I found a good deal on some scrap 7075-T651 aluminum plate on eBay, so going to try that out for the adapter plate. 1.114" x 4.75" x 11.875" costed $30 shipped. I'm thinking scrap for this part would be the best way to go, since I don't think that thickness or dimensions are all that critical. Total mass will make some amount of difference in warm-up time, so after testing I may trim it down.

The same size from McMaster would have costed a bit more than $90 + shipping.

When do you expect to start construction? I'm getting impatient. Just kidding. Well no, not really

OldNuc wrote:My point, which has been missed, is you have almost unlimited preinfusion pressure control with a manual lever. The spring lever has a maximum pressure that may be manually reduced. Once you move on to hybrid levers then every design will be different and an attempt to automate what can be done with a manual or straight spring lever.

The manual lever was never routinely, if at all, used in a commercial setting either. The spring lever was an attempt to automate the process with existing technology.

My spring lever has a direct link from the lever to the piston. I can override the spring by pushing up on the lever and providing even more pressure than the spring could alone. I almost never have reason to do so, but I can if necessary.

TomC wrote:This doesn't give true pressure profiling. At best, it gives blind pressure profiling if you leave the lever down the whole time and just manipulate the pump (via the mod). But even with that you only have about 20 or so seconds before the pump times out.

The only pressure profiling the Strega can do with the pump is the pre-infusion ramp. Once the lever is released from lock, it's off the microswitch and the pump shuts off.

Could you deactivate the pump whatsoever and use line pressure for a preinfusion? This would be a repeatable way to manipulate the profile as well: you have the choice of straight line pressure or a slow ramp.

I feel like a thread should be started about commercial lever pressure profiling techniques. I've had some interesting results attempting to emulate Synesso's 2 stage preinfusion "ideal" pressure profile with my lever.

FJ60Cam wrote:When do you expect to start construction? I'm getting impatient. Just kidding. Well no, not really

I know! I'm getting impatient too.

I plan to start as soon as I receive major parts. Critical ones I'm waiting on are the group head from Germany (USPS tracking says it's in the ocean or in limbo...one day it will just show up)...and I'm waiting on Ascaso to send thermoblocks (and a few other parts, but mostly minor). They haven't even sent my order yet, I just hope they'll send it out soon.

Once I get the GH and TB I can determine fitting sizes. I'm probably going to go with US sized fittings and tubing, just because it's cheaper and I can get stuff local if I really need, I'll just get the 3 adapters I need to go from NPT to whatever BSPP or BSPT size is there. I love the metric system, but I'm not willing to pay a lot more to special order a roll of 6mm or 8mm tubing.

Those BSPP & BSPT are common hydraulic fittings and the adapters to 37 or 45 degree tube fittings are low cost. In case you have not found them.

Yeah I should be able to come up with the right fitting, but until I get the parts in hand I haven't been able to find the correct size. Documentation is just parts lists, no true spec sheets that I've been able to find.

GH looks to be 3/8 or 1/2", and guessing the TB will be 1/4" but again these are just guesses for now unless anyone can verify.

In lieu of parts, been playing around in 3D, I'm thinking in general that strut channel will be easiest to start with on the prototype.

Added in the hydraulics today to test fit sizes and fittings. This one was all planned with imperial (NPT and 1/8" tubing) compression fittings. But I have been thinking to switch to metric tubing, solder ferrules and BSPP threads. Advantages of compression is that soldering isn't required, but downside is that they don't like to be over-tightened and if moved too much can leak.

I'm not certain which route to go, as far as cost, though compression fittings are usually more, because I'd have to special order the metric stuff and British fittings, I think it will come out about the same.

Right now the lower box will house electronics like Arduino, and will plan to wrap the hydraulics in a Acrylic clear box to give the regulator and pressure gauge places to "mount".

Bottom right is line inlet, OPV is in the center bottom, and you can see the Velox style "mystery tube" come out the front from the OPV. Most machines use a plastic tube here, but I think copper will look cooler. The real "mystery tube" is just to the left of the TB on the outlet, this is a 1/8" NPT connection to allow a thermocouple probe to be inserted inline and read water temp.

have you thought about threaded rod for the vertical supports? woops - edited due to saturday night engineering woops. threaded rods would deflect too much