Hacker News Reader

You can get electronic probes that measure the stock automatically so you don’t need precision blanks. The probe loads in the tool changer so it can be completely automated. Automatic tool setting makes it so operators don’t need to measure new tooling in tool holders, and tooling wear can be monitored automatically.

I dabble in running a small machine-shop, and we are able to automate a good chunk of what people still do manually. The stock we use is cheap, straight from the mill stuff as we have the machine measure the stock with an electronic probe. The machines also have 20 pallets, so once the stock is loaded, the operator can leave the machine for 20x the cycle time of a part. The pallets don’t even have to be the same product, so we can queue up replacement of inventory with just the quantity that a customer ordered and offer a bunch of made-to-order parts with reasonable turnaround times.

The machines also monitor spindle vibration so they can tell if a tool looses an insert, and the tool-setter is used to check if solid tooling is still intact.

The only manual parts are taking raw materials off the suppliers truck, unloading finished parts (next on automation list), final assembly (working on automation for this), occasionally loading new tools as they wear/break and fulfillment.

The machines also monitor spindle vibration so they can tell if a tool looses an insert, and the tool-setter is used to check if solid tooling is still intact.

That's a key feature. For unattended operation, you must have good fault detection. This tends to be an overpriced extra cost option on machine tools.

There are a lot of things in industrial automation that cost more than they should. Motors with encoders, for example.

> There are a lot of things in industrial automation that cost more than they should. Motors with encoders, for example.

Not really. Motors with encoders aren't really much different in price from the alternatives at industrial sizes.

What you do see is that the transition from hobbyist machines to production machines is quite a significant price change. The jump from, say, a Tormach to a Haas is almost x10 (about $10,000 to $100,000).

This is not a surprise. Those machines are expected to run 24/7 and, if they don't, people are going to get angry and reputations come into play.

This space is optimized for production and if you're not, you're the outlier. Pre-Covid I accidentally tripped a Sunday delivery at the office from one of the machine tool suppliers--scared the hell out of me when someone knocked on my office door at 3:00PM on a Sunday. The delivery guy was just as confused--he had never delivered to such a nice office area. We both had a good chuckle about it all.

(Side anecdote: I had a really nice conversation with the late founder of Tormach many moons ago at a LittleMachineShop open house about servomotors vs steppers. He was quite blunt--the issue wasn't motor cost but customer service cost. His customer service budget would need to go up about $300K per year for about 3 years every time he introduced or changed some major machine feature. So, any change needed to earn $1M over 3 years and then be net positive after that in order to get implemented. Servomotors wouldn't pass that threshold--so unless a competitor forced him to, that upgrade wasn't happening.)

Most things I’ve found to be reasonably priced for what they are.

Most products are made with much higher quality materials than you would find in consumer gear. Also the “rated” spec for parts is expected to be understated as the “unreliable” part is one that fails in under 7-10 years of being run at the absolute limit of its spec. If a part fails in 2 years I will completely stop using that vendors products, as having a machine that is worth $1k/hr going down for even a day or two wipes out any savings.

Another factor is the total sales volume of automation products is low, so the engineering costs dominate pretty much everything in that space, even though everything is somewhat optimized to reduce engineering time (the buyers and/or vendors).

I don't think actuators are crazy overpriced really. It's true that if you are going to bother packaging them you are probably using decent-to-good quality everything, but that's what you want for non-toy projects anyway. And for toy projects if your budget is really tight no big deal to set up the encoder yourself on this one-off.

Wow! That really does sound closer to what I thought CNC meant before I stepped into a machine shop.

That's pretty amazing stuff.

This rabbit hole goes as deep as your budget allows.

If you're curious, search for Renishaw probes on youtube. They make some of the best mainstream tooling in this space.

To turn on the probe, type G65 P9832. The CNC software world needs serious disruption / dev UI updates.

Is this a profitable business?

If you are careful yes. Doing job shop work (making other peoples parts) is hard to make a good profit as people expect overseas dumping rates.

The real profit comes from making your own products, as then you can force competition to also build their own factory to compete. By having lean production we can have a very large part catalog without having large amounts of inventory for low sales velocity parts.

We have at least a hundred variants that may only sell a dozen or two $100 parts per year, but they only cost us a line in the catalog to maintain the SKU. Since the products are for industrial use, most of our customers like the fact that we have in some cases been making the exact same part for nearly 30 years, which encourages them to design our products into theirs as we never discontinue products, so they don’t have to re-engineer theirs (our products in turn get used in machinery that might have a 10-100 unit/year global market).

You've got me super curious. What sort of industries are you catering for when making your own products?

Profitable? Yes.

Easy money? No

Fat margins? Hahahahahaha

(I.e. it's like most industries)

As I understand it, the economics of machine shops are a bit weird because of the financing cost of keeping up with the latest equipment. If you have old machines, and not money to buy new machines, then you run old machines.

The most modern shops are in extremely high demand, expensive, always busy, happy to turn down work. If you can design something in a way that lends itself to conventional techniques, you can get it into a smaller shop that may have some idle capacity, or run on the "tool room" machines in the big shop. The big shops always keep a few old machines around for tooling and jig work, rework, and one-offs.

The smaller shops are also willing to take work that's not 100% detailed, even hand drawings. So you don't necessarily even need a CAD operator. "Do things that don't scale."

In kind of an odd analogy, my old high school band mate built a recording studio from cast-off obsolete equipment that he bought for pennies on the dollar, and it meant that he couldn't take the biggest jobs, but he was instantly profitable and never in debt. Likewise, I have a very small side business that involves some basic metalworking, and I do all of it with powered hand tools and jigs that I made from plywood and carbide drill bushings. My capital cost was under 100 bucks.

> I had always had in my mind that with CNC machines you just stick the metal in the vise, load the program, hit start, and you're good to go, but there's manual calibration, facing off and the like that needs to be done before every run.

Much of it depends on the volume.

If you're building a million of something, the up-front cost to automate every step of the way makes sense.

If you're only building 10 of something once every few months, paying someone to do the manual operations 10 times makes more sense than investing in all of the fixturing, programming, and other tasks.

Really though, a lot of smaller machine shops have older CNC machines that are paid for and otherwise sitting idle. Hiring someone for $60/hr to do all the manual steps can keep that machine profitable.

It's all about the tools the shop has. Sapphire probes (edge finders) aid in a lot of the process. Mastercam allows you to simulate the machine process (and you can usually simulate it completely). Every shop is different – the shop I'm at here has a few lathes, robo-drills, 5th axis, and a few older pieces of hardware (which still are able to receive G-Code).

I was definitely using edge finders (it seems like machining in general would be way way way more work without edge finders) and occasionally Mastercam.

Definitely never used a 5-axis mill or robodrill though.

I guess my main point of comparison was to laser cutters, which really were basically push button automatable in comparison.

Granted the problem is a lot easier (purely 2-D cuts) and the cutter loses a lot of precision for thick material, but any time I got to use a laser cutter I was blown away by easy everything is and kept wondering whether a similar process could ultimately take root for machining.

The forces involved in CNC machining is a large complicating factor, compared to laser (or 3d-printing). In a laser one can just throw the material onto the bed, and the results will be fine - not so on a CNC. And that one is quite inherent to the paradigm.

Other aspects could likely be simplified and automated to a larger degree than today. In many areas solutions exists, but are quite high budget - things like tool changers, material loading and unloading.

Machining can be simpler if you've got a couple precision features that can be clamped to with hard fixturing. It's all about positioning the workpiece accurately so the fixed g-code program can do its thing.

That was before “good” machine shops had probes in every machine.