Author Archives: Ben

Performance graphs for our 25D Metal Gearmotors

via Pololu Blog

We have published performance graphs (2MB pdf) for our 25D Metal Gearmotors! Each chart is based on hundreds of individual measurements that reveal how the speed, current, power, and efficiency of that particular gearmotor version depend on the applied load (i.e. torque). Our test methodology is the same as the one we used to make our Micro Metal Gearmotor performance graphs, so you can see our blog post about that for more information.

25D mm metal gearmotor undergoing dynamic performance testing.

These characterizations are yet another way we set our gearmotors apart from the many similar-looking alternatives out there. When you get your gearmotors from us, you know what kind of performance to expect, and you can count on consistency from batch to batch.

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).

Performance summary table from 25D mm Metal Geamotor datasheet.

Our Black Friday/Cyber Monday sale has started!

via Pololu Blog

Our Black Friday / Cyber Monday sale is going strong, and we have been working hard to make and ship the products that people are getting great deals on. Most of the sale coupons can be used on backorders if we happen to run out of stock, but you should still get your orders in early since lead times on some popular products can get long.

Please note that our usual same-day shipping guarantee is suspended during the sale, though so far we have been able to keep up with orders as they have been coming in, and we are closed Thursday, Nov 28th (tomorrow) for Thanksgiving. Happy Thanksgiving!

New product: Toshiba TB67S128FTG stepper driver carrier

via Pololu Blog

Our wide selection of stepper motor drivers has grown once again, this time with the addition of a full breakout board for Toshiba’s TB67S128FTG. The TB67S128FTG has many of the same great innovative features as the TB67S2x9FTG carriers we released last year, including Active Gain Control (AGC) for automatically reducing the current when full torque is not needed and Advanced Dynamic Mixed Decay (ADMD) for smoother, more even microsteps. On top of that, it adds features such as microstepping down to 1/128th-step and an optional serial interface. The driver offers a wide operating voltage range of 6.5 V to 44 V, and it can deliver 2.1 A per phase continuous (5 A peak) on our carrier board without any heat sink or forced air flow, making it our highest-current integrated driver (bested only by our discrete MOSFET High-Power Stepper Motor Driver 36v4).

These stepper motor driver carriers first debuted at Toshiba’s booth at Maker Faire Tokyo in August, and now that we finally have the drivers in volume, we are able to offer them to you! All of the driver’s control pins and outputs are available, so it can function as a complete evaluation board for the TB67128FTG, yet it is compact enough to integrate into actual projects without taking up an excessive amount of space:

TB67S128FTG Stepper Motor Driver Carrier, top view with labeled pinout.

Introductory special

As with all of our new product announcements, we are offering an introductory discount to make it extra easy to try out this new driver. Be among the first 100 customers to use coupon code TB67S128INTRO (click to add the coupon code to your cart) and up to three units for just $7.95 each.

New product: Tic 36v4 USB Multi-Interface High-Power Stepper Motor Controller

via Pololu Blog

I am pleased to announce the release of the Tic 36v4 USB Multi-Interface High-Power Stepper Motor Controller, the fifth model in our line of Tic Stepper Motor Controllers. The Tic 36v4 features a discrete MOSFET stepper motor driver that can deliver up to approximately 4 A per phase, without a heat sink or forced air flow, over a broad 8 V to 50 V operating range. With the ability to provide more than twice as much current as any of our previous stepper motor controllers, this is our highest-power Tic yet, and the first that can drive the most demanding stepper motors we carry (#1474 and #1478) with their full rated current (2.8 A).

Tic 36v4 USB Multi-Interface High-Power Stepper Motor Controller controlling a #1478 stepper motor from USB.

The Tic 36v4 supports microstepping resolutions down 1/256 step, which is 8 times smaller than any previous Tic model. These new, finer microstep resolutions make it increasingly important to be able to take steps at a high speed since with microsteps that small, it takes up to 51,200 of them to complete one revolution on standard stepper motors with 200 full steps per revolution. The Tic firmware takes care of that for you: it is designed to be able to produce up to 50,000 steps per second, meaning that you can get 58 RPM out of most of our stepper motors even when using 1/256 step mode. Every power of two step mode between full stepping and 1/256 is supported, allowing you to choose the right trade-off between speed and resolution.

An oscilloscope capture showing the current through one coil of a stepper motor as the Tic 36v4 takes 25600 microsteps per second in 1/256 step mode.

By default, the Tic 36v4 uses an automatic mixed decay mode for current regulation. In this mode, it dynamically selects between fast or slow decay based on the actual coil current, allowing it to achieve extremely smooth stepping in most applications without a lot of manual tuning—especially at high microstepping resolutions. (Isn’t that a nice sine wave in the picture above?)

However, if you want more control, this Tic also gives you the option to select a fixed decay mode and adjust several timing parameters to fine-tune the current decay behavior. This can be easily done with the Tic’s free graphical configuration software.

The decay mode settings for the Tic 36v4 in the Tic Control Center software.

Like the other members of the Tic family, the Tic 36v4 makes basic speed or position control of a stepper motor easy, with lots of configurable parameters (e.g. max speed and acceleration) and 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)

This video gives a brief demonstration of these interfaces in action:

The Tic 36v4 is available with connectors soldered in or without connectors soldered in. If you do not need the high-level interfaces provided by the Tic, we also offer the Pololu High-Power Stepper Motor Driver 36v4.

Here is a handy comparison chart with all five Tic stepper motor controllers:

Tic T500

Tic T834

Tic T825

Tic T249

Tic 36v4
Operating voltage range: 4.5 V to 35 V(1) 2.5 V to 10.8 V 8.5 V to 45 V(1) 10 V to 47 V(1) 8 V to 50 V(1)
Max continuous current per phase
(no additional cooling):
1.5 A 1.5 A 1.5 A 1.8 A 4 A
Peak current per phase
(additional cooling required):
2.5 A 2 A 2.5 A 4.5 A 6 A
Microstep resolutions: full
Automatic decay selection: Yes Yes Yes
Automatic gain control (AGC): Yes
Driver IC: MP6500 DRV8834 DRV8825 TB67S249FTG discrete MOSFETs
Price (connectors not soldered): $19.95 $29.95 $29.95 $39.95 $49.95
Price (connectors soldered): $21.95 $31.95 $31.95 $41.95 $51.95

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

Introductory special

As usual, we are offering an extra introductory special discount on the Tic 36v4, to help share in our celebration of releasing a new product. The first hundred customers to use coupon code TIC36V4INTRO can get up to five units for just $24.95! And we’ll even cover the shipping in the US!

New high-gear ratio Micro Metal Gearmotors

via Pololu Blog

Our Micro Metal Gearmotors are now available with 380:1 gearboxes, offering a new high gear ratio option between our existing 298:1 and 1000:1 versions. Unlike the 1000:1 gearmotors, which uniquely require a longer, more expensive gearbox to achieve such a big reduction, the 380:1 gearboxes fit everything in the same volume as all our lower gear ratios, so they are the same price as those lower-ratio versions and they work with all our micro metal gearmotor brackets.

What really sets these new units apart from our other gear ratios are their stainless steel gearbox plates, which are more durable than the ubiquitous brass ones, especially in applications with non-negligible radial loads. They also look way cooler!

380:1 micro metal gearmotor with stainless steel gearbox plates.

Micro metal gearmotor with brass gearbox plates.

The main point of this higher gear ratio is not to deliver more total torque but rather to enable slower speeds and lower current draws than our lower gear ratios at the same loads. That said, the 380:1 gearbox can withstand higher torques than our lower gear ratios thanks to its use of progressively thicker gears toward the output. Both the 380:1 and 1000:1 gearboxes have a recommended instantaneous torque limit of 2.5 kg*cm, while the lower gear ratios have a recommended limit of 2.0 kg*cm (note: we strongly advise keeping applied loads well under these instantaneous limits).

These new gearboxes are available paired with each of our five motor winding options in compact single-shaft or encoder-friendly dual-shaft configurations, resulting in the ten new options shown as related products at the bottom of this post. These are just 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.

No-Load Speed
Stall Torque
Max Power

(Gearbox Only)

(Gearbox & Motor)
(kg ⋅ cm) (oz ⋅ in)
12 V high-power,
carbon brushes
0.75 A 0.06 A 6000 0.09 1.3 5:1 HPCB 12V 5:1 HPCB 12V dual-shaft
3000 0.17 2.4 1.5 10:1 HPCB 12V 10:1 HPCB 12V dual-shaft
1100 0.39 5.4 1.1 30:1 HPCB 12V 30:1 HPCB 12V dual-shaft
650 0.67 9.3 1.1 50:1 HPCB 12V 50:1 HPCB 12V dual-shaft
450 1.0 14 1.1 75:1 HPCB 12V 75:1 HPCB 12V dual-shaft
330 1.3 18 1.1 100:1 HPCB 12V 100:1 HPCB 12V dual-shaft
220 1.8 25 1.0 150:1 HPCB 12V 150:1 HPCB 12V dual-shaft
160 2.5 35 1.0 210:1 HPCB 12V 210:1 HPCB 12V dual-shaft
130 3.0 42 1.1 250:1 HPCB 12V 250:1 HPCB 12V dual-shaft
110 3.3 46 1.0 298:1 HPCB 12V 298:1 HPCB 12V dual-shaft
85 5.0 69 1.1 380:1 HPCB 12V 380:1 HPCB 12V dual-shaft
35 10 140 1000:1 HPCB 12V 1000:1 HPCB 12V dual-shaft
6 V high-power,
carbon brushes
1.5 A 0.10 A 6000 0.09 1.3 5:1 HPCB 6V 5:1 HPCB 6V dual-shaft
3000 0.17 2.4 1.3 10:1 HPCB 6V 10:1 HPCB 6V dual-shaft
1100 0.45 6.2 1.2 30:1 HPCB 6V 30:1 HPCB 6V dual-shaft
650 0.74 10 1.2 50:1 HPCB 6V 50:1 HPCB 6V dual-shaft
430 1.1 15 1.3 75:1 HPCB 6V 75:1 HPCB 6V dual-shaft
330 1.6 22 1.3 100:1 HPCB 6V 100:1 HPCB 6V dual-shaft
220 2.0 28 1.1 150:1 HPCB 6V 150:1 HPCB 6V dual-shaft
160 2.8 39 1.1 210:1 HPCB 6V 210:1 HPCB 6V dual-shaft
130 3.2 44 1.1 250:1 HPCB 6V 250:1 HPCB 6V dual-shaft
110 3.4 47 1.0 298:1 HPCB 6V 298:1 HPCB 6V dual-shaft
85 5.0 69 1.1 380:1 HPCB 6V 380:1 HPCB 6V dual-shaft
33 11 150 1000:1 HPCB 6V 1000:1 HPCB 6V dual-shaft
6 V high-power
1.6 A 0.07 A 6000 0.11 1.5 5:1 HP 6V 5:1 HP 6V dual-shaft
3000 0.22 3.0 1.6 10:1 HP 6V 10:1 HP 6V dual-shaft
1000 0.57 7.9 1.5 30:1 HP 6V 30:1 HP 6V dual-shaft
590 0.86 12 1.3 50:1 HP 6V 50:1 HP 6V dual-shaft
410 1.3 18 1.4 75:1 HP 6V 75:1 HP 6V dual-shaft
310 1.7 24 1.3 100:1 HP 6V 100:1 HP 6V dual-shaft
210 2.4 33 1.2 150:1 HP 6V 150:1 HP 6V dual-shaft
150 3.0 42 1.1 210:1 HP 6V 210:1 HP 6V dual-shaft
120 3.4 47 1.1 250:1 HP 6V 250:1 HP 6V dual-shaft
100 4.0 56 1.1 298:1 HP 6V 298:1 HP 6V dual-shaft
84 5.5 76 1.1 380:1 HP 6V 380:1 HP 6V dual-shaft
31 12 170 1000:1 HP 6V 1000:1 HP 6V dual-shaft
6 V medium-power
0.67 A 0.04 A 4400 0.06 0.8 5:1 MP 6V 5:1 MP 6V dual-shaft
2200 0.11 1.5 10:1 MP 6V 10:1 MP 6V dual-shaft
720 0.33 4.6 0.57 30:1 MP 6V 30:1 MP 6V dual-shaft
420 0.54 7.5 0.55 50:1 MP 6V 50:1 MP 6V dual-shaft
290 0.78 11 0.54 75:1 MP 6V 75:1 MP 6V dual-shaft
220 0.94 13 0.50 100:1 MP 6V 100:1 MP 6V dual-shaft
150 1.3 18 0.48 150:1 MP 6V 150:1 MP 6V dual-shaft
100 1.7 24 0.46 210:1 MP 6V 210:1 MP 6V dual-shaft
88 2.2 31 0.48 250:1 MP 6V 250:1 MP 6V dual-shaft
73 2.4 33 0.44 298:1 MP 6V 298:1 MP 6V dual-shaft
57 3.6 50 0.53 380:1 MP 6V 380:1 MP 6V dual-shaft
22 6.5 90 1000:1 MP 6V 1000:1 MP 6V dual-shaft
6 V low-power
0.36 A 0.02 A 2500 0.05 0.7 5:1 LP 6V 5:1 LP 6V dual-shaft
1300 0.10 1.4 10:1 LP 6V 10:1 LP 6V dual-shaft
450 0.29 4.0 0.31 30:1 LP 6V 30:1 LP 6V dual-shaft
270 0.44 6.1 0.29 50:1 LP 6V 50:1 LP 6V dual-shaft
180 0.64 8.9 0.29 75:1 LP 6V 75:1 LP 6V dual-shaft
130 0.74 10 0.25 100:1 LP 6V 100:1 LP 6V dual-shaft
90 1.1 15 0.25 150:1 LP 6V 150:1 LP 6V dual-shaft
65 1.6 22 0.25 210:1 LP 6V 210:1 LP 6V dual-shaft
54 1.7 24 0.23 250:1 LP 6V 250:1 LP 6V dual-shaft
45 2.0 28 0.22 298:1 LP 6V 298:1 LP 6V dual-shaft
36 2.9 40 0.27 380:1 LP 6V 380:1 LP 6V dual-shaft
13 5.5 76 1000:1 LP 6V 1000:1 LP 6V dual-shaft

New 5:1 Glideforce light-duty linear actuators

via Pololu Blog

We have filled out our line of 5:1 Glideforce Light-Duty Linear Actuators to include all of Concentric’s available lengths by adding 2″, 6″, 8″, and 10″ versions, with and without feedback, to our existing 4″ and 12″ options. The low gear ratio makes these our fastest (but weakest) linear actuators, capable of lifting up to a few dozen pounds at speeds up to 1.7″ per second (44 mm/s) at 12 V. For stronger but slower options, we have versions available with a 10:1 gear ratio or 20:1 gear ratio.

This brings our total selection of light-duty actuators to 36 options:

@ 12 V
@ 12 V
@ 12 V
(LD) 5:1
15 kgf
[34 lbs]
4.4 cm/s
3.6 cm/s
1.2 A –
3.2 A
2″ LACT2P-12V-05 LACT2-12V-05
4″ LACT4P-12V-05 LACT4-12V-05
6″ LACT6P-12V-05 LACT6-12V-05
8″ LACT8P-12V-05 LACT8-12V-05
10″ LACT10P-12V-05 LACT10-12V-05
12″ LACT12P-12V-05 LACT12-12V-05
(LD) 10:1
25 kgf
[55 lbs]
2.8 cm/s
2.3 cm/s
1.2 A –
3.2 A
2″ LACT2P-12V-10 LACT2-12V-10
4″ LACT4P-12V-10 LACT4-12V-10
6″ LACT6P-12V-10 LACT6-12V-10
8″ LACT8P-12V-10 LACT8-12V-10
10″ LACT10P-12V-10 LACT10-12V-10
12″ LACT12P-12V-10 LACT12-12V-10
(LD) 20:1
50 kgf
[110 lbs]
1.5 cm/s
1.2 cm/s
1.2 A –
3.2 A
2″ LACT2P-12V-20 LACT2-12V-20
4″ LACT4P-12V-20 LACT4-12V-20
6″ LACT6P-12V-20 LACT6-12V-20
8″ LACT8P-12V-20 LACT8-12V-20
10″ LACT10P-12V-20 LACT10-12V-20
12″ LACT12P-12V-20 LACT12-12V-20