Rotary pump mod for Rancilio Silvia Pro - flow restrictor?
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I was originally planning on sticking a Procon Micro Vane pump into my MaraX, but it was just barely too large for the frame, so that idea got canned.
I still have the pump, though, and with a Silvia Pro on its way to me, so that got me thinking: Can I make it work in the Silvia Pro? The space problem seems to be less concerning given the machine's slightly greater width (25cm vs 22cm) plus the greater internal space for the power supply (a 24V switching supply).
The concern now, though, is whether or not it would turn the machine into a puck destroyer. I don't know how much flow restriction there is in the Silvia group, so that's the main concern.
With the MaraX, it would have been a simple matter of adding a flow control device to the group, but I worry I may have to add a restrictor somewhere in the plumbing on the Silvia.
So - does anybody know if there's much in the way of restriction, or would rotary-ing this thing turn it into a water monster without additional mods?
UPDATE 2/14/23: I established this further down - there's about an 0.7mm flow restrictor in the solenoid valve seat. Flow rate is on the high side of normal at about 9.3ml/s at 9 bars.
I still have the pump, though, and with a Silvia Pro on its way to me, so that got me thinking: Can I make it work in the Silvia Pro? The space problem seems to be less concerning given the machine's slightly greater width (25cm vs 22cm) plus the greater internal space for the power supply (a 24V switching supply).
The concern now, though, is whether or not it would turn the machine into a puck destroyer. I don't know how much flow restriction there is in the Silvia group, so that's the main concern.
With the MaraX, it would have been a simple matter of adding a flow control device to the group, but I worry I may have to add a restrictor somewhere in the plumbing on the Silvia.
So - does anybody know if there's much in the way of restriction, or would rotary-ing this thing turn it into a water monster without additional mods?
UPDATE 2/14/23: I established this further down - there's about an 0.7mm flow restrictor in the solenoid valve seat. Flow rate is on the high side of normal at about 9.3ml/s at 9 bars.
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Just found this and thought it was a cool idea. Any luck with the flow restrictor and a rotary pump on the Pro?
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The main difference between the rotary pump and the vibe pump is that the rotary builds up pressure more quickly and maintains it more evenly than the vibe pump. You can adjust the pump pressure on the rotary pump, but its build up time is still shorter than the vibe pump. The faster pressure build up means you may lose some "pre-infusion" when you make espresso on the Silvia, but I don't see why it will necessarily make the machine a "puck buster." The Silvia group uses a 3 way solenoid and has a "jet breaker" just above the shower screen. I suppose you could reduce the chances of busting channels in your puck by using a puck screen.
I may well be wrong about this, in which case someone will correct me.
I may well be wrong about this, in which case someone will correct me.
- borrik
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What should be improved? What are the expectations from such upgrade?? Just to have Frankenstein machine with rotary pump inside?
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Wow, coming back to this after a hot second. Turns out it does have a flow restrictor inside the solenoid valve, I believe about 0.7-0.8mm orifice. This would explain its substantially lower water debit than the original Silvia (mine maxed out at 6.7ml/s vs the regular Silvia being more like 8-9ml/s).
The Linea Mini being a primary example of this where it runs at about 16.7ml/s at 9 bars with the 0.8mm gicleur, which is very high.
Actually, yes! I've just about finished the project. Just waiting on a new hose gasket.Caffeinesweats wrote:Just found this and thought it was a cool idea. Any luck with the flow restrictor and a rotary pump on the Pro?
Noise, primarily. DC motor rotaries are much quieter (and easier to damp) than vibration pumps.borrik wrote:What should be improved? What are the expectations from such upgrade?? Just to have Frankenstein machine with rotary pump inside?
Too high water debit can do odd things to a puck. Basically it makes it way less forgiving with regard to puck prep because of the extremely fast head fill and pressure ramp.Pressino wrote:The main difference between the rotary pump and the vibe pump is that the rotary builds up pressure more quickly and maintains it more evenly than the vibe pump. You can adjust the pump pressure on the rotary pump, but its build up time is still shorter than the vibe pump. The faster pressure build up means you may lose some "pre-infusion" when you make espresso on the Silvia, but I don't see why it will necessarily make the machine a "puck buster." The Silvia group uses a 3 way solenoid and has a "jet breaker" just above the shower screen. I suppose you could reduce the chances of busting channels in your puck by using a puck screen.
I may well be wrong about this, in which case someone will correct me.
The Linea Mini being a primary example of this where it runs at about 16.7ml/s at 9 bars with the 0.8mm gicleur, which is very high.
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Further update:
With the pump (a Procon 61R1FBF2ZAP - a mag drive 15gph with a brushed DC motor integrated) attached and leak free, the water debit appears to be about 9ml/s - high, but not out of the realm of reasonable. It's also substantially quieter.
With the pump (a Procon 61R1FBF2ZAP - a mag drive 15gph with a brushed DC motor integrated) attached and leak free, the water debit appears to be about 9ml/s - high, but not out of the realm of reasonable. It's also substantially quieter.
- borrik
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Congratulations for the successful upgrade, but DC motor, switching power supply.... Just curious, why these parts were chosen for the upgrade? Why not AC pump?
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First, I got the pump stupid cheap - about a hundred bucks on ebay, open box unused. Second, the DC motor models are substantially smaller, like barely larger than a vibration pump. From the outside, you can't even tell anything has changed, until the pump doesn't shake your entire kitchen. Third, DC motors are even quieter than AC induction motors because they don't hum.
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This was really cool to come back to. Well done! I might have to keep my eyes peeled for a cheap rotary pump myself.
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So, I ended up replacing the steam fill pump with that one rotary too. It's nearly silent now, which is great(!).
I ended up adding a 2 way solenoid and a second relay for the steam fill circuit (this machine has 2 vibration pumps stock, so replacing them both with 1 pump was a little tricky).
I ended up adding a 2 way solenoid and a second relay for the steam fill circuit (this machine has 2 vibration pumps stock, so replacing them both with 1 pump was a little tricky).