AssafL wrote: (or you could use resistors and a diode with a LED...).

I'm a beginner with electricity and still reading up on it. I knew what I diode did but didn't know you could use it to rectify AC. (I'm still on the DC volume on allaboutcircuits.com!) although it does make sense when I think about it.

I was planning on using a laptop power supply or one of the power supplies you can get from arduino sites. This diode-bridge thing seems cooler though. I also wanted to add a timing chip to get a fade-in/out effect.

Ah - a two way NO makes sense. I thought you were doing a 3 way switch.

You don't need a full rectifier for an LED. You need to wire a diode in parallel bet reverse to the LED (which is also a diode). It's function is to limit the reverse voltage on the LED (which can't handle full mains).

You'll need a Diode like a 1n4148. Or 1n4001-4007.
And the resistor would be to limit 110v to 20mA or so.
So 110v/0.02= 5500 ohm. 5.6k ohm is the next standard value.
But most resistors are rated 1/8w. So 110v^2/5.6k > 2 watt. So I would take 4 resistors of 1.5k and wire them in series with the LED. These would need to be rated at 1/2 watt.

Hope this helps...

AssafL wrote:I can't think of a BSPT or NPT in an espresso machine. Are there any tapered connections in espresso machines?

Unless there is a washer/gasket between the fittings it is a tapered thread..

http://www.ralstoninst.com/news/story/t ... spt-seals/

Well, you can have a tapered fitting (e.g. a tapered tube or a ball ended tube) that doesn't need a tapered thread.

Can you think of an espresso machine fitting that isn't tapered, gasketed or uses a crush washer and instead relies on threads? I can't...

AssafL wrote:I can't think of a BSPT or NPT in an espresso machine. Are there any tapered connections in espresso machines?

AssafL wrote:Well, you can have a tapered fitting (e.g. a tapered tube or a ball ended tube) that doesn't need a tapered thread.
Can you think of an espresso machine fitting that isn't tapered, gasketed or uses a crush washer and instead relies on threads? I can't...

I'm not a Espresso Machine Mechanic, just a Machinist..

Just realized I never concluded this on here. I had been posting photos on instagram and a little on my personal blog.
Couple of photos. I got rid of terminal blocks once I discovered wago's from kafatek.




http://www.shawndo.com/2016/06/25/flow- ... on-part-01

any news?
thx

That last post was the conclusion. It is done now. Ask any questions if you got 'em

ok
i thought something is missing

did you test your need valve?
Variable Pressure Infusion Modification Results: a Paper
approved in your opinion (in a positive way)

thx

Yes, the needle valve i got (part number on the blog post previously linked) works well.

I visited another HB member with a slayer and saw how he adjusted his needle valve and i just tried to copy that since he had great espresso.

Instead of setting it by the flow rate (i.e. 40g/30sec) I adjusted it by the amount of time it takes to fill the headspace and for the gauge to start climbing. I set mine so that group pressure gauge starts climbing at around 10 seconds to match the Slayer I sampled.
This is faster than the default Slayer settings but works well.