Autogate production

[Alan in Little Washington]

I finalized my autogate design, and have begun converting all my blast gates to full automatic actuation.

I am just about finished converting all my 6" gates. I added a radius to all edges, a touch of gray paint, and mounted the actuating cylinders to the gate bodies. I am in the process of making new slides, necessitated by the throw of the cylinders. I'll post a complete wrap-up of the process with more pics and parts info, etc. when I get done. With the cylinders and solenoid valves from Ebay and other misc. parts from McMaster-Carr and Lowes, each conversion is running about $20 each.

One gate is already finished and mounted on my jointer. One gate is yet to be modified (the white gate in the front center). The remaining five 6" gates are awaiting installation of new slides.




New slide temporarily attached to the cylinder with new linkage. It still needs an opening cut in one half.




Cylinder to slide attachment detail.

[jeff...]

Originally Posted by Alan in Little Washington

I finalized my autogate design, and have begun converting all my blast gates to full automatic actuation.

I am just about finished converting all my 6" gates. I added a radius to all edges, a touch of gray paint, and mounted the actuating cylinders to the gate bodies. I am in the process of making new slides, necessitated by the throw of the cylinders. I'll post a complete wrap-up of the process with more pics and parts info, etc. when I get done. With the cylinders and solenoid valves from Ebay and other misc. parts from McMaster-Carr and Lowes, each conversion is running about $20 each.

One gate is already finished and mounted on my jointer. One gate is yet to be modified (the white gate in the front center). The remaining five 6" gates are awaiting installation of new slides.




New slide temporarily mounte with new linkage. It still needs an opening cut in one half.




Cylinder to slide attachment detail.

Ah... I see... you are finally getting around to fine tuning the green rocket's thruster system

[McRabbet]

Alan, I must proclaim that

		YOU SUCK, Automatically!

I am extremely jealous of your talent. The Blast Gates look great, but please get rid of all that newspaper, 'cause it just doesn't fit in your very clean shop! . Nice work!

[Bas]

Alan, great stuff!!! You know, I bet there is a market for this system. Should at the very least make a very popular article on a web site somewhere.
Of course, if you want to make money off this, you need to offer blast gates in different colors (PM Gold, Delta Gray, JET ecru etc.)

[RandyJ]

Alan, you are definitely the wizard when it comes to blast gates.
When they are all completed, go ahead and ship 'em to me for the shop test! I'll be happy to give a full product review.
Amazing work!

[Travis Porter]

I remember you got a muffler and you are using air for the actuation, but what is going to cause an actuation? Are you going to use current sensors on your motors or something?

[Alan in Little Washington]

Originally Posted by Travis Porter

I remember you got a muffler and you are using air for the actuation, but what is going to cause an actuation? Are you going to use current sensors on your motors or something?

No sensors, I will direct wire my 110V and 24V powered solenoid air valves- the 24V valves will use 24V from the low voltage control (LVC) on my tablesaw, Jointer, Shaper, and Planer. The 110V solenoids will connect to the switch output on the 110V machines, but I plan to cheat on the 220V machines that don't have LVC- I'll tap off one power leg and the ground lead to get 110V.

All my solenoid valves have two outputs and two exhausts- when one port is pressurized, the other port is exhausted- that arrangement is needed for the double acting cylinders I have which are powered in both directions.

[sapwood]

Originally Posted by Alan in Little Washington

No sensors, I will direct wire my 110V and 24V powered solenoid air valves- the 24V valves will use 24V from the low voltage control (LVC) on my tablesaw, Jointer, Shaper, and Planer. The 110V solenoids will connect to the switch output on the 110V machines, but I plan to cheat on the 220V machines that don't have LVC- I'll tap off one power leg and the ground lead to get 110V.

All my solenoid valves have two outputs and two exhausts- when one port is pressurized, the other port is exhausted- that arrangement is needed for the double acting cylinders I have which are powered in both directions.

Now I know what the folks who can't upload pixs feel like

Roger

[cpowell]

Originally Posted by Alan in Little Washington

No sensors, I will direct wire my 110V and 24V powered solenoid air valves- the 24V valves will use 24V from the low voltage control (LVC) on my tablesaw, Jointer, Shaper, and Planer. The 110V solenoids will connect to the switch output on the 110V machines, but I plan to cheat on the 220V machines that don't have LVC- I'll tap off one power leg and the ground lead to get 110V.

All my solenoid valves have two outputs and two exhausts- when one port is pressurized, the other port is exhausted- that arrangement is needed for the double acting cylinders I have which are powered in both directions.

Alan, are you going to fuse the secondary of your LV (24VAC) transformers? I realize the coils on the 24VAC solenoid valves (SeVs) are very low power, and SeVs generally fail open, just thinking about secondary protection for the transformer and potential issues down the road. If your LV transformer has primary or secondary protection then you're already covered. Does the LV transformer secondary have a true neutral connection?

I'd also fuse protect the 110V SeVs.

As a PE I have to let everyone know it's not acceptable to use a ground wire as a neutral conductor.


Chuck

[Travis Porter]

So how are you actuating the solenoids? Are you going to have a LV on/off switch at each tool?

[Bas]

Originally Posted by Alan in Little Washington

No sensors, I will direct wire my 110V and 24V powered solenoid air valves- the 24V valves will use 24V from the low voltage control (LVC) on my tablesaw, Jointer, Shaper, and Planer. The 110V solenoids will connect to the switch output on the 110V machines, but I plan to cheat on the 220V machines that don't have LVC- I'll tap off one power leg and the ground lead to get 110V.

I'm with Roger here. I need a little translation. Are you saying the gate opens when you turn the machine on?

Originally Posted by Alan in Little Washington

All my solenoid valves have two outputs and two exhausts- when one port is pressurized, the other port is exhausted- that arrangement is needed for the double acting cylinders I have which are powered in both directions.

OK, so closing a gate is just as "active" as opening one, unlike say a door which is electromagnetically sealed (if you turn off the power or the power fails, the door opens).

So, does your setup keep the last port open, even if you turn off the machine? I.e. don't close the port until until you activated a different machine. Otherwise, the gates would open and close every time you turned the table saw on and off. I assume that's the case, but how are you accomplishing that? Note that "magic" is an acceptable answer here

BTW, the more you describe the system, the more

[Alan in Little Washington]

Originally Posted by cpowell

Alan, are you going to fuse the secondary of your LV (24VAC) transformers? I realize the coils on the 24VAC solenoid valves (SeVs) are very low power, and SeVs generally fail open, just thinking about secondary protection for the transformer and potential issues down the road. If your LV transformer has primary or secondary protection then you're already covered. Does the LV transformer secondary have a true neutral connection?

I'd also fuse protect the 110V SeVs.

As a PE I have to let everyone know it's not acceptable to use a ground wire as a neutral conductor.

Chuck

The LVCs are the standard, Delta units that mount on the back of the machine. All the transformers have fused secondaries, no true neutral.

I know it is not acceptable to use a ground for the neutral. I'm back to the same old issue that I had putting 110V work lights on my 220V drill press and bandsaw.

Originally Posted by Travis Porter

So how are you actuating the solenoids? Are you going to have a LV on/off switch at each tool?

Nope, no switches. As soon as the machine is turned on it activates (is directly wired to and powers) the solenoid. When powered, the solenoid reverses the air flow to the cylinder, which opens the gate. When the machine is turned off the solenoid returns to its rest state and ports air to the other end of the cylinder, causing the gate to close. If I cycle the machine on and off 10 times the blast gate opens and closes 10 times.

Originally Posted by Bas

I'm with Roger here. I need a little translation. Are you saying the gate opens when you turn the machine on?

YES!

So, does your setup keep the last port open, even if you turn off the machine?

No, turn the machine off and the gate closes.

I.e. don't close the port until until you activated a different machine. Otherwise, the gates would open and close every time you turned the table saw on and off.

There is no interaction between blast gates. Each gate opens/closes when its machine is turned on and off!

I assume that's the case, but how are you accomplishing that? Note that "magic" is an acceptable answer here

Every machine has its own blast gate only activated by that machine. If one machine is on, only one gate (that machine's gate) is open. If three machines are running, each gate- all three gates- are open. When a machine is turned off, only its gate closes.

BTW, the more you describe the system, the more

Thanks!

[cpowell]

So,....

The solenoids have 3 ports, 1 input port, and 2 output ports, let's call them port 'P', 'A', and 'B'. There are also exhaust ports, one for 'A' and also one for 'B'. 'P' is the input supply PRESSURE port, typically from a regulated compressed air system. Port 'A' is piped (tubing) to one side of the cylinder. Port 'B' is piped to the other side. Exhausts can be either open directly to atmosphere or sometimes will have flow control devices which limit the rate of air movement to prevent the controlled devices from "slamming" open or closed.

The solenoid coil will be energized whenever the machine start coil is energized, or, in the case of machines with a simple switch, the solenoid coil will be energized when the switch is 'ON'. With a start coil device, the energized wire can either come from the "hot" side of the coil or a normally open auxiliary contact on the contactor. With a simple switch, the "hot" wire comes from the load side of the switch (between the switch and the actual motor load).

Thinking in logic terms, if the machine is on, Logic = 1. If off, Logic = 0.

Logic = 0
P------>B
A------>Exhaust

Solenoid coil is de-energized. Pressure goes to port 'B', causing the gate to CLOSE. Port 'A' is open to exhaust so that as the cylinder is closing the air on the low pressure side of the cylinder is vacated to allow cylinder movement.

Logic = 1
P------>A
B------>Exhaust
Solenoid coil is energized. Pressure goes to Port 'A' causing the gate to OPEN. Port 'B' is open to exhaust so that as the cylinder is opening the air on the low pressure side of the cylinder is vacated to allow cylinder movement.

This type of system, with one input port and two output ports, is very similar logically to a single pole double throw relay. The net result is that it supplies positive pressure to either OPEN or CLOSE the cylinder at all times. It uses pressure to ensure that the gate stays in the desired position, whether open or closed.


Chuck

[Alan in Little Washington]

Right on! Thanks Chuck!

In engineering symbology a 5/2 valve:

[Travis Porter]

I am dense. I have a basic understanding of relays, electricity, etc, but something still isn't clicking.

You have a solenoid that activates a pneumatic relay.

The solenoids are 110V or are they 24V?

Are you going to take the output side of the machine switch wire and wire it to the solenoid?