Grizzly G0720 Motor Power Supply Repair - Part 2

Right before Christmas, my three-year-old Grizzly G0720 (AKA SIEG SX4) milling machine's main controller board released some of it's magic smoke. In the previous post I went over the initial troubleshooting steps that led me to believe that my failure was due to a blown output transistor. This appears to be a very common failure point of these brushless motor controllers and the replacement boards are very costly. Since the cost of output transistor replacement is less than 1/10th of the replacement board I decided to attempt it before buying a new board. If you find yourself in a similar situation, this post will guide you through the replacement process.

Grizzly G0720 Motor Power Supply Repair - Part 1

A couple of years ago, I sold my Grizzly G0463 milling machine and upgraded to the larger Grizzly G0720R (SIEG SX4). To this point, various SIEG machines I've owned have been pretty reliable but my luck finally ran out a day before Christmas. In the middle of power-taping a hole at low speed, the spindle abruptly stopped with a loud clunk and would not restart.

Updated DRO Adapter for iGaging Scales

It's been almost two years since the release of last revision of TouchDRO Adapter for iGaging and Shahe scales. During that time I've learned a lot from the interaction with the customers and received a lot of good feedback about the board. Overall the board has been very well received and has proven to be mostly trouble-free. There were a few minor design decisions that caused some issues or confusion for some people, though. For 2020, I decided to tweak the design a bit to make it even more user-friendly. The new board looks very similar to the previous revision and functions pretty much the same, but has a few updates that will make it more convenient to set up.

Adapter Board for Shahe and iGaging Capacitive DRO Scales

TouchDRO adapter for iGaging and Shahe scales is designed to work with several models of 3V capacitive linear DRO scales manufactured by Sanhe Measuring Instrument Co.,Ltd. and distributed under different brand names. It supports up to four linear scales, directional tachometer and a probe or tool height setter input. The circuit is designed and laid to provide reliable operation of capacitive DRO scales and significantly reduce the effect of shop noise and electrical interference on the scales, compared to a do-it-yourself adapter.

TouchDRO Supports new Chinese DRO Scales

TouchDRO "Black" Adapter Support All of The Shown Digital Readout Scales Now 

A few weeks ago, I finally found some time to experiment with the new Shahe Digital Linear Scales 5403-xxx and 5204-xxx. Electrically these scales are compatible with other 3V capacitive DRO scales such as iGaging DigiMag, EZ-View DRO and iGaging Absolute DRO. This means that adding support for the new scales is a matter of updating the firmware of the TouchDRO adapter for iGaging and Shahe DRO scales. After cursory check of scale protocol, I was expecting this to be a relatively easy addition to the existing firmware since they use the familiar BIN6 protocol. In practice, supporting Shahe "Remote DRO" scales ended up requiring a complete rewrite of large portion of the firmware. While at it, I decided to invest some more time into adding several other improvements that have been on my "to do" list for some time now. After several weeks of testing and debugging, the new firmware is ready to be released. In addition to the added protocol support, the updated firmware includes a few major performance and stability tweaks that will make capacitive DRO scales behave much more reliable in a shop environment.

Shahe 5403 and 5204 Digital Linear DRO Scales Overview

For several years the so-called "remote DRO" capacitive scales, manufactured by Wenzhou Sanhe Measuring Instrument Co.,Ltd. have been the mainstay of budget do-it-yourself DRO setups. These scales first appeared in the USA around 2011 under iGaging brand as "DigiMag Remote DRO" or "DigiMag" but then started showing up all over the internet under various brand names, including AccuRemote, Shars and unbranded generic version. A few years ago iGaging has redesigned the display of the scales and rebranded them as EZ-View DRO. Around the same time Shanhe introduced two new models of the Remote DRO scales that look rather similar to the original model but have several key differences.

A few months ago I ordered a couple different lengths of each scale in order to test and reverse engineer the communication protocol, and finally was able to get to it over the holiday break. In short, these scales would work very well for a budget DRO build, but require different firmware to decode the position. As I'm working on adding the support to the firmware, let's take a closer look at the data format these scales use and other important characteristics.

Blu-DRO Now Uses the TouchDRO iGaging DRO Adapter

UPDATE Sep. 7, 2020Al stopped selling Blu-DRO boxes earlier this year. As I've been getting a large number of inqueries about Blu-DRO or some other enclosure for the TouchDRO adapters, I decided to try selling a kit that includes a pre-assembled board and a 3D printed enclosure. At this point it's available for the TouchDRO Adapter for iGaging DRO Scales and can be purchased on the new TouchDRO.com website.

I get a fair number of emails asking if I sell fully assemble board, in a box, ready to go. Although I have seriously thought about offering a fully turn-key version of the iGaging DRO controller, I couldn't get the numbers to pensil out: the cost of making a custom injection molded enclosure is ridiculously high, and 3D printed enclosures take too much time and I couldn't find a way to make it scale. Meanwhile, I knew that Al at blu-DRO.com has been selling fully enclosed Arduino TouchDRO controllers. I've met Al "virtually" on TouchDRO Bata Testing Google+ community, where he had been a frequent poster, always willing to help or answer questions. Furthermore, the feedback I got from people who purchased blu-DRO units was very positive about his level of customer support, etc. After some "noodling around" I decided to email Al and see if we can find a way to work together. A few emails later we decided that I will sell the boards to Al in bulk at a bit of a discount so he can use them in his units. This seemed to be a win-win situation: Al would get more robust controllers for the blu-DRO and I can stop worrying about creating a turn-key version of TouchDRO.

Virtual Layout Feature Preview

In the last post I showed some of the updates coming to the next version of TouchDRO. The new version will include a lot of tweaks, UI changes and improvements aimed to make the DRO even more flexible and efficient to use. As is, TouchDRO can already do much more than and old-school DRO, but next version is getting a number features that will push the limits of what you can do with a non-CNC mill or lathe. One of those features is the ability to set a background image in layout view and use the mill or the lathe to trace the contour.

Sneak Peek of the New TouchDRO Version

It's been awhile since the last major TouchDRO version release and I'm getting an increasing number of emails asking if I'm still developing the app. The answer is "definitely yes", and the new version is getting very close to be ready for beta testing. It has a number of new features and countless quality-of-life changes. I've been testing it in my shop for some time now and most of the functionality is pretty stable so it's a good time to post a quick preview of some of those changes and new features.

SIEG X2 Mini Mill CNC Build - Component Selection

In the last post I outlined my plan for building a CNC mini mill from a set of SIEG X2 castings. As the first step I wanted to order the parts for the mill itself, ignoring the steppers, controllers, etc. and make sure that I can get it up to snuff. There is no set budget for this project, so the choice of the parts is mostly based on availability (and common sense). The two areas I wanted to concentrate on are spindle accuracy and overall repeatability. With that in mind, in this post I will explain what parts I chose to buy and why.