safety interlocks

[scottp55]

Within a week of pulling the trigger on a desktop with spindle. But the machine will eventually be used in an environment with many mentally handicapped people around. will buy the plexi shield and Brady mentioned a collet wrench interlock(standard or option?) that I wasn't aware of. without going "bot in a box" How would I put a safety interlock on the shield that would cause a pause(does spindle retract and stop,or just retract?) when any guard is removed? Any ideas how to keep these kids perfectly safe? we would even consider something like a laser beam to define a safety zone painted on floor(beam breaks machine pauses). thanks all. Scott

[scottp55]

We are also going to install additional prox switches at X,Y limits and the upper Z.

[chiloquinruss]

I believe on the newer bots there is a key lock that starts / turns on the machine, the wrench gets safety wired to that key. This means you can't accidently turn the machine on with the chuck wrench stuck in the router / spindle. Russ

[coryatjohn]

I believe on the newer bots there is a key lock that starts / turns on the machine, the wrench gets safety wired to that key. This means you can't accidently turn the machine on with the chuck wrench stuck in the router / spindle. Russ

There are two switches, one is a big red one that turns the power on and off to the control box and subsequent systems. The second is the spindle interlock that only controls power to the spindle/router. That's the one that has the key attached to the wrench. Kind of annoying but obviously a good safety feature.

[scottp55]

Thanks guys, A guy that worked at my Dads old machining shop just suggested building the table with the table supports extended to a no reach over height and using the posts to support 4 heavy duty hinged plexi? panels with wired magnetic catches. How would the switches be wired to cause the desktop to "pause"? Any ideas on access for VFD for "tweaking"?

[myxpykalix]

scott,
you could build a plastic box with a door on the front that has to be closed in order to engage the power via a switch like this:
http://www.mpja.com/SPDT-Mini-Snap-Switch-with-Roller/productinfo/16317%20SW/

There are others there look around to see what you can find...:D

[Brady Watson]

The Desktop doesn't have a spindle safety interlock. You could put any number of safety switches on the machine (such as one that would trigger a stop when you opened the shielded door) - wire them in normally closed configuration in series so power would flow through all the switches. If one was triggered (the wire was 'broken' - switch went open), then it would stop.

You could easily wire one end of these switches into any free input available (say input #3) and then go into the VN fill-in sheet and set the characteristics for input #3 to be a NC switch that triggers a stop. This *should* cause an e-stop condition and essentially fire off an SO,1,0 - which should trigger the spindle off. You can use any type of switch that you want, I would do a NC switch on everything because if a wire is broken, it is a fail safe.

-B

[scottp55]

Thanks people, shopbot does offer a "full" enclosure($950) as well as the "partial"($195) but neither one offers what I need. Just asked NC if spindle interlock can be made an option for desktop. forwarded Jack and Bradys to my "whiz kid" brother who has agreed to help with all electronic and computer needs as I can touch but not grasp (well I did ONCE grasp 100 amp) electrical details. All good ideas so far.

[gordon]

There are several options available that will help meet your safety needs. The full enclosure has an interlock on the door that will pause the tool and stop the spindle when opened, as well as, prevent the spindle from starting if open when trying to start it. There are 2 switched run in parallel that are connected directly to the controller card. The door opens up wide enough to access the tool from the front and allow loading of materials and fixtures. Though, if you wanted to modify the enclosure by adding an additional door to the back, we can provide you with the additional switches and guidance on how to connect them.

The posts above are correct in that our Buddy and Gantry tools have a keyed interlock switch in the door on their respective enclosures. The key is attached to the collet wrench so that when performing a manual tool change the key has to be removed from the lock in order to reach the spindle collet. The switch will only allow removal of the key when it is in the OFF position. A similar switch can be added to a DeskTop. On a spindle tool the frequency drive has a toggle switch on the bottom to cut the power for tool changes. If this isn't enough for your safety requirements, there's an electro-mechanical contactor that can be switched with a keyed switch similar to the ones on our bigger machines that will cut power to a spindle or router during bit or pallet changes.

Anything more than the options above we would need to work on a solution. There are lots of products and methods that can be added to a tool/enclosure to jack up the level of safety we would be happy to assist you with.

[Ryan P]

We do have an enclosure for the Desktop unit that has built in switches as mentioned above. The Switches will allow movement of the axis but will not allow the spindle to start when the door is open. If the door is opened when the spindle is running the machine will pause all movement and stop the spindle I have attached a rendering of the unit. Another benefit of the full enclosure is it reduces the noise of cutting and contains the chips.

[scottp55]

Thanks to all for the info, very timely arrival of info from shopbot sold a machine. Will know a lot more about safety concerns after facility tour tomorrow and see what machinery and safety levels they are using. They are currently shredding secure documents and rebuilding pallets,better jobs are needed and welcome and hopefully we can help them. Scott

[myxpykalix]

Ryan,
Your enclosure looks suspiciously like Maxwell Smarts "cone of silence":eek::D