Brick with Holes 1x12 #3895: Uses in Circuit Cubes Builds
By Circuit Cubes | Tenka Inc. | Published: 2026-10-14
Category: Product Reviews
A practical buying guide to the 1x12 brick with holes #3895: when its length and holes solve real build problems, and when a shorter brick is the smarter buy.
Quick answer
Buy the Brick with Holes 1 x 12 #3895 when you need one continuous 12-stud run with holes for axles, pins, or wiring, and you are willing to plan around its length. If you only need a few studs of reinforcement, the 1 x 4 #3701 gives you more flexibility for less. The 1x12 is a frame-building part, not a starter part.
What the 1x12 brick with holes actually solves
A 12-stud brick with holes is a span part. It carries load across a long gap without a seam, and the holes let you pass an axle, pin, or wire through the brick instead of routing around it. That combination matters in Circuit Cubes builds where a motor or battery cube sits in the middle of a frame and the surrounding structure has to stay rigid without blocking the moving parts.
The tradeoff is commitment. Once a 1x12 is in place, it defines the length of that edge. If your design changes, you may have to remove several connected pieces to swap it out. Shorter bricks let you adjust one section at a time.
Where the 1x12 earns its place in a build
Use it for chassis rails on wheeled builds, for the top and bottom of a vertical frame that holds a Geared Motor Cube, or as a mounting spine when you want the battery cube to slide along a straight line. In each case the value is the same: one part gives you a straight, hole-aligned run that stays straight under light load.
It is less useful on curved or angled shapes, and it is overkill for small decorative sections. If a build only needs a 4- or 6-stud stiffener, a long brick adds weight and removes adjustment options without adding strength you will notice.
How the 1x12 and 1x4 work together
The practical approach is to keep both in your parts bin. Use the 1x12 for the main span, then use 1x4 bricks to brace it at the ends or to fill gaps between the long brick and the rest of the frame. Because both are bricks with holes, the hole spacing lines up, so you can mix them on the same edge without changing your pin or axle plan.
If you are building a frame that will be taken apart often, favor the 1x4. If you are building a display piece or a test rig that stays assembled, the 1x12 saves time and reduces the number of joints that can work loose.
Decision rules for buying the 1x12 brick
- Rule 1: Buy the 1x12 only if the span is 12 studs or longer: Measure the edge you are reinforcing. If it is shorter than 12 studs, the 1x12 will overhang or force you to redesign the corner. Use 1x4 bricks instead and join them. Shorter than 12 studs: choose 1x4.
- Rule 2: Buy the 1x12 if you need holes in a straight line: The holes are the reason to pick this part over a plain brick. If your axle, pin, or wire path runs straight through the frame, the 1x12 keeps that path aligned in one piece. No hole path: a plain brick may be cheaper and simpler.
- Rule 3: Buy the 1x12 if the build stays assembled: Long bricks save time and reduce joint count, but they are harder to remove during revisions. If you rebuild often, favor 1x4 bricks even on long edges. Frequent rebuilds: stock 1x4 first.
- Rule 4: Buy the 1x12 in small quantities first: Order one or two, test the fit in your actual frame, then reorder. The catalog does not list option types or a multi-pack for #3895, so each order is a single brick. Test one span before committing to a full frame.
Product facts
- Brick with Holes - 1 x 12 - #3895: Brick with Holes - 1 x 12 - #3895 is a single building brick part listed under Parts, brand Tenka Inc., quantity 1. You are buying one long brick, not a set, so order the number you need for the span and keep a few spares if the build is a keeper.
- Brick with Holes - 1 x 4 - #3701: Brick with Holes - 1 x 4 - #3701 is a single building part, size 1 x 4, part number #3701, quantity included 1, brand Tenka Inc. The 1x4 is the flexible companion piece: use several to make a span you can adjust, or to brace the ends of a 1x12 without cutting into your long-brick supply.
- Cube Combo: Cube Combo includes the classic Battery Cube, which delivers approximately 3.7 - 4.2 volts DC when switched on, and the Geared Motor Cube, which rotates at more than 1,000 RPM. These are the two cubes most likely to sit inside a frame built from 1x12 bricks, so plan hole alignment around where the battery and motor need to sit.
Is the 1x12 brick with holes right for your build?
Best for
- Builders making a long, straight chassis rail or frame edge that needs holes for axles or wiring
- Display or test builds that stay assembled and benefit from fewer joints
- Anyone pairing the brick with a Cube Combo who wants the battery and motor cubes mounted inside a rigid frame
Not for
- Builders who revise designs often and need to swap one section at a time
- Small builds that only need a few studs of reinforcement
- Anyone who has not yet confirmed the 12-stud length fits their layout
