mhoy wrote:The part number is stamped into the brass and I can't read it.

47702

Mark, I think that your pump is aftermarket. Judging by the look of your machine before you gave it some love, I am sure it went through a pump replacement. I think that Elektra pumps all have a custom sticker over the bearing/shaft cover, that has their logo on it:



I believe this is a Rotoflow (Fluid-O-Tech) pump, but I am not sure. Stefano, do you know?

My machine is still in pieces. I've been busy helping a friend work on his car (putting a late-1990s M3 engine into a 1980s 325i... he will be driving well over the speed limit if he ever finishes it!). Today, he cut my beat-up portafilters out; now I have two nicely cut (on a rotary table) bottomless Elektra portafilters. I also got to put the portafilter handles on the lathe and have a go at them. They have a couple of minor scratches that would require a lot more work than I care to do to get out, but they look super-glossy after a little time at ~1800 rpm covered in high-gloss polishing compound. I also got some MAAS polish and have been buffing my metal pieces. Tomorrow I hope to finally touch up the frame and make my insulation template.

P.S. This is one of the most amusing things I have seen today:

mhoy wrote:http://www.adernet.com/hydropure/

Led Zeppelin in MIDI. On a professional web site. Willy Nilly. Classic.

shadowfax wrote:I believe this is a Rotoflow (Fluid-O-Tech) pump, but I am not sure. Stefano, do you know?

Since it is physically identical to the brand new Rotoflow/F-O-T pump I just received the other day I would say that's a pretty good guess.

Has anyone opened one of these up to see what they use for a seal on the output shaft? There seem to be a number of these pumps leaking within 1-2 years which isn't much of a service life.

John,

Which part do you want to see? The shaft area? It appears to turn on a sealed bearing at the point where you can see the pump shaft enter the pump body. I am going to assume that this is not a pressure-bearing bearing, though. IIRC, there are several bearings (more than 2) on rotary pumps.

I wish I could take my old one apart. Unfortunately, it seems to be secured by a lid that is threaded on and requires a special tool to remove. I might be able to rig something up to do this job, if my machinist friend has time to lend a hand.

The Elektra is back together. I haven't had a chance to snap any pictures of her with her cover and lid on yet, but you can see the pictures on my Flickr Set, along with descriptions of some of the obstacles I came up against.

you can see that my bent tap lever replacements went well; now I have straight steam/water tap handles!



I've also insulated the boiler with good old melamine foam. Seems to be working well so far, it keeps the thing a little tame in terms of heat dissipation:



One thing that is rather disappointing is how difficult it is to tame the rattling on this machine. The pump really gets the whole frame vibrating, and I had a heck of a time finding vibrations and padding them.

After all that, now I can hear the end of the water dance distinctly, at least. That's a plus. In the future I can really, really see myself looking into mounting the pump externally, on massive rubber feet.

The espresso has been horrible so far. That's disappointing, but not surprising. I haven't had enough coffee to make very much until this evening, and I've been preoccupied with silencing her a little bit. I think I overflushed at first, and the Robur seems to be set way too tight, even at a light dose. The pump pressure is registering 9.5 bars against a blind filter basket... That seems like it's on the high end, so it surprises me that I would need to loosen the grind vs. Vetrano. With this high flow rate pump and lack of preinfusion, I would have guessed quite the opposite.

The one thing that is quite funny is that all the pours have been nearly picture-perfect, albeit super-ristretto slow. I was worried that Elektra would coax some ugly pours out of the Robur. One of the first ones had some minor channeling late in the shot (just flourishes, no spritzes), but that's to be expected, I think, from a 50 second shot. This is encouraging to me--I have some hope that once I get the brew pressure set right and get the hang of flushing technique for this monster, I will have no trouble getting superb shots.

One potential pitfall in my learning this machine is the pressurestat. It seems to have a deadband of 0.3-0.4 bars. I'd rebuild the thing, but at this point I think I am going to live with it until I can set my PID up. I have the Fuji PXR3 and an SSR. I'm working on getting a Swagelok fitting to mount the TC in the boiler, based on Eric's excellent help, so hopefully that will be done by the end of the month at the latest. I also need a project box, a heat sink for the SSR, and to decide on where to mount the PID box (and what box to get, for that matter).

This is shaping up to be a fun project. Certainly a number of frustrations, but I think ultimately this will be more fun for me than just getting a brand new machine.

shadowfax wrote:One thing that is rather disappointing is how difficult it is to tame the rattling on this machine. The pump really gets the whole frame vibrating, and I had a heck of a time finding vibrations and padding them.

I found that my pump was slightly touching the back frame, I moved the frame vs the pump and it now clears by the width of two playing cards. It's now WAY quieter.

I also placed small pieces of rubber where ever loose parts come together. Drip tray, under drip tray, top covers, etc. Cork may work better as I found that one of the plastics I picked has a melting point around that of a hot espresso machine.

Mark

shadowfax wrote:the Robur seems to be set way too tight, even at a light dose. The pump pressure is registering 9.5 bars against a blind filter basket... That seems like it's on the high end, so it surprises me that I would need to loosen the grind vs. Vetrano. With this high flow rate pump and lack of preinfusion, I would have guessed quite the opposite.

Lack of preinfusion requires coarser grind, in my experience. High pump pressure also has a slight tendency to require coarser grind.

Beautiful job you're doing.

PS: Will the plastic cable ties used to hold on the insulation crack and fail in the heat?

mhoy wrote:I found that my pump was slightly touching the back frame, I moved the frame vs the pump and it now clears by the width of two playing cards. It's now WAY quieter.

I also placed small pieces of rubber where ever loose parts come together. Drip tray, under drip tray, top covers, etc. Cork may work better as I found that one of the plastics I picked has a melting point around that of a hot espresso machine.

Mark

Dan K. mentioned in an old post that one of the main sources of vibration was the cover under the drip tray and he was right. I've put some rubber between the end part (furthest away from the front of the machine) of this cover and the incoming water hose and it made all the difference in the world.

Is the motor/pump assy rubber mounted on the Elektra?

shadowfax wrote:John,

Which part do you want to see? The shaft area? It appears to turn on a sealed bearing at the point where you can see the pump shaft enter the pump body. I am going to assume that this is not a pressure-bearing bearing, though. IIRC, there are several bearings (more than 2) on rotary pumps.

I wish I could take my old one apart. Unfortunately, it seems to be secured by a lid that is threaded on and requires a special tool to remove. I might be able to rig something up to do this job, if my machinist friend has time to lend a hand.

I'd like to see what it looks like inside, how they keep the water from leaking out by the shaft & if the seal is replaceable. If you don't use it & wouldn't mind sending it up to CT. I could open it up & post some pics. I have some adjustable pin wrenches so removing the cover shouldn't be a problem. It would be interesting to see what kind of damage, if any, these pumps suffer when they get scaled up inside. If its not a big deal to remove the cover opening them up for a thorough cleaning when they get scaled up should accomplish more then just pouring some solution in & hoping for the best.

JohnB. wrote:Is the motor/pump assy rubber mounted on the Elektra?

Yes. You can vaguely see the right side mount in this picture:



The pump motor is mounted on 2 brackets that are formed from cutting and bending the frame inwards. There's a thick, round rubber gasket that fits between the motor and the mounting bracket. I would need to procure or manufacture my own mounting system to outboard the pump, though.

As far as the pump is concerned, I think I am going to keep it for myself. I will try to take it apart and post pics later in the month. After that I hope to get it rebuilt and keep it for a spare. In the meantime, this picture from a post by Dan might help:



It's a procon pump, but I would be surprised if the internal differences were particularly significant between this and a F-O-T pump. It appears to be sealed by the inner 2 bearings which are compressed by that spring-loaded assembly labeled "mechanical seal assembly."