Hi, Thanks to you and all the contributors for creating this wonderful tool! Hope you are feeling better by now.
I have a question about the Arm Calculator: when using 2 Neo motors each with its own MaxPlanetary gearbox powering opposite sides of the arm, should I use combined reduction in the Ratio field or per-motor reduction? For example, if each Neo has 20:1 MaxPlanetary attached to it, should the Ratio be 20 or 40 Reduction?
You should use 20:1 in this case.
Hi all,
I’m looking for community help on this, since it’s a larger task that I simply don’t have the bandwidth to do on my own.
I would like to have a full library of all:
from all major vendors - REV, TTB, AM, WCP, VEX, etc - including part numbers, links, bore, and part “type” (e.g. HTD, RT25, #25 chain, #35 chain, 20DP, etc).
This probably involves scraping vendor sites OR vendors providing said list of parts (I’m fine with either).
If you would like to help out, please DM me, it would be appreciated. Results should be stored in JSON in the following formats, typed via TypeScript because I don’t know JSON-schema:
// Not restricted to these vendors, just examples
type Vendor = "WCP" | "AM" | "TTB" | "REV" | "VEX";
// Not restricted to these bores, just examples
type Bore = "NEO" | "Falcon" | "775" | "550" | "1/2 Hex" | "3/8 Hex" | "...";
type Measurement = { magnitude: number; units: string };
type PulleyData = {
type: "HTD" | "GT2" | "RT25";
teeth: number;
pitch: Measurement;
bore: Bore;
vendor: Vendor;
url: string;
partNumber: string;
}[];
type SprocketData = {
type: "#25" | "#35";
teeth: number;
pitch: Measurement;
bore: Bore;
vendor: Vendor;
url: string;
partNumber: string;
}[];
type GearData = {
dp: number;
teeth: number;
pitch: Measurement;
bore: Bore;
vendor: Vendor;
url: string;
partNumber: string;
}[];
Individual contributors are not expected to scrape/gather all data on their own, that would be too much (which is why I am asking for assistance).
This would allow for improvement to calculators by increasing accuracy of available parts lists on calculators. For example, I would like to create a calculator that you give a final target reduction, and it finds a multi-stage set of reductions for you, using actually available COTS parts.
Thank you!
@Michael_Leicht of Cougar Robotics had all of the vendor sprockets in a powerful spreadsheet they used in a similar way. Probably worth asking if 1403 would be willing to contribute to this application.
Can I feature request for the sort out gear stages piece? Let me select an inventory of parts on hand.
It reduces the search space and maybe let’s teams use what they have on hand saving them money.
This is a good idea, I’ll add this.
I’d like to thank @apoorva for getting everything from AM and REV so quickly!!
Hi all,
Some quick updates.
This now factors in acceleration, deceleration, and current limits, and should be much more accurate than before. Previously, the calculator assumed the motors were generating stall torque with no current limit, which is not really realistic. This loosely follows a trapezoidal motion profile, but it won’t be as accurate as the WPILib ElevatorSim class. It does some hand-waving and whatnot in order to prioritize speed of execution (and I’m also struggling to recall my diffeq & linalg anyhow).
It also supports angled elevators, which I don’t expect to be too common outside of 2023, but you never know.
I expect some bugs or issues here. Please feel free to reach out if you find any, or if you have UI/UX complaints/suggestions.
I’m looking for some renders for the following home page links:
The renders should be png files at 1280x960 resolution with transparent backgrounds (or an easily removable background). They should be of similar vibes to the ones that already exist on the home page; that is, please don’t render a full robot.
That is really all the specs for it. You’re free to use some artistic liberty here. Feel free to post your creations here or send them over DM, whichever you want. I am not sure what I’ll do if I get multiple renders for the same page. I haven’t planned that far ahead yet. I don’t know. I’m winging it.
I am also in need of a render of a cross-section of a pneumatic cylinder. This is for the docs on the pneumatics calculator, which currently has a beautiful todo: fixme in place of it.
I am not very good with Fusion or Inventor nowadays and so would appreciate community help here.
Note that all of these numbers do not include the most common adblockers. 90% of you use an adblocker, but I suspect that number is lower on school machines.
All data is recorded between Jan 7 (kickoff) and April 22nd (champs) (3 months, 21 days).
There were 15,928 total visits. At best, with 90% adblock usage, that’s roughly 160k visits. A more reasonable 75% adblock usage puts it at 63k visits.
Between April 22nd and October 6th (today), there were an additional 9,239 visits.
| Referrer | Visits |
|---|---|
| 5,474 | |
| ChiefDelphi | 638 |
| WPILib Docs | 568 |
| DuckDuckGo | 41 |
| Yahoo | 34 |
| Yandex | 29 |
| Browser | Visits |
|---|---|
| Chrome | 12,207 |
| Safari | 2,827 |
| Firefox | 892 |
| PaleMoon | 2 |
Shoutout to that guy, I guess?
| System | Visits |
|---|---|
| Windows | 9,737 |
| iOS | 2,295 |
| macOS | 1,744 |
| Android | 1,579 |
| Chrome OS | 366 |
| Linux | 209 |
| Location | Visits |
|---|---|
| USA | 13,275 |
| Canada | 556 |
| Israel | 357 |
| Turkey | 244 |
| Mexico | 171 |
| Taiwan | 129 |
| Malaysia | 7 |
| Slovakia | 7 |
| South Africa | 6 |
| Location | Visits |
|---|---|
| California | 2,242 |
| Texas | 1,170 |
| Michigan | 831 |
| New York | 755 |
| Virginia | 654 |
| (unknown) | 603 |
| Massachusetts | 573 |
| Washington | 547 |
| Minnesota | 370 |
| New Jersey | 357 |
| Illinois | 354 |
| Oregon | 354 |
| Pennsylvania | 340 |
| Georgia | 326 |
| Missouri | 297 |
| Language | Visits |
|---|---|
| English | 14,838 |
| Chinese | 153 |
| Spanish | 148 |
| Turkish | 136 |
| Hebrew | 120 |
| Portugese | 93 |
| Dutch | 70 |
| German | 48 |
| Russian | 48 |
| French | 40 |
I hope this tool has been useful this year. Cheers to another season.
Out of curiosity was the power draw removed in lieu of current limiting? I kinda miss the estimated power draw.
There was an estimated current draw before, but yes that is currently gone, since it (incorrectly) assumes your motor is constantly at the current limit (before, it assumed your motor was constantly at stall). It’s on my to-do list to fix this with some diffeq but I need to go and re-learn diffeq.
Got a new COTS item that has undocumented or abnormal looking mounting holes? I’ve added a new “calculator” that lets you input a hole size and it will tell you:
This uses the close/normal/free/loose/tapped hole diameters from Onshape. The threads-per-inches for each bolt size were decided based on how common they are on McMaster.
Would it be possible to support servos instead of just motors in the various calculators? For FTC especially, adding servos like Axon MAX+ – Axon Robotics would be helpful (because the 8-motor max often pushes team into using servos for certain mechanisms). I’m currently trying to verify that a couple of those Axons can move an arm on our bots and have been guestimating it as either similar to 1 Axon = 1 Core hex or 2 Axons = 1 Core hex.
If you can find the data the Team 77 Design Calc should pretty easy to update. There’s a data page at the end and you can just put information in a new row.
No intent to add servos right now, sorry. It’s a long term to-do item to allow custom motor specs, though.
Thanks for all the work that’s gone into makinf these tools! Just curious, is there any updates on progress with the aforementioned drivetrain calculator?
I wish, I’ve prioritized it less due to the swerve era and everyone basically running the same drivetrain year over year (with some wiggle room, ie varying pinions).
I can get something online before kickoff most likely, it might not have any graphing, but it will have the same overall calculations as ILITE sim. I’ll bump it up on my to-do list.
I think there’s still good reasons to have another acceleration sim available, even with more people running Swerve:
I hope you find the time this fall. Thanks for your work!
You should be able to adapt the kV/kA calculation from the linear mechanism calculator, as well.
I’ve added a spacer “calculator” that helps you find the minimum number of spacers to use to fill up a weirdly sized gap.
It’s not very intelligent; it will just try the largest spacers that will fit until there’s nothing else that can. This is technically the greedy solution to the change-making problem / knapsack problem. It could be improved by an adventurous contributor.
I’ve also been working on an ILITE simulator port. More to come later. It’s not quite done yet.
