For my birthday, I am excited to share two new products to help get your projects moving: dual motor driver boards for Arduino and for Raspberry Pi based on Maxim MAX14870 drivers, which on these boards (without additional cooling) can power motors with a continuous 1.7 A (2.5 A peak) from a voltage source anywhere from 4.5 V to 36 V. This makes the driver ideal for powering a wide range of motors including our high power micro metal gearmotors, and our 12 V 20D mm metal gearmotors. We like the MAX14870 so much that already we make a single driver carrier for it, and we use it on our A-Star 32U4 Robot Controller SV. These new boards make it easy to control two motors using the MAX14870 with an Arduino or Raspberry Pi.

The Dual MAX14870 Motor Driver Shield for Arduino is designed to plug directly into an Arduino or another microcontroller board with the Arduino form factor. It connects the Arduino I/O pins to the two-pin speed/direction interfaces as well as the fault output pins, and our open-source library is available to help you get started. The shield can be set up to power your Arduino device from your motor power supply, which is especially helpful if you are using an Arduino or compatible device with an operating voltage similar to that of the MAX14870, such as our A-Star 32U4 Prime SV. Additionally, the board can be customized to use the advanced features of the MAX14870 drivers or change the pin mappings.

The Dual MAX14870 Motor Driver for Raspberry Pi has many of the same features as the Arduino version, but it is designed to plug into the GPIO header on a compatible Raspberry Pi (Model B+ or newer), including the Pi 3 Model B and Model A+. We provide an open-source Python library to make it easy to interface with the board. This board also has a location to connect a step-down 5 V regulator to power the Raspberry Pi from your motor’s power supply.

Dual MAX14870 Motor Driver for Raspberry Pi (assembled) on a Raspberry Pi 3 Model B.

D24V10F5 5V 1A step-down voltage regulator soldered directly to Dual MAX14870 Motor Driver for Raspberry Pi (compact, permanent connection).

I am really excited about these boards because the Raspberry Pi expansion board is the first PCB I ever designed, and the Arduino shield was designed by my friend David S. Both of us are engineering students at the University of Nevada, Las Vegas who work at Pololu to complement our studies. It has been a great experience for us to learn how to design these products from the development engineers here at Pololu. Plus, getting to share these products for the first time with you is a fun way to celebrate my birthday!

As usual for our new product releases this year, we’re offering an extra introductory discount: the first 100 customers to use coupon code MAX14870INTRO can get any mix of up to 3 of these boards for $7.77 each. (Click to add the coupon code to your cart .) Note that this introductory offer applies only to the units without connectors soldered in.

Related products

	Dual MAX14870 Motor Driver Shield for Arduino
	Dual MAX14870 Motor Driver for Raspberry Pi (Partial Kit)
	Dual MAX14870 Motor Driver for Raspberry Pi (Assembled)

Our new programmer, the Pololu USB AVR Programmer v2.1, was supposed to be a minor update to our existing programmer, coming right after the A-Star 328PB Micro that we released last month, with the main point of excitement being the Las Vegas-inspired $7.77 price. But as we were testing the combination of the programmer with the A-Star, we were getting brown-out resets on the programmer when it powered the A-Star. The relevant part of the circuit was just a P-channel MOSFET that connected the programmer’s own logic voltage (which we call VDD) to the VCC pin of the ISP connector:

MOSFET-based target VCC power control used on Pololu USB AVR Programmer v2.

The problem was caused by the MOSFET turning on too well (quickly and with low resistance), causing the logic voltage on the programmer to drop if the VCC of the target device had more than a few µF of discharged capacitance on it. The bigger the capacitance on VCC, the bigger the voltage drop on VDD, until eventually the drop was big enough to trigger the brown-out reset protection on the programmer’s microcontroller. We tried various firmware tricks with our existing hardware, such as turning on the MOSFET for very short pulses to gradually charge up the target device’s VCC capacitance, but none of them worked reliably enough. So in the end, we decided to redo our PCB and put in a dedicated high-side power switch with a controlled slew rate. The new programmer can now power target boards with up to about 33 µF on their logic supplies.

These are the two other improvements we made to the new v2.1 programmer over the older v2 programmer:

• Plugging a v2 programmer into a 3pi robot could cause one of the motors to briefly run at full speed because the programmer’s circuitry for measuring VCC could inadvertently pull up one of the 3pi’s programming pins (which doubles as a motor driver input) before the GND connection was established. The v2.1 programmer has improved circuitry for measuring VCC which limits the duty cycle of this effect to about 0.2%, so the motor won’t move (but it might make a 25 Hz clicking sound).
• The v2 programmer would typically brown-out if a 5 V signal was applied to its RST pin while it was operating at 3.3 V. The v2.1 programmer does not have this problem.

The v2.1 programmer is otherwise identical to the v2 programmer, which means it’s a USB AVR microcontroller programmer that can program targets at 3.3 V and 5 V and offers an extra UART-type TTL serial port (like the popular FTDI USB-to-serial adapters) that can be super handy for debugging, bootloading, or even general connection of your project to a USB port.

Pololu USB AVR Programmer v2.1, labeled top view.

The v2 programmer was already a good deal at under $12, but at $7.77, and with free shipping in the USA, we hope to make AVR development extremely accessible. The manufacturing improvements and other cost reduction initiatives I have been blogging about this year help us make this offer without losing money on it, but I am not expecting to be making money directly off of the programmers, either. My goal is to give you the best value in a basic tool you will use over and over as you build your own projects, with the hope that that will help you keep Pololu in mind the next time you need some electronics or robotics parts.

And, as usual for our new product releases this year, we’re offering an extra introductory discount: the first 100 customers to use coupon code AVRPROGINTRO get that already great $7.77 price dropped to $5.55 (limit 2 per customer). (Click to add the coupon code to your cart.)

Related products

Pololu USB AVR Programmer v2.1

We are now carrying Ion Motion Control’s line of single-channel RoboClaws, the Solo 30A and Solo 60A. These versatile, high-power motor controllers have nearly all the same features and performance capabilities as their dual-channel 2×30A and 2×60A counterparts, just with one fewer motor channel. Just like the rest of the RoboClaw family, the Solos support a variety of interfaces, including USB serial, TTL serial, RC hobby servo pulses, and analog voltages, and integrated quadrature decoders enable closed-loop position or velocity control.

Unlike our selection of dual-channel RoboClaws, the Solos also feature a rugged, all-metal case that protects the driver while simultaneously serving as a heat sink, and they have four 12 AWG unterminated leads for supplying power and connecting a motor.

The following table shows our full updated offering of RoboClaw motor controllers:

	Solo 30A	Solo 60A	2x7A	2x15A	2x30A	2x45A ST 2x45A	2x60A
Motor channels:	1		2
Operating voltage:	6 V to 34 V		6 V to 34 V
Continuous output current:	30 A	60 A	7.5 A	15 A	30 A	45 A	60 A
Peak output current:	60 A	120 A	15 A	30 A	60 A	60 A	120 A
5V BEC max current:	1.2 A		1.2 A (V5B or later)	3 A
Size	60 × 32.5 × 23.5 mm		48 × 42 × 17 mm	74 × 52 × 17 mm			100 × 86 × 25 mm
Weight:	130 g		18 g	60 g			295 g
Price:	$101.95	$124.95	$89.95	$112.95	$152.95	$191.95	$199.95

Related products

	RoboClaw Solo 30A Motor Controller
	RoboClaw Solo 60A Motor Controller

Our Tic stepper motor controllers are pretty awesome, and the new Tic T500 we released today should make stepper motors even more accessible for your next project. This latest version features a broad 4.5 V to 35 V operating range that covers everything from small 2-cell lithium battery packs up to 24 V batteries or power supplies while costing just $20 in single-piece quantities. This video gives you a quick overview of what the Tic stepper motor controllers offer:

The Tics make basic speed or position control of a stepper motor easy, with support for six high-level control interfaces:

• USB for direct connection to a computer
• TTL serial operating at 5 V for use with a microcontroller
• I²C for use with a microcontroller
• RC hobby servo pulses for use in an RC system
• Analog voltage for use with a potentiometer or analog joystick
• Quadrature encoder input for use with a rotary encoder dial, allowing full rotation without limits (not for position feedback)

The Tic T500 is available with connectors soldered in or without connectors soldered in. Here is a handy comparison chart with all three Tic stepper motor controllers:

	Tic T500	Tic T834	Tic T825
Operating voltage range:	4.5 V to 35 V(1)	2.5 V to 10.8 V	8.5 V to 45 V(1)
Max current per phase (no additional cooling):	1.5 A	1.5 A	1.5 A
Microstep resolutions:	full half 1/4 1/8	full half 1/4 1/8 1/16 1/32	full half 1/4 1/8 1/16 1/32
Automatic decay selection:
Price (connectors not soldered):	$27.95	$39.95	$39.95
Price (connectors soldered):	$29.95	$41.95	$41.95

1 See product pages and user’s guide for operating voltage limitations.

Basically, the new T500 does not offer the finer microstep resolutions of the T834 and T825, and the T834 supports very low operating voltages while the T825 supports higher operating voltages.

For those of you interested in more of the details of the stepper motor driver, the Tic T500 uses the new MP6500 from MPS, which we also offer on some low-cost MP6500 breakout boards with analog (small trimmer potentiometer) and digital (via PWM) current limit setting options.

In keeping with the tradition we started this year, we are offering an extra discount for the first customers, to help share in our celebration of releasing a new product. The first hundred customers to use coupon code T500INTRO can get up to two units for just $15.53! (Click to add the coupon code to your cart.) And we’ll even cover the shipping in the US! Note that this introductory offer applies only to the units without connectors soldered in.

Related products

	Tic T500 USB Multi-Interface Stepper Motor Controller
	Tic T500 USB Multi-Interface Stepper Motor Controller (Connectors Soldered)

Today we are releasing our newest A-Star programmable controller, the A-Star 328PB Micro. It is basically our version of the ubiquitous Arduino Pro Mini type products, but with the newer ATmega328PB microcontroller. The board itself is pretty straightforward (though the updated AVR is exciting), so the main thing I want to share in this post is our history with the Atmel ATmega328PB microcontrollers (this was before Microchip acquired Atmel) and how this product would not have existed without our lower-cost manufacturing initiative that I have been discussing.

We have been using the ATmega8, and then the ATmega48, ATmega168, and ATmega328P, since 2004 in many of our user-programmable products because of their versatility and excellent free compiler support (which also made Arduino possible). We first heard about the ATmega328PB in early 2014. The product kept being delayed, and I did not get a quote for them until October 2015. I ordered a reel right away; it arrived in March 2016. Over those two years, we put our AVR-related efforts into the ATmega32U4, releasing several A-Star 32U4 programmable controllers and using it on robots like the Zumo 32U4. The ATmega32U4 was a superior part with native USB and more I/O lines, making it a better fit for many of our applications. By the time we finally got the ATmega328PB parts, we had the A-Star 32U4 Micro available for just $12.75, making it less exciting to put effort into a lower-performance product that might end up costing almost the same amount.

Original ATmega168-based Baby Orangutan robot controller from 2005 (left) next to A-Star 32U4 Micro boards.

The new manufacturing equipment I ordered in the fall of 2017, along with the availability of our latest AVR programmer, brought attention back to the feasibility of a basic ATmega328PB carrier. I was hesitant to put effort into a product where we could not offer something substantially more compelling than what was already available. Despite the ATmega328PB being out in the wild for almost two years, it still had not really made it into many Arduino products, so I thought that perhaps we could offer something there. But more importantly, I wanted to see how low we could price it. I was aware of Arduino Pro Mini clones available on eBay and the AliExpress-type sites for under $3. Most official Arduino Pro Mini type products cost more like $10. For this project to be worthwhile, I wanted to get under $5.

It turns out we had to squeeze quite a bit just to get to the upper limit of that “under $5” goal, and so we are releasing this product at a unit retail price of $4.95. It’s not the under-$3 you can find for the absolute cheapest clones, but if you get the A-Star 328PB Micro from us, you are getting a well-supported, well-made product (each unit is 100% automatically visually inspected and 100% functionally tested) and supporting a company that is doing more than just copying products that are already out there.

It is my hope that by being able to offer the A-Star 328PB Micro for under $5, we are offering something meaningful, giving you a new option for general-purpose controllers at the price of a cheap lunch. I am interested to hear what you think. Is the 328PB interesting when you can get USB for not much more? Is the price low enough for you to buy from us instead of getting it from China?

We are offering the A-Star 328PB Micro in four voltage and frequency combinations:

• 5 V, 16 MHz (blue power LED)
• 5 V, 20 MHz (red power LED) Note: See item-specific page for speed warning.
• 3.3 V, 8 MHz (green power LED)
• 3.3 V, 12 MHz (yellow power LED)

A-Star 328PB Micro pinout diagram.

The A-Star 328PB Micro provides access to all 24 I/O lines of the microcontroller and ships with an Arduino-compatible serial bootloader; you can also use an AVR in-system programmer (ISP) for access to the entire chip. We recommend our USB AVR Programmer v2, which supports both programming interfaces and can be configured to run at either 3.3 V or 5 V.

Last but not least, we are continuing our plan of offering new products at the highest quantity price break at single unit quantities as an introductory celebration. That means that for the first 100 customers, you can get an A-Star 328PB Micro for just $3.87! (Must use coupon code AS328PBINTRO; click to add the coupon code to your cart.)

While we assemble (and design and document and ship and support) the boards here in Las Vegas, we still get the bare PC boards from China, where they are currently on holiday celebrating Chinese New Year. That is constraining how many units we can make at the moment, so we are limiting shipments to 5 units per customer. However, the introductory coupon has no quantity limit, and you can order more than five at that price if you would like. Backordered units are likely to ship within a few weeks.

Related products

	A-Star 328PB Micro - 5V, 16MHz
	A-Star 328PB Micro - 5V, 20MHz
	A-Star 328PB Micro - 3.3V, 8MHz
	A-Star 328PB Micro - 3.3V, 12MHz

Our new Balboa T-shirts are here! They feature our latest robot, the Balboa 32U4 balancing robot, within an enlarged outline of the 43-tooth gear option for the Balboa gearbox, accompanied by our call to “Engage Your Brain”. These pre-shrunk cotton shirts are available in several colors (navy blue, cardinal red, or black) and a range of youth and adult sizes.

Stylish.

It’s a Balboa!

Chic.

Related products

Balboa 32U4 Balancing Robot Kit (No Motors or Wheels)

We are excited to expand our colorful selection of stepper motor drivers with carrier boards for the brand new MPS MP6500 stepper motor driver!

Monolithic Power Systems’ MP6500 can drive a bipolar stepper motor from a 4.5 V to 35 V supply with up to 1/8-step microstepping. On our four-layer, 2 oz copper carrier boards, the MP6500 can deliver up to approximately 1.8 A per phase continuously without a heat sink or forced air flow, making this new module the highest-current stepper motor driver we carry among all the ones that share this form factor.

14 March 2018 Update: After further testing of more units, our initial characterization of the maximum continuous current capability was too high, so we have lowered it to 1.5 A. Please keep in mind that the exact maximum current you can get out of the driver at a given temperature will depend on your supply voltage and stepper motor characteristics.

Unlike most other stepper motor drivers, the MP6500 features internal current sensing, which allows it to measure the motor’s coil current even during the off period of the PWM cycle. Combined with its automatic decay selection, this allows it to regulate the current especially accurately to produce smoother motion and higher speeds, as shown in the below oscilloscope capture from the MPS application note AN120 (1MB pdf).

Compare this with waveforms from a stepper driver that uses a more typical method of peak current control:

In addition to a version with potentiometer current control like most of our other stepper motor drivers, we also offer the MP6500 on a board with digital current control. This second version enables a microcontroller to dynamically set the current limit in steps of 0.5 A (up to a maximum of 2 A) by simply driving one or two inputs low. Alternatively, supplying an analog voltage or PWM signal allows finer control of the limit within the 0 to 2 A range.

Current limit vs. potentiometer setting for the MP6500 Stepper Motor Driver Carrier, Potentiometer Current Control.

Current limit vs. PWM duty cycle for the MP6500 Stepper Motor Driver Carrier, Digital Current Control.

Introductory special: just $2.97 each! Must use coupon code MP6500INTRO, limited to first 200 customers, limit 5 per customer.

Related products

	MP6500 Stepper Motor Driver Carrier, Potentiometer Current Control
	MP6500 Stepper Motor Driver Carrier, Digital Current Control

We have expanded our selection of Glideforce linear actuators from Concentric International to include their industrial-duty and medium duty series as steps up in power from their light-duty series that we have been offering for many years now.

The medium-duty actuators are available in five different stroke lengths ranging from 4″ to 12″ and with or without feedback potentiometers, and they have a dynamic load rating of 225 lb, which means they can handle twice the load of their light-duty counterparts:

Glideforce Medium-Duty (MD) series of linear actuators with feedback.

Glideforce Medium-Duty (MD) series of linear actuators without feedback.

The industrial-duty actuators are real monsters compared to the medium-duty and light-duty units. The versions with an acme screw drive can handle dynamic loads up to 550 lb, and the versions with a ball screw drive (which is much more efficient than an acme screw) can handle dynamic loads up to a 1000 lb. Each drive option is available in six different stroke lengths ranging from 4″ to 24″ and with or without feedback potentiometers:

The following lets you compare all of our Glideforce linear actuator options:

Note that we are currently out of stock of many of the industrial-duty versions, but we will be getting more as Concentric makes them available. For units where the expected lead time is several months, we have disabled backorders; please contact us if you are interested in placing an order now for one of those units.

To see all of our linear actuators, visit our linear actuator category.

I am excited to announce our first voltage regulators with multi-turn trimmer potentiometers! I have wanted to add multi-turn pots to our products for a long time, but the problem has been that they are really expensive. They also tend to be quite big, at least compared to many of our boards, which we try to keep compact, and the smaller, surface-mounted ones are especially expensive. My latest round of looking for lower-cost options did not pan out, but I decided to just give it a try with the expensive parts.

The new S9V11x regulators that feature these potentiometers are buck-boost regulators that can output a voltage that is lower, the same, or higher than the input voltage. There are also versions with a multi-turn pot for adjusting the undervoltage cutoff threshold, so that if you use these with batteries, you can prevent overdischarging them. With twelve turns of adjustment available, it’s much easier to precisely set the voltages on the modules than with the single-turn potentiometers we have used on other adjustable regulators.

The output and cutoff multi-turn adjustment potentiometers on the S9V11x voltage regulators.

While I have been talking mostly about the potentiometers, the main regulator is pretty magical, too, giving you quite a bit of power over a broad operating input range in a small size.

Typical maximum continuous output current of Step-Up/Step-Down Voltage Regulator S9V11x

Our stock products are available in several combinations of adjustable and fixed output voltage and cutoff. If you have a higher-volume application, we can make them with fixed voltages wherever you need them. You could initially prototype your design with the adjustable version and then get fixed ones made once you know exactly what voltage you need.

Regulator		Input (V)	Output (V)	Low-voltage cutoff	Size	Price
	#2868 S9V11MACMA	2* – 16	2.5 – 9 (fine-adjust)	fine-adjust	0.50″ × 0.60″ × 0.25″	$14.95
	#2869 S9V11MA		2.5 – 9 (fine-adjust)	–		$11.95
	#2870 S9V11F5S6CMA		5 (6 V selectable)	fine-adjust		$11.95
	#2871 S9V11F3S5CMA		3.3 (5 V selectable)	fine-adjust		$11.95
	#2872 S9V11F3S5		3.3 (5 V selectable)	–	0.50″ × 0.60″ × 0.17″	$8.95
	#2873 S9V11F3S5C3		3.3 (5 V selectable)	3 V (fixed)		$8.95
	#2836 S9V11F5		5	–	0.30″ × 0.45″ × 0.17″	$14.95
* The regulator has a minimum start-up voltage of 3 V, but it can operate down to 2 V after startup. It is disabled when the input voltage is below the low-voltage cutoff.

I am very interested to see what people think of the multi-turn adjustment feature. If these new regulators sell decently or customers ask for it, we will add the multi-turn potentiometers to our other regulator offerings. Is the extra expense worth it? Or do you know of a good, low-cost, multi-turn potentiometer we could consider for future products like this?

Related products

	2.5-9V Fine-Adjust Step-Up/Step-Down Voltage Regulator w/ Adjustable Low-Voltage Cutoff S9V11MACMA
	2.5-9V Fine-Adjust Step-Up/Step-Down Voltage Regulator S9V11MA
	5V Step-Up/Step-Down Voltage Regulator w/ Adjustable Low-Voltage Cutoff S9V11F5S6CMA
	3.3V Step-Up/Step-Down Voltage Regulator w/ Adjustable Low-Voltage Cutoff S9V11F3S5CMA
	3.3V Step-Up/Step-Down Voltage Regulator S9V11F3S5
	3.3V Step-Up/Step-Down Voltage Regulator w/ Fixed 3V Low-Voltage Cutoff S9V11F3S5C3
	5V Step-Up/Step-Down Voltage Regulator S9V11F5

20D mm metal gearmotor CB with long-life carbon brushes.

20D mm metal gearmotor CB with long-life carbon brushes and an extended motor shaft.

Magnetic Encoder Kit for 20D mm Metal Gearmotors assembled on a 20D mm metal gearmotor with extended motor shaft.

Last month when we introduced versions of our 20D gearmotors with long-life carbon brushes, we mentioned units with extended motor shafts were in the works. Well, I’m happy to announce that option is now available for both the 12V CB and 6V CB 20D gearmotors, making it possible to use them with encoders like our magnetic encoder kit. The following table shows our full selection of 20D gearmotors, which has now grown to 72 options:

Rated Voltage	Brush Type	Stall Current @ Rated Voltage	No-Load Speed @ Rated Voltage	Approximate Stall Torque @ Rated Voltage	Single-Shaft (Gearbox Only)	Dual-Shaft (Gearbox & Motor)
12 V	long-life carbon (CB)	1.6 A	570 RPM	26 oz-in	25:1 12V CB	25:1 12V CB dual shaft
			450 RPM	33 oz-in	31:1 12V CB	31:1 12V CB dual shaft
			225 RPM	58 oz-in	63:1 12V CB	63:1 12V CB dual shaft
			180 RPM	75 oz-in	78:1 12V CB	78:1 12V CB dual shaft
			140 RPM	85 oz-in	100:1 12V CB	100:1 12V CB dual shaft
			110 RPM	110 oz-in	125:1 12V CB	125:1 12V CB dual shaft
			90 RPM	130 oz-in	156:1 12V CB	156:1 12V CB dual shaft
			72 RPM	160 oz-in	195:1 12V CB	195:1 12V CB dual shaft
			57 RPM	200 oz-in	250:1 12V CB	250:1 12V CB dual shaft
			45 RPM	250 oz-in	313:1 12V CB	313:1 12V CB dual shaft
			36 RPM	290 oz-in	391:1 12V CB	391:1 12V CB dual shaft
			29 RPM	350 oz-in	488:1 12V CB	488:1 12V CB dual shaft
6 V	long-life carbon (CB)	2.9 A	590 RPM	22 oz-in	25:1 6V CB	25:1 6V CB dual shaft
			470 RPM	28 oz-in	31:1 6V CB	31:1 6V CB dual shaft
			230 RPM	54 oz-in	63:1 6V CB	63:1 6V CB dual shaft
			190 RPM	62 oz-in	78:1 6V CB	78:1 6V CB dual shaft
			150 RPM	72 oz-in	100:1 6V CB	100:1 6V CB dual shaft
			120 RPM	87 oz-in	125:1 6V CB	125:1 6V CB dual shaft
			93 RPM	110 oz-in	156:1 6V CB	156:1 6V CB dual shaft
			75 RPM	130 oz-in	195:1 6V CB	195:1 6V CB dual shaft
			60 RPM	170 oz-in	250:1 6V CB	250:1 6V CB dual shaft
			46 RPM	220 oz-in	313:1 6V CB	313:1 6V CB dual shaft
			37 RPM	260 oz-in	391:1 6V CB	391:1 6V CB dual shaft
			30 RPM	310 oz-in	488:1 6V CB	488:1 6V CB dual shaft
6 V	precious metal	2.9 A	590 RPM	22 oz-in	25:1 6V	25:1 6V dual-shaft
			470 RPM	28 oz-in	31:1 6V	31:1 6V dual-shaft
			230 RPM	54 oz-in	63:1 6V	63:1 6V dual-shaft
			190 RPM	62 oz-in	78:1 6V	78:1 6V dual-shaft
			150 RPM	72 oz-in	100:1 6V	100:1 6V dual-shaft
			120 RPM	87 oz-in	125:1 6V	125:1 6V dual-shaft
			93 RPM	110 oz-in	156:1 6V	156:1 6V dual-shaft
			75 RPM	130 oz-in	195:1 6V	195:1 6V dual-shaft
			60 RPM	170 oz-in	250:1 6V	250:1 6V dual-shaft
			46 RPM	220 oz-in	313:1 6V	313:1 6V dual-shaft
			37 RPM	260 oz-in	391:1 6V	391:1 6V dual-shaft
			30 RPM	310 oz-in	488:1 6V	488:1 6V dual-shaft

Note: Stalling or overloading gearmotors can greatly decrease their lifetimes and even result in immediate damage. In order to avoid damaging the gearbox, we recommend keeping continuously applied loads under 50 oz-in (3.5 kg*cm) for the versions with precious metal brushes and under 70 oz-in (5 kg-cm) for the versions with carbon brushes (the ones with “CB” in the name). Stalls can also result in rapid (potentially on the order of a second) thermal damage to the motor windings and brushes, especially for motors like this that can deliver a lot of power for their size; a general recommendation for brushed DC motors is to limit continuous current to approximately 25% of the stall current.

Related products

Magnetic Encoder Pair Kit for 20D mm Metal Gearmotors, 20 CPR, 2.7-18V