Ref: limit switches and inhibits
 

Much that has been discussed is ok for "Hobby" or home type machines.

As someone that retrofits drives and controls fora living I yet to
hear much about the real world issues of safety and "Safety
Standards".

The attached link is a 5 axis digital drive I completed last week and
every possible safety issue has been adressed.

http://s32.photobucket.com/albums/d1...current=m5.jpg

In large gantry machines like this, all axes drive motors have brakes
to ensure a quick stop in an error condition.

Soft over travel limits are set and deal with normal overtravel
condition and extreme overtravel result in a complete drive shutdown.

E Stops are handled by relays designed for this purpose.
http://www.pilz.com.au/products/cont...y/index.en.jsp

Not being critical but none of this would work in any real world
manufacturing plant.

db

Ref: limit switches and inhibits
 

On 2010-06-26, Dave B wrote:
Much that has been discussed is ok for "Hobby" or home type machines.

As someone that retrofits drives and controls fora living I yet to
hear much about the real world issues of safety and "Safety
Standards".

The attached link is a 5 axis digital drive I completed last week and
every possible safety issue has been adressed.

http://s32.photobucket.com/albums/d1...current=m5.jpg

In large gantry machines like this, all axes drive motors have brakes
to ensure a quick stop in an error condition.

Soft over travel limits are set and deal with normal overtravel
condition and extreme overtravel result in a complete drive shutdown.

E Stops are handled by relays designed for this purpose.
http://www.pilz.com.au/products/cont...y/index.en.jsp

Not being critical but none of this would work in any real world
manufacturing plant.

Looks very nice Dave. How *would* you do this in a real world
manufacturing situation? (without adding additional limit switches,
etc).

i

Ref: limit switches and inhibits
 

On Fri, 25 Jun 2010 22:05:35 -0500, Ignoramus31989
wrote:

On 2010-06-26, Dave B wrote:
Much that has been discussed is ok for "Hobby" or home type machines.

As someone that retrofits drives and controls fora living I yet to
hear much about the real world issues of safety and "Safety
Standards".

The attached link is a 5 axis digital drive I completed last week and
every possible safety issue has been adressed.

http://s32.photobucket.com/albums/d1...current=m5.jpg

In large gantry machines like this, all axes drive motors have brakes
to ensure a quick stop in an error condition.

Soft over travel limits are set and deal with normal overtravel
condition and extreme overtravel result in a complete drive shutdown.

E Stops are handled by relays designed for this purpose.
http://www.pilz.com.au/products/cont...y/index.en.jsp

Not being critical but none of this would work in any real world
manufacturing plant.

Looks very nice Dave. How *would* you do this in a real world
manufacturing situation? (without adding additional limit switches,
etc).

i
All of the information and advice that has been given is right on
target for your application.

I like the idea of dropping the drive out when you hit the
overtravels.

Have the limit switches part of the E stop string and use a push
button for an overide.

Hold the button down until you jog off the switch and then push the
drive reset button and reset the estop string.

Sounds like you are on the right track !

db

Ref: limit switches and inhibits
 

On Fri, 25 Jun 2010 22:05:35 -0500, Ignoramus31989
wrote:

On 2010-06-26, Dave B wrote:
Much that has been discussed is ok for "Hobby" or home type machines.

As someone that retrofits drives and controls fora living I yet to
hear much about the real world issues of safety and "Safety
Standards".

The attached link is a 5 axis digital drive I completed last week and
every possible safety issue has been adressed.

http://s32.photobucket.com/albums/d1...current=m5.jpg

In large gantry machines like this, all axes drive motors have brakes
to ensure a quick stop in an error condition.

Soft over travel limits are set and deal with normal overtravel
condition and extreme overtravel result in a complete drive shutdown.

E Stops are handled by relays designed for this purpose.
http://www.pilz.com.au/products/cont...y/index.en.jsp

Not being critical but none of this would work in any real world
manufacturing plant.

Looks very nice Dave. How *would* you do this in a real world
manufacturing situation? (without adding additional limit switches,
etc).

i
I would have three per axis +- OT and the home or reference switch.
This are great to use very comapce and have cam rails with adjustable
cams.
http://www.euchner-usa.com/LimitMultiple.asp

db

Ref: limit switches and inhibits
 

Ignoramus31989 wrote:

On 2010-06-26, Dave B wrote:
Much that has been discussed is ok for "Hobby" or home type machines.

As someone that retrofits drives and controls fora living I yet to
hear much about the real world issues of safety and "Safety
Standards".

The attached link is a 5 axis digital drive I completed last week and
every possible safety issue has been adressed.

http://s32.photobucket.com/albums/d1...current=m5.jpg

In large gantry machines like this, all axes drive motors have brakes
to ensure a quick stop in an error condition.

Soft over travel limits are set and deal with normal overtravel
condition and extreme overtravel result in a complete drive shutdown.

E Stops are handled by relays designed for this purpose.
http://www.pilz.com.au/products/cont...y/index.en.jsp

Not being critical but none of this would work in any real world
manufacturing plant.

Looks very nice Dave. How *would* you do this in a real world
manufacturing situation? (without adding additional limit switches,
etc).

Particularly considering that the 5 limit switch and no brakes on the
servos *was* a "real world manufacturing plant" design, though from a
few decades ago.

The series2 Bridgeport knee mill certainly doesn't have enough mass or
weight to need servo brakes, or hydraulic counterbalance on the Z axis
as is common on the big iron.

I used to work on some big gantry machines back when and they certainly
were a lot of fun. Not exactly home shop size though when they weigh
60,000#.

Ref: limit switches and inhibits
 

On 2010-06-26, Pete C. wrote:

Ignoramus31989 wrote:

On 2010-06-26, Dave B wrote:
Much that has been discussed is ok for "Hobby" or home type machines.

As someone that retrofits drives and controls fora living I yet to
hear much about the real world issues of safety and "Safety
Standards".

The attached link is a 5 axis digital drive I completed last week and
every possible safety issue has been adressed.

http://s32.photobucket.com/albums/d1...current=m5.jpg

In large gantry machines like this, all axes drive motors have brakes
to ensure a quick stop in an error condition.

Soft over travel limits are set and deal with normal overtravel
condition and extreme overtravel result in a complete drive shutdown.

E Stops are handled by relays designed for this purpose.
http://www.pilz.com.au/products/cont...y/index.en.jsp

Not being critical but none of this would work in any real world
manufacturing plant.

Looks very nice Dave. How *would* you do this in a real world
manufacturing situation? (without adding additional limit switches,
etc).

Particularly considering that the 5 limit switch and no brakes on the
servos *was* a "real world manufacturing plant" design, though from a
few decades ago.

The series2 Bridgeport knee mill certainly doesn't have enough mass or
weight to need servo brakes, or hydraulic counterbalance on the Z axis
as is common on the big iron.

Actually it has a pneumatic support for the knee. It is not absolutely
necessary, just a convenience.

I do not know about brakes, but the drives are four quadrant drives.

I used to work on some big gantry machines back when and they certainly
were a lot of fun. Not exactly home shop size though when they weigh
60,000#.

Ref: limit switches and inhibits
 

Dave B wrote:

Much that has been discussed is ok for "Hobby" or home type machines.

As someone that retrofits drives and controls fora living I yet to
hear much about the real world issues of safety and "Safety
Standards".

The video of the spinning machine was nice.


Wes

Ref: limit switches and inhibits
 

On Sat, 26 Jun 2010 13:19:29 -0400, Wes
wrote:

Dave B wrote:

Much that has been discussed is ok for "Hobby" or home type machines.

As someone that retrofits drives and controls fora living I yet to
hear much about the real world issues of safety and "Safety
Standards".

The video of the spinning machine was nice.


Wes


Thanks Wes

db

Ref: limit switches and inhibits
 

On Sat, 26 Jun 2010 08:14:50 -0500, "Pete C."
wrote:


Ignoramus31989 wrote:

On 2010-06-26, Dave B wrote:
Much that has been discussed is ok for "Hobby" or home type machines.

As someone that retrofits drives and controls fora living I yet to
hear much about the real world issues of safety and "Safety
Standards".

The attached link is a 5 axis digital drive I completed last week and
every possible safety issue has been adressed.

http://s32.photobucket.com/albums/d1...current=m5.jpg

In large gantry machines like this, all axes drive motors have brakes
to ensure a quick stop in an error condition.

Soft over travel limits are set and deal with normal overtravel
condition and extreme overtravel result in a complete drive shutdown.

E Stops are handled by relays designed for this purpose.
http://www.pilz.com.au/products/cont...y/index.en.jsp

Not being critical but none of this would work in any real world
manufacturing plant.

Looks very nice Dave. How *would* you do this in a real world
manufacturing situation? (without adding additional limit switches,
etc).

Particularly considering that the 5 limit switch and no brakes on the
servos *was* a "real world manufacturing plant" design, though from a
few decades ago.

The series2 Bridgeport knee mill certainly doesn't have enough mass or
weight to need servo brakes, or hydraulic counterbalance on the Z axis
as is common on the big iron.

I used to work on some big gantry machines back when and they certainly
were a lot of fun. Not exactly home shop size though when they weigh
60,000#.


Wasn't the best choice of words just wanted to point out different
ways of thinking and doing things.

After four decades of doing this I have seen a lot of different ways
of doing the same thing. Some better than others.

Hopefully I wont have another decade of this.after awhile they all
look the same.

Back under my rock.........

db

Ref: limit switches and inhibits
 

On 2010-06-26, Wes wrote:
Dave B wrote:

Much that has been discussed is ok for "Hobby" or home type machines.

As someone that retrofits drives and controls fora living I yet to
hear much about the real world issues of safety and "Safety
Standards".

The video of the spinning machine was nice.

What video?

i

Ref: limit switches and inhibits
 

On Sat, 26 Jun 2010 17:29:30 -0500, Ignoramus11285
wrote:

On 2010-06-26, Wes wrote:
Dave B wrote:

Much that has been discussed is ok for "Hobby" or home type machines.

As someone that retrofits drives and controls fora living I yet to
hear much about the real world issues of safety and "Safety
Standards".

The video of the spinning machine was nice.

What video?

i
Retrofit I did with hydraulic servos
http://s32.photobucket.com/albums/d1...nt=Spinvid.flv

db