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Author Topic: Bridgeport Knee Mill Conversion?  (Read 270452 times)

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Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #80 on: May 17, 2016, 05:45:22 AM »
Thanks, will be using servo index homing so the switch quality is not important really.

I guess having a home switch and using soft-limits is just not safe on a big machine?

Offline dude1

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Re: Bridgeport Knee Mill Conversion?
« Reply #81 on: May 17, 2016, 06:12:02 AM »
if it can rip your arm off all safety stuff should be done

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #82 on: May 17, 2016, 06:24:01 AM »
But limits are machine protection not user.

Offline dude1

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Re: Bridgeport Knee Mill Conversion?
« Reply #83 on: May 17, 2016, 06:29:06 AM »
can be both you can tye it into the door as well if it has one

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #84 on: May 17, 2016, 06:35:37 AM »
Yes but what i am saying is - is it ok to rely on soft-limits alone to stop the machine self destructing?

Obviously it will be homed as a first step every start-up.

Offline RICH

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Re: Bridgeport Knee Mill Conversion?
« Reply #85 on: May 17, 2016, 07:30:36 AM »
Quote
Yes but what i am saying is - is it ok to rely on soft-limits alone to stop the machine self destructing?

It all depends on the level of protection for the machine that one wants to have and the working environment that they are in.
Don't have any switches on any of my machines, but, they are rather  small and no damage will occur.

If it's for safety then you would want to be  redundant.

RICH

Offline Hood

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Re: Bridgeport Knee Mill Conversion?
« Reply #86 on: May 17, 2016, 07:36:24 AM »
The Soft Limits on the CSMIO's work great and are better than the ones via Mach with the PP or for that matter Mach/SmoothStepper (unless it has changed) and likely a lot of other  external controllers.

The CSMIO Know where the limits are and so will use the deceleration (acceleration) in motor tuning and will stop exactly on the soft limit using that decel. With Mach and the PP you need to set up a slow zone and you have to work that out by trial and error.

Personally I like Limit switches on my machines, I don't like to rely fully on software.
I do not have the limits going to Mach only as that again means you are relying on software.
I have my limits in an E-Stop chain which is totally hardware, ie it goes  via a pilz style safety relay, that relay will stop my servo drives, take away enables from the drives and in addition will also send a signal to Mach to E-Stop, so added safety.



I always have separate homes for each axis and shared limits for all axes, this allows me to have home switches inboard of the extents and can save a lot of moving if the axes are large.
 If you have these home switches stay triggered once reached then you can home from being already on a home switch with the CSMIO, It will see the switch is triggered and will do the back off move only.

Another good thing with  doing that (limits being hardware operated)  is it will always stop if you hit a limit even during Homing.
The way Mach works when homing is it ignores the limits, so if something goes wrong then hitting the limit will do nothing and you end up crashing the axis.

Hood

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #87 on: May 17, 2016, 07:37:41 AM »
Just looking at machine safety.

I think the weak point is the drive belt but still capable of transmitting damaging torque from a 750w servo at 2:1 and doing 3000rpm?

I guess I will find a spot for limits ;)

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #88 on: May 17, 2016, 07:40:20 AM »
The Soft Limits on the CSMIO's work great and are better than the ones via Mach with the PP or for that matter Mach/SmoothStepper (unless it has changed) and likely a lot of other  external controllers.

The CSMIO Know where the limits are and so will use the deceleration (acceleration) in motor tuning and will stop exactly on the soft limit using that decel. With Mach and the PP you need to set up a slow zone and you have to work that out by trial and error.

Personally I like Limit switches on my machines, I don't like to rely fully on software.
I do not have the limits going to Mach only as that again means you are relying on software.
I have my limits in an E-Stop chain which is totally hardware, ie it goes  via a pilz style safety relay, that relay will stop my servo drives, take away enables from the drives and in addition will also send a signal to Mach to E-Stop, so added safety.



I always have separate homes for each axis and shared limits for all axes, this allows me to have home switches inboard of the extents and can save a lot of moving if the axes are large.
 If you have these home switches stay triggered once reached then you can home from being already on a home switch with the CSMIO, It will see the switch is triggered and will do the back off move only.

Another good thing with  doing that (limits being hardware operated)  is it will always stop if you hit a limit even during Homing.
The way Mach works when homing is it ignores the limits, so if something goes wrong then hitting the limit will do nothing and you end up crashing the axis.

Hood

I'm getting to like this CSMIO controller more and more and i haven't even bought it yet :)

Offline Hood

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Re: Bridgeport Knee Mill Conversion?
« Reply #89 on: May 17, 2016, 07:50:41 AM »
Here is a pdf showing he main wiring of my plasma, as you can see I have one button that starts the computer, it then uses the computers power supply to draw in a contactor which feeds mains to the 24v supplies which start the CSMIO and the servo drives logic etc. I then have a Start/Stop button which will bring in another contactor that feeds the mains to the servo drives. And as mentioned I have the E-Stop and limits via the safety relay and also fault signals from my servo drives go to an additional relay in that E-Stop chain.

I do not have the connections from the  safety relay to the CSMIO shown but basically they go to the CSMIO and tell it there has also been an E-Stop, so added safety from both hardware and software. I also have that safety relay  taking away enables from the drives and lastly, also not shown is I have fault signas from the drives going to the servo faults in the CSMIO plugin, again just added safety.
Hood