Thor, or should that be Zeus?

**Chaz** · 21-06-2017

Argh, good progress, getting tuning right and then with the limits / home switches I was doing some test. I ended up somehow going past the X ++ endstop which has fortunately only cost me lost time as I now need to repack the ballnut and some of the cart bearings. Could have been a lot worse. Not sure why it ignored the limit switch.

I was setting the X and Y axis to be reversed as they are the wrong way around ( + and - direction ). Do people normally do it on Mach 3 or reverse either the -10 to 10V or swap motor leads (and encoder feedback)?

**AndrewMawson** · 21-06-2017

Bad luck Chaz

However I do seem to remember posting this about a week ago (post #283)

"However my personal preference on big powerful machines is to have the home switches inside the boundries set by the limit switches, and have the limit switches trigger powering off of the drives. Also to have the limit switches within the boundries of mechanical stops that limit travel before ball screws over travel."

**Desertboy** · 21-06-2017

Originally Posted by AndrewMawson

Bad luck Chaz

However I do seem to remember posting this about a week ago (post #283)

"However my personal preference on big powerful machines is to have the home switches inside the boundries set by the limit switches, and have the limit switches trigger powering off of the drives. Also to have the limit switches within the boundries of mechanical stops that limit travel before ball screws over travel."

Hi Andrew, would a latched relay be suitable to perform the functions you describe?

**Chaz** · 21-06-2017

Originally Posted by Desertboy

Hi Andrew, would a latched relay be suitable to perform the functions you describe?

Andrew, yes, point made. I thought of the same.

Desertboy, fairly easily done with the CS Labs. It has sub 100ms error checking and can instantly disable the servos in a fault / trip condition.

**AndrewMawson** · 21-06-2017

I think the main point is to have a physical limit to save the ball screws if there is a runaway - preferably with a hard neoprene or other suitable plastic buffer.

As for the latched relay then yes that's the easy way to do it, but it needs to be a fast acting relay.

**Chaz** · 24-06-2017

Suppose this means it works.

Speeds and Feeds

24000 rpm - 6mm endmill
Cutting Rate 4000mm/min
Lead / Ramp at 1440 mm/min

This was run at 80% speed. Overall happy with the cut considering there is no finish pass.

DOC is 5mm, WOC is 1.2mm

Still got more to do, but happy with the initial results.