2nd and Subsequent Gate Valve Construction

[Penri]

Terry

I am in the process of mechanically assembling 4off gate valves, I'll drop them off at WMT either later on today or tomorrow morning.

Penri

[TerryJC]

Do you want the four that I collected this morning back?

[Penri]

I've used the the stock I have here to build these ones. If you can bring the stuff you collected this morning I'll assemble those later.

I've finished putting the valve and actuators on the brackets and attaching the couplers on all four. I'm just about to search for suitable material for the position indicator you requested and then I'll attach that and fit the electronic box. It should all be done shortly and delivered to WMT tomorrow morning.

[TerryJC]

OK. Will do.

[TerryJC]

Well it's taken a while!!!

After many trials and tribulations, I believe that I now have a reliable method of construction. The biggest problem that I've had is getting round the poor quality DuPont contacts and shrouds that we got from China, which were found to make unreliable connections. Before I had identified this issue I had damaged a couple of Pis and a couple of A/D Converters (the A/Ds don't like 3.3 V on the input channel and 0 V on the power pin; they short and destroy the Pi).

We now have 6 completed Gate Valves (seven including the installed g4gatepi behind the Wendy House). The attached file shows the IDs of the different devices and this info will be incorporated into the Design Spec at some point in the future. (The sixth valve will be configured as g4gatepi so that I can substitute the one onsite and upgrade the wiring.) I think we should consider creating a label to stick onto the case of each device so that the hostname, IP Address and ID are readily available; just a thought.

Along the way, I have updated the Installation Specification and Composite Design Doc for the Gate valves and I've just uploaded the latest versions to the fileserver.

I have 6 SD Cards burnt and almost ready to go. Two have the correct IP addresses etc (g4gatepi and g6gatepi). I will do the four for the Matrix Pump before Tuesday and I will also need to update config.py and copy it to each card before then.

[hamishmb]

Excellent, good work

Now we just need the software

[Penri]

Good news, looking forward to Tuesday when we can plan integration.

[TerryJC]

I hadn't realised just how long it had been since I completed the builds describe above. The current situation is that five Gate Valves are installed; the Wendy Butss Valve, which has been in use for a long time, the Stage Butts Gate Valve which is installed and running, but not yet being controlled by the Stage Butts SAC and three Lady Hanham Butts Valves which are plumbed in but not yet powered.

Yesterday, I took away from the Workshop four Gate Valve Assemblies (sans electronics) and noted that there were two completed Gate Valves on the shelf. In addtion, I have a completed Gate Valve which forms part of the Test Rig (along with a working SAC).

To fully assemble the remaining Gate Valves I need:

• 4-off Raspberry Pi Zeros. We have these.
• 4-off Motor Drive Boards. We have five of these.
• 4-off DC/DC Converters. We have 17 these!!! (These were only 0.62p each so I ordered 30, on the basis that PSUs are vulnerable. As it happens they've proved remarkably robust, despite the odd cock-up (like putting 30 V on the input instead of 12.
• 4-off A/D Converters. We have these.
• 4-off Ethernet Adaptors. We have these.

Leaving aside the Gazebo Butts, we therefore only need two more finished assemblies to allow us to complete the Matrix Pump and I intend to make a start on these this weekend. Clearly these aren't urgent, but it would be good to get them out of the way, so that I can then concentrate on assembling spares for the SACs and Gate Valves in the system.

I had been asked to get involved in another Railway Project, but nothing has come of it yet. If it turns out to be needed, then I'll put these devices on the back burner.

[TerryJC]

Yesterday, I took away from the Workshop four Gate Valve Assemblies (sans electronics) and noted that there were two completed Gate Valves on the shelf. In addition, I have a completed Gate Valve which forms part of the Test Rig (along with a working SAC).

Well. It's been getting on for a year since I wrote that but the Minster Music & Bells plus Tiny-TVs have consumed my thoughts and time since then.

Penri,

A question. Are you aware of any Gate Valve substitutions since I wrote the above? That post indicated that there were two Gate Valves in the WMT Workshop back then and that ties in with what you told me in our telecon recently. I had thought that the Gate Valve that I had was a faulty one, but it seems that it should have been alright. However, it has proved to be faulty and (remarkably) the 5 V supply to the Pi came up at 6.1 V! It had also lost its SD Card at some point, so I am building another one now.

This has left me a bit confused because the Gate Valve that formed part of the Test Rig certainly used to work but it couldn't have done with the PSU I/P that high.

Hopefully the high voltage hasn't damaged the Pi, but I won't know that until I have something that I can run on it.

[Penri]

Hello Terry

When I looked earlier in the week i could only see one assembled gate valve in the workshop, As i said during the phone call I dipped my hand in another cardboard box and pulled out a linear actuator, since then I not had the opportunity to review my home and WMT stock against the published parts inventory.
I can't remember doing any substitutions, the installed gate valves at WMT are all as they were when put in originally.

Penri