Open Source Lever Project - Page 30

A haven dedicated to manual espresso machine aficionados.
EspressoForge (original poster)
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#291: Post by EspressoForge (original poster) »

Started drilling my 7075 aluminum plate. Here is the printed template I'm using:
http://espressoforge.com/wp-content/upl ... uminum.pdf

Since I don't own a mill or drill press, I'm doing this by hand! Dimensions aren't so critical, and aluminum is pretty soft so it hasn't been a big deal so far. My procedure is:
  1. Lay template over stock
  2. Use a center punch or nail to mark and make pilot marking
  3. Use a 1/8" drill bit and drill pilot holes w/ WD40 as coolant and working slow (4 holes nearer to center to mount the grouphead don't need to go all the way through, but they can)
  4. Use a 1.25" hole saw for center hole
  5. Group holes will be M8x1.25 tapped, since I have tapping hardware this will make the backside a little cleaner than adding washers and nuts and I believe will be plenty strong since the plate is 1.11" thick
  6. Outside holes are for 3/8" stainless hardware and will be through-holes. Will be using fiberglass washers to help insulate the plate from the frame.
To drill the big hole it did take me a while, probably just under 10m, but I took some pictures and did it slow, I also did it over 2 sessions as I didn't want my drill to get too hot from the torque required.





Not the prettiest, but will get the job done.

EspressoForge (original poster)
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#292: Post by EspressoForge (original poster) »

HB member hankua has offered me a bottomless portafilter to use for the project. Will let me gather Scace (which I already a v1) on the unit one I get out set up, hoping by next weekend to have most of the parts for testing.

OldNuc
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#293: Post by OldNuc »

A good drill press and new 135 degree coated drill bits make that a much easier job. If you have to drill with a hand held drill be sure to use new bits and the correct cutting oil, WD-40 is not cutting oil and kerosene will work better and is cheaper.

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#294: Post by EspressoForge (original poster) replying to OldNuc »

Yes definitely agree. A drill press makes sure your holes will be square and not kill your back. I have lots of cutting oils, but wanted to show that with a new hole saw ($11) and a hand drill, this could be done. But investing in better tools makes the job go faster. With the right tools and work bench, this whole plate could be drilled and tapped within an afternoon. With hand tools it can be done, but will take you that much longer.

I'm planning on making a move in the next year or so, once we do that I've been wanting to get an old Bridgeport for prototyping, maybe a lathe as well.

Hand tapping is also kind of fun, I like seeing threads being made, and M8 into aluminum is very easy. 3/4" NPT into aluminum wasn't so easy by hand!



OldNuc
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#295: Post by OldNuc »

A good condition Bridgeport is very expensive and a worn out Bridgeport is just expensive.

EspressoForge (original poster)
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#296: Post by EspressoForge (original poster) replying to OldNuc »

Thanks for the advice, I'm sure there are other options, but the last I checked it was old Bridgeport vs new Chinese. Nothing good in life is cheap...I wonder how much money I've spent on coffee...

Got the group test mounted. Looks good, I like the 8mm bolts, makes leveling the lever easy. 10mm bolts may work, but they barely fit through the group holes and would mean drilling and tapping must be perfect. I could have special ordered stainless Allen key bolts, but picked up these stainless hex head bolts a lot cheaper locally.


OldNuc
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#297: Post by OldNuc »

Yes, first step is to get it to work then the 2nd step is to make it look good. The 10mm polished SS allen bolts would definitely look better.

The Mini mills are relatively cheap and that plate can be machined in one of them with no major hassles.

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pizzaman383
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#298: Post by pizzaman383 »

EspressoForge wrote:Got the group test mounted.
<image>
That looks familiar :D
Curtis
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“Taste every shot before adding milk!”

EspressoForge (original poster)
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#299: Post by EspressoForge (original poster) »

OldNuc wrote:Yes, first step is to get it to work then the 2nd step is to make it look good. The 10mm polished SS allen bolts would definitely look better.

The Mini mills are relatively cheap and that plate can be machined in one of them with no major hassles.
Unfortunately for me, I don't and wouldn't often need to mill aluminum. I'd need something capable of stainless, but I think a lathe may work out better than a mill for me.
pizzaman383 wrote:That looks familiar :D
It should! I took a lot from your build thread. Mounting method to my frame will be a bit different is all. If the direct method doesn't provide enough heat, I'll be adding cartridge heaters to the plate like you did.

I also just got a cheap piece of scrap 7075 aluminum which came much thicker than I planned, what was your copper plate dimensions?

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pizzaman383
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#300: Post by pizzaman383 »

EspressoForge wrote:
It should! I took a lot from your build thread. Mounting method to my frame will be a bit different is all. If the direct method doesn't provide enough heat, I'll be adding cartridge heaters to the plate like you did.

I also just got a cheap piece of scrap 7075 aluminum which came much thicker than I planned, what was your copper plate dimensions?
My copper plate is 4"x6"x3/4". I used copper because water was going to flow through it. I wish I had thought to use a feed tube like your design. The aluminum plate would be better for heat transfer.

There is significant heat transfer from the plate to my frame. I didn't insulate the bolts or the horizontal plate-bottom support and they bled a lot of heat in those spots.
Curtis
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“Taste every shot before adding milk!”