Before I get started, I want to thank the incredible community on the Hobby Machinist forum.
Here’s the thread discussing this issue.
I also owe Precision Matthews an apology. I came out swinging and it had nothing to do with them.
This post is going to mostly be a recap of that forum with some additional commentary.
I hope that doesn’t violate anyone’s copyright.
I’m also going to assume intermediate understanding of metal lathe operation.
It’s just too hard to stop and explain everything. Furthermore, assuming no knowledge gets tedious for the more initiated reader.
I’m also going to do a real hack here and link directly to the images from the forum.
So, here I am, new lathe, super excited. Never had a new lathe before and I’d never set up or adjusted a lathe before.
Let me turn it over to me back then to explain what happened when I made my first cuts.
When running the power feed, the lathe creates regular ripples on the surface that are measurable high spots. When feeding using the lead screw, the ripples are not present. I’ve tried a wide range of speeds, feeds, DOC, tool geometry, and two materials (12L14, 6061 AL). No matter what, the ripples have persisted.
Here are the images I posted.
Powerfeed, .0025/rev (slowest), 6061 ALLeadscrew, .004/rev, 6061 AL
As you can clearly see, one had really clear ripples.
The rippled were visible, measurable, and could easily be felt. So the difference between high and low spots was deveral thou.
I’ll expand the post later but to make it complete I’ll just to the end of the story.
I assumed that the carriage only relied on the top way surfaces. You know what they say about assumptions…
The rack that pulls the the carriage along pushes the near side of the carriage up and down a little as it moves.
Without anything to counter those forces, the carriage actually lifts slightly with each tooth of the rack.
The carriage also has gibs that control the fit against the sliding surfaces of the ways.
This gib is on the underside of the far way that prevents this lift.
The carriage gib is also extremely inaccessible. To add insult to injury, the exploded diagram that came from the factory did not show the gib.
Bottom line is I wouldn have spun in circles for months if not for extremely helpful people on the Hobby Machinist forum. Experience is everything.
Welcome to Hexo! This is your very first post. Check documentation for more info. If you get any problems when using Hexo, you can find the answer in troubleshooting or you can ask me on GitHub.
This post is about as self refferential and it gets. Today we will be discussing the mechanics behind this blog and why I made the decisions I did. I’ll admit I wrote this after I chose this platform so the requirements process is just a reflection of my thought process.
The Problem
I’ve been messing around on the internet since I was in single digits. I’ve made and abandoned probably hald a dozen Wordpress sites over the years. Let’s accept Wordpress as my baseline and define some requirement. First a list of problems then their converse requirements.
Anti-requirements
Wordpress is heavy. It’s a full stack interactive web app. It requires a database and uses really complicated PHP.
Wordpress CMS absorbs whatever you give it. I can’t easily source control the content or move the content from place to place.
The configuration is some complex that I can’t figure out what I did 6 months later.
Requirements
Content storage system is simple. Preferrably, can write in plaintext.
Support for both included and embedded media.
Robust online community.
Compiles to a self-contained and rendered output.
Simplicity is bliss.
The Solution - Hexo + Digital Ocean + GitHub
The header gives it away. The solution I’ve landed on is a tool chain with three components, Hexo as the blog framework, GitHub for source control and cloud storage, and Digital Ocean for deployment.
I’ll keep it simple – I believe Hexo meets all my stated requirements. Hexo is an opensource blog framework based on NodeJS.
Hexo allows me to write in Markdown with which I’m very familiar. I can add images, links, and all the standard rich content. Hexo appears to be under active development and is open source. At writing, the latest version was released only a few months ago.
Digital Ocean is the platform I selected for deployment. Over the last few years they have an ever improving app platform which allows you to deploy static sites for free. FREE. You connect your GitHub repository to the platform and allow it to access your repo. It then handles the rest and a few minutes later your site is live. Everything, from Hexo to Digital Ocean, is so simple that I had a deploy site in the 1.5 hours I had to kill at LAX on May 14, 2022.
Running This Blog
This section is my attempt to help myself. As I mentioned above, I’ve always gone on to something new and lost the knowledge about how to work with the blog. In 6 months when I want to write something, or my laptop has changed, or whatever, will I know how to add to this blog? No. So let me channel my professional discipline and insist on documentation. Eilif, DOCUMENT YOUR WORK!.
I’ll presume you found the source code because, well, this wouldn’t make any sense otherwise.
Hexo is written in NodeJS and required that it is installed and executable on your system to compile this blog. https://nodejs.dev/download/package-manager/ is the NodeJS installation page for most systems. Let’s install it.
For Mac I suggest using Homebrew which is amazingly simple.
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brew install node
Now we have to install this blog and make it executable. Who knew blogs were exeutable. The naive programmer might try something like chmod 777 ./blog.exe. Pro-tip, don’t do that. Technically the blog isn’t executable, NodeJS is. Alright, enough silliness.
In this particular blog, the entire thing is structured as a node project/app with some scripts. Ensure you’re in the <github_root>/blog directory and run
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npm install
This will install Hexo and all the dependencies and plugins.
You should now be able to run either hexo generate to compile the HTML or hexo server to run a local server. It should like basically identical to what you’re reading right now.
Adding Content
If the hexo scripts above don’t work, you’ll have to sort that out before you can do anything further.
To start a new post run
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hexo new"NAME OF PAGE HERE"
This will create a new Markdown file in <github_root>/blog/source/_posts and a folder of the same name at the same path.
The output of hexo generate writes to <github_root>/blog/public. If all else failes, this is a copy of the latest deployed copy of the blog.
To add your new content run the following sequence (assumes your terminal is at <github_root>/blog)
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hexo generate
As mentioned this will write the HTML out to /public
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git add ./*
This will add everything in the directory not excluded by .gitignore to the staged files
Dear reader, This blog isn’t for you. I’m not sure it’s really for anyone but it’s probably for me. For years now I really wish I had somewhere to write about the things I do.
The story of a really big washer and some squishy wood
Where do I start? I’ve never blogged about anything but I have to start somewhere. I have an idea for a post strucutre… let’s try this.
I’m an impractical hobbiest.
I don’t have externally supplied requirements or constraints like I might at work.
Still, most of my projects start with a problem, lead to a solution, and have a journey in between.
My biggest constraint in any project are the limits of my own skills and knowledge.
This constraint is followd distantly by monetary limitations and finally limitations in my equipment.
There are always exceptions to this, money and the right equipment can help offset the lack of skill in certain circumstances.
Let’s take a ridiculous example and talk about making a perfect steel cylinder 4” long with a diameter of .500”.
The diameter has a tolerance of +/- .001 and should have no measurable taper.
Now, there is probably someone who can make such a shaft with a file and thousands of hours.
I cannot. So, we look toward modern technology and some financial expenditure.
I caved and bought the right tool for the job, a metal lathe.
Since the reader probably cares, I bought a PM-1130v from Precision Matthews with the DRO.
Maybe I’ll write a review someday.
With this tool, what would require tremendous time investment and skill is achievable quickly by an amateur.
Alright, that was a pretty contrived example of the skill, money, equiptment debate.
Problem
My lathe is installed on a custom wooden bench.
Let’s not talk about the bench quality… it’s strong enough but I’m no woodworker.
The top of the bench if a butcher block top from Home Depot.
Like any good lathe owneer, I bolted it to the bench.
This is essential for safety but also improves rigidity.
I tightened the bolts with standard 3/8 washers.
As the wood settled, the bolts got loose.
I tightened some more, the bolts again got loose.
How could I ensure safety, improve ridigity, or (spoiler alert) “level” the lathe, if I cant’ tighten it down?
The Solution
Really big washers. Bigger washers should distribute the pressure across a larger area.
Build Log
The source material was some unremarkable 1018 mild steel 1/8in plate. It’s remarkable that I had such a material in stock. It was an impulse purchase on Ebay. Cut out two squares and drilled a 3/8 hole through the center. The goal was to create as large a washer as I could fit in the material. It turns out to be around 1.8in. If I was better at my cutting and drilling I probably could have gotten the full 2 inches. Alas, it won’t matter here.
I’ve been following Quinn Dunki (Blondihacks) on YouTube for some time now. If you aren’t familiar with her work, go check it out. What makes her channel so valuable to me is her use of attainable smaller machine tools and her shop space constraints. This makes her content more directly relateable to me. I digress. Quinn is always talking about the importance of the setup. Making these washers was no different.
I started with a 3/8 bolt. I held the hex head in the 3-jaw chuck and trued it up as best I could. Then I drilled center in the end of the bolt. I put a nut all the way down the bolt to serve as a spacer, then the squares with holes are placed up against the spacer nut. Lastly, a clamping nut is put up against the work completing the stackup. A photo of this setup is shown below.
Aannnd, after some gnarly interrupted cuts, we have big round washers. Overall, this setup and technique worked really well.
Final Thoughts
These are the first functional parts I made on this lathe.
I’m surprised with myself since this setup is fairly advanced for day 3 with a lathe.
Writing many months later, this bolt clamping method for workholding has actually been useful half a dozen other times since.
In one application, I needed to face a thin, flat piece of plate. I made a fixure with threads and a shoulder.
The plat piece threaded on in the middle and I faced both sides. Note to someone replicating the method, you will slovely face away your fixture.
If you can design your part so you don’t need to face to the middle you can reuse this fixture forever.
