I like to grow herbs and vegetables for cooking, and this year I am adding Thai peppers and jalapenos. My plan is to smoke the jalapenos to make chipoltes. I can’t wait, but I need to get an early start on these peppers in our colder climate. And, so I have created an indoor seed starting and growing platform. Later, I will ty to use this for growing some herbs indoors, and I will also apply some of my hydroponic experience to make an insert for hydroponic growing.

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Every growing season I found myself juggling trays, heat mats, lights balanced on boxes, and awkward height adjustments as seedlings shot up faster than expected. It worked — but it was messy, unstable, and never quite dialed in.

The Logical Grow Platform (LGP) was designed to solve that problem in a clean, modular, fully printable way.

Instead of building a temporary setup every spring, the LGP creates a dedicated growing platform that holds your seed trays, integrates optional bottom heat, supports a common LED grow panel, and adjusts smoothly as your plants grow — all while staying compact enough to print on a standard 250mm bed.

It’s a system meant to grow with you, not something you outgrow in two weeks.

What It Is & How It Works

At its core, the LGP is a snap-together main body that holds seed starting trays inside a raised platform, with two adjustable threaded posts that support a removable light hood above.

The hood holds a standard aluminum LED grow panel, while the base can optionally house a low-power reptile-style heater for bottom warmth during germination.

As seedlings emerge and stretch upward, you simply rotate the posts to raise the light — keeping an optimal distance without stacking books or rebuilding your setup.

Everything is modular:

• Trays drop in and swap out easily
• The hood lifts off instantly for watering or transplanting
• Height adjusts smoothly with precise control

Key Parts & Mechanisms

The LGP is built around a few carefully designed functional elements.

Snap-Together Main Body
The base assembles from interlocking pieces using tongue-and-groove joints and internal latches. It locks rigidly while still allowing disassembly if needed.

Adjustable Threaded Posts
Each post raises or lowers the hood smoothly with every rotation — about 6mm (roughly 1/4”) per turn.

An extended grip rib acts as a visual rotation marker so you can keep the hood perfectly level if you want precise alignment.

The posts can also be printed mirrored if you prefer counter-rotating motion instead of both turning the same direction.

Two-Piece Snap Hood
The hood prints in two identical halves that slide together over the LED panel and lock underneath with printed clips — no hardware required.

Integrated Cable Strain Relief
Both the hood and base include built-in cord management points to protect and route power cables cleanly.

Size & Dimensions

Despite being a complete growing platform, the LGP stays compact enough for shelves, desks, and indoor grow spaces.

The footprint is roughly 445mm long by 180mm wide, with height adjustable from about 175mm up to nearly 390mm depending on post position.

It comfortably fits multiple Logical Grow trays while remaining stable and easy to move.

Printing Notes & Recommended Settings

The Logical Grow Platform is designed as a functional print — strength matters more than cosmetic perfection.

Recommended settings focus on durability:

• 0.4mm nozzle
• 0.2mm layer height
• Thick walls and solid top/bottom layers
• 40% cubic infill for general use or 100% for maximum longevity

PLA works well for indoor use, while PETG or ASA are ideal for higher heat or long-term durability.

Everything prints support-free in strength-optimized orientations.

Post-Print Setup & Motion Release

Because the adjustable posts are printed with tight tolerances to eliminate wobble, they may need a quick break-in.

This is done by gently squeezing or tapping the post sections, then fully extending and retracting them once or twice until motion becomes smooth.

An included Post Tool acts as a small wrench to help rotate the internal elements if needed.

Once loosened, the movement becomes effortless and precise.

Assembly

Assembly is entirely snap-fit — no screws, glue, or hardware required.

Main Body
The end pieces slide into the center section and click into place using built-in latches.
If the bottom tongue-and-groove features don’t perfectly self-align, a gentle flex will seat them flush.

Adjustable Posts
Prepared posts press into the connectors in each end of the base and snap securely.

Hood
The two hood halves slide onto the LED panel and lock together underneath using printed clips.

The hood then rests directly on the adjustable posts for quick removal.

Everyday Use & Operation

Using the LGP quickly becomes second nature.

Start seeds in your trays, drop them into the base, and optionally add bottom heat for faster germination.

Once sprouts appear, lower the hood close to the seedlings for strong early growth. As plants stretch, rotate the posts to raise the light smoothly.

The hood lifts off instantly for watering, thinning, or transplanting.

Everything stays organized, stable, and perfectly positioned through every growth stage.

Why This Design Exists

The Logical Grow Platform was created to replace the unstable pile-of-stuff grow setups most of us end up using.

It’s about:

• Clean organization
• Smooth mechanical adjustment
• Modular expansion
• Turning seed starting into a proper system

It also forms the foundation of the broader Logical Grow ecosystem — with interchangeable trays, accessories like filling funnels and reusable plant markers, and future modules designed to scale from germination through indoor growing.

Like all LogicalPlanet designs, it’s built to be practical, durable, and satisfying to use.

The post Logical Grow Platform (LGP) first appeared on logicalplanet.

I use utility knives all the time in the shop — opening boxes, trimming prints, cutting filament, breaking down packaging — and I wanted something that felt solid, safe, and predictable, without relying on tiny springs, metal hardware, or complicated internals.

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That’s what led to SLUK: a fully 3D-printed, self-locking utility knife designed around simplicity, reliability, and everyday use.

What Makes SLUK Different

The defining feature of SLUK is right in the name: self-locking.

Instead of a traditional spring-loaded slider or button lock, SLUK uses geometry and friction to lock the blade carrier in position automatically. Once extended, it stays put. When retracted, it stays put. No extra parts, no tiny mechanisms, and nothing to wear out quickly.

It’s a very “3D-printing-native” solution — using shape, tolerance, and material behavior instead of hardware.

Designed for Standard Utility Blades

SLUK is designed around standard utility blades, which are inexpensive, widely available, and easy to replace. The blade is fully enclosed when retracted, and the body provides a comfortable grip without being bulky.

The goal wasn’t to reinvent the utility knife — just to make a clean, functional version that prints well and works reliably.

Printing and Assembly

This design is intentionally straightforward to print and assemble.

• Fully 3D printed
• No supports
• No metal hardware
• Simple press-fit assembly

PLA works well, and PETG or ASA are also good options if you want a bit more durability. As with most functional parts, decent wall thickness matters more than extreme infill.

The tolerances are forgiving, but like most sliding parts, good extrusion consistency helps.

Why I Made This

There are lots of utility knives out there — cheap ones, fancy ones, disposable ones. What I wanted was a printable tool that earns a permanent place in the shop, one that’s easy to understand, easy to maintain, and safe to toss in a drawer or toolbox.

SLUK is the result of that thinking: simple, solid, and designed to work the way you expect it to.

Give It a Try

If you print one and put it to use, I’d love to hear how it holds up for you. Feedback, tweaks, and edge cases are always welcome — that’s how these designs get better over time.

The post SLUK – Self-Locking Utility Knife first appeared on logicalplanet.

Over the last few years, toilet paper manufacturers have been steadily shrinking the inner cardboard core. That doesn’t sound like a big deal… until you realize that a lot of holders (especially simple or minimalist ones) rely on a fairly consistent core size to work properly.

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My original tank-mounted toilet paper holder worked great for years. Then suddenly rolls started falling off, rattling around, or just not fitting the way they used to. That’s what led to this second-generation redesign.

What Changed in Gen 2

The biggest difference in this version is the post itself.

Instead of relying on a rigid diameter that assumes all TP cores are the same, the Gen 2 design uses a compliant, flexible post that adapts to different core sizes — including the smaller modern ones. It grips the roll securely without binding and without needing springs, bearings, or hardware.

The rest of the design stays true to the original goals:

• Fully 3D printed
• No hardware
• No supports
• Simple, functional, and easy to print

It still mounts directly on the back of the toilet tank, keeping the roll accessible without drilling holes or installing wall brackets.

Single and Double Roll Versions

I’ve included both single-roll and double-roll variants.
The double version is surprisingly handy — not just as a backup roll, but also if you like having different paper types available.

Both versions use the same compliant post idea, so they handle modern rolls equally well.

Print Settings

Functional designs (such as this one) generally require more strength than non-functional designs and more strength than the typical default slicer settings provide, so please review your slicer settings carefully.

This product was designed for a 0.4mm nozzle and a 0.2mm layer height. For best results, I suggest the following:

Assembly Notes

No assembly required.

Why This Update Matters

This is a good example of why I like iterative, real-world design. Nothing about toilet paper holders is glamorous — but when something that used to work suddenly doesn’t, the fix needs to be simple, reliable, and durable.

Gen 2 exists because the world changed slightly, and the design needed to adapt.

Try It Out

If you’ve noticed rolls slipping off older holders or not fitting the way they used to, this version should solve that problem cleanly. As always, feedback is welcome — especially if you run into edge cases or unusual roll sizes.

The post Toilet Paper Holder 2 first appeared on logicalplanet.

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What I ended up with is this fully 3D-printed, modular wall-mounted spool storage system. It’s snap-together, it’s expandable in all directions, and the spool trays actually collapse up into the wall assembly when I need my wall space back. It’s been a game changer in my workspace.

What This Is

This system is designed to hold standard 1 kg filament spools and let you build as much storage as you need without a bunch of screws, brackets, or bulky racks. The trays are printed parts that rotate up into their housings, creating a compact footprint while still being easy to access. The rail system makes it easy to keep multiple rows aligned and expandable.

It’s perfect for:

• Print farms
• Compact workshops
• Maker spaces
• Anyone who hates tangled filament and messy shelves

How It Works

1. Build the Walls
   Snap the wall components together — they key into each other so you know everything is aligned properly.
2. Assemble the Trays
   Each tray part has a keyed rotation so it sits square in the wall assembly and can pivot up or down smoothly.
3. Mount to Rails
   Slide the assembled trays onto the rail system. You can add more rails and spacers to widen or stack more rows.
4. Collapse for Space
   Want the wall back? Just rotate the trays upward flush against the wall rails.

This system isn’t locked into any particular number of spools — you add as many as you like by linking rails and adding spacers.

Printing Notes

As with most of my functional designs, strong walls and good infill give the best results. I’ve been printing these in PLA with the following general settings:

The trays and rails print reliably without fiddly supports, which makes batch printing them for a larger system quick and predictable.

Assembly

Installation

Try It and Tell Me What You Think

I hope this helps you get a better handle on spool storage — it’s made a big difference in my shop.

The post Logical Wall Mounted Spool Storage first appeared on logicalplanet.