Well, you should have contacted me because I switched over to the stainless MGFR with the 4 mm gears and (hopefully) built-in relief valve. I may very well be able to add to the order.

edit - and would be happy to do so.

Hi, Jacob.

I've talked directly to Fluid-o-Tech USA. But they could ship it to a friend that is in NY and coming back to Brasil at next week.

I know that one doesn't need much information to ship goods to Brasil, as customs here just wanna know the value of the package to charge tax and I would have to pick the package there and pay in cash. But I don't know how is the procedure to ship something to your country.

I don't have the pump yet, but I have pictures (very good friend this one!):







Very small, but indeed the 24V power source will require more space. The pump and motor itself could fit most vibe pump housing depending on the machine. As I think about playing with it outside the machine, no problem.

Márcio.

Just to add some info, this is what I got from them, about 200 x 300 and flow:

The difference between the 200 and 300 is just the seal method. The 200 series is much more commonly used than the 300, and is a little bit cheaper. It should be adequate for your application. It's tough to extrapolate out the flows at such low rpms and high or varying pressures, but I have an estimate. At 500 RPM and 0 psi, you'd get about 10 L/h. But you would need around 1500 RPM just to get 0 flow at 130 psi (meaning all the flow is slipping through the clearances of the pump and the outlet is completely closed off). So to get a small flowrate at 130 psi you'd need greater than 1500 rpm. The slope of the flow/pressure curve changes with RPM too so that makes estimations hard. Also, the .3 ml per revolution is approximately correct, but as pressure increases, more and more of that flow ends up slipping backwards through the tiny clearances in the pump. So you might be OK just using the varying RPM's and internal slip to help you achieve the varying profile you want.

About the relief valve, I had to buy this one they keep in stock as this friend could bring to me, so no bypass (and I would prefer BSP ports, but not mandatory for a home prototyping device). As I've said, I plan to put one externaly for safety reason - to limit the pressure line if anything goes wrong on the control.

Márcio.

erics wrote:Well, you should have contacted me because I switched over to the stainless MGFR with the 4 mm gears and (hopefully) built-in relief valve. I may very well be able to add to the order.

edit - and would be happy to do so.

Eric, how do I contact you? I would be very interested in a "turn key" product to add to me single group Linea!

Eric, how do I contact you? I would be very interested in a "turn key" product to add to me single group Linea!

Mitch - my email address is right below by sig.

Unfortunately, there is no such thing as a "turn-key" product. FOR EXAMPLE, F-O-T USA has, in stock, pump/motor units with no bypass. These come in a cardboard box and THAT's IT. In this particular case, I opted for the pump having a built-in bypass because that is what I am accustomed to in a previous life - hence the 4 week delay in getting pump/motor units from Italy.

Now I happen to have some wiring diagrams (pdf doc) graciously sent me by F-O-T USA which I offered to pass on a few posts ago and available for the asking. This endeavor is slotted for the "adventure" department.

Carneiro wrote:Hi, Jacob.

I've talked directly to Fluid-o-Tech USA. But they could ship it to a friend that is in NY and coming back to Brasil at next week.

Thanks Márcio

This tells me that I can't do this all by my self, so big thanks to those I were in contact with yesterday

erics wrote:The only drawback I see to this pump (either FG100 or MGFR) is the size of the "typical" 24VDC power supply - it is about twice the footprint of the pump/motor unit.

When will you guys turn your pump-motor power supply on and off?
I have a 5A switched-mode power supply that I'll use for a start. I don't like the big inrush current so I don't like the idea of turning it on and off every time the motor goes on and off. I hope a SMPS will draw a low standby current?

When will you guys turn your pump-motor power supply on and off?

The pump-motor power supply (120-240 VAC to 24 VDC) should not be switched on/off by means of the input AC voltage. I received that response from these guys - http://www.trcelectronics.com/ .

Rather, the DC output should be switched and this would be done with either an appropriate SSR or electro-mechanical relay. In this manner, the autofill circuitry is not affected. But, I would defer to someone a little more electrically knowledgeable than I on that one.

Does anyone have an idea about how to control the speed of the pump? Is is possible to get a slider to control speed much like a paddle?

mitch236 wrote:Does anyone have an idea about how to control the speed of the pump? Is is possible to get a slider to control speed much like a paddle?

Both the TMFR pump and all the gear pumps I have seen at least have options to have a 0-5V control input that sets the speed. In the case of my TMFR pump, there's an on-off signal separate from the 0-5V signal, meaning that 0V will deliver the minimum pump speed if the pump's on-off signal is on. From drawings I have seen of the gear pumps, it looks like they have no distinct on-off signal, and turning the pump to 0V will turn it off entirely.

To push a signal to this, you'll need either a PID that has an analog 0-5V output, or you can make your own with a 5V power supply and a potentiometer or rheostat. On my setup, this is basically a "volume" knob for pump speed (indirect pressure control), like you can see here.

I had a chance to check out the La Marzocco USA offices/warehouse/showroom when I was in Seattle a week ago. They showed me the controller that they use, and from what they said you couldn't exactly wire it straight to the gear pump: in the Strada EP's case, it connects to a brain box that interprets the signal in some way to translate it as input to their profile recorder, PID, and whatever else. The guy I talked to didn't appear to be an expert on the machine, though (most of the company was in Milan for Out-Of-The-Box), and it may be that this thing could be repurposed on the top of a standard GS3 and wired into a custom, directly-coupled, manual pump setup.