Expobar Brewtus II rotary conversion

Need help with equipment usage or want to share your latest discovery?
godlyone

Postby godlyone » May 27, 2009, 9:43 pm

Hi guys, I am in the process of converting the brewtus II to having a rotary pump.
Many of you have seen my thread on the harsh espressos I have been getting and I hope this will improve the taste.

Before you start saying there is no difference, I feel as if the vibe pump is unreliable. I had a few times where I hit the brew switch and nothing happened. I tried again.. nada. After unplugging the machine and power cycling (turning on and off a few times) it started to work again. Other brewtus users have reported the same thing. Also I have a feeling that the pressure is fluctuating during extraction as I sometimes see the needle moving.

Either way, the machine will be quieter and not have a stagnant tank of water in it.

So I have a procon pump which I got from ebay
part# 111A125F11AA
rated at 250psi and 125gph (way overkill I know) but it only cost 30 bucks brand new.

I gathered the parts to go from the carbon filter to the pump, and now need to get the parts to go from the out side of the pump to the espresso machine.

I also need to get a motor. I don't think it will fit inside the machine, so I am going to have the pump/motor be external. To go from pump to machine I think a 3/8 to 1/4" line will work (anyone confirm this)?

But I also wanted to ask what kind of motor I should get? Is 1/3hp enough? 1/4?

Also which rotation do I need? CCW?

Thanks again - will post pics during install!

User avatar
erics

Postby erics » May 27, 2009, 11:11 pm

I would tell you that you are headed for trouble. That pump is so oversized for espresso machine use that you may very well NOT be able to tune it down. A short visit to the Procon website will reveal a lot: http://www.proconpumps.com/index.htm
I am not too familiar with Procon code numbers but the most common Fluid-O-Tech pump used for our espresso machines is a model No. 054. My suggestion would be to contact these guys: http://www.jcbeverage.com/index.html and see if they have a motor pump combo you can trade in on with the idea being to get the Procon equivalent to the Fluid-O-Tech 054 or, for that matter, a motor and rebuilt FOT 054.

Your intermittent vibe pump problems may very well be a slightly maladjusted brew switch.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

godlyone

Postby godlyone » May 28, 2009, 12:24 am

couldn't I just use the OPV to further turn it down to whatever pressure I wanted?

From the procon website my part number shows that it can be tuned from 151 to 250 psi.

Could I set it to 151psi and then set the OPV to whatever pressure I wanted?

I did send them an email though.

Thanks

hperry

Postby hperry » May 28, 2009, 12:58 am

w/o equivocation your problem will not be solved by going from a vibe pump to a rotary. The problem will continue to exist after you change. If I were going to change, why not use the Brewtus unit? Regardless, you are headed down a blind alley.
Hal Perry

godlyone

Postby godlyone » May 28, 2009, 1:05 am

Well I wanted to make the change even if that does not solve the taste issue.

My question is whether the pump I have would work and what motor would be good for it?

I did email the Brewtus folks to ask if they sell a conversion kit.

Thanks

User avatar
erics

Postby erics » May 28, 2009, 1:08 am

No, because there is too much flow involved. The "OPV" in a rotary pump equipped machine is more properly termed an expansion valve because it is (in that capacity) there to relieve pressure due to thermal expansion in the hx. In your case it would be the brew boiler and small hx in the steam boiler.

The relief/regulating valve in the rotary pump is there to bypass a substantial portion of the pump's flow from the discharge port back to the suction side of the pump.

In addition to all of this, you still need a relatively high hp motor because the pump flow characteristics have not really changed much - they are just redirected.

Your best bet is to duplicate EXACTLY what the BIII-R has installed, both from an electrical and hydraulic standpoint.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

godlyone

Postby godlyone » May 28, 2009, 3:05 am

I did a little bit of googling and found this:

http://www.engadget.com/2006/08/08/how-...o-machine/

That and other posts I've seen (here and coffeegeek) say that even though procon says this pump is only adjustable from 151-250psi, it can easily be set to 130 psi.

So what size motor would be ok? On the site above it seems that they use a 1/3HP GE motor.

godlyone

Postby godlyone » Jun 06, 2009, 12:19 am

I'm still trying to decide between keeping this pump or getting a smaller one as advised.

Does anyone know where to buy a pump/motor combination? Ideally small enough to fit in the brewtus, but if that's not possible it could be external

karmacafe

Postby karmacafe » Jun 06, 2009, 9:49 am

I recently replaced a procon pump in my Astoria one-group with a Fluid O Tech pump and bought it directly from them.

http://www.fluid-o-tech.com/contactus.html

I got the PA1504 and Shawn said it was a popular pump for espresso machines but they also have a compact series if you are worried about space. Buying it direct was much less expensive than buying it anywhere else.