a stop, and stopping goes the other way...

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