Ha ha, made ya look
Seriously I've been preparing for that day that is taking way too long to get here. I will have to modify my PhlatStandI made for my MKI to accommodate the MK3. The MK1 was sideways on the side of the table. Due to space limitations, I'll have to have the MK3 going the length of the extended table. Pics to come.
Thread on original PhlatStand here : viewtopic.php?f=107&t=410

Also started to gather some goodies I'll be adding.
Limit switches
Limit switch over-ride switches with safety covers to help make sure the over ride switches aren't accidentally left "off"
Physical E-Stop switch
Wire to hook it all up.

Should I consider homing switches, or would they not be worth it since the bit is easily seen with the MK3?

Just waiting for the man in the big brown truck Attached files

 

Well on my MKI when the gantry hit a limit switch, I was unable to jog the gantry until I turned the over ride switch off (broke the circuit) Then I could jog off of the limit switch.
I would think there would be a way to back off (travel away from limit switch ), but I don't see how as the limit switches are in parallel and there is only one port on the card per axis.

Is there a better way?

 

I use an override switch too. Your not able to jog off the limit switch because the limit switch disables the axis from moving.

I don't know of a better way.

 

I think we're talking about the hard limit I plan on putting physical limit switches on the Y and Z axis. Yoram asked why an over ride was needed. I think I am stuck with using an over ride switch as my board does not support separate direction limit switches. That would be useful for example if the Y hit the right limit, the board would know, and allow me to jog left, but not right until the limit switch was opened.

In the OP I posed the question about hard homing switches. I believe Dennis (Dorsal) installed those pre MK3. I was asking if they are really that helpful since on the MK3 you can see the cutting bit, so it would be really easy to manually zero the Y and Z by sight.

 

I'm using a SPST switch as all it has to do is break the circuit to over ride ( closed circuit means limit hit). When running the over ride switch needs to be closed so that when the open limit switches are closed when hitting the limit, it will halt the axis. I chose to do one for each axis as opposed to 1 common one ( could just break the ground if doing that) because.... well I'm not sure why. That's just the way I did it on my MK1 and I'm sure I had a reason at the time

 

:mrgreen:
Dave, this looks great, can't wait to to see this set up!
Mark and Trish

 

KYYU, I need to stay with the MACH3, and no USB board for now. No newer PC to run the USB software.

Dennis... wow you work 60 miles away... that's a fir piece as they saw in this neck of the woods That's a great point about homing switches... would let me do tool changes if I decide to get that fancy. And no offense taken.
--Dave--

 

Looks like I REALLY will be starting mine soon

I'll be sure to post how I do the limit/Panic switches... Attached files

 

Not sure for the USB board as I have the older driver board. On that board there is one connection each for X,Y,Z,Common. I'm sure someone with the USB board can provide info. This feature is rather common, and Kyyu indicated that they were there on the USB board.

I'm using some wire I got from work. It is scrap that they cut off from running limit switches to the PLCs. Some guys use Cat5 networking cable, but that is solid wire, but I am a little leery about solid wire being in an environment where it can move. It tends to break easily.

Yes only Y and Z will need limit switches. No machine crash should the X axis run-a-muck

 

I know it's been said before, but I just have to say it again... The amount of work that Mark and Trish (and helpers) put into this thing is OUTSTANDING... EVERY detail has been worked out. The build video alone had to have taken a TON of time.
I Actually started on the build yesterday afternoon, and with dinner, watching Return of the Pink Panther with my son, I am up to step 7 and this includes painting the thing. I am taking my time as I want to enjoy the build, and make sure everything is right. But honestly,so far, I can't see how you could build it wrong.

I was gonna work on it a bit today, but it was too nice to not go flying. Great day for flying, but not so good for a flying buddy. He lost his jet today, and I had to help fight a forest fire. Defiantly not something I was planning on doing today. Attached files

 

Ouch! Expensive day for your friend. That stinks, big time.
We aren't allowed to fly turbines at our field because of the fire hazard they present. Good thing your extinguishers were good. We found out recently that ours didn't work when someone tried to use it on a lipo that caught fire. Fortunately they didn't really need the extinguisher.

 

Shaun; I was amazed at how small the crash site was for how large a plane, but I was also equally amazed at how HOT the fire was. Most of the aluminum was melted or distorted. We did find one circuit board for one of the power boxes he had, and it was just an empty board. No components left. By the time we got to it ( about 3/4 of a mile over rough terrain) there was nothing left of the plane, just a BIG camp fire. After we got the bulk of the fire out, I went to lean against a tree about 10 foot from the impact, and it was too hot to touch. We don't have any official bans on turbines, but the few guys (only 2 ) at our field that fly them, don't fly them if it has been dry.
I haven't seen a lipo fire (lucky), but hear they can be pretty fierce. This is why I NEVER charge my batteries inside. I don't even store them inside unless it's below 0 outside in the winter.

Tom, the switches do NOT come with the kit. I am adding them just for an extra piece of mind. I had them on an my modified MKI machine. They seemed to make more sense there as you could not see the Y/Z gantry, but I figured I would add them here just as a safety measure. With the stock steppers you will stall the motors before doing any real damage to the machine.
As far as placement I have a few ideas, but will decide on the final location once I get the PPIII built. I'll be sure to post pics.

 

That's where I got mine, but got these ones as they have quick connect terminals instead of solder.

http://www.mpja.com/prodinfo.asp?number=18085+SW

The Quick connect terminals make for easier swap out if needed. I did actually break one of them apart on my MK1.5 when I was taking it apart. With the quick connects it was really easy to swap.

 

Here is where I put my limit switches. One on each end of the cabinet where the Y/Z gantry is. (1st Pic). E-Stop in foreground.
2nd & 3rd Pic is for the Z gantry. I really need to make some better whiskers, but I was in a hurry at this stage to get the PP3 running, and so far they appear to work just fine.
4th Pic is of the over ride switches. Covers should help determine if they are in position (not overridden) to cut. There are LEDs that light when an axis is tripped, but with the overhead gantry it is easy enough to see. I used generic LEDs that I had, and used a single 150 ohm resister at the common ground. The LEDs aren't the brightest, but are OK.
5th pic shows the holes being drilled. Tape used to mark location so they are straight and centered.
6th Pic is of how I mounted the 4 limit switches. Attached files