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Performance graphs for our Micro Metal Gearmotors

Posted by Ben on 5 April 2018
Tags: motors

After spending many months conducting thousands of motor tests, we are excited to finally publish performance graphs for our micro metal gearmotors (2MB pdf). In some sense, this datasheet is the culmination of a decade of work to improve our processes and better characterize our gearmotors, and we have come a long way since those early tests clamping motors in vises and making them lift ever heavier bags of steel bearings. Here is one of the setups we are using now:

Micro metal gearmotor undergoing dynamic performance testing.

The key thing is to be able to apply a measurable, variable load while the motor is spinning, which we do via an electromagnetic brake coupled to a torque meter. A combination of programs running on an A-Star 32U4 Prime test controller and a PC automatically sweep the load through a sequence of points while measuring parameters such as speed, current, and torque (plus internal test rig currents, voltages, etc).

Micro Metal Gearmotor performance test setup.

These performance characterizations are the latest example of our continued commitment to being the best source for this popular form factor of gearmotor. You might see similar-looking motors elsewhere, but no one comes close to our offering, from the quality of the gears to our exclusive long-life carbon brush options to the overall breadth of our selection (over 100 versions!), all in stock for shipment the day you order.

Please note that we are still in the process of updating the specifications on our website to match new, more accurate data from the performance graphs, so if you notice discrepancies between what is in the datasheet and what is on the product page, go with the datasheet.

If you have any questions or feedback about these graphs or if there is additional information you would like to see available for our motors, please feel free to contact us (or just leave a comment below). And if you are wondering about graphs for our larger gearmotors, don’t worry, those are coming! (If you need something before those datasheets are done, just let us know and we might be able to get you preliminary data for a particular gearmotor.)

Performance summary table from Micro Metal Geamotor datasheet.

New products: RoboClaw Solo 30A and 60A Motor Controllers

Posted by Ben on 16 March 2018
Tags: new products

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: $79.95 $99.95 $69.95 $89.95 $124.95 $169.95 $199.95

New products: MP6500 Stepper Motor Driver Carriers

Posted by Ben on 12 January 2018
Tags: new products

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.

Want to move heavy loads? We've got the linear actuator for you!

Posted by Ben on 29 December 2017
Tags: new products

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:

Actuator
Type
Max
Dynamic
Load
No-Load
Speed
@ 12 V
Current
Draw
@ 12 V
Nominal
Stroke
Length
With Feedback Without Feedback Approx.
Weight
Light-Duty
(LD)
15 kgf
[34 lbs]
4.4 cm/s
[1.7″/s]
1.2 A –
3.2 A
4″ LACT4P-12V-05 LACT4-12V-05 1.3 kg
12″ LACT12P-12V-05 LACT12-12V-05 1.6 kg
50 kgf
[110 lbs]
1.5 cm/s
[0.57″/s]
2″ LACT2P-12V-20 LACT2-12V-20 1.2 kg
4″ LACT4P-12V-20 LACT4-12V-20 1.3 kg
6″ LACT6P-12V-20 LACT6-12V-20 1.4 kg
8″ LACT8P-12V-20 LACT8-12V-20 1.5 kg
10″ LACT10P-12V-20 LACT10-12V-20 1.5 kg
12″ LACT12P-12V-20 LACT12-12V-20 1.6 kg
Medium-Duty
(MD)
100 kgf
[225 lbs]
1.5 cm/s
[0.58″/s]
1.1 A –
4.6 A
4″ MD122004-P MD122004 1.1 kg
6″ MD122006-P MD122006 1.2 kg
8″ MD122008-P MD122008 1.3 kg
10″ MD122010-P MD122010 1.4 kg
12″ MD122012-P MD122012 1.5 kg
Industrial-Duty
(ID)
with Acme
screw drive
250 kgf
[550 lbs]
1.7 cm/s
[0.66″/s]
2.4 A –
13.2 A
4″ LACT4-500APL LACT4-500AL 4.2 kg
6″ LACT6-500APL LACT6-500AL 4.4 kg
8″ LACT8-500APL LACT8-500AL 4.7 kg
12″ LACT12-500APL LACT12-500AL 5.3 kg
18″ LACT18-500APL LACT18-500AL 6 kg
24″ LACT24-500APL LACT24-500AL 7 kg
Industrial-Duty
(ID)
with ball
screw drive
450 kgf
[1000 lbs]
1.7 cm/s
[0.66″/s]
2.4 A –
13.2 A
4″ LACT4-1000BPL LACT4-1000BL 4.6 kg
6″ LACT6-1000BPL LACT6-1000BL 4.9 kg
8″ LACT8-1000BPL LACT8-1000BL 5.1 kg
12″ LACT12-1000BPL LACT12-1000BL 5.6 kg
18″ LACT18-1000BPL LACT18-1000BL 6.5 kg
24″ LACT24-1000BPL LACT24-1000BL 7.4 kg

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.

Closed December 25 and January 1

Posted by Ben on 21 December 2017


We will be closed for Christmas on Monday, December 25 and for New Year’s Day on Monday, January 1. Orders placed after 2 PM Pacific Time on December 22nd or 29th will be shipped on the following Tuesdays.

And last call for our Christmas sale — only about 15 hours to go!

Merry Christmas and happy New Year!

(A Little More Than) Twelve Days of Christmas Sale

Posted by Ben on 6 December 2017



If you missed our Black Friday sale or realize you didn’t quite get everything you wanted, don’t fret: we have all active Pololu-brand and PCX products on sale for 12% off, and we are offering 20% off twelve broad categories of our products. The sale runs through noon PST on Friday, December 22, but be careful to order early for delivery before Christmas. Save on your Christmas shopping, or stock up now on robot parts for the new year. Check out the sale page for all the discounts and coupon codes. Merry Christmas!

Our 20D gearmotors with long-life carbon brushes are now available with extended motor shafts

Posted by Ben on 27 November 2017
Tags: new products

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.

Black Friday deals keep coming from Pololu and from Adafruit

Posted by Ben on 24 November 2017


Our Black Friday/Cyber Monday Sale is nearing the halfway point; thank you to all of those who have already ordered! Today’s doorbusters are gone, but the rest of the daily specials are still active, and a lot more great deals are still coming your way, including the weekend deals we just released. We’re not doing any doorbusters Saturday and Sunday, just lots of extra discounts on big categories, so take your time looking around.

The weekend deals include two items we have never had on sale before: smart servos from XYZrobot and a 6DOF robot arm based on those servos. We recently released an Arduino library for the A1-16 smart servos and arm, making them especially easy to expand beyond their preconfigured sequences for use in your own advanced projects.

Our doorbusters will return starting at 6 AM on Cyber Monday, and rumor has it that might be a prime opportunity to snag one or two of our new Balboa balancing robots!

By the way, our friends at Adafruit are having their own Black Friday sale this weekend, with 15% off their entire catalog and 20% off their Feathers and accessories, plus free items for orders over certain amounts. You can find all the details on the Adafruit blog.

New 20D gearmotors available with 12 V windings and with long-life carbon brushes

Posted by Ben on 30 October 2017
Tags: new products

We love motors here at Pololu, and we are committed to offering you the best selection so that you can find just the right drive solution for your project. Our latest efforts have gone into expanding our selection of 20D gearmotors to include 12 V versions, which have approximately the same performance at 12 V as our 6 V versions do at 6 V, just with half the current draw. This in turn enables the use of lower-current (and typically lower-cost) motor drivers in applications with access to higher voltages.

Additionally, we noticed that our original 6 V versions do not last as long as we would like in some applications, so we made these new 12 V versions with long-life carbon brushes instead of precious metal brushes, and we released new versions of our 6 V motors with long-life carbon brushes as well. These versions have “CB” in their names, and they can be differentiated from versions with precious metal brushes by their copper-colored terminals.

20D mm metal gearmotor precious metal brushes (left) next to 20D 6V CB and 12V CB long-life carbon brushes.

Please note that making the brushes more robust can just move the failure point to the windings or gears if you try to push the motors too hard, but if you use them around their nominal voltages and keep the continuous load low (under around 20% of the stall torque or 1 kg-cm, whichever is lower), the carbon brushes allow the motors to last several times longer than versions with precious metal brushes.

Changing the brushes does affect the performance in ways beyond lifetime (e.g. the starting voltage is generally a little higher with the carbon brushes), so we are continuing to offer precious metal versions of our 6 V motors for now, but we might phase those out in the future. Please contact us or post a comment below if continued availability of the precious metal versions is important to you.

Currently, only the 6V versions with precious metal brushes are available with a rear motor shaft that can be used to add an encoder, like our magnetic encoder for 20D mm metal gearmotors, but the 6V CB and 12V CB motors should be available with this rear shaft option by the end of November.

With the addition of these new units, our selection of 20D gearmotors now spans nearly fifty 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
450 RPM 33 oz-in 31:1 12V CB
225 RPM 58 oz-in 63:1 12V CB
180 RPM 75 oz-in 78:1 12V CB
140 RPM 85 oz-in 100:1 12V CB
110 RPM 110 oz-in 125:1 12V CB
90 RPM 130 oz-in 156:1 12V CB
72 RPM 160 oz-in 195:1 12V CB
57 RPM 200 oz-in 250:1 12V CB
45 RPM 250 oz-in 313:1 12V CB
36 RPM 290 oz-in 391:1 12V CB
29 RPM 350 oz-in 488:1 12V CB
6 V long-life
carbon
(CB)
2.9 A 590 RPM 22 oz-in 25:1 6V CB
470 RPM 28 oz-in 31:1 6V CB
230 RPM 54 oz-in 63:1 6V CB
190 RPM 62 oz-in 78:1 6V CB
150 RPM 72 oz-in 100:1 6V CB
120 RPM 87 oz-in 125:1 6V CB
93 RPM 110 oz-in 156:1 6V CB
75 RPM 130 oz-in 195:1 6V CB
60 RPM 170 oz-in 250:1 6V CB
46 RPM 220 oz-in 313:1 6V CB
37 RPM 260 oz-in 391:1 6V CB
30 RPM 310 oz-in 488:1 6V CB
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.

Free Circuit Cellar magazine October 2017

Posted by Ben on 2 October 2017
Tags: new products

Get a FREE copy of Circuit Cellar magazine’s October 2017 issue issue with your order, while supplies last. To get your free issue, enter the coupon code CIRCUIT1017 to your shopping cart, or click the link. The magazine will add 6 ounces to your order weight when calculating your shipping options.

For back issues and more information, see our free Circuit Cellar magazine offers.

New Products

Dual MAX14870 Motor Driver for Raspberry Pi (Assembled)
Pololu USB AVR Programmer v2.1
Tic T500 USB Multi-Interface Stepper Motor Controller
250:1 Micro Metal Gearmotor MP 6V
Jrk G2 24v21 USB Motor Controller with Feedback
Jrk G2 18v19 USB Motor Controller with Feedback
Tic T500 USB Multi-Interface Stepper Motor Controller (Connectors Soldered)
RoboClaw Solo 60A Motor Controller
210:1 Micro Metal Gearmotor MP 6V
Jrk G2 24v13 USB Motor Controller with Feedback
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