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Roboting: A Guide for Total Noobs

Brian Gray

By: Brian Gray
New: 11-08-2018 11:26 AM
Updated: 11-13-2018 11:36 AM
Total downloads: 989 times


A basic, yet thorough, guide to common practices, available materials and COTS solutions for novice FRC members.

This guide was began as a simple reference for new team members and kept growing in size and scope over a 2 month period between May and July 2018. It starts simple with wheel types and assembly, to drivetrains, and eventually onto wiring and controls, where it ends abruptly.

This is still very much a work in progress and is not presented here as a final document.

As this was originally purely intended for in-house use, many graphics and snippets of text were liberally appropriated along the way as the project progressed. The intention was not to outright steal, but to illustrate ideas along the way where time was limited. That said I did create many of the graphics within, so if I were a DJ it'd be called sampling.

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11-08-2018 01:03 PM

kristinweiss


Unread Re: paper: Roboting: A Guide for Total Noobs

This is awesome! Thanks for sharing it!



11-08-2018 01:14 PM

Brian Gray


Unread Re: paper: Roboting: A Guide for Total Noobs

I've been debating whether to upload this or not, but here goes:

This guide was originally intended for novices joining our team and was written over a 2-month period, following the epic spanking that was our 2018 FRC season. It's a work in progress and is somewhat disjointed in places.

If you are like me and have students who repeatedly propose using "a thing...that goes into a thing...and sort of...does stuff" during brainstorming and prototyping stages, then this might be for you. It's more to acquaint students with the different "things" in FRC and give brief descriptions of the "stuff" they can do.

It is purposely designed for those with short attention spans and features a lot of pictures and brief snippets of text.

It is, however, totally not finished, hence the rather abrupt ending.

Please let me know what you think and any changes you suggest.

Also, I did a lot of hasty Google image searches, so apologies to anyone who sees their photos or graphics used without permission.



11-08-2018 01:31 PM

Andrew_L


Unread Re: paper: Roboting: A Guide for Total Noobs

This is amazing, I love it. Thank you so much for sharing!

If you ever make any revisions, I'd suggest adding flex wheels to the wheel section! They've got tons of options in durometers and sizes, and are fantastic for intakes and other roller subsystems. I doubt I'll design a robot without them ever again.



11-08-2018 01:47 PM

Brian Gray


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by Andrew_L View Post
This is amazing, I love it. Thank you so much for sharing!

If you ever make any revisions, I'd suggest adding flex wheels to the wheel section! They've got tons of options in durometers and sizes, and are fantastic for intakes and other roller subsystems. I doubt I'll design a robot without them ever again.
I believe they are referred to as compliant wheels in the wheel subsection titled "other wheels"...or something like that.



11-08-2018 01:48 PM

philso


Unread Re: paper: Roboting: A Guide for Total Noobs

That's very comprehensive! Thanks for all your hard work.



11-08-2018 01:55 PM

Andrew_L


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by Brian Gray View Post
I believe they are referred to as compliant wheels in the wheel subsection titled "other wheels"...or something like that.
Gotcha - the section only mentions AndyMark Compliant Wheels, which are a specific type of wheel only available through AndyMark. Since other sections mentioned multiple variations and suppliers for different robot parts, it seemed like Flex Wheels were being left out. There's definitely similarities between the two, but they're different in terms of use cases and available mounting styles. I figured I'd bring it up since more options for teams is never a bad thing.

That aside, this guide is going to be mandatory reading for my team. The thoroughness makes it an invaluable training resource that I can't wait for my students to use!



11-08-2018 02:08 PM

Brian Gray


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by Andrew_L View Post
Gotcha - the section only mentions AndyMark Compliant Wheels, which are a specific type of wheel only available through AndyMark. Since other sections mentioned multiple variations and suppliers for different robot parts, it seemed like Flex Wheels were being left out. There's definitely similarities between the two, but they're different in terms of use cases and available mounting styles. I figured I'd bring it up since more options for teams is never a bad thing.

Completely understand. I tried to go with the generic/proper term for each component, but a few placeholders got left along the way. In this particular case I found a vendor who makes urethane wheels and rollers that they referred to as compliant, so I took that as corroboration. This was a tricky one.

Quote:
That aside, this guide is going to be mandatory reading for my team. The thoroughness makes it an invaluable training resource that I can't wait for my students to use!
Wow. I'm humbled. Thanks.



11-08-2018 02:16 PM

trycatch


Unread Re: paper: Roboting: A Guide for Total Noobs

I haven't finished looking through this, but this legit looks incredible. I wish I'd had this when we started years ago. I've already sent this to a rookie team in our area.



11-08-2018 03:25 PM

Ryan Dognaux


Unread Re: paper: Roboting: A Guide for Total Noobs

This is seriously fantastic. Nice work and thanks for sharing it.



11-08-2018 03:25 PM

Andy Baker


Unread Re: paper: Roboting: A Guide for Total Noobs

Brian Gray, you are my hero. This is fantastic!

Many, many people will be using this great resource during this year and years to come.

Sincerely,
Andy B.



11-08-2018 05:17 PM

tjf


Unread Re: paper: Roboting: A Guide for Total Noobs

Brian,

What a fantastic collection of resources you've put together! That being said, I've noticed some of my own photos and resources thrown into it (Specifically the latch section and those immediately before and after, as indicated by choice in photos.), as well as that of others that I've used in sources I suspect you used.

You openly admit that it's incomplete; In a more complete version, do you intend to link / reference the year & team of the robot you're exhibiting a feature of? I specifically did that myself in my own resources, as I knew that some people wanted to do additional research on their own, and a team number and season is a good starting point.

Thanks for putting together a cohesive collection of resources, I'm sure this will be used for many years to come!



11-08-2018 07:13 PM

sanddrag


Unread Re: paper: Roboting: A Guide for Total Noobs

This is amazing. Perhaps the best I've ever seen. I can't begin to imagine the time this must have taken to put together. You have done an incredible service for the FIRST Robotics community with this one. The students you work with are so fortunate to be guided by someone with your drive and passion for it. Thank you for sharing!



11-08-2018 07:16 PM

Katie_UPS


Unread Re: paper: Roboting: A Guide for Total Noobs

There is so much information that I could populate a preseason from this single resource! This is fantastic!

Just as a suggestion that will help teams make weight - not all gears need to be steel. My team has found that most gears are fine as 7075 aluminum (a la VEXPro) and typically we only need steel gears for very high loads (ie catapult crank, pinions).

Also, I highly recommend the pixy (https://pixycam.com/pixy-cmucam5/) as another camera option - its cheap and easy and makes vision tracking very accessible.



11-08-2018 07:28 PM

AllenGregoryIV


Unread Re: paper: Roboting: A Guide for Total Noobs

So I like a lot of this presentation but I noticed some of the information is misleading or just incorrect in places. I'd be worried about just giving this to new students.

The slide on live vs dead axles is particularly troubling. The descriptions of using omni wheels in tank drives seems inconsistent as well with some of your example photos. You also mention a limit of only 4 air tanks on a robot that hasn't been in the rule book for over a decade. A lot of FTC specific items get used in example photos that don't really make sense, like tilerunner.



11-08-2018 09:17 PM

Brian Gray


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by Ryan Dognaux View Post
This is seriously fantastic. Nice work and thanks for sharing it.
OMG FUN...eeeeeeee!!!!!

Quote:
Originally Posted by Andy Baker View Post
Brian Gray, you are my hero. This is fantastic!

Many, many people will be using this great resource during this year and years to come.

Sincerely,
Andy B.
This made my day. Your presentations from 10 years ago were really what inspired me to start work on this. It started with a few tweaks at first and then scope creep happened. I'm sure you noticed your sections on arm forces and torque.

Quote:
Originally Posted by tjf View Post
Brian,

What a fantastic collection of resources you've put together! That being said, I've noticed some of my own photos and resources thrown into it (Specifically the latch section and those immediately before and after, as indicated by choice in photos.), as well as that of others that I've used in sources I suspect you used.

You openly admit that it's incomplete; In a more complete version, do you intend to link / reference the year & team of the robot you're exhibiting a feature of? I specifically did that myself in my own resources, as I knew that some people wanted to do additional research on their own, and a team number and season is a good starting point.

Thanks for putting together a cohesive collection of resources, I'm sure this will be used for many years to come!
So, about that. When I started work on this, there was no one resource that was quite what I wanted, but then you uploaded Encyclopedia Robotica and it was amazing. So amazing that I really wasn't sure if it was worth continuing. I do know that I borrowed liberally from it, but continued to make changes and edits to where it was hard to remember what was stolen and what was not. My justification was that this was designed for a handful of rural students out in the middle of nowhere.



Quote:
Originally Posted by Katie_UPS View Post
Just as a suggestion that will help teams make weight - not all gears need to be steel. My team has found that most gears are fine as 7075 aluminum (a la VEXPro) and typically we only need steel gears for very high loads (ie catapult crank, pinions).

Also, I highly recommend the pixy (https://pixycam.com/pixy-cmucam5/) as another camera option - its cheap and easy and makes vision tracking very accessible.
Good point. We've used aluminum gears.

I had planned to include Pixycam towards the end.

Quote:
Originally Posted by AllenGregoryIV View Post
So I like a lot of this presentation but I noticed some of the information is misleading or just incorrect in places. I'd be worried about just giving this to new students.

The slide on live vs dead axles is particularly troubling. The descriptions of using omni wheels in tank drives seems inconsistent as well with some of your example photos. You also mention a limit of only 4 air tanks on a robot that hasn't been in the rule book for over a decade. A lot of FTC specific items get used in example photos that don't really make sense, like tilerunner.
The FTC specific items were shown because they illustrated the point I was trying to make. The Tilerunner was chosen because I couldn't find any suitable pics of the FRC KOP chassis and the wheel placement is similar. I believe the other pic was for direct gearing. That was just a lazy fix, probably not the best example.

In writing this, there was no outline, just a wishlist of topics and things sort of snowballed and were reiterated several times. Sections were deleted or moved several times and info was hastily researched in places where I felt I needed to double check on things. By the time I took a break from it, I was pretty sure that it was rife with mistakes, so I was hesitant to post it.

I'm not an engineer. I'm just an hourly employee who works in the automotive industry and this was almost entirely written on 20 minute breaks and lunches over a 2 month period. My background is in art and literature, but I grew up programming on C64s and learning electronics from Forest Mims manuals. I know some stuff, but I'm far from being classically trained.

So bearing that in mind, if the coach of a hugely successful team with boatloads of funding finds a few boo-boos in all of this, I probably did okay.



11-08-2018 09:41 PM

scottandme


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by Brian Gray View Post
<snip>

So bearing that in mind, if the coach of a hugely successful team with boatloads of funding finds a few boo-boos in all of this, I probably did okay.
Not sure if attacking Allen is the best way to go here, since he maintains a huge assortment of FRC resources, and knows what goes into maintaining and updating something like this. Also unclear how his team budget has anything to do with this.

The document is a great primer, and is well laid out, but there are definitely some incorrect or misleading statements. How about being open to revision instead of attacking people who suggest edits? If you intend this to be a helpful document for new students, you should be open to making edits.



11-08-2018 09:43 PM

AllenGregoryIV


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by Brian Gray View Post
So bearing that in mind, if the coach of a hugely successful team with boatloads of funding finds a few boo-boos in all of this, I probably did okay.
Honestly wasn't trying to come off as insulting, if I did I apologize. This is a good resource. I was just giving a warning to other teams since Andrew L, Andy Baker, and others endorsed it so heavily, that teams should do some due diligence before giving it to "noobs" to learn from.



11-08-2018 09:57 PM

Mike Schreiber


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by Brian Gray View Post
I'm not an engineer. I'm just an hourly employee who works in the automotive industry and this was almost entirely written on 20 minute breaks and lunches over a 2 month period. My background is in art and literature, but I grew up programming on C64s and learning electronics from Forest Mims manuals. I know some stuff, but I'm far from being classically trained.

So bearing that in mind, if the coach of a hugely successful team with boatloads of funding finds a few boo-boos in all of this, I probably did okay.
Allen you've officially made it! You're hugely successful and have all the money!

This is a good resource, but I think Allen and others were just providing constructive criticism so it can be improved. It's a great starting point and a good thing to show your team. No resource is perfect, and we can all learn from reviewing these types of presentations.



11-08-2018 10:36 PM

Brian Gray


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by AllenGregoryIV View Post
Honestly wasn't trying to come off as insulting, if I did I apologize. This is a good resource. I was just giving a warning to other teams since Andrew L, Andy Baker, and others endorsed it so heavily, that teams should do some due diligence before giving it to "noobs" to learn from.
Despite how crappy my reply now sounds in retrospect, I didn't take offense and meant no harm. I follow your team's blog and have read several of your resources, so I'm actually honored to receive your feedback

Quote:
Originally Posted by Mike Schreiber View Post
No resource is perfect, and we can all learn from reviewing these types of presentations.
I felt attacked when I read that on Mentor Built last week. That and the piece about LRIs. Yow!



11-08-2018 11:59 PM

Mk.32


Unread Re: paper: Roboting: A Guide for Total Noobs

As a person you have "liberally appropriated" CAD renderings from. I am slightly also concerned about the mis-information as well.

It looks good and but there's a lot of small details that are incorrect or used without context leading to a mis-understanding.

Some examples:

Under the wcd you mentioned "held in place by bolt-on stel blocks" none of the designs you showered were steel, and I don't think anyone has ever used steel in a wcd bearing block

Motor section under 775pro "Will let out magic smoke if stalled for more than 15-17 seconds." If you stall anywhere close to full power, it'll melt in under a few seconds as tested by vex.

Under "Brushed DC Gearmotors" you have a Neverest 60/Window motors under "higher toques" which also isn't really true. As any of the common motors will be much more powerful with a gearbox (which are easy to add).

The NIDEC motor isn't even close to "lightweight" for the power you get out of it nor "efficient/consistent"...

I would worry about sending this to new students just because if they take it as gospel (which new students generally do with the first "document" they read). There's enough incorrect information to cause issues down the road.

Also calling image stealing "dj sampling" doesn't really make it right. Last time I checked when you google a image it generally gives you a source which isn't terribly hard to include.



11-09-2018 07:39 AM

Brian Gray


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by Mk.32 View Post
Under the wcd you mentioned "held in place by bolt-on stel blocks" none of the designs you showered were steel, and I don't think anyone has ever used steel in a wcd bearing block
I would agree. I've never used steel, nor do i know anyone who has.

Quote:
Originally Posted by Mk.32 View Post
Motor section under 775pro "Will let out magic smoke if stalled for more than 15-17 seconds." If you stall anywhere close to full power, it'll melt in under a few seconds as tested by vex.
This has also been my experience as well. I suspect this was a typo that stuck.

Quote:
Originally Posted by Mk.32 View Post
Under "Brushed DC Gearmotors" you have a Neverest 60/Window motors under "higher toques" which also isn't really true. As any of the common motors will be much more powerful with a gearbox (which are easy to add).
I grouped motors with preinstalled gearboxes, such as window motors and Neverrests, together with the other FRC legal motors. By stating "higher torque", I was referring to it's performance relative to its theoretical self sans gearing (such as a Denso throttle motor vs a window motor), versus, say, comparing it to a CIM or other legal motor.

Quote:
Originally Posted by Mk.32 View Post
The NIDEC motor isn't even close to "lightweight" for the power you get out of it nor "efficient/consistent"...
The NIDEC motor was basically irrelevant last year, and I felt it barely merited inclusion, but I did so on the off chance it was the first of more BLDCs to come. That said, brushless DC motors in general are 10-15% more efficient and have the potential for greater power density.

Quote:
Originally Posted by Mk.32 View Post
Also calling image stealing "dj sampling" doesn't really make it right. Last time I checked when you google a image it generally gives you a source which isn't terribly hard to include.
Again, this was created for approximately 12-15 students in a school district where tractors drive down the road. I had no intention of sharing it publicly (until yesterday, on a whim), so I wasn't concerned about including citations. I don't have 35 mentors. I have myself and 5-6 others who stop by to help occasionally when they feel like it. I was just trying to come up with something to help my team. If you would like your work removed just let me know on which page it's located and it's gone.



11-09-2018 07:45 AM

marshall


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by Brian Gray View Post
Again, this was created for approximately 12-15 students in a school district where tractors drive down the road. I had no intention of sharing it publicly (until yesterday, on a whim), so I wasn't concerned about including citations. I don't have 35 mentors. I have myself and 5-6 others who stop by to help occasionally when they feel like it. I was just trying to come up with something to help my team. If you would like your work removed just let me know on which page it's located and it's gone.
I think you have a misunderstanding of how fair use works. Let’s ignore that though and instead focus on improving your resource.

I don’t think a single soul has asked you to remove anything so far but a couple people are asking you to credit them for their work. It seems like if you are willing to remove content then you should be willing to give attribution to the creators. Just a thought.



11-09-2018 08:04 AM

Brian Gray


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by marshall View Post
I think you have a misunderstanding of how fair use works. Let’s ignore that though and instead focus on improving your resource.

I don’t think a single sole has asked you to remove anything so far but a couple people are asking you to credit them for their work. It seems like if you are willing to remove content then you should be willing to give attribution to the creators. Just a thought.
That's fair enough. I would actually be open to collaborating with others on this if anyone is interested.



11-09-2018 09:43 AM

MrBasse


Unread Re: paper: Roboting: A Guide for Total Noobs

This is a wonderful resource and I hope to use it with some of our new members to get them up to speed, thank you!

But it got me wondering, why is there so much hatred for steel in FRC as a structural member? We use steel every year and stay under weight by 10-15 pounds. We also use aluminum regularly. But, I think that a blanket statement that says "Steel should only be used when it’s strength is crucial..." is misleading. Another benefit of steel is that it can be bent back into position multiple times without failing, can take impact fantastically well (never had a stress fracture with steel in 8 years), and can make use of a smaller profile than it's aluminum counterpart without compromising strength.

We often use .5 square .0625 wall steel tubing in place of 1x1 aluminum and have never had an issue. Our entire superstructure was steel this year aside from our arm and we weighed in at 108 pounds (with a battery).

No arguments that aluminum has it's place and is a fantastic material for a lot of FRC structural members, but steel shouldn't be dismissed so quickly either.



11-09-2018 09:48 AM

Monochron


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by Brian Gray View Post
Again, this was created for approximately 12-15 students in a school district where tractors drive down the road.
If you take the feedback people are giving (even though they might be a bit dismayed with some of the things you included), this could be one of the most useful rookie resources I have seen. It is accessible, eye catching, and detailed. Keep soliciting feedback and you'll probably get fantastic information from a lot of really experienced people.
I've already shared it with my team and hope to share further updates you make to it.

Credit the peeps, improve the deets, enjoy some conceit.



11-09-2018 01:06 PM

Mk.32


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by Brian Gray View Post
Again, this was created for approximately 12-15 students in a school district where tractors drive down the road. I had no intention of sharing it publicly (until yesterday, on a whim), so I wasn't concerned about including citations. I don't have 35 mentors. I have myself and 5-6 others who stop by to help occasionally when they feel like it. I was just trying to come up with something to help my team. If you would like your work removed just let me know on which page it's located and it's gone.
I am not sure if you're trying to make me feel sympathy because you guys are a rural team or whatever.

But I often create presentations/training materials for the team's I've been on, and it's usually just myself doing the work, so yes I have spent plenty of time googling images and using them. But 99.9% never make the day of light (and the ones that do get a 2nd go though to check citations/editing), releasing it "on a whim" doesn't make it okay.

And as Marshall has said no one is asking you to remove images/graphics. Since we are all here to share and learn but a little credit would be nice.



11-09-2018 02:42 PM

xszym


Unread Re: paper: Roboting: A Guide for Total Noobs

I really love this guide, because of pictures. Im sure it will be easy understable to new members. Thanks for making and sharing this!



11-09-2018 04:02 PM

Brian Gray


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by MrBasse View Post
steel shouldn't be dismissed so quickly either.
Agreed. I was just repeating the rule of thumb that I've heard over and over. As long as your design does what you want and you make weight do what you want.

Quote:
Originally Posted by Monochron View Post
Credit the peeps, improve the deets, enjoy some conceit.
Well put. One thing I won't do is conform to anyone else's style or format. It's not a white paper, nor is it intended to be one. It's designed to be engaging for people with short attention spans.

Quote:
Originally Posted by Mk.32 View Post
a little credit would be nice.
Point taken. Is it just the one WCD model or are there more?



11-09-2018 04:13 PM

GeeTwo


Unread Re: paper: Roboting: A Guide for Total Noobs

Totallly blown away. This tells everything a team member needs to know, apart from some fiddly details of their specialty. The level of detail is just right for those who can learn from reading and are motivated to do so.

That said, I have noticed a number of tweaks and tunes to suggest, and I will be putting these in a word or similar document and attaching here in coming days. Please understand in advance, my goal is to help you take a great resource into something even better.

Edit: Can't attach on this thread, so here it is, as a spoiler to reduce the "wall of text"

Spoiler for comments/critiques/corrections:
Definitely intended to help make this better, not tear it down!
  • 2: table of contents.
    • 1) Not sure if you have enough authoring software, but having links here would be awesome.
    • 2) #12, Control System overview - looks like you reused the title from #6. How about "Components which turn the designers' and driver's choices into what the robot does."?
  • 14: Make the point here that two support points are needed for cantilevered axles, and that the bolt-on blocks provide these.
  • 15: This does not agree with my understanding of "live" vs "dead" axles at all. Your description is of "driven" vs "undriven" wheels. What you show on the left side front and rear is only a "live axle" if the sprocket/pulley drives the axle, and through the axle, drives the wheel. A wheel with a "dead axle" may be driven through a sprocket or pulley coupled to the wheel directly, with the axle only serving as a pivot point for the wheel to spin about. The KoP chassis has what I would consider "dead axles" front and back, though all those wheels are driven.
  • 21: Pebbletop is noted primarily as providing a better coefficient of friction in the forward/reverse direction than as a scrub force -- ON CARPET. It works as sort of a paddlewheel in a carpet situation.
  • 29: Another con of ball casters is that they cannot be driven, or at least not easily.
  • 30: Major con of track tank drive is possible inability to turn, esp if track length is nearly as long as or longer than the spacing between the tracks.
  • slide 34: I would have three classes: skid/steer (what you call tank, and is also called differential these days), Holonomic (which would NOT include crab/swerve or octanum), and actuated/steered wheel drive trains (crab/swerve, octanum/butterfly, as well as auto/fire truck steering).
  • 37: 4W tank may be four "solid" wheels, provided that the wheelbase (distance from front to back wheels' interface with the road/carpet) is less than the track width distance between left and right wheels), assuming the same CoF in the forward vs sideways directions.
  • 39: Pro: better at handling ramps and other irregulatities than 6 wheel, less likely to high center. Also: may have wheels on a plane, provided corners are omnis.
  • 41: using pebbletop on the corners may also meet this method.
  • 44: I think you underestimate the difficulty of programming heres vs holonomic (omni/mecanum) drive trains; you make holonomic sound harder than swerve.
  • 45: I would state that this is often called "Holerith" in FRC. It is equivalent to Mecanum, apart from the gearing - Holerith must be 42% faster to be truly equivalent to mecanum.
  • 47: I thing you're understating the "pros" of having three wheels. Kiwi is remarkably insensitive to irregularities in the drive surface, compared to mecanum or Killough/X drive.
  • 48: Slide drive - Based on experience in 2015, I would never recommend a "fixed location" strafe wheel. Find a way to define how much weight the strafe wheel supports, e.g. through a pneumatic cylinder.
  • 49: I would consider Octanum/Butterfly less complex than crab/swerve.
  • 50: Here is where the rubber meets the road on Holonomic vs steering wheel drive systems. Steering wheels (swerve and crab) do NOT experience reduced pushing power. Their complexity, however, is even greater than holonomic
  • 54: Cons: can be hard to work on in the pits. Let me point you to a couple of mitigations I posted here: https://www.chiefdelphi.com/forums/s...d.php?t=166642 to simplify wheel and motor replacement.
  • 59: Should also note that welded joints are not repairable at competition.
  • 63, and nearby: 6063 (and 6061) are best noted for extrusions, and 5052 for sheet metal marts. 5052 is capable of being welded or bent without losing much strength, but the strength of 6061 and 6063 are greatly dependent on annealing and are reduced by bending and welding. 6061 is generally what you'll get at hardware stores and home centers; it is better at corrosion resistance, but less machinable than 6063, which is generally preferred for robots.
  • - Let me state that I do not have a lot of info on plastics, so I have let this section go.
  • 95: Scissor lefts can be made far more linear (bypassing the problem you note that "loads very high to raise at beginning of travel") by lifting at a different pivot point. If you lift at the pivot directly above the fixed point, the leverage/gear ratio becomes constant.
  • 99-101: I'm not entirely sure what point you’re trying to make here.
  • 104, etc - I noted a low emphasis on "intake mechanisms." These are usually at least as important as "moving" and "shooting" mechanisms.
  • 106: note that if your claw has rollers on both sides, they must move in opposite directions, requiring either two motors or a bit more complex gearing.
  • 112: note that intakes and shooters may sometimes be the same mechanism.
  • 121: I didn't get quite what the point of this one was.
  • 125: 1.0 gallon air tank max? where is this from?
  • 126: Max of 4 tanks? where is this specified? 3946 used 7 tanks this size in 2013, and I saw more on other robots then and in 2015.
  • 128: Most solenoid valves are "air piloted" - this means that air actually does the main switching, so they need a minimum supply air pressure (typically 30 psi) to function properly.
  • 131: Would emphasize Pro #6, "can maintain position at stall without failure".
  • 137: last bullet: Rules require one ESC per motor capable of 100+ watts of power.
  • 138/39: A bit out of date - the motor normally preinstalled on AM PG motors has always been an RS775-15, though the 9015 (RS500) was available as an option. AndyMark doesn’t sell the 9015 any longer.
  • 157: introduction of planetaries with no reason as to why these are not mormally used for drivetrains. One of the big ones is that they are rather sensitive to transverse loads on the output shaft, and another is that most PG gearboxes used in FIRST use the smaller 32dp gears.
  • 163+: transmission - no reference to using a shaft to transmit power
  • 166: reference to #35 as "standard bike chain". Bike chain is 1/2" pitch (#40), #35 is 3/8" pitch.
  • 168: "[belt] does not stretch like chain." Chain doesn't actually stretch, but rollers do wear in, which results in chain appearing to "stretch".
  • 171: cool - wasn't familiar with this at all!
  • 185: I think the title should be CAN motor controller. Bullets 3 - suggest “as an alternative” rather than “as well”, which implies it can do both at the same time.
  • 186-7-8: way more detail than most will need; I suggest some TLDR tags.
  • 206: here, when covering wire gauge would be a good time to talk about sizing wires to breakers and fuses (2018’s R59). Even if they don’t remember specifics, team members need to know this rule exists, and is for safety.
  • 222: single turn potentiometer shown; multi-turn potentiometers usually have the wipe at the end farthest from the shaft.
  • 224: TLDR: Actually, I think it's more like couting spokes as most encoders count many times per revolution.
  • 232/234: I would also include non-laser IR sensors. At short ranges (up to about a foot), they work great and are much less expensive than short-range ultrasonics or LIDAR
.



11-10-2018 01:26 PM

chrisrin


Unread Re: paper: Roboting: A Guide for Total Noobs

Best packaging I’ve seen - it is the visuals-centric approach that makes it special. You are a talented designer.

Agree it’s only right to include attributions... It’s what we tell students they must do, and what we demonstrate carries even more weight than what we tell.

Seems like you have several people who have already invested hours reviewing the guide and providing you the informational edits that will make it air tight as far as accuracy. Look at what Gus just did alone - amazing community here.

Kudos! I have shared already, and people love it!



11-10-2018 04:31 PM

Brian Gray


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by GeeTwo View Post
Edit: Can't attach on this thread, so here it is, as a spoiler to reduce the "wall of text"ER
This is exactly the kind of help that is constructive and greatly appreciated. So many good insights here. The amount of time you put into reviewing this will not be in vain.

This was started with the intention of keeping things brief for presentation purposes and then it just sort of got out of hand and grew to its current size. Eventually I just made myself stop before it turned into 300-400 pages. By then I couldn't pay anyone to read it, much less collaborate.

Quote:
Originally Posted by chrisrin View Post
Agree it’s only right to include attributions... It’s what we tell students they must do, and what we demonstrate carries even more weight than what we tell.

Seems like you have several people who have already invested hours reviewing the guide and providing you the informational edits that will make it air tight as far as accuracy. Look at what Gus just did alone - amazing community here.
Message received. In addition to Gus, I received a number of suggestions via PMs, which I will also use.



11-10-2018 10:10 PM

GeeTwo


Unread Re: paper: Roboting: A Guide for Total Noobs

Quote:
Originally Posted by Brian Gray View Post
This is exactly the kind of help that is constructive and greatly appreciated. So many good insights here. The amount of time you put into reviewing this will not be in vain.

This was started with the intention of keeping things brief for presentation purposes and then it just sort of got out of hand and grew to its current size. Eventually I just made myself stop before it turned into 300-400 pages. By then I couldn't pay anyone to read it, much less collaborate.
My pleasure! Let me know how else I can help.

I am certainly familiar with these things growing as you try to get in more detail. In my case, I usually limit the scope to let the detail in - this is definitely the bolder option.

Also, looking over my comments (which I can no longer edit):
34+: Another actuated drive type I haven't seen much lately is "lobster". This is typically a second set of skid/steer wheels perpendicular to the primary which can be pushed down to lift the main drive off the carpet. Sometimes the motors/gearboxes are re-used through bevel gears or other similar system, sometimes there are duplicate drive trains. There is also a butterfly variant called "grasshopper".
45: Not Holerith, but Killough for "X drive". Confusingly enough, in FTC and Vex they use Killough to refer to kiwi. I used Killough correctly a few items down.
63: parts, not marts
137: Note 100W is not the way the rules are stated, but this is effectively what they are according to the motor/controller lists.
157: Planetaries are more sensitive to radial forces because they usually only have a single bearing at the output, or perhaps two bearings next to each other. Providing a bearing at the end of the shaft would definitely mitigate this problem, but would not resolve the issue that 32dpi teeth are smaller and thus more sensitive to shock loads breaking them than 20dpi teeth, other things being equal.
232/234: Sharp (the copier company) makes some great, dirt cheap (many less than $5) IR sensors of both the beam break and rangefinder style. Sparkfun, Pololu, Adafruit, and RobotShop all carry many of these, sometimes with carriers to simplify connecting them to a DIO or Analog Input.



11-11-2018 06:08 PM

ChopinWood


Unread Re: paper: Roboting: A Guide for Total Noobs

Fantastic is an understatement, IMO. The breakdown, page layout, colors, pictures & illustrations make it super easy to consume for a noob! It is the opposite of typical guides which are usually boring or intimidating.

I've been looking for something like this for years, to help bringing students up to speed with design, as you can't start designing until you're familiar with the components used.

With all the great feedback you've gotten, especially from GeeTwo, your guide will become a more valuable treasure than it already is.

Thank you for sharing it with us!



Yesterday 06:45 AM

Zagar


Unread Re: paper: Roboting: A Guide for Total Noobs

What a great resource! Thank you for compiling all of this information into one place. With everything I read, and the adjustments, this will become a hand out for many teams, not just new teams. I'm looking forward to seeing the more finished product, understanding that this is truly a living document. Again, thank you Brian!!



Yesterday 11:47 AM

Brian Gray


Unread Re: paper: Roboting: A Guide for Total Noobs

Thanks for all the positive feedback, especially GeeTwo who really combed through this thing and put a lot of time into making improvements.

Roboting: A Guide for Total Noobs 10.5 (Revision list 11/12/2018)

The following is a list of corrections to be made in the next revision of this document as suggested in this thread.
Note: this does not include photo credits (and text credits, where and if applicable), which will be determined before the next release, after the below changes are made.


Spoiler for Revision List:
  • Andrew_L
    • suggest adding flex wheels to the wheel section! They've got tons of options in durometers and sizes, and are fantastic for intakes and other roller subsystems.
  • tjf
    • I've noticed some of my own photos and resources thrown into it (Specifically the latch section and those immediately before and after, as indicated by choice in photos.), as well as that of others that I've used in sources I suspect you used.

    • You openly admit that it's incomplete; In a more complete version, do you intend to link / reference the year & team of the robot you're exhibiting a feature of? I specifically did that myself in my own resources, as I knew that some people wanted to do additional research on their own, and a team number and season is a good starting point.
  • Katie_UPS
    • Just as a suggestion that will help teams make weight - not all gears need to be steel. My team has found that most gears are fine as 7075 aluminum (a la VEXPro) and typically we only need steel gears for very high loads (ie catapult crank, pinions).

    • Also, I highly recommend the pixy (https://pixycam.com/pixy-cmucam5/) as another camera option - its cheap and easy and makes vision tracking very accessible.
  • AllenGregoryIV
    • The slide on live vs dead axles is particularly troubling.

    • The descriptions of using omni wheels in tank drives seems inconsistent as well with some of your example photos.

    • You also mention a limit of only 4 air tanks on a robot that hasn't been in the rule book for over a decade.

    • A lot of FTC specific items get used in example photos that don't really make sense, like tilerunner.
  • Mk.32
    • Under the wcd you mentioned "held in place by bolt-on stel blocks" none of the designs you showered were steel, and I don't think anyone has ever used steel in a wcd bearing block

    • Motor section under 775pro "Will let out magic smoke if stalled for more than 15-17 seconds." If you stall anywhere close to full power, it'll melt in under a few seconds as tested by vex.

    • Under "Brushed DC Gearmotors" you have a Neverest 60/Window motors under "higher toques" which also isn't really true. As any of the common motors will be much more powerful with a gearbox (which are easy to add).

    • The NIDEC motor isn't even close to "lightweight" for the power you get out of it nor "efficient/consistent"...
  • GeeTwo
    • 2: table of contents.Not sure if you have enough authoring software, but having links here would be awesome.

    • #12, Control System overview - looks like you reused the title from #6. How about "Components which turn the designers' and driver's choices into what the robot does."?

    • 14: Make the point here that two support points are needed for cantilevered axles, and that the bolt-on blocks provide these.

    • 15: This does not agree with my understanding of "live" vs "dead" axles at all. Your description is of "driven" vs "undriven" wheels. What you show on the left side front and rear is only a "live axle" if the sprocket/pulley drives the axle, and through the axle, drives the wheel. A wheel with a "dead axle" may be driven through a sprocket or pulley coupled to the wheel directly, with the axle only serving as a pivot point for the wheel to spin about. The KoP chassis has what I would consider "dead axles" front and back, though all those wheels are driven.

    • 21: Pebbletop is noted primarily as providing a better coefficient of friction in the forward/reverse direction than as a scrub force -- ON CARPET. It works as sort of a paddlewheel in a carpet situation.

    • 29: Another con of ball casters is that they cannot be driven, or at least not easily.

    • 30: Major con of track tank drive is possible inability to turn, esp if track length is nearly as long as or longer than the spacing between the tracks.

    • slide 34: I would have three classes: skid/steer (what you call tank, and is also called differential these days), Holonomic (which would NOT include crab/swerve or octanum), and actuated/steered wheel drive trains (crab/swerve, octanum/butterfly, as well as auto/fire truck steering).

    • 34+: Another actuated drive type I haven't seen much lately is "lobster". This is typically a second set of skid/steer wheels perpendicular to the primary which can be pushed down to lift the main drive off the carpet. Sometimes the motors/gearboxes are re-used through bevel gears or other similar system, sometimes there are duplicate drive trains. There is also a butterfly variant called "grasshopper".

    • 37: 4W tank may be four "solid" wheels, provided that the wheelbase (distance from front to back wheels' interface with the road/carpet) is less than the track width distance between left and right wheels), assuming the same CoF in the forward vs sideways directions.

    • 39: Pro: better at handling ramps and other irregulatities than 6 wheel, less likely to high center. Also: may have wheels on a plane, provided corners are omnis.

    • 41: using pebbletop on the corners may also meet this method.

    • 44: I think you underestimate the difficulty of programming heres vs holonomic (omni/mecanum) drive trains; you make holonomic sound harder than swerve.

    • 45: I would state that this is often called "Killough" in FRC. It is equivalent to Mecanum, apart from the gearing - Killough must be 42% faster to be truly equivalent to mecanum. (Confusingly enough, in FTC and Vex they use Killough to refer to kiwi.)

    • 47: I think you're understating the "pros" of having three wheels. Kiwi is remarkably insensitive to irregularities in the drive surface, compared to mecanum or Killough/X drive.

    • 48: Slide drive - Based on experience in 2015, I would never recommend a "fixed location" strafe wheel. Find a way to define how much weight the strafe wheel supports, e.g. through a pneumatic cylinder.
    • 49: I would consider Octanum/Butterfly less complex than crab/swerve.

    • 50: Here is where the rubber meets the road on Holonomic vs steering wheel drive systems. Steering wheels (swerve and crab) do NOT experience reduced pushing power. Their complexity, however, is even greater than holonomic

    • 54: Cons: can be hard to work on in the pits. Let me point you to a couple of mitigations I posted here: https://www.chiefdelphi.com/forums/s...d.php?t=166642 to simplify wheel and motor replacement.

    • 59: Should also note that welded joints are not repairable at competition.

    • 63, and nearby: 6063 (and 6061) are best noted for extrusions, and 5052 for sheet metal parts. 5052 is capable of being welded or bent without losing much strength, but the strength of 6061 and 6063 are greatly dependent on annealing and are reduced by bending and welding. 6061 is generally what you'll get at hardware stores and home centers; it is better at corrosion resistance, but less machinable than 6063, which is generally preferred for robots.

    • Let me state that I do not have a lot of info on plastics, so I have let this section go.

    • 95: Scissor lefts can be made far more linear (bypassing the problem you note that "loads very high to raise at beginning of travel") by lifting at a different pivot point. If you lift at the pivot directly above the fixed point, the leverage/gear ratio becomes constant.

    • 99-101: I'm not entirely sure what point you’re trying to make here.

    • 104, etc - I noted a low emphasis on "intake mechanisms." These are usually at least as important as "moving" and "shooting" mechanisms.

    • 106: note that if your claw has rollers on both sides, they must move in opposite directions, requiring either two motors or a bit more complex gearing.

    • 112: note that intakes and shooters may sometimes be the same mechanism.

    • 121: I didn't get quite what the point of this one was.

    • 125: 1.0 gallon air tank max? where is this from?

    • 126: Max of 4 tanks? where is this specified? 3946 used 7 tanks this size in 2013, and I saw more on other robots then and in 2015.

    • 128: Most solenoid valves are "air piloted" - this means that air actually does the main switching, so they need a minimum supply air pressure (typically 30 psi) to function properly.

    • 131: Would emphasize Pro #6, "can maintain position at stall without failure".

    • 137: last bullet: Rules require one ESC per motor capable of 100+ watts of power. (Note 100W is not the way the rules are stated, but this is effectively what they are according to the motor/controller lists)

    • 138/39: A bit out of date - the motor normally preinstalled on AM PG motors has always been an RS775-15, though the 9015 (RS500) was available as an option. AndyMark doesn’t sell the 9015 any longer.

    • 157: introduction of planetaries with no reason as to why these are not mormally used for drivetrains. One of the big ones is that they are rather sensitive to transverse loads on the output shaft, and another is that most PG gearboxes used in FIRST use the smaller 32dp gears. Planetaries are more sensitive to radial forces because they usually only have a single bearing at the output, or perhaps two bearings next to each other. Providing a bearing at the end of the shaft would definitely mitigate this problem, but would not resolve the issue that 32dpi teeth are smaller and thus more sensitive to shock loads breaking them than 20dpi teeth, other things being equal.

    • 163+: transmission - no reference to using a shaft to transmit power

    • 166: reference to #35 as "standard bike chain". Bike chain is 1/2" pitch (#40), #35 is 3/8" pitch.

    • 168: "[belt] does not stretch like chain." Chain doesn't actually stretch, but rollers do wear in, which results in chain appearing to "stretch".

    • 171: cool - wasn't familiar with this at all!

    • 185: I think the title should be CAN motor controller. Bullets 3 - suggest “as an alternative” rather than “as well”, which implies it can do both at the same time.

    • 186-7-8: way more detail than most will need; I suggest some TLDR tags.

    • 206: here, when covering wire gauge would be a good time to talk about sizing wires to breakers and fuses (2018’s R59). Even if they don’t remember specifics, team members need to know this rule exists, and is for safety.

    • 222: single turn potentiometer shown; multi-turn potentiometers usually have the wipe at the end farthest from the shaft.

    • 224: TLDR: Actually, I think it's more like couting spokes as most encoders count many times per revolution.

    • 232/234: I would also include non-laser IR sensors. At short ranges (up to about a foot), they work great and are much less expensive than short-range ultrasonics or LIDAR. Sharp (the copier company) makes some great, dirt cheap (many less than $5) IR sensors of both the beam break and rangefinder style. Sparkfun, Pololu, Adafruit, and RobotShop all carry many of these, sometimes with carriers to simplify connecting them to a DIO or Analog Input.
.



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