So...neydor wrote:Hi Pete,
I have been following most of the BDB threads and I'm very interested in going rotary as well. I have many questions on that topic, but is probably best to create a new treat about that. Do you mind creating a new thread about it, and show some of your tips on how to do it. I got some of the info from various of your post but would like to know more. I'm pretty handy myself, I have access to plum in and cabinet space. I'm looking at a pump and motor on ebay that I could buy. I have more questions as of to how to connect to the bdb and how to operate the machine. Anyway, I will like to thanks you for all the work you have done on these threats as well.
It's very important to fully understand what this means. Plumbing and rotary'ing go hand in hand and attempting one without the other makes a very easy project into one that is very very hard. Second, fitting the pump inside the machine will be impossible unless you can find a tiny, expensive, non-standard pump and motor, and even then, you might still have tremendous challenges. I did it the easy way, the way it's done at your favorite shops... The pump and motor are under the sink, next to the water filter, which feeds the pump. You are going to have to be OK with these realities or face a tremendous challenge. Once you are OK with this, the rest is easy. Incredibly easy in fact, especially if you are already comfortable with plastic water filter tubing and fittings.
You will need a pump and a motor to drive the pump:
I bought a standard pump that is used all over commercial espresso and the beverage industry in general. From a beverage supply business on eBay, This one: https://www.ebay.com/itm/151352970969 This one uses a big inexpensive motor that you would never find on the inside of a home machine. But it's under the sink so the size doesn't matter to me. There is no reason you must buy from this vendor. I have no association with him. There are probably dozens of businesses that sell motor/pump combos, and you don't have to shop from an expensive espresso supply that sells more compact motors... unless you want to, which is also perfectly fine. I did not feel the need to pay for compactness. TL;DR commercial espresso machines don't use espresso pumps. There is no such thing. They use fluid/beverage pumps. The same pumps as in soda dispensing machines and a million other fluid pump uses.
Connecting water to the pump:
The pump has an input and an output. On mine, the input of the pump is fed by the softener/filter I have under my sink. I set my water filter up using 3/8" tubing. But most let you use 1/4" tubing as well. Doesn't matter. Use whatever you want. The Procon pump I have has female 3/8 NPT input and outputs, so I went to Big Orange and got a couple of John Guest 3/8 male NPT, to 3/8" push to connect tubing females. Here: https://www.homedepot.com/p/John-Guest- ... /300753462 One for the inlet and one for the outlet. Pushed the 3/8" plastic tube from the filter into the inlet side of the pump.
Connecting the pump to the machine:
You splice into the tube on the machine, were the stock pump, pumps into the system, which starts with a run through the steam boiler via heat exchanger. (see pic below) Coming off the pump, I have 3/8" tubing. At some point, I used a reducer to change from 3/8" to 1/4" tubing. This one: https://www.homedepot.com/p/John-Guest- ... /300753460 What is left now is to connect the 1/4" tubing to the machine. The machine uses 4mm PTFE tubing, which for plumbing plastic fittings, is close as makes no difference to 5/32, and 1/4" is close to 6mm. This is key. So I ordered a bag of these: https://www.amazon.com/gp/product/B00N4 ... UTF8&psc=1 , and connected the 1/4 tubing from the pump, to the 4mm tubing of the machine.
Controlling the pump:
The pump motor will have a cord, or lugs to add your own. At this point you have to make a decision. Do you want to tie the pump to the power button on the machine, which also ties it to the solenoid? Or do you want to de couple the pump from the solenoid so that you can control each separately? I went with the latter. And it's easier too. Even before I went rotary, I had put in an interrupt switch, so that I could turn off the pump for blooming the puck, while the solenoid still remains energized. With this MO, you start the shot the usual way with a button on the machine, which energizes the solenoid as usual, then you flip another switch to turn power on the pump. To finish the shot, I push the button on the machine which closes the solenoid to pump pressure, and vents the rest to the drip tray... which is what it does anyway on a stock machine. Then I flip off the power to the pump, which is doing nothing anyway after you de energize the solenoid, except running and pumping water in a circle. You don't want to forget to turn off the pump or it will eventually heat up the water it's pumping in a circle, going nowhere.
Here is the 1/4 to 4mm reducer to connect water to the machine:
Here is a cap I put where I cut the tube between the stock pump and the steam boiler. You want to cap the stock pump, or the steam filler pump will work against an air leak and have to pump harder:
Here, I added some 4mm PTFE tubing I bought off Amazon, to the factory 4mm PTFE tubing. Connected with a cheap 4mm union:
This ^^^ last bit is not required. I just did it to give myself more working room to slide the machine around here and there without pulling on the tubing.
Random thoughts: (I may add to this from time to time)
-The BDB is blessed with it's own separate steam pump and boiler fill system. So I keep a wee bit of water in the reservoir, just for steam. You don't need much though as steaming doesn't use much water.
-You may (probably should) splice in some shutoff valves. I have one in the 1/4 section of tubing from the pump to the machine, and one in the 3/8 tubing after the filter but before the pump. The 1/4" one is probably superfluous but I had it lying around.
1/4" shutoff: https://www.homedepot.com/p/John-Guest- ... /300753479
3/8" shutoff: https://www.homedepot.com/p/John-Guest- ... /300753478
-You could/should also put in a check valve so hot water can't back flow from the machine to the pump and filter. I have not done this. But I should. They are about $30 on Amazon IIRC.
-Finally, I used high pressure tubing for the 1/4 run. A little extra piece of mind. This tubing is overkill, but I was so excited to get going I didn't spend much time shopping for something in between: https://www.amazon.com/gp/product/B074K ... UTF8&psc=1
And finally the gravy: HTH