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Best Industrial Equipment For The Garage

Let’s say you want to learnplay with real industrial automation equipment in your garage (or living room, if you’re single), not toys like the Lego Mindstorm. After all, learning is fun, and it’s cheaper than taking college classes (that’s what I tell my wife). Unless you’re rich, buying surplus is the way to go.

In the past, if you lived in the right area you could visit the local surplus store. Silicon Valley used to have a lot, but most of them disappeared during or after the dot-bomb bubble and subsequent crash. Still, there are a few places left, such as Triangle Machinery (the best place for mechanical stuff) and Excess Solutions. DeAnza College hosts the monthly Electronics Flea Market.

Now the overall situation is better because of on-line sites such as eBay (still the best overall), craigslist (worth checking, but probably best for test equipment), DoveBid (typically best for test equipment or large industrial equipment), and PlcCenter.

Mechanical items such as stages and motors are pretty easy to use. But when looking for equipment such as motion controllers or PLC’s, you need to consider:

  1. What software does the equipment require? The best case is when the equipment comes with software or you can download the software from the manufacturer’s web site. Next best is when the necessary software is at least somewhat reasonably priced (so you can afford to buy it (e.g. some PLC software)). The worse case is copy protected software (Allen-Bradley, Cognex, and many others).
  2. Does it come with documentation or can you download it?
  3. Are the necessary accessories readily available? If it’s a rack, backplane, or snap-together system (many PLCs, Opto 22, Beckhoff, Wago, etc), you have to be able to get all the required pieces (backplane, power supply, CPU, I/O modules, etc). For a motion controller, are the break out boards and cables readily available?
  4. What are the power requirements? Many servo drives are 3 phase 240V or 480V.
  5. Is it readily available surplus? Important if you want to expand later.
  6. Have you used it before? Familiarity obviously helps.

My recommended list:

  • Galil motion controllers. Yeah, the two letter commands are stone age. But Galil controllers are readily available on eBay, you can download all the essential software and documentation, the connectors and breakout boards are readily available (but if you buy them new they might cost more than the controller cost on eBay!), and it’s easy to get started.
  • Opto 22 PACs. I haven’t used them, but software for the SNAP controllers is free, and they’re often available on eBay.
  • DVT smart cameras. Software for the older models is free, and they’re often available on eBay. I’ve heard that software for newer (after Cognex bought DVT) models is protected.
  • CANOpen is a mixed story. CANOpen availability is good (AMC DX15C08 Digiflex drives are readily available at great prices, other drives such as Copley Accelnet, Copley Stepnet, Baldor MintDrive, and Kollmorgen Servo Star are occasionally for sale, and I/O controller such as Wago 751 series are sometimes seen). However, you will need a CANOpen interface (I recommend Acacetus VCCM or Peak USB-CAN because they’re supported by CanFestival). Getting started with CANOpen is still a lot of work; starting from no knowledge, it takes much more effort than getting a Galil system up and running.
  • Plenty of others, including many I haven’t heard of. Other possible examples include Logosol, Animatics SmartMotor (also stone age commands, but…), and JR Kerr’s PIC-Servo boards (quirky, but affordably priced new).

Not recommended:

  • MEI motion controller without software – nice boards (the XMP looks really nice), and occasionally seen on eBay, but IIRC the software is $4900 for the older systems and $19,000 for the XMP.
  • Cognex Insight smart cameras. Nice systems, often available on eBay – but every time you install the software you have to call Cognex to get a key for that particular PC.
  • Most PLC’s, especially any you have not used, unless they come with programming software and the appropriate licensing (dongles, disks, etc). The “big name” vendors like Allen-Bradley tend to like nasty copy protection schemes – software keys that have to transferred via floppy disks are the worst, since they are so easily lost (and who has floppy drives anymore?) . At least hardware dongles are harder to lose.
  • Anything you don’t know about or can’t find out about.

Some good sources for cables and breakout boards:

Sometimes it takes patience and multiple sources to put a working system together. I bought my Wago 751 series CANOpen controller from eBay, but I bought the I/O modules from PlcCenter (they were available at reasonables prices). I bought my Festo CPV-10 CANOpen control module from eBay about a year before I found the CPV-10 pneumatic manifold and valves available at a reasonable price.

Note: go here for my 2011 Update

Tony

23 comments

1 Benson Hougland { 08.27.08 at 12:13 pm }

Tony- If you’re interested, I’ll get you a SNAP PAC system to toy around with. I use one at home for sprinkers, spa control, landscape lighting, power monitoring, etc. You’re correct; the software is free. And so is the Simulator. But to get a real feel of the capabilities, you’ll want some I/O. Let me know. -Benson

PS: Real nice blog you’ve got here. And thanks for the Opto 22 plug.

2 Bob Lazar { 09.02.08 at 8:17 am }

Tony, glad I came across your blog. I just recently nabbed myself a few AMC Digiflex drives you mentioned on eBay and now looking for a good cheap CAN interface. I had missed the Gridconnect (Acacetus VCCM?) you linked to so I’m grateful. Have actually used this product with the AMC drives?
Thanks
-Bob

3 Tony { 09.02.08 at 11:31 am }

Bob,
Unfortunately, not yet because my time has been very limited. I’ve played with it a bit, and verified it’s the same as the Acacetus VCCM, and started to dig into CanFestival. In the near future I will be doing a lot more with CANOpen, and will continue to post about my experiences. At work, I’ll probably use the Peak USB CAN interface (US$250).

Note that the AMC DriveWare program only works with Advantech, Ixxat, Kvaser, Vector, and ESD – I currently don’t have the budget for any of those. CanFestival under Windows supports Peak, CAN-mVCCM (GridConnect Light), Ixxat, and Anagate.

I’d appreciate it if you would share your experiences, too. I will be posting more about the Digiflex drives – right now I’m working on an order for connectors for my Digiflexes. If you want to do a breakout of the HD44 connector, look at Amphenol’s Cables On Demand for affordable HD44 cables and ASI for affordable HD44 break out (terminal) boards.

4 Bob Lazar { 09.04.08 at 7:05 am }

Tony,
Damn, not what I wanted to hear about the DriveWare app. There is ver 5.4.2 does have options for other interfaces but prob won’t work with the DX range anyway I assume. Those CAN interfaces listed are all rather expensive!
I think I will ask the CNCZone community if anyone has had experience with these drives. I will certainly share anything relevant on your blog, no problems.
Thanks for the links to the connectors, some reasonable prices for the cables. I too will need to go through the connector ordering stage when I receive my drives soon and decide how I’m going to mount these. BTW, I plan to use these with Trilogy linear motors I’ll be getting soon. Should be all fun!
Bob

5 Tony { 09.04.08 at 4:15 pm }

Bob,
Look at the bright side – a new AMC DPCANTE-020B080 (roughly equivalent to a DX15C08) will cost about US$680 new. The DP series are now using dual RJ45 jacks for CANOpen (yeah!) and RS-232 for setup, similar to Copley’s Accelnet Panel series and Elmo’s current CANOpen drives. The Copley drives can also use CANOpen for setup, but IIRC you have to use Copley or Kvaser interfaces.

The DX15C08 datasheet lists the four manufacturers I gave. Using AMC’s support page, it appears that the latest DriveWare version for DX15C08’s is 2.57. I installed the DDW 2.57 software; it also listed the Port AT-CAN-MINI interface (also supported by CANFestival under Linux) and the Ifak PCI-board.

Unfortunately, I do not think these commercial CAN interfaces show up on eBay frequently. I have the same issues with my AMC drives – most likely I’ll setup the drive over CAN, and do without the fancy GUI (I haven’t found servo tuning to be rocket science).

I’m planning on getting one cable and one breakout board, but for the rest of my drives I’m looking at getting HD44 connectors and will just wire up what I need. When you buy the servo drives on eBay, it’s easy to spend more on cables and such than on the drives.

I’ve seen linear motor demos, but they’ve never made sense at work. OTOH, I’ve had fun with porous air bearings.

6 Tom { 05.19.09 at 7:10 am }

I too have some of the DX15C08 drives. When buying surplus can interfaces on ebay watch out for ESD interfaces, some have custom firmwares, making them incompatible with DriveWare. The only way to tell is contact ESD support with the serial number, I just got stung that way, and am waiting for a service quote to fix it.

I too have trilogy linear motors in mind for my next cnc build, and hopefully i can get the AMC drives working with them soon. Tony, perhaps a post on your air bearing experiences would be a valuable addition to the site?

As much as i would like to use air bearings, the only hope of that would be to make some myself, as the prices i have seen are astronomical.

7 Tony { 05.19.09 at 11:26 am }

Tom,
Thanks for your input. As noted, the big name CAN interfaces (Ixxat, Kvaser, etc) aren’t common on Ebay, although right now there’s an Ixxat PCI/CAN interface on eBay for $50. I ended up getting tired of looking and bought a new Ixxat CAN USB Compact. It’s a nice unit (I’m also using them at work now), but it wasn’t cheap.

Air bearings are cool, but I doubt that they would be a good match for machining (unless you’re doing micro-machining). If you want to know more, check out New Way Air Bearings and look at their white papers — they are the experts, not me. IIRC, one round graphite air bearing is around $250 new, so if your stage needs 4, you’re already at $1000. They also make air bushings.

BTW, I’d be very interested in hearing more from you and Bob about using the AMCs for CNC machines.

8 Tom { 05.19.09 at 12:07 pm }

Tony,

Thanks for the tip on the Ixxat, have just bought it 🙂 For $50 its a steal, and if ESD arent too expensive with their service fee it will give me a spare for work.

9 Tom { 05.19.09 at 12:17 pm }

Oops, seems i cut off a chunk of my first post.

On the air bearing front, the real attraction is that porous air bearings (at least the puck type) are so mechanically simple. Its pretty much the only precision linear motion system you could build in a home shop.

I have some good references on the bearing design aspects, only problem is i cant find porous carbon suppliers who quote permeability of their materials 🙁

10 Tony { 05.20.09 at 11:04 am }

Tom,
You’ll like the Ixxat. Besides being supported by many drive manufacturers (at least AMC, Copley, and Elmo), it has an up to date CANFestival driver.

Since I’ve being using Copley’s CMO library, I haven’t worked much yet with CANFestival. But I plan on doing a lot of CANOpen posts over the next few months, covering CANFestival, cabling, and adapters.

The air bearing stage is conceptually simple (e.g. start with 2 slabs of polished granite, the air bearings, and a drive mechanism), but it gets more complicated when you’re building a production machine (with flexures, air filters, air regulators, etc), and the porous graphite air bearings are easy to damage.

We’ve used them when we needed very level travel. If you just need to know where you are precisely along the stage’s axis, you don’t need air bearings — just a linear encoder (which isn’t cheap, either, unless you can live with the 0.0005″ resolution and the mounting hassles of the US Digital model) .

11 Tom { 05.20.09 at 3:35 pm }

Tony,

The air bearing stuff is early days for me yet, i have a lot of prototyping to look forward to before anything else. Out of interest, do you get your porous air bearings repaired, or just buy new when they get damaged?

Actually i have been having some good luck scrounging linear encoders from ebay recently. I have 4 0.5um renishaw readheads sat in my junk box now, and enough tape for a small mill.

I have been reading through the rest of your site, on the version control side of things, have you tried AnkhSvn? Its a free visual studio plugin for version control checkin, and its pretty intuitive.

12 Tony { 05.20.09 at 10:39 pm }

Tom,
It was only one puck, but with a pretty big gouge, so we just bought another one. But we always check for correct air pressure before moving.

Sounds like you’re set for linear encoders — that’s great.

I haven’t tried AnkhSvn; I’ve always used subversion, trac, and Tortoise-svn. That setup has worked well for me; maybe partly because I have a lot of non-Visual Studio files in subversion.

13 Bob { 05.22.09 at 7:46 pm }

Hi Tony & Tom,

On the porous bearing I have, I was extremely lucky to have purchased 6 of them from an engineer in the US who actually designed ultraprecision machines ( http://www.precitech.com ).
He was interested in my project and graciously decided to sell what he had to me. That’s the only way I could possibly afford these babies. Luck! He also sold me 7 other non porous bearings as well. Some of them had been obviously crashed and repaired and I hope they still work OK as I’ve had no chance to test them yet. Until that time, I had considered making them (porous or slot) myself. This engineer I mentioned suggested that it is possible to make them with EDM graphite but admitted that he never managed to find out what type it was. One can never have enough bearings and I’m still thinking of trying one day. But as you point out Tom, where can one find porosity info of these materials? The prospect of being able to make them is irresistible though.
Anyway, my biggest challenge with these air bearings will be trying to get a surface plate of some description. They are no where near as cheap here as in the US sadly. 🙁 I’m getting desperate now and considering table top Granite. Tried self leveling Epoxy but doesn’t seem to be anywhere near as good as promised.
Many challenges (and money) ahead!

14 Tony { 05.26.09 at 4:30 pm }

Bob,
You are indeed very lucky.
Some ideas for the bearing surfaces:
1. If you only need a very small surface, you could use an optical flat. But these aren’t cheap new, either (e.g. look at Edmund Optics, IIRC, a 6″ flat is >US$1000).
2. IIRC, we used custom ground and polished granite. But that’s not a cheap solution. However, granite reference blocks should work pretty well, and are a lot cheaper. I’d look at machine shop supply companies (e.g. Rutland/Airgas US, or maybe a woodworking store, for new ones, and machine shops, eBay, and such for used ones.

Also, as I’ve mentioned before, I appreciate all your updates; I am very open to adding new ways to keep in touch to this site (such as improving the comments, mail lists, forums, or such).

15 Bob { 05.27.09 at 5:17 am }

Tony,

I’m always checking out eBay. 🙂 Thanks for the links. I had a quick look but they don’t seem to ship to Australia. Besides, the weight is the problem when shipping Granite and The fact that they use UPS is the other problem, very costly indeed. I envy you guys! 😉 I have looked for some large Granite parallels for the axes to run on (4 bearings). Also trying to find some steel parallels for the guideway since I would need the bearings (2) to be magnetically preloaded. I need about 150mm travel on one axis, say 100mm on the other so I may need 18″ parallels to do it. The air bearings are large @ 2-1/2″ you see? God I’m starting to think “float glass” now. Anyway, just a little more patience & luck is needed right now. So close! Forum sounds like a good idea to me Tom. 🙂 Can’t wait to hear more of your project too.

16 Tony { 05.27.09 at 11:23 am }

Bob,
I linked to Rutland/Airgas because I know they sell granite surface plates. Here’s a starting point for finding Australian suppliers.
I need to get some more posts up first, but I’ll look at improving feedback soon.

17 Tom { 05.27.09 at 3:45 pm }

Hi Bob, Tony,

I have done some research into running surfaces for such bearings, and one option that seems to be the best bet for low cost one off parts using epoxy replication.

This is a process where a mold release is sprayed onto a conventional surface plate, then the epoxy is poured with contact to the plate, the resulting surface is very close to the flatness of the granite.

You can also use replication techniques to attach the air bearings to the moving truck whilst maintaining parallelism between the truck and the track, without having to precisely machine the bearing mounts (see link).

Check this out, i think the approach has quite a few benefits: http://pergatory.mit.edu/perg/research/Cortesi/index.html

As for porosity, i have a mathematical simulation of a porous air bearing in matlab, and the critical value is porosity over thickness of the material. Also i have a step by step process for decreasing apparent porosity of the material, as well as measuring flow, this all used to be done by hand in the past.
The critical choice seems to be getting high enough porosity in the first place.

Poco graphite have a product called TM which looks like a good contender, i have emailed them to see if they have porosity information (there is a small amount available for two other products in their guides).

Tony, one improvement that would be very welcome here would be the option of email notification of further comments.

I am on CNCZone by the way, nickname is daedalus

Regards,
Tom

18 Bob { 05.29.09 at 5:56 am }

Tom,

Yes I’ve been thinking about the replication idea you mention. No way around it, I’m going to have purchase at least an 18″ surface plate or parallel for that. Also thought about epoxy coating some steel for my guideways to cheat my way out of precision grinding. Looks like in reality I either I have to get them specially made from steel or I need to think about vacuum preloading. Float glass is another idea one I’m looking at too.
I have also seen the Axtrusion concept in your link, interesting idea.
I too have seen some patents and papers that show porosity is the critical variable and made vague suggestions of how it is adjusted. Sound quite laborious and somewhat explains their cost. Kudos for getting a hold of the procedure documents and Matlab sim! I’ve wondered too if it’s possible to use porous ceramic or even plastic instead.
For conventional bearings the only really useful info I found was this; http://www.nsc.co.jp/en/tech/report/pdf/n9304.pdf
It has dimensions of the layout and basic performance. I’ve wondered if laser machining could be used to make a copy if it was economical. Anyway all interesting stuff to think about, one day I would love to try it.

I recognize you daedalus from CNCZone. My nic is Zathras BTW.

Tony, thanks for the search link. I’ve found some prices for surface plates here and I’m looking at 2.5K for 39″ x 25″. Youch!

Cheers guys

19 Tony { 05.29.09 at 10:27 am }

Tom & Bob,
Email comment notification should be working; please comment here if it isn’t. I plan on making more improvements later.

From my perspective as a system integrator, air bearing costs are already reasonable (given the cost of the rest of a high precision system). However, if you’re paying out of pocket for personal use, it’s a different matter.

New Way Bearings sells three types of porous air bearings: graphite, ceramic, and silicon carbide. Right now, they only seem to mention graphite, but if you google you can find part numbers for the others.

BTW, another technology that’s really cool and fits very well with air bearings is Nanomotion’s piezo motors. IIRC, it’s about $1000 for a motor and analog input servo amp — I’d love to use them at work, but haven’t found a good match yet (I can’t spec stuff just because it’s cool).

20 Bob { 05.31.09 at 1:23 am }

Tony,

Agreed, they are quite reasonable costs when you consider their performance and application in industry.
I had no idea New Way was selling ceramic version, amazing. Thanks for the link.

BTW, I have only recently found, to my delight, that NewWay have been posting very nice vids on YouTube;
http://www.youtube.com/results?search_type=&search_query=New+Way+Air+Bearings&aq=f

Yep, love the piezo motors myself. We can only dream of playing at the moment although I did recently find this actuator by Elliptec which does not require (apparently) a complex amplifier/driver;
http://www.youtube.com/results?search_type=&search_query=elliptec&aq=f

Cheers,
Bob

21 Tony { 06.05.09 at 12:28 pm }

Grrr, Bob, you made me dig out my Piezeoeletric motor info and write a new post; please check it out. I find some of the other companies more interesting than Elliptec.

I wonder if there are problems with the non-graphite porous air bearings. Several years ago when we were building the machine with the porous graphite pucks, New Way was pretty open about the ceramic air bearings — now it looks like they don’t want anyone to know about them.

22 Bob { 06.06.09 at 6:44 am }

Sorry Tony, I didn’t twist your arm 😉 Well done on the post, it should go in Wiki.

Interesting point about the ceramic bearings. Why are they so guarded about them? Hmmmm odd.

-Bob

23 Drum Rotators { 12.21.10 at 10:10 pm }

Tony, Thanks for sharing very useful post. I like your blog and love to see such kind of more posts, keep writing.

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