Frosted Senior Member Joined: 1 Jun 2008 Posts: 20 Location: Seattle Expertise: I like coffee
Espresso: Dalla Corte Supermini, La... Grinder: Mazzer Mini, Super Jolly,...
Posted Sat Jun 7, 2008, 9:44pm Subject: Re: Andreja Rotary Pump
Here is another picture with both sides on the machine. This has to be a plumbed connection since the rotary pump sits where the water reservoir was. You can also see that the inlet for the plumbing was added to the bottom. That involved adding 3/8" spacers to the feet. I intend to find new feet that are the proper height, but I haven't gotten around to that. Moving the water inlet to the bottom rather than the back makes a brew-pressure adjustment easier, since there are no longer hoses attached to the back panel, which is all you have to remove to adjust the pump.
To mount the pump/motor I had to construct a platform (stainless-steel) to set it above the plumbing and electrical connections at the bottom of the machine. I wanted to do this mod with a minimum of alteration to the original machine (I only had to drill two extra holes in the frame), so now the platform gave me a greater opportunity to mount the pump/motor in the proper place and not have to reroute a bunch of plumbing and electrical. Using a small 110v motor (the same as in the Vetrano) and a short flange pump, the whole assembly fits nicely side to side. I cut holes in the platform for the pump inlet and outlet hoses to pass through and it is mounted to the base with four screws (two at the back and one on each side). The mount that came with the motor had to be modified (hack-saw and drill) and I mounted it on rubber vibration mounts similar to the ones used on the Vetrano.
I changed all of the original teflon hoses from 5/3mm to 6/4mm (6/4mm fittings are easier to find). I already had a plumb-in kit for the machine. I used the supplied jumper wires for the low water alarm and a supplied wire for an additional motor ground wire that was needed. The kit also had the fitting for the overflow hose to the drip tray.
Sourcing the BSP fittings was a challenge but I did find a very good source that had a much greater selection than the typical espresso parts suppliers. A 3/8" to 1/8" fitting for the pump turned out to be not so common. I put a T-fitting on the pump outlet to attach the brew-pressure gauge and the hose to the boiler and capped the port in the T-fitting from the boiler to the expansion valve where the pressure gauge was previously attached. I then routed the hose from the expansion valve to the drip tray for overflow. All of this was done using my Vetrano as a model. The last thing was fabricating a new panel that goes under the cup warmer panel, since the original was designed to hold the reservoir. I hope this helps, I will post a few more photos. If you want any additional information, let me know.
To answer a question, other than the change in the teflon hose diameter and pump adjustments, I made no additional changes to the flow rate.
Mark- I did it very carefully. I made a paper pattern to layout all of the holes, taped it to the stainless and used a center punch to mark the centers so the drill bit wouldn't drift. I bought three high-quality bits (and used two), took my time and used generous amounts of cutting oil. The drill press helped too.
pumpkinscastle Senior Member Joined: 10 Jan 2008 Posts: 247 Location: Cincinnati, OH Expertise: I live coffee
Espresso: Quickmilll Vetrano Grinder: Mazzer Super Jolly
Posted Sat Jun 21, 2008, 7:30am Subject: Re: Andreja Rotary Pump
Seeing from yourr profile that you own both, QM Vetrano and the (modified) Andreja Premium, would you say that the latter now feels/performs like the former? Or does it somehow differ? Great modification by the way! I wished I were that handy with such stuff.
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