Years back I managed to find one of those “dream” home shop machinery deals. An Emco Maximat V10P lathe was sitting in a dusty pile at the back of a bike shop in Alameda, CA. This is a very much sought-after home shop machine. The shop owner said the machine was taking up space, so we made a deal and it followed me home for a more-than-fair price. It’s been a great lathe, but was in far from tip-top shape and has needed some TLC and upgrades. One thing that I’d been meaning to address for long time, is that oil constantly dribbled out of the quick-change gearbox onto my bench. What follows details that fix.
This is a repair of Bose L1 tower PA system. These skinny tower speakers are somewhat of a marvel because they are designed to stand behind the musician (aimed RIGHT AT the microphone) and don’t generate feedback (in most situations). Ah, the miracles of DSP.
It turns out these PA’s have a frequent failure in their power supply. Read on for details.
I recently got a Tormach PCNC 770 CNC milling machine. So far, I’m very happy with it (but have not cut much yet). I figured that since I wouldn’t be using flood cooling, that I could get away without a full enclosure. But even with mist rather than flood, chips were shot everywhere, so I decided to roll my own enclosure using 80/20 parts https://www.8020.net/
There are lot of similar designs on-line, but the one I used most for guidance was by sauni68 on YouTube: https://www.youtube.com/watch?v=FddiAAuI2Rg
His was a design for a PCNC 1100, but his video still has several good tips that are appropriate for the 770.
NOTE 7/2020: I have discovered a limitation on how fast the saddle can be moved without losing Z counts. I assumed this would be faster than I can crank by hand, but it turns out that you can lose counts even at moderate cranking speed – somewhere between 1″/sec and 2″/sec carriage movement. It appears a faster uC than the MSP430 is needed. I will update when I have a solution.
This is an outstanding machine DRO for hobbyists, not just an outstanding DIY project, but a super DRO even compared to high-end pro machines. The beauty of TouchDRO is that it uses a (cheap) Android tablet for the display and control (I used a 1st-generation Nexus tablet – $50 on eBay) while the scales connect to a small (user-built) box that wirelessly sends data to the tablet via Bluetooth. The extra cute thing about this particular DRO installation is that all that parts are very small and don’t interfere with any travel distances or setups on this already smallish machine.
This is bender specifically made to put a very tight radius bend in 5/32″ brass rod for banjo hooks. The original design was modified from this: http://www.micromark.com/universal-bender,8229.html but required a few revisions to get the desired result. Finally, when I was able to force the rod into a tight radius bend, some would crack. I learned that they needed to be heated with a torch before bending, but don’t have to be bent while hot.
The key difference between this and the little universal bender (besides less “slop” and tighter-tolerance fittings) is the movable round die is a “cam” that can be pivoted (with a 3/4″ wrench) and forced tightly against the stationary die while the bend is being made.
This was also my first exercise with hardening O1 tool steel. There are tons of guides on line covering this topic so I won’t go into detail here. Having the working surfaces hardened may not be necessary for bending brass but I wanted to play with O1 steel and this was pretty forgiving applications for a first try. It went quite well.
I found two heavily trashed Ainsworth antique balance scales at the flea market. $40 later, they followed me home. Between the two carcasses, I was able to get parts to assemble one complete unit. Continue reading
This is a home build of a two-channel tube-based studio preamplifer / direct box. The project web site is here:
There are several recommendations/changes I have for future G9 builds, but it will take some time to get it all posted. Here’s an interior shot of my completed preamp.
This home-made surface mount device (SMD) tweezers/probe is made from scrap PCB material and plugs into a DVM or capacitance/inductance meter for easy measurement of tiny SMD components Continue reading
Hello. This will be my web notebook for various build and repair projects. Build projects include metal shop tools and hardware, as well a electronics, including tube gear.
Many repairs I do are on products from un-cooperative manufactures where schematics and technical support is intentionally restricted, so I hope the information I present here will be useful to others.