home / limit vs home and limit switch

[Gary Campbell]

Like slodat and Tom, I use individually configured inputs, but as home, not limit. This will allow the machine to home to them. Then set soft limits to take care of the machine travel

[ShawnM]

Like slodat and Tom, I use individually configured inputs, but as home, not limit. This will allow the machine to home to them. Then set soft limits to take care of the machine travel

As Captain Obvious just pointed out on a simple three axis machine you need three switches for the machine to home to. They are Home switches, not limit switches. Then setup the soft limits for max travel and be done. No need to take up a ton of valuable inputs for unneeded switches.

Set up the flags on the proximity switches so they pass in front of the switches, it's best not to have the flags inline with the switches to eliminate any chance of damage in the event of a crash. The machine has hard stops and it'll stop without destroying your proximity switches.

[tblough]

What you are homing to determines whether you set them up as home or limit switches. If you are homing to a CLI or some other index pulse from your drives, then you set up limit switches at the travel limits.

If your drives do not have an "index" signal, then you use home switches and place them slightly in front of what you would consider the limit of travel.

My personal opinion is that open loop steppers, or closed loop drives (stepper/servo) that do not have a fault output, need limit switches at BOTH ends of travel. Unless your motors are so small that no damage can occur from an overtravel. Soft limits only work if there is no posibility of loosing steps.

As to being "valuable" inputs; inputs are a one-time cost of $18 apiece when you buy them in lots of 16.

[ShawnM]

As to being "valuable" inputs; inputs are a one-time cost of $18 apiece when you buy them in lots of 16.

Since the first 8 cost approximately $41 a piece I would say that makes them valuable, no?

[Gary Campbell]

As to being "valuable" inputs; inputs are a one-time cost of $18 apiece when you buy them in lots of 16.

Since the first 8 cost approximately $41 a piece I would say that makes them valuable, no?

Buy 16 inputs at $18 each and get 16 outputs FREE!!

[ShawnM]

As to being "valuable" inputs; inputs are a one-time cost of $18 apiece when you buy them in lots of 16.

Since the first 8 cost approximately $41 a piece I would say that makes them valuable, no?

Buy 16 inputs at $18 each and get 16 outputs FREE!!

But wait, if you act now, when you buy the first 8 inputs we'll throw in the first 8 outputs for free. Don't wait, pick up that phone now and order yours today.

[suntravel]

Since the first 8 cost approximately $41 a piece I would say that makes them valuable, no?

Buy 16 inputs at $18 each and get 16 outputs FREE!!

But wait, if you act now, when you buy the first 8 inputs we'll throw in the first 8 outputs for free. Don't wait, pick up that phone now and order yours today.

I placed the order on Tuesday, but after reading this, I should have ordert 2 for double savings

Uwe