I’ve been chipping away at getting my ZA-6 to do machine tending on my Tormach 1100S3 for a while now. It’s been a super interesting journey as I sort of went from being a complete robot n00b to someone who is moderately competent at running the ZA-6 and now has a working machine tending set-up on my 1100.
There’s been a few places I’ve been discussing this around the Internet, but seems like this is probably the right home for the conversation. If anyone is considering trying to tend a CNC machine with a ZA-6, I’m happy to share what I’ve learned along the way.
The starting point is probably this video that shows everything in action, and then you can work backward from that to see what I was up to along the way:
@bigtchopshop Thanks for sharing all this! I’m really excited to see you blazing this trail.
I saw a number of VersaBuilt products in use at IMTS yesterday. This machine demo was using two Multigrip vises (same as in the above video) to do 1rst op/2nd op work on flat aluminum bar:
Awesome! Yes. The Op2 workflow on VersaBuilt is particularly interesting because as far as I have seen, almost everyone else defers to pallets/fixtures for Op2. Although the reasons for deferring make sense to me knowing what I know now, it would still be way better to have the robot able to do that Op1 → Op2 transfer, so I think Versabuilt has that dialled.
I’m actually going through this exact thinking right now and there are arguments for both approaches (Versabuilt Op2 vs. Pallet/Fixture Op2). And. realistically, the answer is you probably need both depending on the mix of work. I am a job shopper, so it’s always high mix / low qty.
This is my current thinking:
Pros of Versabuilt Op2 Approach:
Assuming you’re doing fairly conventional 2-Op parts, this is a path to basically fully autonomous “one and done” parts going on and coming off the machine. In my job shop, a surprising number of parts would be totally fine with this workflow and come off the machines basically “done”. So, that’s strong.
Once you’ve already invested in the VersaBuilt system and the robot and CNC programs to handle it, then a reasonable amount of the extra effort to do Op2 stuff is sort of “cut and paste” or, at least you have a workflow and process to accomodate adding it to your code.
Cons of Verabuilt Op2 Approach:
The soft jaws are relatively complex/expensive compared to conventional fixturing. You could probably stretch them out a long way by putting intermediate fixturing, or a sacrificial surface on them to be able to re-use them for multiple parts. Or, for bonus marks, write a full-auto robot/mill program that makes them so you can make your own whenever the machines are idle.
You’d end up training and maintaining a second vise position, which would double your set-up overhead if you end up bumping out of position at some point. This isn’t terrible once you’ve got things set up as it happens infrequently. But, when it does, it’s no fun, and less fun with 2 or more pick up points.
Pros of a Pallet Based Approach
The robot does the same thing day in and day out - load pallet. Training and programming wouldn’t ever really need to change much. You have X pallet stations trained for pick up and however many bases trained on the machine and that’s that. Likewise, I think training could be a bit easier as it’s not as delicate of an interface to land a pallet onto a zero point base as the VersaBuilt jaws.
Supports more than a 2 Op workflow (albeit with manual loading and additional fixture overhead)
Ultimately, you could get pretty fancy with having different pallets set up for different jobs and the robot and CNC shaking hands on what GCode to run on each pallet with a bit of a scheduler and some macros. So, for a job shop running lots of different jobs, this gets interesting.
Cons of a Pallet Based Approach
Way more fixturing overhead, thinking about fixtures, clamps, pins, Mitee-bites, etc.
Requires human intervention to load and prep each pallet, so does not scale without humans.
Depending on the system, pallets and hardware can be expensive.
Payload weight also starts to become a factor. Even a small pallet can weigh a couple kg, so you need to be wary of pallet+workholding+part weight from a payload perspective.
Somewhat apples and oranges though depending on the use case. If you’ve got 100 of the same parts to run, that looks different than running 10 batches of 10 parts. So, that’s sort of why I say there may not be an alternative to being able to run things both ways.
One thing that would potentially be kind of neat would be to machine the mechanical interface from a set of Versabuilt Jaws into the side of a pallet… so that you could also pick up pallets with the VersaBuilt jaws and be able to mix and match if you had both a VersaBuilt vise, and some sort of zero point pallet base on your table.
