r/CNC • u/ExternalOne6090 • 4d ago
ADVICE XM12 VMC update – designing a 20-pallet robot cell. What are we overlooking?
Hi everyone,
Quick update on the XM12 VMC from my last post:
We've now ordered the mineral-cast frames for the first two test machines, as well as the cast-iron table, saddle and spindle head. Next we'll order the sheet metal, machined parts, linear rails, ballscrews, etc., basically starting with whatever has the longest lead time.
See the attached images for the internal construction of the mineral-cast frame with rebar reinforcement and embedded steel parts.
In parallel, we've designed a 20-pallet robot automation system. We're planning to order the robot this or next week for testing, but there are still a few things we're unsure about and I'd really appreciate feedback from people with automation experience before we order all the parts.
20 or 30 kg robot?
Our pallet + vise already weighs around 11 kg without the workpiece. Would you go straight for 30 kg to have more headroom?
Pallet/vise size?
The current vise has around 80 mm clamping range. Would you want something larger for a machine this size, even if that means heavier pallets? And in general, would you prefer more smaller pallets or fewer larger pallets with more workholding capacity?
Loading/unloading?
Currently all 20 pallets can simply be accessed from the front through the double doors. Is that practical, or would you prefer a dedicated loading station?
For control we're planning a Siemens S7-1200 + Riverdi HMI, showing every pallet position and whether it's empty, loaded, waiting, finished, etc., plus the job queue and machine/robot status.
The S7-1200 communicates via PROFINET with a central PROFINET/IO-Link master. From there, IO-Link connects to one decentralized I/O module on each individual pallet rack. Each rack therefore has its own local I/O module, which connects directly to the sensors for pallet presence, position monitoring, etc.
What else would you want from the HMI or automation system? And what would you change before we order all the parts?
Any feedback is appreciated!
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u/CooperMFG 4d ago
The 30kg robot seems like the safer bet, a 9kg headroom on the 20kg robot is a bit too close for comfort especially if you were to use a larger/heavier Lang vise etc that would take up even more of that weight.
Could there be an option to support a 96mm pneumatic zero point/workholding? I know it's personal preference but a lot of people like that ecosystem and already have workholding to suit.
Is there any reason why the zero point base is in the middle of the table? If it was closer to to one side there might be more clearance for the robot arm over the edge of the table, either that or a riser plate would help.
20 pallets sound like a good number, it's a relatively small VMC so I wouldn't expect to be making massive parts on it. What is the maximum pallet size you can fit in there at the 20off ?
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u/Most-Vehicle-7825 4d ago
I think it would be very useful to load/unload while the cell is running and the robot is moving. How long does one cycle for a part take?
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u/ExternalOne6090 4d ago
I think it would be possible to unlock the door and STO the robot arm when a part is running so you can load or unload and if you not close the door in time the machine will just wait and continue when its closed and safe again.
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u/TriXandApple 4d ago
Once again, you're missing a 0 off the end of your target price
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u/ExternalOne6090 4d ago
I have not stated a price for the automation part. But i am interested, do you have more insight in what such automation cells and a machines on both sides would cost from other manufacturers?
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u/TriXandApple 4d ago
You'd be looking about 60-80k gbp from erowa, plus integration fee if you didnt buy it turnkey with the machine
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u/ExternalOne6090 4d ago
Wait are you sure you dont miss a zero? thats cheaper than the 120k cheap Haas robot with 3 pallets included? i thought Erowa is much more expensive. Cause thats the price i aimed for.
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u/TriXandApple 4d ago
Which haas automation cell are you talking about?
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u/ExternalOne6090 4d ago
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u/Bendingunit123 3d ago
I know your not targeting the us market but in the us that same pallet loader from haas costs 81k usd instead of the 116k usd your link was showing. I’m guessing it’s because they build in the us and ship it to Europe. Maybe it would be worth trying to get pricing from an eu based company for comparison.
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u/ExternalOne6090 3d ago
No thats not correct. The robot costs here CHF 122k (Swiss franks) which are 150k usd
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u/Bendingunit123 3d ago
Yeah your right I realized I clicked on the robot package and not the pallet loading system. Either way the correct US price for me is 115k USD / CHF 94k. It’s still a crazy up charge I’m guessing the changes for compliance must be driving the cost way up.
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u/TriXandApple 4d ago
I don't know where you got that price, but they are not going to sell many at that price.
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u/ExternalOne6090 4d ago
It shows CHF 122k which are 111k GBP. Well i dont know what people pay for automation cells i dont have one :D
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u/CNC_er 4d ago
That robot seems to get really close to the table when reaching into the CNC machine. Might end up smushing itself into a pile of chips if the chips don't get cleared away.
Chip/swarf management is very important for automated cells. Make sure to make a frame or something similar of coolant nozzles inside the enclosure and a good chip conveyor. If chips can pile up somewhere during a long run they will and that usually creates at least one serious issue like a way cover getting smashed.