select tube size for motorized window blinds
  Bulletin - 3 Levels of Blind, Shade, & Window Control 

Level 1 - RollerTrol™ Simple Remote Controls: We designed our system so that you can start out with our simple wall mount and hand held remotes for our shade/blind motors and skylight/window openers, then upgrade later to a more advanced system. Your investment is preserved as any remotes you purchase will still work, even if you upgrade to level 2 or 3 later. The remote control signals will be 'learned' and used by the higher levels of automation (see our blind & shade automation guide).

Level 2 - BroadLink® RF-IR Blaster Automation Hub: See our affordable blind and shade hub, operated by Android and IOS apps. This RF-IR blaster hub can learn RF radio signals for our blind motors and skylight/window openers and IR learning for TV. Convert old phones and tablets into WiFi home automation controllers! You can also add support for voice control systems such as Alexa® and Google Home®.

Level 3 - Z-WAVE® Blind Automation: This protocol is often used in home automation systems. We have a Z-Wave interface for roller shade and blind motors, and Z-Wave control of our skylight and window opener systems. You can also use Alexa® and Google Home®.

Mermet® Custom Shades: For those of you wanting a more complete solution, we are also offering high quality shade and blind fabrics from Mermet®, mounted on standard tubing. Our motors just slide in and lock in place - no fuss no muss! Please check our Custom Blinds and Shades website for info.

Our high quality DIY remote control RollerTrol™ DC tubular motors are perfect for making custom remote control window blinds and shades, skylight shades, projector screens, awnings, banners, conveyers or any application where you need a rotating tube.

The low voltage DC operating current is safe for children or adults, and you do not need to be an electrician to install these.

We hope the following information and specifications will help you make the right choice when selecting your tubing, but please feel free to contact us at any time if you have any questions.

The most important factors when choosing the right motor for blinds or other applications are drive size, lift capacity, and control options:

In this article we will focus on the drive size and how it affects your choice of tube size.

We have two basic physical sizes of 12 volt motors: the standard series with a 35mm drive adapter, and the mini series with an 18mm drive adapter:

standard tubular motor for blinds and shades   mini motor for blinds and shades

Please Note: our standard series (35 mm drive adapter) is designed to fit inside industry standard 1.5" tubing. If you purchase a shade with 1.5" tubing, the motor will simply slide into the tube, and the cut-outs on the drive wheel will lock to the splines inside the tube. The splines (grooves/slots) are usually used to lock the edge of the material in place.

Please Note:We are now also providing pre-made shades cut to size and mounted on 1.5" tubing, with a hem bar. Please feel free to contact us for a quote anytime.

Each model is available with and without built-in remote control. Units without remote control are typically used in situations where there is already a home automation system in place (see our home automation controllers for more info about this).

The standard series is designed to work in most situations with almost any window size where you want to install a motorized blind or shade with remote control. There are two models in this series, with different gearing and lift capacities: 6 lb (2.7 kg) @ 34 rpm and 12 lb (5.5 kg) @ 28 rpm.

The mini series, although slower, is designed to fit inside the cardboard roller typical of most retail rolller style shades that you may have already installed. The ability to retrofit existing shades with the 'mini' can save you a lot of money. Our 'mini' may be the smallest tubular motor available anywhere, and it has many other potential applications due to its small size.

We recommend aluminum tubing as a good choice for the roller material, although you can use cardboard, plastic and steel tubing if it suits your purpose. The following pertains to aluminum tubing, but the dimensions can be applied generally to other types of tube material. There are 3 important dimensions to consider (other than length):

OD (Outer Diameter)
WT (Wall Thickness)
ID (Inner Diameter)

Tubing is generally specified as OD, but the wall thickness can be different, producing a different ID.

Also, do not get confused by the difference between TUBING and PIPE. Tubing is generally used as a construction material (specified as OD) whereas pipe (specified as ID) is generally used to carry liquids and gas, and typically has a thicker wall than tubing. Pipe might actually be a better choice if you have a long span and want to minimize sag.

There is also special tubing available with a splined wall (eg. Rollease®) that our motors are also designed to work with. It is more difficult to obtain and more expensive than standard round tubing. Our standard series will fit perfectly in Rollease® 1.5" tubing.

You can use any type of tubing for your blinds, the only critical dimension is the ID (inside diameter) because this is what the drive adapter has to fit inside, and come into contact with (if a friction fit doesn't suffice, you can drill a hole and insert a screw to lock it).

Our motors use very standard tubing available at any metal provider or welding shop. However, it is not a problem to reduce the diameter of the drive adapter (file or grinder) to fit some other close size. It is also not a problem to build up the diameter with tape. For more info on motor insertion, see our article about how to insert tubular motors into tubing.

For the Standard series, the approximate designation for a metal tube supplier is:

1.5" tubing (6061 Aluminum Round Tube)

OD (Outer Diameter): 1 1/2" = 1.5" = 38mm
WT (Wall Thickness - typical): 1/16" = 0.065" = 1.7mm
ID (Inner Diameter for drive adapter): 1 3/8" = 1.37" = 35mm

For a quick solution, we have found that 1 1/4" EMT conduit (the type used for electrical wiring in your home) fits the Standard series perfectly, and can be found at any building supply store like Home Depot.

We recently made a roller shade for a family room, and we bought a 3 foot length of 1 1/4" black ABS plumbing drain pipe for about $3 at Home Depot, then we went over to Fabricland and bought some roller shade material for about $30.

We inserted one of our battery motors into the tube (filed the drive wheel down a bit), attached the fabric with some masking tape, assigned the motor to a channel on the remote, screwed it into the wall with our mounting brackets, and it was done. Works perfectly, even without a locking setscrew.

For wider shades we would recommend that you use 1 1/4" EMT steel pipe instead, if you have any concerns about sag.

For the Mini series, the approximate designation for a metal tube supplier is:

1.0" tubing (6061 Aluminum Round Tube)

OD (Outer Diameter): 1" = 26mm
WT (Wall Thickness - typical): 1/8" = 0.125" = 3.2mm
ID (Inner Diameter for drive adapter): 3/4" = 0.75" = 18mm

For a quick solution, we have found that thin wall 3/4" copper pipe (the type used for water pipe in your home) fits the Mini perfectly, although it is expensive.

For the Maxi series, the approximate designation for a metal tube supplier is:

2.5" tubing (6061 Aluminum Round Tube)

OD (Outer Diameter): 2.5" = 64mm
WT (Wall Thickness - typical): 1/8" = 0.125" = 3.2mm
ID (Inner Diameter for drive adapter): 2.3" = 60mm

For the Battery series, use the Mini or Standard series designations, depending on which one you choose.

It does not matter how long the tube is from a power perspective or bracket strength (they are very strong). What's important is the weight of the fabric and tensioner bar at the bottom. Our standard series motors have a lift capacity of 6 or 12 lbs, measured with 1.5" tubing. If you use a larger diameter, the speed will increase but the lift capacity will decrease.

Here are a few online references, but it will usually be a lot cheaper for you to buy it locally:$LimAcc

Please note that all models with built-in radio use our multi-channel remotes and/or VERA web interface.

Here is a motor comparison table to help you choose the right one for your purpose:

Tubular Motor Comparison Matrix: (*key specifications in yellow)

Tube OD
Volts Idle
Current (mA)
Standard Series: (25mm housing diameter)
TMDP-12-25-15-32-R Y 12/5.5 1.37/35 1.5/38 1.5 32 12 0.07 1500
TMDC-12-25-15-28-NR N 12/5.5 1.37/35 1.5/38 1.5 28 12 0 1500
TMDG-12-25-16-40-RB Y 16/7.25 1.37/35 1.5/38 1.1 40 12 0.07 n/a
HEAVY DUTY Series: (28mm housing diameter)
MAXI Series: (35mm housing diameter)
TMDG-12-35-45-9-R Y 45/20 2.4/60 2.5/64 10 9 12 0.07 4000
TMDG-12-35-45-9-NR N 45/20 2.4/60 2.5/64 10 9 12 0 4000
TMDG-12-35-45-9-RB Y 45/20 2.4/60 2.5/64 10 9 12 0.07 n/a
Battery Series (repeated above) - built-in rechargeable Li battery with solar panel option
TMDG-12-25-16-40-RB Y 16/7.25 1.37/35 1.5/38 1.1 40 12 0.07 n/a
TMDG-12-35-45-9-RB Y 45/20 2.4/60 2.5/64 10 9 12 0.07 n/a

Making the Right Motor Choice:

The first step is to calculate the weight of your intended load. If your application is for shades, blinds, screens or any other project that uses fabric or some type of material on a roller tube, you may first want to read our article about how to calculate blind or shade material weight. Note that the length or weight of the roller tube has little effect on the motor requirements, but the diameter of your tube and the fabric or load weight does.

Once you have an idea of your load requirements and tube size, use the table above to select the right motor (mouse over the table cells for explanation of a particular parameter). You can also see more detailed information and further comparison information by clicking on the model number of the motor in the table. This will take you to the appropriate page in our tubular motor and automation product catalog.

We sincerely hope you enjoy using these advanced tubular motors; if you have any questions, please feel free to contact us at any time!