Building a lever machine.... from scratch - Page 52

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Marcelnl

Postby Marcelnl » Jan 14, 2019, 8:08 pm

bidoowee wrote:All you wanted to know about chrome but were afraid to ask.

Complicated? Nah! Laborious? No!! Who the &*$& came up with that as an idea for a commercially viable industrial process?


it works though, as clearly indicated by the fact that some chrome plating looks great after approximately 50-60 years of protecting the base metal..
LMWDP #483

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arcus

Postby arcus » Jan 15, 2019, 1:02 am

bidoowee wrote:In other news and although there isn't anything to actually see as a result, production on the first batch of machines has officially started :)


That's awesome! Congratulations!!

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bidoowee

Postby bidoowee » Jan 15, 2019, 9:39 pm

Marcelnl wrote:it works though, as clearly indicated by the fact that some chrome plating looks great after approximately 50-60 years of protecting the base metal..


Oh yeah - there is no doubt that it works! It is an old-school technique that reached its apogee with the excesses of the post-war American auto industry: acres of Jetsons-esque sheet metal, fins and shiny things for a time when steel, gas and asphalt were cheap as dirt.

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Which is not to say that I don't love it but I have to agree with Paul Pratt when he says that chrome is outmoded as an industrial finish. Apart from the fact that it is labor-intensive, it is really not so hot from an environmental point of view. Brass however, still has to have some kind of coating to prevent the inevitable discoloration. And besides, this project is nothing if not old-school ;)

Marcelnl

Postby Marcelnl » Jan 16, 2019, 6:24 am

agree on that, though it seems that many people do not include longevity in their concern about environmental aspects of things...I'm pretty sure my Urania or Faemina do less damage overall than my next door neighbour using a all in one with a lifespan of pretty much 2-3 years.
Same discussion would apply to chrome, what other coating is available that will withstand up to 60 years?
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OldNuc

Postby OldNuc » Jan 16, 2019, 9:40 am

Nickle plate predates the use of chrome. Chrome is brittle and prone to cracking, nickle is flexible. Cracked chrome no longer protects the base metal and rusting under the plating progresses rapidly.

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bidoowee

Postby bidoowee » Jan 16, 2019, 4:39 pm

Marcelnl wrote:agree on that, though it seems that many people do not include longevity in their concern about environmental aspects of things...I'm pretty sure my Urania or Faemina do less damage overall than my next door neighbour using a all in one with a lifespan of pretty much 2-3 years.
Same discussion would apply to chrome, what other coating is available that will withstand up to 60 years?


This is an excellent point that raises some interesting questions. I absolutely agree that it is vital to consider longevity in any assessment of the environmental impact of a product. I suspect and would like to believe that you are correct in your assertion that a high-quality steam-age technology machine has a smaller total-lifespan environmental footprint than a contemporary value-engineeered disposable pod machine but I'm not sure. It is a very complex calculation to make. Assume for the moment that initial price is a good reflection of the real cost of the product both in terms of the materials and energy required to produce it and the long term environmental impact of that production in terms of pollution. This is obviously not a good assumption for a number of reasons: first, down-the-road environmental costs are rarely taken into account (for example, I think it fair to say that the real as opposed to actual cost of fossil fuel consumption is only now becoming apparent). Secondly, the retail price of the pod machine may not reflect the real cost of production or even the cost of materials and fabrication as it is likely sold at little to no profit or even as a loss-leader: its price is artificially low because the profit is made on the sale of the consumables i.e. the pods. A heroin vs syringe scenario if you will forgive the metaphor. Additionally, the economies of scale are entirely different: the pod pushers would like to see a machine on every kitchen counter and in every hotel room, whereas our steam engines were intended to sit on the bar at the café to serve everyone within walking distance. So, bearing that in mind, if we look at the cost-over-lifespan for the two different models at say $4000 to $5000 over 40 or 50 years (which is probably rather generous on average) and $200-$300 over 2 to 3 years (which if anything is a little ungenerous) we can see that there are at least similar in magnitude.

So if the real costs of the two models of machines are at least similar, what about the operating costs? Considered on a single coffee basis, the pod machine is much more efficient in its energy use than the steam engine. Bringing tens of kilos of metal and water to brewing temperatures requires 1300watts for at least one hour at, roughly, a 75% duty cycle. The pod machine is also 1300watts but requires a one minute preheat and a thirty second brew. That is a factor of at least 30:1 in favor of the pod.

Conversely, when one considers packaging, pods are an environmental catastrophe. I buy my beans in 1kg bags and the coffee to packaging ratio is something like 100:1. Pods contain 7-9g of coffee and probably a similar amount of plastic and or energy-intensive aluminum (a staggering 1:1 or perhaps 2:1 ratio!), almost all of which goes to landfill.

My guess is that it is possible that this last consideration outweighs the others.

What I meant when I said that chrome is outmoded is that there are alternatives that have similar longevity. Powder coat is one - which is under consideration. Replacing the brass with stainless steel is another - but then this would be a different project. What I do know is that, in grand scheme of things, it makes very very little difference if I use chrome or not simply because of relatively small number of machines that will be produced. If the companies that make machines aimed at people who are willing to pay $140/kg for low-grade Arabica cut with lowest-grade Robusta as long as it doesn't make a mess and George Clooney endorses it were to choose to use chrome, it would be a different story.

But I digress.

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bidoowee

Postby bidoowee » Feb 02, 2019, 2:37 pm

Moderator note: The Clooney conversation started a rabbit trail, so I moved it here. drgary

Ok, so my initial post on subject was intended to stimulate conversation about the ecological footprint of coffee machines. Instead we talked about Clooney and the N-word. Oh well :lol:

An update! After what seems like months (because it actually has been months) of tedious admin work, we're back making things again! The first order of business is setting up for production of the wooden tap handles. The handle is a tricky part for a number of reasons. First of all it is wood, which is just a hassle because of the dust. Second of all, because they aren't radially symmetrical (i.e. they have lobes), they can't just be turned on the lathe in a few minutes; rather, if you have been following this thread, you will remember that the final shaping is done on the mill. Thirdly, there are a couple of tolerances that have to be respected in the depths of the various bores so that the there is neither too much nor too little slop in the valve stem thread. Necessary modifications to said valve stem to allow the wooden handle to be installed require that the each valve be entirely disassembled btw. In fact, the tap assembly is a just a giant PITA and I should really just use the Fugly plastic handles that come with the Pavoni tap valves. But, as you also may remember, that would not be in keeping with the stubborn and uncompromising nature of this particular author.

So, motivations established, the first order of business is a better mounting system for the concentric radial vise (aka lathe chuck) on the mill table. The benefits of this are twofold: it leaves the regular milling vise free and, because it can just hang out on the mill, it is repeatable - it's always in the same place.

The lathe chuck is installed on my particular lathe with a clever system of cam-lugs which are removable and indeed have been removed from the chuck in the photo. The lugs go in the set of three large holes in the raised boss on the back of the vise and are kept at the correct height and orientation with three screws that fit in the adjacent smaller holes. It is a great system and it would be fantastic to be able to just drop the chuck onto an adapter plate on the mill, tighten down the lugs and away-you-go.

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Ain't gonna happen - way too much work. Instead, I'm going to do one of those "here's one I made earlier" tricks. This is a piece of 1/2" mic6 tooling plate aluminum from an old jig that just happens to already have a bolt pattern that fits the mill table. It has been used an ablative or sacrificial plate on various other projects and it is in need of a little (tough) love with a face mill.

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Several minutes of back and forth later: a nice, mostly rasa, tabula.

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Flipped over on the other side, it is time to cut some shoulder holes.

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And because it was quicker to change tools then to figure out why the CAM program didn't want to complete the actual bolt holes themselves, a quick drill program finishes up the machining.

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The three more-than-slightly-esoteric M10x1 fine thread bolts that required a special trip to see Steve at my favorite hardware store: HarSupCo.

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Esoterica installed we move on to further shop-made quasi-unicorns: low-clearance socket head cap screws that fit in the width of the plate. These were made for the original jig because the plate was too thin to accommodate the heads of the 1/2-13 screws - no sense in not using them again!

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A half-day's work later and now the chuck is properly clamped to the table.

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bidoowee

Postby bidoowee » Feb 10, 2019, 4:18 pm

Another week and I made.... a tap handle. Just the one.

Setting up for a production run of handles is a little bit more complicated than it was for the other wood parts that were made with good old-fashioned non-CNC machines. For starters, I had to add two new circuits to the electrical panel and run them to the control cabinet of the mill. One is for the high-speed spindle and the other is for the shop-vac that powers the dust extraction system. I want to be able to control them directly from the CAM code. What's a few wires more added to this collection?

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The magnetic contacter and SSR in the bottom left corner do the switching - no particular reason for those selections, just what was big enough for the job and that happened to be on the parts shelf.

The other gizmo required, if gizmo is the right word for this assemblage of almost garbage, is the dust extractor itself. I made this a while ago, but I'm not sure if I put a photo up here. Probably not as it is pretty embarrassing: scraps of (cracked) acrylic tubing, ABS pipe and nitrile rubber held together with epoxy and (two different kinds of) tape. But, boy does it work ;) The offset of the extraction tube creates a vortex in the main tube and not ONE speck of dust escapes. I make more mess making toast.

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The CAM programming is all about getting the cutter bit to engage the workpiece with the right load and so that the fibres of the wood grain are cut towards remaining material to avoid splintering.

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Clean as a whistle.

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That was a test piece of maple. Mahogany is the real deal.

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Once both the front and back bores are finished, the part goes onto a fixture jig and into the lathe for the exterior contouring. Before:

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... and about 30 seconds after. This operation would take 45 minutes to an hour on the mill and the surface finish wouldn't be anywhere close.

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Then, still on the same fixture jig, the part goes back to the mill for the final profiling.

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And yes, as you have probably already noticed, this is a new design! I had a think about the old design. I like the form; which is why I went to so much trouble to make it. But it really is problematic. Apart from the fact that it takes a long time to machine, has to be finished by hand and requires a modification to the valve stem, it is also hard to install. The tiny retaining ring requires special retaining ring pliers that I happen to own, but are pretty unlikely to be found in your average shop, let alone the toolbox in the cupboard under the stairs or in the garage. Note that the retaining ring rides on a washer that I lost down the back of the radiator in the kitchen while I was taking the photo; so washer not shown.

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This one is designed specifically for the modern Pavoni valve. The larger opening in the face allows a split or hairpin cotter pin to be used instead of the retaining ring. This is a much more robust design which installs without any tools at all (shown here before the final sanding and finishing).

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Here are the two designs, both oiled, side by side. I'm going to have another go this week at refining the new design a little.
Which one do you like best?

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LObin

Postby LObin » Feb 10, 2019, 6:02 pm

Love the new design!

The retaining clip is better and I like the shape and size of the knob better than the old one. From an aesthetic point of view, I kinda find the knobs look a tad small on the Aurora.
Plus, C-clips pins are always a pain to remove anyways. They should come with a "wear eye protection" warning!




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arcus

Postby arcus » Feb 10, 2019, 6:37 pm

The new design looks great! I definitely prefer the new style.