The full range of round to square base converters laid out together, from 20mm round up to 100mm square.

Round to Square Bases Shape and Size Converters 3d Print Full Range

20mm To 20mm Square Converter x1pc
$2.48
$2.48
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The full range of round to square base converters laid out together, from 20mm round up to 100mm square.
  • The full range of round to square base converters laid out together, from 20mm round up to 100mm square.
  • Feature diagram of a round to square base converter: round socket, aligned top edge and open underside.
  • Size comparison chart showing the round to square base converters side by side, smallest to largest.
  • Close-up of a pile of 3D-printed round to square base converters, showing the printed layer lines.
  • Close-up of a pile of 3D-printed round to square base converters, showing the printed layer lines.
  • Three round to square base converters on a cutting mat, each holding a 25mm round base in its corner clips.
  • Technical drawing of the 20mm round to 25mm square base converter, with dimensions in millimetres.
  • 20mm round to 25mm square base converters, pack of 10, 3D-printed in PLA.
  • 20mm round to 25mm square base converters, pack of 25, 3D-printed in PLA.
  • 20mm round to 25mm square base converters, pack of 50, 3D-printed in PLA.
  • 20mm round to 25mm square base converters, pack of 100, 3D-printed in PLA.
  • Technical drawing of the 20mm round to 30mm square base converter, with dimensions in millimetres.
  • 20mm round to 30mm square base converters, pack of 5, 3D-printed in PLA.
  • 20mm round to 30mm square base converters, pack of 10, 3D-printed in PLA.
  • 20mm round to 30mm square base converters, pack of 25, 3D-printed in PLA.
  • 20mm round to 30mm square base converters, pack of 50, 3D-printed in PLA.
  • 20mm round to 30mm square base converters, pack of 100, 3D-printed in PLA.
  • Technical drawing of the 20mm round to 40mm square base converter, with dimensions in millimetres.
  • 20mm round to 40mm square base converters, pack of 5, 3D-printed in PLA.
  • Technical drawing of the 25mm round to 25mm square base converter, with dimensions in millimetres.
  • 25mm round to 25mm square base converters, pack of 5, 3D-printed in PLA.
  • 25mm round to 25mm square base converters, pack of 10, 3D-printed in PLA.
  • 25mm round to 25mm square base converters, pack of 25, 3D-printed in PLA.
  • 25mm round to 25mm square base converters, pack of 50, 3D-printed in PLA.
  • 25mm round to 25mm square base converters, pack of 100, 3D-printed in PLA.
  • Technical drawing of the 25mm round to 30mm square base converter, with dimensions in millimetres.
  • 25mm round to 30mm square base converters, pack of 5, 3D-printed in PLA.
  • 25mm round to 30mm square base converters, pack of 10, 3D-printed in PLA.
  • 25mm round to 30mm square base converters, pack of 25, 3D-printed in PLA.
  • 25mm round to 30mm square base converters, pack of 50, 3D-printed in PLA.
  • 25mm round to 30mm square base converters, pack of 100, 3D-printed in PLA.
  • Technical drawing of the 25mm round to 40mm square base converter, with dimensions in millimetres.
  • 25mm round to 40mm square base converters, pack of 5, 3D-printed in PLA.
  • 25mm round to 40mm square base converters, pack of 10, 3D-printed in PLA.
  • Technical drawing of the 25mm round to 50mm square base converter, with dimensions in millimetres.
  • 25mm round to 50mm square base converters, pack of 5, 3D-printed in PLA.
  • Technical drawing of the 28mm round to 25mm square base converter, with dimensions in millimetres.
  • 28mm round to 25mm square base converters, pack of 5, 3D-printed in PLA.
  • 28mm round to 25mm square base converters, pack of 10, 3D-printed in PLA.
  • 28mm round to 25mm square base converters, pack of 25, 3D-printed in PLA.
  • 28mm round to 25mm square base converters, pack of 50, 3D-printed in PLA.
  • 28mm round to 25mm square base converters, pack of 100, 3D-printed in PLA.
  • Technical drawing of the 28mm round to 30mm square base converter, with dimensions in millimetres.
  • 28mm round to 30mm square base converters, pack of 5, 3D-printed in PLA.
  • 28mm round to 30mm square base converters, pack of 10, 3D-printed in PLA.
  • 28mm round to 30mm square base converters, pack of 25, 3D-printed in PLA.
  • 28mm round to 30mm square base converters, pack of 50, 3D-printed in PLA.
  • 28mm round to 30mm square base converters, pack of 100, 3D-printed in PLA.
  • Technical drawing of the 28mm round to 40mm square base converter, with dimensions in millimetres.
  • 28mm round to 40mm square base converters, pack of 5, 3D-printed in PLA.
  • 28mm round to 40mm square base converters, pack of 25, 3D-printed in PLA.
  • Technical drawing of the 28mm round to 50mm square base converter, with dimensions in millimetres.
  • 28mm round to 50mm square base converters, pack of 25, 3D-printed in PLA.
  • Technical drawing of the 32mm round to 40mm square base converter, with dimensions in millimetres.
  • 32mm round to 40mm square base converters, pack of 5, 3D-printed in PLA.
  • 32mm round to 40mm square base converters, pack of 10, 3D-printed in PLA.
  • 32mm round to 40mm square base converters, pack of 25, 3D-printed in PLA.
  • 32mm round to 40mm square base converters, pack of 50, 3D-printed in PLA.
  • 32mm round to 40mm square base converters, pack of 100, 3D-printed in PLA.
  • Technical drawing of the 32mm round to 50mm square base converter, with dimensions in millimetres.
  • 32mm round to 50mm square base converters, pack of 5, 3D-printed in PLA.
  • 32mm round to 50mm square base converters, pack of 10, 3D-printed in PLA.
  • 32mm round to 50mm square base converters, pack of 25, 3D-printed in PLA.
  • 32mm round to 50mm square base converters, pack of 50, 3D-printed in PLA.
  • Technical drawing of the 40mm round to 40mm square base converter, with dimensions in millimetres.
  • 40mm round to 40mm square base converters, pack of 5, 3D-printed in PLA.
  • 40mm round to 40mm square base converters, pack of 10, 3D-printed in PLA.
  • 40mm round to 40mm square base converters, pack of 25, 3D-printed in PLA.
  • 40mm round to 40mm square base converters, pack of 50, 3D-printed in PLA.
  • Technical drawing of the 40mm round to 50mm square base converter, with dimensions in millimetres.
  • 40mm round to 50mm square base converters, pack of 5, 3D-printed in PLA.
  • 40mm round to 50mm square base converters, pack of 10, 3D-printed in PLA.
  • 40mm round to 50mm square base converters, pack of 25, 3D-printed in PLA.
  • 40mm round to 50mm square base converters, pack of 50, 3D-printed in PLA.
  • Technical drawing of the 50mm round to 50mm square base converter, with dimensions in millimetres.
  • 50mm round to 50mm square base converters, pack of 5, 3D-printed in PLA.
  • 50mm round to 50mm square base converters, pack of 10, 3D-printed in PLA.
  • 50mm round to 50mm square base converters, pack of 25, 3D-printed in PLA.
  • 50mm round to 50mm square base converters, pack of 50, 3D-printed in PLA.
  • Technical drawing of the 50mm round to 100mm square base converter, with dimensions in millimetres.
  • 50mm round to 100mm square base converters, pack of 5, 3D-printed in PLA.
  • Technical drawing of the 60mm round to 100mm square base converter, with dimensions in millimetres.
  • 60mm round to 100mm square base converters, pack of 5, 3D-printed in PLA.
  • Technical drawing of the 70mm round to 100mm square base converter, with dimensions in millimetres.
  • 70mm round to 100mm square base converters, pack of 5, 3D-printed in PLA.
  • Technical drawing of the 80mm round to 100mm square base converter, with dimensions in millimetres.
  • 80mm round to 100mm square base converters, pack of 5, 3D-printed in PLA.
  • Technical drawing of the 90mm round to 100mm square base converter, with dimensions in millimetres.
  • 90mm round to 100mm square base converters, pack of 5, 3D-printed in PLA.
  • Technical drawing of the 100mm round to 100mm square base converter, with dimensions in millimetres.
  • 100mm round to 100mm square base converters, pack of 5, 3D-printed in PLA.
  • 20mm round to 50mm square base converters, pack of 5, 3D-printed in PLA.
  • 20mm round to 25mm square base converter, single piece, 3D-printed in PLA.
  • 20mm round to 30mm square base converter, single piece, 3D-printed in PLA.
  • 20mm round to 40mm square base converter, single piece, 3D-printed in PLA.
  • 25mm round to 25mm square base converter, single piece, 3D-printed in PLA.
  • 25mm round to 30mm square base converter, single piece, 3D-printed in PLA.
  • 25mm round to 40mm square base converter, single piece, 3D-printed in PLA.
  • 25mm round to 50mm square base converter, single piece, 3D-printed in PLA.
  • 28mm round to 25mm square base converter, single piece, 3D-printed in PLA.
  • 28mm round to 30mm square base converter, single piece, 3D-printed in PLA.
  • 28mm round to 40mm square base converter, single piece, 3D-printed in PLA.
  • 28mm round to 50mm square base converter, single piece, 3D-printed in PLA.
  • 32mm round to 40mm square base converter, single piece, 3D-printed in PLA.
  • 32mm round to 50mm square base converter, single piece, 3D-printed in PLA.
  • 40mm round to 40mm square base converter, single piece, 3D-printed in PLA.
  • 40mm round to 50mm square base converter, single piece, 3D-printed in PLA.
  • 50mm round to 50mm square base converter, single piece, 3D-printed in PLA.
  • 50mm round to 100mm square base converter, single piece, 3D-printed in PLA.
  • 60mm round to 100mm square base converter, single piece, 3D-printed in PLA.
  • 70mm round to 100mm square base converter, single piece, 3D-printed in PLA.
  • 80mm round to 100mm square base converter, single piece, 3D-printed in PLA.
  • 90mm round to 100mm square base converter, single piece, 3D-printed in PLA.
  • 100mm round to 100mm square base converter, single piece, 3D-printed in PLA.
  • Technical drawing of the 20mm round to 20mm square base converter, with dimensions in millimetres.
  • 20mm round to 20mm square base converter, single piece, 3D-printed in PLA.
  • 20mm round to 20mm square base converters, pack of 5, 3D-printed in PLA.
  • 20mm round to 20mm square base converters, pack of 10, 3D-printed in PLA.
  • 20mm round to 20mm square base converters, pack of 25, 3D-printed in PLA.
  • 20mm round to 20mm square base converters, pack of 50, 3D-printed in PLA.
  • Technical drawing of the 20mm round to 25mm square base converter, with dimensions in millimetres.
  • 20mm round to 25mm square base converter, single piece, 3D-printed in PLA.
  • A single converter that gives a 75mm round base a 75mm square footprint, shown alone.
  • Technical drawing of the 75mm round to 75mm square base converter: 74.01mm square, 5mm tall.
  • Three converters that give a 75mm round base a 75mm square footprint, shown loose.
  • Five converters that give a 75mm round base a 75mm square footprint, shown loose.
Round to Square Bases Shape and Size Converters 3d Print Full Range

Round to Square Bases Shape and Size Converters 3d Print Full Range

3 reviews

$2.48
$2.48
Shipping calculated at checkout.
Key Dimensions · This Option
Fits base 20 mm round
Converts to 20 mm square
Overall height 4.0 mm
Outer footprint 20.0 × 20.0 mm
Material 3D-printed PLA
Number of packs
In stock

Same-day dispatch before 3pm Mon–Fri · Free UK delivery over £70 · 30-day returns

DWG · Product Information

PROJ: CONV/RO-SQ/20-20/1 · SHEET 2 / 4

View · Overview

Product overview

Drop a miniature on its round base into one of these converters and it occupies a square footprint — no rebasing, no glue, no magnets, nothing removed from the model. It lifts out again just as easily, so one collection can move to a rank-and-flank system such as Kings of War and go back to its round-based game afterwards. Sizes run from 20mm round up to 100mm square, and each converter is 3D-printed to order in black PLA in the UK; we usually keep some stock, but we may need a while to process your order. The converters stack with the Open Basing System’s own bases, trays and other converters.

  • No glue, magnets or rebasing — the round base sits in a socket and holds by friction fit, and an open underside lets the base be pushed out from below without gripping the model; where the square is barely larger than the round base, the converter is a four-corner clip that grips the base at the corners instead.
  • The base’s top edge sits flush with the converter, so the model is not raised.
  • Textured top surface matches the rest of the range, and PLA takes primer and acrylics, so the converter can be finished to match existing basing.
  • 3D-printed black PLA, made to order in the UK — fine layer lines and a Z-seam are normal, not defects, and become less visible under primer.
  • Works with Open Basing System bases, movement trays and other converters.

Compatible with popular tabletop miniatures; not affiliated with, endorsed by or produced by Games Workshop.

Notes · Q & A

Can a converter change my base footprint without rebasing?

OBS converters are designed to adapt an existing base where the selected conversion route fits that original footprint. Fit is route-specific, so confirm the selected option and technical drawing before ordering. Check Technical Specifications where added height matters.

How do I choose the correct converter?

Start with the footprint you already have, then select the target footprint you need. Compare both the accepted inner fit and the outer footprint with the technical drawing; matching nominal labels alone is not enough.

How should I use the technical drawing?

Choose your option first, then use the technical drawing and Technical Specifications to check the physical dimensions of the product. When matching an existing part or accessory, use the drawing rather than relying on the product name alone.

Can I rely on the nominal size alone?

No. Products with similar nominal sizes can have different physical dimensions or fit differently across brands and systems. Check the technical drawing, specifications and any product-specific compatibility note before ordering.

Notes · Logistics

Shipping

Orders placed before 3PM (Mon–Fri) are dispatched same day. Free UK delivery on orders over £70. International shipping available.

Returns

If you're not happy with your purchase, contact us within 14 days for a full refund or exchange. Items must be unused and in original packaging.

Table · Specification

Technical specifications

Product details
Brand
Hobby Heaven
Product code
CONV/RO-SQ/20-20/1
Type
Base
Shipping weight
20 g
Conversion
Fits base
20 mm round
Converts to
20 mm square
Geometry
Overall height
4.0 mm
Outer footprint
20.0 × 20.0 mm
Material & finish
Material
3D-printed PLA
Classification
Range
Base Converters
Format
Physical

Product

Round to Square Bases Shape and Size Converters 3d Print Full Range

Code (proj)

CONV/RO-SQ/20-20/1

Ship. weight

20 g

Brand

Hobby Heaven

Hobby Heaven · Open Basing System

Sheet 2 / 4

End of sheet
  • 5 stars: 3 (100%)
  • 4 stars: 0 (0%)
  • 3 stars: 0 (0%)
  • 2 stars: 0 (0%)
  • 1 star: 0 (0%)
R
Rob
Excellent in every way

Great quality, great price, and arrived really quickly too. The 25mm round to square especially fit really snuggly for the most part so no need to do anything to hold the models in.

Rob review photo
S
Shane Child
Open Basing System

The Team where very helpful on selecting the correct bases that would work across both "Age of Sigmar/Warhammer The Old World" for my Warriors of Chaos. Fantastic solution especially if you buy 100 pieces per type needed.

S
SnufflePox
25mm circular to 30mm square converters

A solid product. Quality is good with a decent finish and minimal print lines - nothing that shows through final basing.
Dimensions are spot on, giving a decent grip on GW bases without having to use any excessive force but still allowing rotation for ranking up. Base height is a couple mm taller than a GW 30mm, but looks fine, and allows for the bottom of the converter to stop the order final based falling through.
Price is reasonable - not a cheap as chips bargain, but a fair price given the hobby.
Overall - very satisfied and will be ordering more.