No the podcast is not dead! After a very large pause (for various reasons – a story for another day) the podcast is back with an episode recorded way back in September. Nevertheless the conversation is timeless and just as applicable today as it was when it was recorded. In this episode John Saunders, the man who went from a humble machine shop apartment in New York City to a full fledged machine shop in Ohio, joins us and talks shop. Some of the things we talk about include:
It’s been a long time since we have posted an episode and that has been my (Justin’s) fault. I won’t go into the details but I wanted to let everyone know that the podcast will continue in the near future. In the meantime I wanted to wish everyone a Merry Christmas and Happy and Healthy 2019 home shop machinists style. Stay tuned!
2 episodes in one month! We can’t believe it either. Don’t worry though we didn’t cut on quantity to get it out – this episode is still over 2 hours. We won’t talk about the quality. Max, Stefan and Justin give shop updates (it has been about 4 months since Stefan has been on – that’s long enough for Stefan to build an entire Saturn V rocket in his basement). After that we talk about making money in the home $hop – when your hobby turns into a business. And no we aren’t the Business of Machining Podcast. In between the weirdness:
Stefan is busy making telescope parts for the Hubble Space telescope a local company requiring telescope parts.
Stefan is on the lookout for a new lathe. He would like a Hardinge HLV (don’t we all!).
Justin and Max suggest looking at the Taiwanese clones like Cyclematic or Feeler
Stefan broke down and bought a face mill with carbide inserts:
A few months ago I purchased one of the popular import 5C collet chucks for my home shop. I’ve been investigating different ways to employ a proper collet setup in the home shop for awhile. At first I was considering going the ER collet route and purchasing, or making, an ER collet backplate for my lathe due to the large grip range of ER collets and that they are very plentiful. From a manufacturing engineering standpoint ER collets are not considered proper work holding collet, being designed specifically for tooling, but they actually do a good job in the home shop for work holding provided you are aware of the short comings:
ER collets are generally not available in square or hexagon. This isn’t as big of deal as it may seem – many folks use ER collets and simply grip on the the edges of non round stock.
ER collets require more grip length than almost all work holding collets. This is probably the biggest downfall to using ER collets in the home shop. Holding onto a very short part in an ER collet in most cases is asking for trouble. Even more sketchy would be holding onto just the edges of short square or hexagonal parts in an ER collet.
ER collets require relatively high tightening torques. This isn’t a big deal with the smaller sizes, but once you get into the larger sizes (greater than ER20) it becomes a pain. For example ER32 is recommended to be torqued at 100 foot pounds!
No emergency or soft collets available. I suppose you could make up some soft ER collets fairly quickly though.
No ER pot chucks, clutch collets, step collets, oversize collets, or whatever you want to call them.
Most of the above reasons are relativity minor when comparing ER to standard work holding collets. Many of the above downfalls of ER collets are offset, especially when you are starting out, by the fact that you can use ER collets and collet chucks for both work holding and tool holding. ER collets also have a very large grip range – meaning you need fewer collets to cover a range of sizes. This can save money on tooling, which can be a big deal in the home shop and was precisely why I was seriously considering using ER as I already had a some collets in the shop. When you consider you can purchase the ER collet backplates for less than $100 or make them easily in your home shop it’s a logical choice.
But I decided to go with a standard work holding collet, mainly for reasons 2 and 5. I chose 5C as it is by far the most popular work holding collet available. There is a plentiful used market and new collets are inexpensive. Soft and clutch collets are inexpensive and I can get them next day from a local tooling supplier.
There are a few options for the actual collet chuck. Import ones are available from numerous suppliers for below $200 and this is the route I went. I actually ordered it off Amazon Canada. If you are looking for something of higher reputation (note generally most of the import one are actually decent) you can purchase a standard accuracy Bison ones for around $500 with a stated .0008″ TIR. A super precision one is available for $900 with a stated .0004″ TIR.
My import 5C collet chuck has less than .0008″ TIR, which is less than the stated accuracy of the standard Bison one at less than half the cost. It is very well finished and so far works exceptionally well. I have ordered inexpensive $12 emergency collets for it, and also I have been using it with a custom bored 3″ pot chuck recently for a repetitive job. With careful loading I was indicating less than .0005″ runout on this job.
A few weeks ago now I also made a video of the chuck, including some of the mounting of it on the 2 lathes in the shop. I recommend people to get a standard backplate one and either make up your own backplate or buy one. By mounting the chuck on a backplate it gives you an interface to adjust the TIR to zero – if the mounting system is directly manufactured into the chuck your options are probably limited to regrinding the taper in situ to improve accuracy of the chuck.
If you are a more of your make your own tools type Andy Lofquist over at Metal Lathe Accessories has an interesting 5C collet chuck kit that you can machine yourself.
After a one month hiatus due to a number of reasons (typical of home shop machining), Max and Justin are joined by the King of 16″ South Bend lathes: Tom Utley. But nobody in the hobby calls him that. He is King Tutley. Tom, an engineer by day, is best know in this hobby for his time (over the last 3 years!) and dedication in taking a clapped out second world war 16″ South Bend lathe and returning it to better than new condition. Some of the interesting topics:
Tom talks about the bench grinders he has been working on that will soon be up for sale. If you are interested in getting a properly restored Baldor bench grinder be sure to get in touch with Tom!
We talk about paint. Is 2 part epoxies worth the trouble for machine tools?
Previously a woodworker Tom has moved into the metal side of things. The people are generally more friendly, albeit slightly less normal.
Why don’t we encourage more to work with their hands? All three of us share our frustrations with a general society that no longer values craft work. Shop work is good for the soul!
Chemical Etching. Tom has done a fantastic job with all the brass name and label plates on his South Bend:
Photo resist etching. More popular with watchmaking types, Max talks a bit about his journey into photo resist etching:
Variable Frequency drives. Tom has put a great deal of effort into the VFD controls, enclosure, and wiring has installed on his lathe. It is one of the best executed projects of such nature on the web:http://www.youtube.com/watch?v=opxVLWTiW7E
For Christmas a few months ago I made a diamond dressing tool for my brother in law. He is a woodworker and uses his bench grinder for the initial sharpening of various wood working tools.
The tool is made up of 4 parts. The body is a piece of steel with an angled lip (one on each side) that is used as a guide against the tool rest on the grinder. It has a threaded hole for the diamond. The diamond is an industrial diamond held in a steel rod – commonly used in surface grinding dressers, modified with threads along most of its length. There is a lock nut and o-ring (to provide some cushion when tightening the nut down) and a handle nut to adjust the distance from the lip to the edge of the diamond.
The tool is useful for most sizes of standard bench grinders as the body has 2 different lip offsets. The threaded diamond is also allows for generous positioning.
After giving him the tool I explained a few of the benefits of such a tool versus a traditional spur style tool:
The amount of grinding wheel material removed is easily controlled as the distance on the single point tool is adjustable.
A single point diamond tool does a better job at getting the wheel round in the first place. This is because the forces involved are significantly less than traditional spur type tools, or even the newer T style diamond tools. Forcing traditional tools up against the wheel isn’t a very steady process and the entire tool floats on the surface of the wheel. In addition your hand can move back and forth with the high and low points on the wheel. As such I’ve found single point tools create a wheel that is rounder, which helps with balancing. (Grinder balancing always happens after a wheel has been dressed).
Unlike spur tools or the cheap T style dressers a properly used diamond tool lasts a long time on a bench grinder and also is very durable for various wheel materials.
I’ve also had a fair bit of interest in people asking if they could buy one of these tools. I’m making up a number of them for others so if you are interested send me an email: firstname.lastname@example.org. I’ll be posting additional information shortly.
As usual I made up a video of making the tool and it also shows how I use it:
Let’s rewind to the summer when I purchased the Rong Fu milling machine for the shop. The mill included an exceptionally well made French made Sagop milling machine vise that had a bit of wear but was very usable. Up until this point I have never heard of Sagop before.
A quick search revealed a basic corporate webpage. It appears that Sagop is still in business and still manufactures a line of workholding products. The vise that I purchased is the smallest of their precision CNC milling vises, a 100mm 800 series vise. The construction of the Sagop is very similar to the Bison precision CNC milling vises. I was also floored to learn the purchase price of this vise. It is listed over 1000 euros with the swivel base – a number that is rather shocking when you consider that it is sitting on a Rong Fu milling machine!
The vise came with the swivel base – a very well made turntable base that allows for 360 degree rotation. A very handy feature in some situations, but for most of the work that I do I usually just bolt the vise directly to the table. This takes up less table space and is also more rigid.
Strangely the vise did not come with any way to mount it to the table. Up until this point I had been using some of those standard import clamps that are sold everywhere. This wasn’t the best solution as these clamps are quite bulky and don’t do the best job of holding in situations like this. So set out and designed up some new clamps to be made.
But first I searched to see if I could find drawings of the vise and / or the swivel base, not only for this project but for future ones. While not directly advertised on Sagop’s website, I managed to find the drawings for the vise and the swivel base:
I modeled the clamp up in Fusion and made up a drawing of it based on the dimensions I found in the above pdfs. Now some folks at this point say CAD is a waste of time for such simple projects, and it maybe for them. But I’m actually quicker at modeling something up in CAD than I am drawing up a sketch on paper so for me I usually start with a 3D model.
The clamps are designed for 3/8 cap screws. I then made up a shop drawing for the clamps:
Making the clamps was a very straightforward process. The most interesting part was when I used the 4 jaw chuck in the lathe to counterbore for the cap screws – I haven’t invested in any counterbore tools yet for cap screws. I need to quit being so cheap.
When they were finished I started to wonder about how I was going to prevent them from rusting. Rust is a very real problem in home shops, and in particular my shop as I live in a climate that is somewhat humid and has significant temperature swings. If you are willing to deal with plating shops you might be able to find a shop to do a zinc coating – but for small one off parts it is often impossible on a budget as most plating shops have a minimum charge that far exceeds what home shop machinists can afford.
I have considered cold bluing products in the past as a simple method to provide some rust protection on parts. In Canada cold bluing is a bit harder to procure than south of the border, and is is also somewhat expensive. So I started to read up on other processes. Hot bluing looked interesting, but involves some nasty chemicals. Rust bluing looked promising but it seemed like a long process – you had to wait around for the rust to happen.
I did some more reading and I recalled an experiment we did in high school chemistry involving a mixture of hydrogen peroxide and salt applied to steel wool. The hydrogen peroxide and salt rusted the steel wool so quickly that you could measure the temperature change. I then did some further searching and I found a fellow Canuck who beat me to the idea of quickly rusting parts using hydrogen peroxide and salt: https://mypeculiarnature.blogspot.ca/2014/08/quick-rust-bluing-back-in-black.html
The process is very simple:
Thoroughly Clean parts using a good degreaser. This step is very important!
Etch parts in acetic acid (common household vinegar)
Rust parts using a warm hydrogen peroxide salt mixture. You can either fully immerse the parts or brush the mixture on. I mixed it up about 1/4 cup peroxide and 2 tablespoons of salt.
Fully submerse parts in boiling water and watch red rust turn to black oxide.
Lightly wipe or wire brush parts.
Repeat steps 2 through 5 until you are happy with the coating.
Dry parts and oil
The final result is a nice black oxide coating that helps protect against rust and looks great:
I made a video of the process, including the making of clamps: