TinyG and gShield FAQ

Choose TinyG if you want a self-contained controller with four motor outputs, rotary axes or jerk-controlled motion. Choose gShield if you have a 3-axis machine and want to run grbl on an Arduino Uno, or g2core on an Arduino Due. See TinyG vs gShield for a side-by-side comparison.

TinyG takes 12–24 V DC and gShield 12–30 V DC for the motors. A 24 V supply is recommended because the motors are more responsive and actually run cooler than at 12 V. Size the current for your motors: about 4.5 A is enough for NEMA 17 motors and 6 A or more is recommended for NEMA 23s. Not every motor draws full current at once, so you do not need to add up every winding. TinyG supplies typically fall between 4 and 15 A.

NEMA 17 motors and most NEMA 23s. The drivers deliver about 2 A per winding, or 2.5 A with fan cooling, so motors rated up to roughly 3 A per winding will work but may not reach full power. TinyG works with bipolar and unipolar motors but not 5-wire "star" motors. A motor's rated voltage does not matter, because the drivers regulate current.

A 12 V or 24 V fan is recommended when motors draw more than 2 A per winding, especially if the board is in an enclosure. TinyG v8 has a 3-pin fan header with a jumper to select 12 V or the motor supply voltage.

gShield does not include an Arduino; buy one separately. gShield v5 works as shipped on R3 Arduinos: the Uno and other ATmega328P boards running grbl, and the Arduino Due running g2core. Older R2 boards such as the Duemilanove need the logic power jumper moved to 5 V. Boards with a non-standard footprint, like the Nano, Mini or LilyPad, will not fit.

No. TinyG is sold as the board only; the power supply, case, fan and the machine itself are not included.

TinyG accepts plain G-code over a USB serial port. CNCjs and Universal Gcode Sender support TinyG and g2core directly, and the TinyG wiki has setup guides for ChiliPeppr, CNCjs and CoolTerm. gShield running grbl works with grbl-compatible G-code senders; the grbl wiki keeps a list.

TinyG has a boot loader, so you can update it over USB without a programmer. Follow Updating TinyG firmware on the wiki.

Yes. TinyG and g2core are on GitHub under GPLv2 with the BeRTOS exception, which lets component files be used in commercial and closed-source products. grbl, which runs on gShield, is a separate open-source project.

Orders ship from Southwest Florida by USPS, with Priority Mail and Express Mail options for domestic and international orders. Orders are processed for shipment within 3–5 business days, and we aim for 3. For international orders we recommend Express Mail International, the only option with door-to-door tracking.

Every Synthetos board is guaranteed free of manufacturing defects and to work on arrival. If yours is defective or dead on arrival, contact us within 30 days of receipt. We cannot replace boards damaged by miswiring, such as reversed power. If you bought from a reseller, please contact the reseller. See warranty and returns.

Yes. Unused items in their original packaging can be returned within 30 days of delivery for a full refund. Return shipping is paid by the customer and is not refundable.

Start with the documentation and the troubleshooting guides. Report firmware bugs on GitHub issues for TinyG or g2core. For anything else, contact us with your board revision, firmware version and what you were doing when the problem happened.