Feetech Chassis on Amazon
The two chassis I got direct from China are now available on Amazon. $15 gets your choice of beautiful aluminum chassis kit with two DC motors PLUS the coveted motor controller board which drives two motors using servo-style pulses. Essentially converts DC motors into CR servos. Mikey Likey. Mine are red, these are blue. I'll have to get blue ones too, I guess.
blue rectangular https://www.amazon.com/gp/product/B06XZC2XDV uses gutted 9g servo-style gearmotors, works fine. Heavy-duty caster seems out of place but works.
blue round https://www.amazon.com/Feetech-FT-DC-006-SMC-Aluminum-Vehicle-FT-SMC-2CH/dp/B06XXS8L1C uses Solarboticsstyle gearmotors in several different gear ratios, 48:1, 120:1 or 256:1 but the description doesn't say which. I favor the 120's myself.
There are a few Feetech offerings on Amazon as well, they look similar. There's a red round with no controller for $15 and a yellow rectangular with low-grade FS90R CR servos, I'd stay clear of those.
blue rectangular https://www.amazon.com/gp/product/B06XZC2XDV uses gutted 9g servo-style gearmotors, works fine. Heavy-duty caster seems out of place but works.
blue round https://www.amazon.com/Feetech-FT-DC-006-SMC-Aluminum-Vehicle-FT-SMC-2CH/dp/B06XXS8L1C uses Solarboticsstyle gearmotors in several different gear ratios, 48:1, 120:1 or 256:1 but the description doesn't say which. I favor the 120's myself.
There are a few Feetech offerings on Amazon as well, they look similar. There's a red round with no controller for $15 and a yellow rectangular with low-grade FS90R CR servos, I'd stay clear of those.
Comments
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Apparently I'm manipulating the world of robot high dollar finance.
They really are crappy motors, in case you didn't know!
Guess I'll just keep watching...
The watching is over! Price on blue round dropped to $12.50 so I nabbed one with free ship thru Amazon Prime. Supposedly includes the 120:1 motors, we shall see.
https://www.amazon.com/gp/product/B06XXS8L1C
https://www.amazon.com/Feetech-FT-MC-002-SMC-Aluminum-Vehicle-FT-SMC-2CH/dp/B06XZC2XDV
Bad news: It comes with 48:1 motors, not the 120:1 claimed
Med news: At least the included controller does a pretty decent job controlling the motors at low speed. Video soon.
I wonder if these would work well on it with some nice servos. Thoughts?
https://www.amazon.com/UniHobby-UH143-Aluminum-Compatible-Universal/dp/B01EDKQERU
A few months back someone gave me one of these, though it was red. Can't remember the guy's name, though. Tall fella with a scraggly beard.
The "gutted" servo worked pretty well. I just don't trust those yellow WowWee-ripoff motors, from any source.
Really? You mentioned bad motors before, I thought you were talking about the blue gutted 9g servos. I've had some bad ones, but all the yellow Vigor/Solarbotics/WowWee motors have been good.
Re: AWD You mean the rectangular chassis? Probably much better 4WD than 2WD, that heavy caster is ridiculous.
Mecanums are cool but pricey. Duane and I like the green VEX mecanums (good price), which I can't find online right now (should I have hoarded those?). Second video.
Feetech chassis review:
My Vex Mecanum bot:
I only have experience with two of the gutted Feetech motors, from the base you so kindly gave me. Those were good, but I admit that two aren't enough of a sample.
The yellow motors (i.e. fake WowWee) are hit-and-miss. As you note, you never really know if you're going to get the 1:48 motors, which are not only a bit lame for robots, but with the low torque pretty much guarantees the robot won't travel a straight line.
I've gotten some for testing that simply stopped after running a few seconds. Munchings and crunchings from inside the gearbox.
The white Solarbotics motors are not the same as the cheap yellow ones that are coming everywhere from China. Theirs are a higher quality, and I believe from the same factory that supplied/supplies WowWee. I don't know what factory(ies) make the yellow motors. They appear to be very widely distributed, where anyone can buy a bunch and sell their Very Own Robot.
But the big fat tires they usually come with are just plain bad. https://www.ebay.com/itm/Smart-Car-Chassis-Tracing-Car-Robot-Chassis-with-Speed-Encoder-Kit-for-Arduino/182856281675?hash=item2a93156e4b:g:D-kAAOSwr6pZ8VvM
(And dig those optical encoder disks of clear plexiglas... shown with the protective paper still on...
My thoughts exactly!
http://forums.parallax.com/discussion/comment/1429941/#Comment_1429941
Read more here https://www.forbes.com/sites/wadeshepard/2017/11/05/how-the-usps-epacket-gives-postal-subsidies-to-chinese-e-commerce-merchants-to-ship-to-the-usa-cheap/#2416534f40ca
The taxpayer is subsidizing this habit. I benefit from it too, but as time passes I'm far more reluctant to get that "free shipping" bonus.
Ken Gracey
Shipping times can be one or two months' long, and because it's so expensive to return defective merchandise, buyers who get a bad part just eat it. I guess the savings make the risk more palatable. For my work I can't rely on the unreliable supply chain -- I write about some kit and three months later it's gone, or changed.
Some time back I renounced hoarding, and I no longer stockpile (in fact a few years ago I gave both Erco and Xanadu bins full of my electronics parts). Just today I ordered some stuff from a few online outfits, and it was everything I need for next month's projects. I don't plan beyond that.
I don't think the free shipping fiasco is a benefit to the Chinese suppliers, either. Between their lack of IP protection, how would anybody even figure out who makes the "original" HRS-04 $1.00 Ultrasonic Sensor? You can't - it's probably made by 100 factories! The consumer just picks the cheapest cost, with free shipping, and this double-whammy simply drives the margins down for Chinese suppliers. I bet they're making about 5 cents on an HRS-04 Ultrasonic Sensor.
Further, take a look at this listing:
https://www.ebay.com/itm/HC-SR04-Sound-Ultrasonic-Wave-Detector-Range-Distance-Sensor-Module-For-Arduino/122185875749?epid=506545892&hash=item1c72d88125:g:7CcAAOSwPCVYBLj3
And look at the messed-up looking product in their main image. The pins are bent in their main marketing photograph!
Free shipping is bad because:
- it promotes hoarding
- it requires a subsidy from the USPS which is a real bad deal
- requires you to buy lots of extras and throw away the failed units, filling our landfills
- promotes copycats and a "race to the bottom"
While I'd love to dig into this much deeper, it's not to the benefit of Parallax for me to spend much time on it. I might spend a few minutes writing a letter to a senator or congressional member.
Ken Gracey
Mike
As a reminder, we're not limited to just writing to only our local representative. I'm pretty sure customs and trade issues are handled by the House Ways and Means subcommitte on trade. Looking it up, Dave Reichert is the current chairman. He's not running for reelection in 2018, so maybe he'd be more willing than otherwise to shake some things up. The same letter could go to all the names listed here:
https://en.wikipedia.org/wiki/United_States_House_Ways_and_Means_Subcommittee_on_Trade
I better hoard those toilet brushes before your letter awakens the sleeping giant and free shipping is no more!
I knew there were more opportunities to influence but I didn't know who to contact. Count on these people also getting a letter. Thanks for the additional ideas, Gordon!
Sometimes the simple act of writing relieves one's mind from the situation, doesn't it? I feel a lot better after putting my thoughts in a letter and doing what we're supposed to do, even though it has no effect.
Ken Gracey
I'll make you a deal, erco. This deal is better than another free shipping ePacket from China, better than HRS-04s that work - and it requires an open-minded person as yourself.
I'd like you to take a photo of your electronics storage area. It might be a whole bay in your garage, or the entire closet of your robot museum. I'd like you to share that photo on the forums so we can all see the success ratios required to properly source these low-cost goods from China. We know that the good parts make it into your robots, but but about the epic fails? What's the ratio of good to bad? We need a photo!
In exchange, I offer you any American-made product from Parallax valued up to $150. Let's call it "Chef's Choice" and you'll be the chef.
Virtual handshake?
Ken Gracey
P.S. If you accept, I'll also order us each three (3) of the $2.17 toilet bowl brushes to see what they're all about. If nothing else, they'll symbolize washing away the dirty stuff that made free shipping possible.
+1
WRT my parts stores, it will be many pics, as they are tucked away in various places. Closets, bins, boxes, racks, in the house and garage! Mixed in with toys, gears, plastic, glue, and various building materials.
I envied Duane Degn a few years ago when he posted his dedicated stack of neatly organized and labeled bins. THAT'S the more photo-friendly storage solution!
He makes his living as a consulting toy designer, and he needs ready access to lots of clever bits and pieces as he creates a new design. My understanding of his process is that he uses these parts for working prototypes, but those parts may and probably won't be used in any final product.
It's guys like me who (used to) collect stuff just to have it and never use it. Part of my problem was Industrial Liquidators. Erco knows what I mean, since he had one around the corner from his house as well...
In this case, I emailed Amazon that the blue robot came with 48:1 motors (not the 120:1 types the seller claimed in his reply to my question) and POOF, the item is gone: https://www.amazon.com/gp/product/B06XXS8L1C
In the Nissan Leaf forum, I recommended a conspicuous value in a home L2 (240VAC) charger (EVSE) at $214. The day after I posted, the price jumped to over $300.
Guess I can add "Internet influencer" to my resume. Either that or "ruiner of all the fun".