Multi homing switches

Is there a way to have have multiple limit switches on each axis. I’m thinking a soft limit switch of the magnetic reed kind then after then a highly precise Metrol switch. I’m wanting it to home at high speed and once the reed switch is tripped it would slow to a crawl till it contacts the last switch. My gole is to have a repeatable home position that’s accurate down to the nats ass.
Thanks guys

JTknives wrote:

Is there a way to have have multiple limit switches on each axis. I’m thinking a soft limit switch of the magnetic reed kind then after then a highly precise Metrol switch. I’m wanting it to home at high speed and once the reed switch is tripped it would slow to a crawl till it contacts the last switch. My gole is to have a repeatable home position that’s accurate down to the nats ass.
Thanks guys

The home sequence does a moderate speed touch and then a slow final touch.

I used the 3 dollar lever switches on some pla printed brackets. With a .0005inch indicator I zeroed on the ground vise jaw. After shutting the machine down and back on it always repeated with in less than .0005 and I have cheap rolled ball screws.

Mine homes at about 30ipm and then does a very slow final touch. 1.5ipm I think

They use home search and home latch velocity and you can adjust them in the ini to suit your needs

Don't worry about homing time, on small machines it doesn't take long even when done properly. I use a combined limit/homing switch on each axis and have never had a crash from the drive running off the other end.

1. Seek at a moderate speed which is dependent on your hardware.
2. Back off at a very low speed until the switch releases, this won't take long as the move is short. You will good repeat ability doing this.
3. My table with rack and pinion drive running on cam rollers will do better than .001" homing repeat ability. I used a 1"/.001" dial indicator for testing.

The real thing you should be concerned with is how accurately you can setup your work piece (G54). For plasma cutting a flame cut or distributor cut piece of stock this will be your limiting factor. I just align the stock on my table using a laser pointer. The sheet stock I get from the distributor can be quite parallelogram shaped and the dimensions are usually -0"/+.5". I tried using jigs attached to the table way back when to get easy repeat able stock placement and just gave up as the sheets varied too much. If you can't live with this kind of accuracy out of plasma cutting then you need to have your material waterjet cut and machined because no air plasma will be better than about +/-.032" and worse over time.

John