Legality of purchasing Planetary Gearboxes from alternative sources.
 

Because it is the offseason and teams maybe wanting to stock up on COTS parts for the 2017 season. Is it legal to utilise Planetary Gearboxes that have been purchased from a supplier like aliexpress in order to save money( a saving of around 50% percent).

There are several different types available from a variety of suppliers, that are identical to the Andymark ones. The motors even have the exact same labelling, and part numbers as the Andymark PG’s. But with a wider variety of ratio options:

https://www.aliexpress.com/store/pro...727631977.html

https://www.aliexpress.com/item/45mm...d08ed0fb&tpp=1

https://www.aliexpress.com/item/45mm-diameter-DC-12V-60RPM-planetary-gear-motor-Reduction-ratio-99-6k-PG45775126000-99-6K-for/32658954651.html?spm=2114.12010108.1000013.2.3FS9a b&scm=1007.13339.33317.0&pvid=1d8f4403-ffec-435d-827e-874e2411aeed&tpp=1 (shows identical part number)

Considering that the motors are identical is it legal to use the gearboxes without replacing the motor?

Re: Legality of purchasing Planetary Gearboxes from alternative sources.
 

Under the 2016 rules, the motors would have had to be the exact part numbers shown in the rules in order to be legal. Gearboxes can be used with the motors replaced, but the motors need to be the legal part number.

Subject to change for 2017, of course.

Re: Legality of purchasing Planetary Gearboxes from alternative sources.
 

The motor model numbers do not appear to be legal by last year's rules, as the rules would have to list RS-775123000, etc, and they do not list those motors.
https://firstfrc.blob.core.windows.n...-manual-04.pdf
page 20

Re: Legality of purchasing Planetary Gearboxes from alternative sources.
 

Please note that even if the gearbox is perfectly legal mechanically, for you to use it on a competition bot, it must be purchased from a legal vendor. Section 4.1 (pages 3 and 4) sets forth criteria necessary for a company to qualify to be a legal vendor. Aliexpress.com may not qualify. In fact, I seriously doubt it.

Of course, it could be argued that none of the vendors we think of as FIRST vendors actually qualify per the written criteria. (Not going there in this post.) This section of the manual is probably one of the most ignored rules in FRC. They should just delete it.

Re: Legality of purchasing Planetary Gearboxes from alternative sources.
 

I am probably missing something really huge and important, but I do not believe the rule says the part must be purchased from a legal VENDOR, but merely that the part must be a standard part commonly available from a VENDOR.

If the rule were written as you suggested, that would mean teams could not sell or even trade COTS parts with each other, which is clearly legal and intended to be legal. The important thing is not where the team actually received the part, but if the part is equally accessible to all teams through a VENDOR.

Teams should note that regardless of how much the team paid for the part, they must list the part in the BOM at the fair market value price that any team could pay for the amount of the part they used on the robot (unless the part is KoP, etc).

As for these specific gearboxes - if you wanted to go this route, I would seek out some documentation from AndyMark specifying that these are identical to a specific AM part number. If the only difference really is the part number marking, I believe this would be considered an equivalent COTS part under Example 4 of the 2016 blue box on page 4.

But really, unless your team is really desperate for those few extra dollars, support our good friends at AndyMark with your business.

The motor rules themselves are more complicated - if those motors don't have identical part numbers already printed on them, I wouldn't push your luck. I'd just use the gearboxes and attach a definitely legal motor to them.

Re: Legality of purchasing Planetary Gearboxes from alternative sources.
 

But really, unless your team is really desperate for those few extra dollars,...

For small growing teams we need to be responsible with our dollars... I have been part of three different teams each with challenges and attributes.. but all have been out classed by those with bigger bank rolls , that are more established... If one looks at the pits independently... there is a huge range of sponsorship... and tools available... It can be overwhelming for a small team to see all that one has when they have all the tools they own in one tool box carried in, while others are offloading like a rock show...

Please help us to make it affordable by all...

Re: Legality of purchasing Planetary Gearboxes from alternative sources.
 

It's hard to parse this post but... Are you trying to make an argument that AndyMark isn't affordable? I think you'll find that you're going to spend more time and money trying to engineer a solution to fit a motor to a gearbox it wasn't designed for or worse you're going to spend hard-earned money and end up buying something you can't use or use mistakenly and then have to engineer around...

Honestly, I can understand teams complaining because a product from AM or Vex doesn't work due to a bad design or something (looking at you GEM gearboxes and CIM encoder widgets!) but I don't understand the complaints about cost. I've been involved with FRC since 2003 and FRC has never been cheaper than it is now for a team to be competitive.

It seems like it is becoming common to see teams not use their resources properly and then blame some grand FRC supplier conspiracy. No one is colluding to make gearboxes more expensive for FRC teams.

AndyMark, Vex, CTRE, and REV have significantly lowered the barriers to entry for FRC teams and are continuing to drive down the costs for those teams to be competitive. Are the parts expensive? Yes. Is FRC expensive? Yes. Do teams need to plan and budget accordingly? Yes. Does FIRST need to provide better resources for teams to plan with? Yeah, they probably do. Are cheaper gearboxes from China a solution? Maybe, but I doubt it.

EDIT: AliExpress is definitely a legal vendor for these gearboxes and other parts but I don't know about the motors and highly doubt the motors are legal.

Re: Legality of purchasing Planetary Gearboxes from alternative sources.
 

To put some actual numbers behind Marshall's claim that it's never been cheaper. ESCs are one of the larger costs in building bots. So I took a look back at the costs of the cheapest legal ESC in FRC going back to 2003. I've attached the graph here. I'm fairly certain you could do that for any single component of FRC bots and find things are getting cheaper. [1]

I'll leave why it feels like it's getting more expensive to compete as an exercise. I have some theories but I think I'd like to see what others think.



[1] My process sucked for this I used archive.org and found the product I was looking for. I'm fairly certain of that flat period from 2005 to 2010 but since IFI's website blocked web crawlers from accessing the 884 page in their robots.txt I don't have that information and can only interpolate. But I don't recall the prices changing drastically in that point. If Paul/JVN/etc have more correct information feel free to correct me.

Re: Legality of purchasing Planetary Gearboxes from alternative sources.
 

Two things:

• What's an ESC? Sorry for my ignorance.
• I notice it is "minimum cost." What happens when you try to graph average or maximum cost. Minimum cost products aren't always necessary as good quality as they were in 2003 (though I'm welcome for someone to prove me wrong).

Re: Legality of purchasing Planetary Gearboxes from alternative sources.
 

Electronic Speed Controller.

Honestly, average/maximum cost graphs are going to be mostly the same since it wasn't until 2010ish that another ESC was allowed and it was more expensive (and actually less effective for most teams) The only year that the cheapest option ISNT the IFI/VexPro Victor line (883/884/SP) is 2016 in which it is the Spark ESC and the Victor retains its 2015 cost.

For reference - I have (if Lydia/RIT group ever ships it back) a box of about a dozen 883s from 2003, they have been abused by several robots over the years and are still mostly ticking (they fried 1.5 of them when they tried to run a giant Ampflow motor off of them and cooked the fets) There's a reason the IFI Victors were a staple in combat robotics for a LONG time. They take a beating and, until recently, there was barely anything comparable on the market.

Edit - to respond to Chris below: I went to archive.org for the site you buy the ESCs from and clicked on the link and checked the price. Whatever it said is what I put there.

Re: Legality of purchasing Planetary Gearboxes from alternative sources.
 

By "minimum cost" I believe Andrew is factoring in things like sales, coupon codes, etc; not saying "this is the crappiest ESC money can buy".

Until the introduction of the Talon SP, the cheapest legal ESCs have been the best ESCs in competition; the Jaguars were generally more expensive and also worse.

Re: Legality of purchasing Planetary Gearboxes from alternative sources.
 

I liked the Jags... Ok, they were bulky, and magic smoke would pour out of them by looking at them wrong and they ended up bricked when doing firmware updates and most teams didn't use them with CAN but we did and we liked them a lot. :(

We haven't had any other motor controller with baked in cable strain relief that I know of.

Re: Legality of purchasing Planetary Gearboxes from alternative sources.
 

Really the biggest problem on top of all of that was the automatic overcurrent "safety feature" that would lock the drive up for longer than a circuit breaker would trip, which was very annoying.

Re: Legality of purchasing Planetary Gearboxes from alternative sources.
 

Where does Andymark get their PG sets from? They don't make them in house otherwise they wouldn't have had to wait for a shipment to come in when they were out of stock. A 25 day lead sounds awful familiar...

When you ask this question, I'd have to know if they were the same gearboxes, and my gut reaction is that they are identical and most like come from the same source.

We aren't in a position this year where money is going to stop us from buying an extra gearbox or two, but why on Earth would I pay double for the same thing? The only noticeabe difference is the price and lead time.

Anyone have one of these in hand to say otherwise?

Re: Legality of purchasing Planetary Gearboxes from alternative sources.
 

You just answered your own question - let's assume they are identical. Can you plan your requirements 25 days out during build season? No? So what you'd really like is some locally sourced components. But since they now have to stock in the hopes of you ordering they've taken on risk, couple that with costs of warehousing and shipping it to you. Really you're paying AM to stock the part for you so you can have it in your greasy hands tomorrow instead of next month.