The GRBL Project

I have been an online seller of hobbyist electronic products for 6 years now. When I created my online store, I looked at several options and wound up going with Tindie. The primary reason was it did not require any ongoing payments and it used PayPal which I was familiar with. They took their payment from sales in the form of a transaction fee (3.5%) as well as a tindie fee (5%). Receiving the proceeds of sales was easy, just hit the Disbursement button and your money (min

I have been selling my products on Tindie.com since 2020. Six years in June, tempus fugit. While it is a bit of a barebones operation, Tindie worked ok for me. I sold thousands of units. Many customers became friends. I learned a lot about what people are doing in the CNC world and learned a lot about online retailing. It was a good experience. But, that all changed in April, 2026. Tindie, owned by Supplyframe, was sold with no announcement to an anonymous buyer. The site

Or, how to correctly use M62-M65 to turn on external devices. Controlling external relays and digital outputs with grblHAL is easy. M62-M65 GCodes (er, MCodes?) are straightforward. Or are they? The Digital Output Control codes allow you to turn external devices on and off. The T41U5XBB and RP23CNC boards have both relay drivers and logic level digital outputs for that. Embed an M62 P0 or M64 P0 in your GCode program to turn the Aux 0 output on. M63 P0 or M65 P0 will turn i

This is not your normal blog post from me by a long shot! Having a small business selling products internationally, I have learned a lot about shipping packages. I have also developed strong opinions about business practices around shipping. Very recently, I ordered several products from a popular hobby electronics company with a "sparkling" reputation. I got a shipping notice within a day and yet 3 days later US Postal Service tracking says they still have not received th

Variable Frequency Drives (VFDs) are a great way to control CNC spindles. A common method of control is using voltage (0-10V). This post describes how to use this with Brookwood Design's CNC controller boards - T41U5XBB or RP23CNC running grblHAL. Though, the information provided is broadly applicable to many other controllers running Grbl. Our examples are shown using the RP23CNC board but connections to the T41U5XBB are basically the same. What is a VFD? A Variable Frequen