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MachinistBlog.com

Plans, projects and how-to's for home machinists

A Pivot to Robotics

I’ve been interested in robotics for a long time and my desire to build a large outdoor rover was the reason I used to buy a mini-lathe about thirteen years ago. That led to a desire to learn how to machine metal, and that led to Machinistblog.com.

Then I decided to start a nonprofit makerspace about eight or nine years ago. That turned into a second full-time (and unpaid) job for five years which did not leave any time for this website, or for making anything.

I’m no longer involved with the makerspace and I like to keep busy, productive and learning. So this last winter I turned my attention back to robotics because it encompasses a lot of my interests and skills:

  • I’ve had a lifelong interest in electronics and I have a degree in electronic technology (which I’ve never used professionally).
  • I’m knowledgeable about computer hardware and I’m pretty certain I could have been a very good professional computer programmer if I’d wanted to go down that path. Unfortunately, my coding skills have become very old and rusty, but I’m working on them.
  • I like designing and building mechanical things and I have the tools and skills to make almost anything.

I’ve built a fairly large number of robotic rovers over the years and I’ve recently come up with some innovative ideas that I want to tell others about. As a result, you are going to start seeing some posts on MachinistBlog.com about robotics, computer vision and machine learning, single board computers like the Raspberry Pi, and computer programming. 

Those topics don’t fit the name of this blog or what I’ve written about in the past. But there’s no point in spending time writing an article if almost no one is ever going to see it, which is what would happen if I created a brand-new website about robotics. MB is no longer highly ranked by Google like it once was, but it is still very visible on the Internet and it gets a lot of visitors. So what I post on here will get found and read.

To prepare for new posts I’ve done some overdue maintenance on MachinistBlog.com:

  • The site has been secured with HTTPS and you will now see a green padlock next to the URL in the address bar. 

This was done with the help of Carol Rehnberg of 4SiteSolutions. I am very picky when hiring someone to work on my websites because I have not been impressed by most of the web designers and system admins that I’ve interviewed. I think Carol is very knowledgeable, has good judgment and is trustworthy. 

Her rates are also very reasonable and she works fast. She charged me for less than an hour of work to fix my SSL problem even though she knew my budget was much higher. So I recommend that you contact her if you need some website maintenance done or a website designed. 

  • I’ve started culling old posts that have not aged well or which were not very interesting in the first place.
  • Broken links are being fixed.
  • I’ve started to prepare for an overhaul of this site’s design by looking at other websites for color and layout ideas, and to see if I can find ideas for making this site more usable and for improving its search engine rankings. 

Review – $40 QCTP for 7x Mini-Lathes

This is a review of a very inexpensive Quick Change Tool Post (QCTP) set for 7x mini-lathes that can be purchased on Ebay for about $38 (including shipping).  It is considerably less expensive than similar size QCTPs that you can find on LittleMachineShop.com and Amazon that cost about $135 to $155 plus shipping.

I purchased it because the cut-off blade holder for my 10-year old A2Z CNC QCTP had broken and I needed another one ASAP.  I didn’t have time to fix it and I couldn’t buy a replacement because the company has gone out of business.  My set was on loan to the SparX 1126 FIRST Robotics Team, where I am a mentor, and it was getting heavy use because we were in the middle of the build season.

So, when I came across this cheap QCTP set on eBay I decided to take a chance and buy it for the team.  The same set is sold by many eBay vendors and I chose this one and paid a higher price, $45, because they were promising delivery sooner than most other vendors and the seller has a high rating.  It was delivered six days after I ordered it.

It’s manufactured in China and it comes with four tool holders – two identical holders for turning and facing bits, a ⅜-inch boring bar holder and a holder for ½-inch cut-off blades.  The tool post is made almost entirely from hard anodized aluminum and the tool holders are made of steel.  In comparison, the $135 QCTP that Little Machine Shop sells for 7x lathes is made entirely of steel and it includes an additional holder that can knurl in addition to hold another tool bit. Continue reading Review – $40 QCTP for 7x Mini-Lathes

Wrench/Hammer Combination Tool for Mini Mill

By Roger Leete

This tool was made for my Grizzly G8689, but it can be adapted to almost any mill.  Just choose the right sized socket for your particular drawbar.  Note that I did not come up with this idea, but found it on the web.  I made the parts based mostly on the materials at hand.  Dimensions are mostly made up on the spot, and measurements were all made with a scale.  In other words, this project requires no careful measurements or has any critical dimensions.

Socket

First step is to find a deep well socket that fits the drawbar.  For my mill, that means 17mm.  I bought sockets at Harbor Freight, but just about any cheap deep well socket will do.  HF has them for about 2 bucks.  As you can see from the pictures below, I cut about 1/2-inch off the drive end, simply parting it off at the line on the socket.  (Some sockets have a different appearance, so roughly 2-3/8-inch long) This dimension is by no means critical.  I was worried that the sockets may be hardened, but a standard HSS parting blade cut it cleanly and easily.  This operation was done on a 7×12 mini lathe, so it’s not like you need an expensive machine to part off.  When you break through to the square bore it will be an interrupted cut, so take it slow at that point, or finish with a hacksaw.   Tip: get or make a carriage lock for your lathe.  It makes parting so much easier.

Next operation was to bore out the square drive hole.  Once again, this was done on the lathe.  The square hole makes for an interrupted cut, so take it slow and easy until you get it round to avoid too much impact on the tool bit.  Drilling first may be easier, to remove the bulk of the material.  You want to bore it out enough for the inner filler piece, but leave enough wall thickness for strength.  My bore is about 5/8-inch diameter, but this is not critical either.  I purposely made the bore tapered slightly.  I’ll explain why in the next step.  Set your compound over a degree or two, and bore it out to size.  The socket machining is done for now.

As purchased on the left, machined on the right

Next piece is the inner filler.  I made mine out of brass for weight, and because that is what I had on hand.  Steel would also work, but I’d not recommend aluminum as you want more mass.  This piece is slightly tapered the same as the bore.  The reason for this is to have it jam up into the socket to facilitate tightening of the hammer head.  Once turned to size, drill and tap for the hammer head screw.  I used 3/8-16, but 1/4-20 would work just as well.  You want enough thread to hold securely, but if you go too deep, you’ll be tapping into the side of the screw when you make the handle.  Using a hacksaw, cut a screwdriver slot in the opposite end. Continue reading Wrench/Hammer Combination Tool for Mini Mill

Update

I feel like I have three full-time jobs. In addition to my day job and I’m working another 20 to 30 hours a week trying to get a nonprofit makerspace started in Rochester NY. My wife and I are also taking care of her father, a widower, whose needs constant care because of failing health. And we’re helping to take care of a daughter and her family. She’s just had surgery for the second time this year to repair a heart valve.

So I’m tired and stressed, but not nearly as much as my wife, who shoulders most of the burden of taking care of family members. I help too, but I mostly take care of our pets and our granddaughter. She is a genuine saint because but she has continued to be very supportive of the makerspace. She understands that I can’t stop working on it because many people are now counting on me to follow through with what I started.

I launched the website for the Rochester Makerspace in mid-May and we now have many supporters, seed money, tools and a dedicated group of volunteers. We still haven’t rented a space but we’re actively looking for the right one. I expect that our doors will be open within the next couple of months and maybe as soon as a few weeks.

I’ll be even busier for a while when that happens. Although I expect my workload to taper off as we figure out the best ways to manage the space. The health problems of my father-in-law and stepdaughter will also end.  So there’s a good chance you’ll see me regularly working on MachinistBlog again someday.

If you’re wondering, the CNC router I’ve been building for more than a year is still not finished, although I’m continuing to work on it. I obviously don’t have much spare time and when I do I’m usually so tired that I’m either unproductive or I make stupid mistakes.

But I’ll bet money that it’ll get finished because it’s going to have a home in the makerspace and there are others who will help me with it.

Thank you Mikey and Roger for answering the questions that Machinistblog’s visitors leave in the comments or on the forum.

Random Quote

Opportunity is missed by most people because it is dressed in overalls and looks like work.

— Thomas Alva Edison