Auto Router-On

[joelinkous]

When searching around on forums dealing with CNC work, one thing popped up that Wow'd me, something seemingly simple that could definitely make the job more convenient: using an output to power a relay to automatically power on/off the router. I can use the SO command to set an output on/off, and simply tack the command at the beginning/end of my part files.

My question is this. Does anyone have their router setup this way? I'm trying to find a relay to suit this purpose. My control box has a 3.41 board (I think? It's a replacement board for my really old 4x8 PRT). I'm asking about this on an electronics forum as well, but I don't know the output voltage of the output connectors. Any help would be awesome.

Thanks in advance.

[thewoodcrafter]

I found some plans for this relay I think in the back of the ShopBot manual I downloaded form there library.
I built it from Radio Shack parts. I have not gotten around to wiring it in to my ShopBot yet.
Look in the back of the manual.

[harryball]

If this is what you are talking about, BE VERY CAREFUL adding auto start to the spindle/router. I considered it but I'm not comfortable giving whirring carbide a mind of its own. I prefer the physical action required to press the button to start things that can remove fingers.

Robert

[paco]

Joe,

I cannot found the original schematic and the one I have is modified for the Alpha board... you might still be able to see something from the original text... if not ask SB for it. It's in the old manual...

Link to image (http://picasaweb.google.com/the.real.paco/SBMisc/photo#5075757361225572418)

[thewoodcrafter]

Robert,
I have seen your argument against this before. Aren't all of the newer machines made this way?
I think all the factory spindle machines are.
The relay for this shop made control is N.O. should be pretty safe. It's not like the relay must be energizes to keep the spindle turned off.

[paco]

I run my router motor on the Alpha contactor (relay) and it never start unless said to... still I wouldn't like to picture it starting while I'm changing the tool bit... so I set the router motor power switch to OFF... just in case...

It's just so cool to be at something else and hearing everything powering off at the end of a file.

[harryball]

I'm not familiar with how the new machines are setup. What I'm speaking of is loading a SB file, clicking run and the spindle firing up and running. I simply prefer the popup box "OK, start the spindle" and press the button, click OK when the spindle is up to speed.

My cautions are meant as just that... you're making >>changes<< to a machine that can remove body parts, not receiving a new working machine that has already been engineered "fail safe".

While in research in college I spent many man hours working on safety interlocks at a large radio telescope to keep people from getting killed. That's been many years ago but one thing sticks with me... it was A LOT HARDER than I ever imagined to make something fail safe. Especially when people get involved, the possible combinations of mistakes is staggering.

Making changes to a system you are already familiar with creates certain dangers stemming from habit.

Making changes to create a new function on equipment may seem straight forward but it is very easy to mix up N.O. and N.C. sides of relays, tap the wrong output etc... do the wrong thing well enough and it can even look like it's working properly when in fact it is not.

You are giving control to start the blade to software which itself has its own set of possible modes of failure. I wouldn't want BETA anything in charge of starting up whirring carbide.

I'm not saying don't do it, I'm just saying BE VERY CAREFUL. I certainly understand why someone would want to change it and considered it myself. I've watched myself make too many mistakes with this thing. I like the added level of safety having a physical switch press in my shop situation.

Robert

[harryball]

Just read Pacos... for a router and not a spindle... I would create a situation where I had to manually push the button to start it but it could shut off automagically. That makes perfect sense, mimics what my spindle does and would keep me comfortable.

You are right Paco, just like killing the breaker to my tablesaw everytime I change the blade. In more than 20 years I've never seen any of my tablesaws turn on by themselves... but I still do it. I also still have 10 fingers and 10 toes :-)

Robert

[beacon14]

When I had my old PR machine I used the schematic in the Shopbot manual to make the relay BUT I added a simple on-off switch to the power cord that fed the router so I had final say over whether the router had power or not. Always off for changing bits, on to run the file, then as Robert says the machine could shut everything down when it was done.

[paco]

Xactly

[joelinkous]

The guy who owns the table had an older program that looks remotely like ArtCam that puts SO,1,1 and SO,1,0 (or is it SO,1,1 and SO,0,1 for toggling output 1?) at the beginning and end of the files along with an additional PAUSE 2 to allow the spindle to get to full speed when turning it on.

I can see how giving the computer full power of the router could be an issue, but I've never seen the outputs toggle without being triggered by my files. In addition, the spindle plugs into an outlet mounted directly beside the spindle, so it would be easy to have the plug pulled while switching bits.

I'll have to read the manual to double check the output voltage of my output connectors, but how would I know which parts I need? Is there a schematic that gives specific values of what transistor/resistor/diode to use?

[randy]

Joe,

Search the forum for "SSR-240D25". This will give you a simple way to achieve your goal -- no components to assemble.

I am hoping to get mine wired in the next week or so.

Randy

[jeff_guinn]

Here's a drawing from an old ShopBot manual that should work if the output ratings are the same as the earlier control boxes.
ShopBot Relay Circuit
ShopBot Relay Circuit.doc (http://www.talkshopbot.com/forum/messages/28/ShopBot_Relay_Circuit-22565.doc) (46.6 k)

[myxpykalix]

Robert...regarding your post on "fail-safe" i'm reminded of this quote:
"Everytime you think you made something idiot-proof, they keep making new and improved idiots."