Newer posts are loading.
You are at the newest post.
Click here to check if anything new just came in.

May 27 2020

Online: Intro to Machine Sewing (Pay-What-You-Can) on Sat, Jun 6

May 26 2020

Audio Output Switcher

At my desktop computer, I switch back and forth between speakers and headphones several times per day, depending on what I’m listening to and whether my toddler is asleep across the hall. Obviously I could just plug/unplug the headphones as needed, but that’s a lot of cycles on the audio jack, and leaves me scrambling for the end of the headphone cord every time I want to plug it back in. Plus, I run my headphones through an external amplifier, so there are a lot of cords involved and some of them are pretty buried. For a long time I handled this switch in software – I ran my speakers from the motherboard audio and my headphones from a PCIe sound card. Some drivers will even let you soft-assign jacks to different outputs, which could save you the second sound card. Then switching devices is just a matter of two clicks in the OS system tray or menu bar.

Software switching works pretty well, but it has a few quirks. Most obvious is that it’s hard to switch devices while you’re running a full-screen program like a game. And even once you switch, some programs won’t actually recheck that setting until they’re relaunched. Finally, I’ve been doing a lot of video conferencing and voice chatting lately, and a lot of those programs completely ignore the system-wide setting and provide their own device selection, which means poking through unfamiliar menus.

In the end, I decided to make my own switch box in hardware.

This is a silly project. You can buy these things on Amazon for $10 or $20 and you’ve got your choice of 1/8″ TRS or RCA jacks, with or without a volume knob, with anywhere from 2 to 8 outputs. But if you don’t immediately see the appeal in spending all day building something you could have bought for less money, I can’t explain it to you. Besides, I wanted a stereo/mono switch for those times I encounter a low-quality video on YouTube with all the audio on one channel, and none of the commercial models offer that.

Project Box

I bought a small aluminum project box that happened to match one of my amplifiers, and got to work making it fancy.

First, I laid out the front and back panels in Inkscape so I could easily transfer them to the laser cutter. Our 45W CO₂ laser can’t cut aluminum, but it can usually bleach the anodizing to make very crisp markings.

I started with a test etch on a piece of plywood so I could make sure I had the settings and positioning right.

Once I got an engraving path I liked, I stuck the aluminum panels in the laser and… nothing.

Whatever dye was used in this anodizing proved very resistant to the laser. Even after an agonizingly slow full-power pass, there was a shadow of an image too faint to even photograph.

Instead, I wrapped the panels in blue painter’s tape and burned the labels through that. Then I lightly sandblasted the mask.

I didn’t get good photos of this process, because I was frustrated and scrambling for ideas, and wasn’t really sure it would even work.

After peeling off the tape and giving them a quick rinse, this is what I ended up with.

Not bad at all.

Electrical

Now for the electrical. You can sometimes get away with converting a stereo signal to mono by just tying the left and right channels together, but this can behave unpredictably when the channels aren’t producing the exact same waveform. It’s better to use a resistor network to make sure the load is always safe for the equipment; I based mine on the summing design here.

Because the resistor network adds a small amount of attenuation, I sketched out two possible circuits. The first option bypasses the resistor network in stereo passthrough, ensuring there’s no loss in quality for the setting I’ll use most often. The second version always leaves the resistor network in place so there’s no change in attenuation when switching between stereo and mono – I understand this can sometimes be useful in audio mastering. It also requires one less switch contact (though you can trim the other circuits down as well, if you don’t insist on switching the ground path like I did – I figured this would help avoid any issues with ground loops). If I had used this option, I would have wanted to make sure my resistors weren’t inductive or capacitive. I understand metal film resistors at these values should be okay, but I didn’t look into it very far.

It’s worth noting that this only works on line-level signals, before the amplifier. If I used my computer’s audio output to drive headphones directly, I would probably have needed to forgo the mono summing and just wired up the A/B switch.

I ordered some isolated RCA jacks and some 3PDT switches, and started hooking everything up. The actual values of the resistors aren’t at all critical, but it’s very important that the left and right channels are well matched. My stash of cheap “1%” resistors are more like 2% at best, so I used a multimeter to pick the closest matching pair I could find.

Finished!

And here’s the fully assembled box. I laid out my panels based on some other audio equipment I had sitting around, but it turns out my RCA jacks in particular had hexes and washers that took up a lot more space than I’d accounted for and covered my labels. This is a minor annoyance at this point, and it’s on the back panel where I don’t see it. I’ll probably replace the panel eventually, but it’s fine for now.

Sponsored post
soup-sponsored
Reposted byLegendaryy Legendaryy

May 20 2020

(Online) Arduino: Sensors and Input/Output on Sat, May 30

May 19 2020

Towelday Online – 25. 5. 2020 19:42h

Die Raumstation c-base unter Berlin Mitte ist weiterhin geschlossen. Aber: Keine Panik!

Der Towelday wird dieses Jahr bei uns im Netz gefeiert. Genauer gesagt über den Kanal jitsi.c-base.org/maihall. (Eventuell gibts parallel noch einen zweiten Stream – ohne Rückkanal – als Backup)

Vorbereitung ist natürlich das A & O: Klar, das ein oder andere Handtuch hat man sowieso neben dem Laptop liegen und den Bademantel haben die meisten wahrscheinlich in wochenlanger Home-Office-Manier schon lange nicht mehr abgelegt. Für den Frottee-Feiertag sollte man allerdings noch seine Lieblingsausgabe des ultimativen Reiseführers zurechtlegen. Allen, die zu diesem Event einen Original Pandemisch-Pangalaktischen Donnergurgler (TM) geniessen möchten, gibts am Ende des Posts eine Zutatenliste zum herunterladen. Jeder sollte sich also die Ingredenzien besorgen und dann wird das Mix-Ritual gemeinsam und zeitgleich aber lokal getrennt vollzogen.

cocktail_construction_chart_1974, Wed Apr 07, 2010, 9:34:58 AM, 8C, 4810×7098, (1687+1659), 100%, archivescurve1, 1/60 s, R52.9, G37.1, B50.8

Fröhlich beschwingt und gut gestärkt kann es dann losgehen mit dem Vorlesen Eurer Lieblingspassagen, Gruppenphotos und anderer Anhalter-bezogener Folklore.

Also, legt Euch alles zurecht, baut Euch einen stilvollen Video-Hintergrund, schlüpft in Euren Lielingsbademantel und gesellt Euch am Montag den 25. 5. 2020 ab 19:42 in den Jitsi-Kanal. So long, Zaphod Beeblepunc!

May 15 2020

There is a new Samco 60 ton 60” full beam press at MMS

Remember last week when we told you that there was a new press at MMS and we would give you photos and videos this week?

First, we have to tell you why having this press is so great.

Visors

A donor – Kapco Metal Stamping, cut a bunch of visors for us for the face shields we are making and donating. A BUNCH. You know this is kind of a pain in the neck for a company – they have to set up their machines and they have to send their people to work on the project and it’s not something that makes money for them. It’s just a really nice, generous, wonderful thing for them to do. But we cannot ask them to do it forever.

We had to find a longer-term solution.

Die

We needed our own die. Apple Die made it for us. It’s pretty! It’s so simple and elegant.

Here’s some detail – this is where it punches the holes where the visor attaches to the frame.

But you can’t just use your hands to mash a piece of plastic on top of a die to make a visor unless you want a lot of blood on the visor, which you do not because then you can’t see out of the visor, which defeats the whole purpose.

Temporary press

So Markus rigged up a small press thingy. But, as you can probably tell, it’s kind of a pain in the neck to operate.

New press

So Markus bought a real press.

He bought a press at auction.

And paid only ELEVEN DOLLARS FOR IT because – well, this is Wisconsin and here, we do not waste.

And now we have power – more power – to stamp out visors and there will not be blood. We can stamp our own visors and make more face shields and donate more face shields and help save more lives and who can argue with that mission?

  

 

The mystery

You may stop reading here if you want. You have the basics of the story. We needed a way to make visors at the shop and now we have it.

But there is more to this story. And it’s a bit of a mystery.

How did this press end up in Milwaukee?

It started in England over 50 years ago.

We know this because Markus is an awesome detective. He found documents stuck inside the cabinet.

The British United Shoe Machinery Company Limited

Who is The British United Shoe Machinery Company Limited (BUSM)?

Who is Samco?

Did Samco sell a machine to BUSM?

Here’s what wikipedia, citing what appear to be reliable sources, says about BUSM:

British United Shoe Machinery (BUSM) Ltd. was the head office in Leicester, England of a company which for most of the 20th century was the world’s largest manufacturer of footwear machinery and materials, exporting shoe machinery to more than 50 countries.[1] In the 1960s and 1970s, it was Leicester’s biggest employer employing more than 4,500 locally and 9500 worldwide.[1] Most of the workforce was recruited via an apprentice scheme which trained a large proportion of Leicester’s engineers.[1][2] The company had “a respected reputation for technical innovation and excellence”,[1] between 1898 and 1960, it developed and marketed nearly 800 new and improved shoe machines and patented more than 9,000 inventions, at one time employing 5% of the UK’s patent agents.[3]

The collapse of the company in October 2000 destroyed the pensions of the workers. Their story became “one of the most vivid examples of what can go wrong with..Private Equity”[4] and brought “shame on Apax.”[5] The company subsequently went into administrative receivership and was the subject of a management buyout. This new company itself went into administration in September 2006. In November 2006 a new independent company, Advent Technologies Ltd, was formed by former workers of BUSM providing technical support, advice and spare parts for the range of BUSM machinery.

I can’t find a website for Samco-Strong, but there are other websites that refer to the company and describe them:

Samco Strong Ltd is supplier of Cutting Presses and other types of machinery to all the Leather Industries, they also operate a fast and reliable Press Knife service.Located in UK.

Samco press cutting systems are cutting time and costs across a wide variety of industries including: gaskets, automotive trim, plastics, foam, rubber, packaging, woodworking and furniture, garment manufacture and textile cutting, carpets and floor covering.

They have the following cutting press: Swing Beam cutting machine, Beam Press,Traveling Head press etc.

“Indeed, virtually every fabric or material die cut process can be – and generally is being – carried out on Samco presses.”

So maybe Samco sold a press to BUSM.

James Brighouse, Ltd

Who is James Brighouse, Ltd? The only thing I can find online about them is a story in the May 8 1964 London Gazette about factories exempt from the “Employment of Women and Young Persons” section of the Factories Act 1961.

Did the press go to Scotland first? To a manufacturer of bobbins and discs? And trawl nets?

That seems to fall along the lines of “Bait, beer, and prom dresses,” but perhaps there are manufacturing overlaps I am not seeing.

Or maybe that envelope on top held parts that the original press owners ordered?

More Samco – the mystery continues

And then there’s this label. It appears to be a shipping label from Samco in Leicester, which is also where BUSM was headquartered, to Boston. Which must be Boston USA, not Boston House, Abbey Park Road, Leicester, which is very confusing.

I don’t know this because I am psychic but because we also have this clue:

We have a packing slip from 1966 with the destination of “Boston,” not “Boston House.” And we know that somehow, this machine ended up in the US. (Deduction.)

We know we got it at auction. And that it appears to have been owned by a plastics company before. But what were they making? And where were  they? In Boston? Or has the machine had other owners since it was shipped to Massachusetts in 1966?

Unless Markus finds more papers stuck somewhere, we are left here: a machine that was built in England before 1966. And it still works.

 

May 08 2020

And…. even more face shields for Milwaukee and beyond

The workers at the Gerald L. Ignace Indian Health Center, Inc. were happy to get their shields as they start COVID-19 testing in Milwaukee.

Donations

Our big news for the week is that we broke $20,000 in donations with our GoFundMe campaign. Yesterday we reached, with a matching donation of $1,000 from GoFundMe, $21,422. This means we are OK for money for now.

Deliveries

The other big news is that we have donated over 5,000 shields. Two weeks ago, we delivered 2,199 shields. Last week, we delivered 1,612. This week, we delivered 805. We are not sure if this is because the need is diminishing because COVID-19 is going away or because health care workers are finally finding suppliers or if it is because the people who need to know about us don’t know about us.

It may be a combination of the two. Yesterday afternoon, we got a request for 200 shields from a woman whose mother is at a local nursing home. Nine of the residents have been diagnosed with COVID-19. The home did not have any face shields at all.

And another person wrote, “My granddaughter requested 25 masks for herself and her coworkers.  She says that the number of patients has eased up but that she is preparing for the expected second wave.”

We do have substantial inventory of both raw materials and finished shields that Markus can store for us.

Clicker press

We mentioned last week that Markus has been working on a clicker press so we can make our own visors.

Markus is testing the new die from Apple Die.

We found a press at auction and paid – are you ready – $11 for it. (We are Wisconsinites. We are frugal.)

As soon as it’s at the shop, we will get photos and video, we promise.

In the news

And finally, we have gotten some really nice press (of the fourth estate type) lately.

When nurses and doctors needed face shields, a couple of young Marquette engineers started creating them Marquette University

With the COVID-19 pandemic and “Safer at Home” order, members of the Milwaukee Makerspace pivoted from using their facility as a space for innovation and learning to one that can create thousands of face shields per week. Urban Milwaukee

The nonprofit Milwaukee Makerspace recently launched a project to get critical personal protection equipment (PPE) to medical professionals, hospitals and clinics at no cost. OnMilwaukee

Volunteer engineers teamed up to make face shields My Frontline Hero

Your work is more appreciated than you will ever know! Helping us to keep our families safe while caring for our patients is the greatest gift you could ever give. Thank you!

Once again if you are in need of face shields, please request them!

May 06 2020

3D Design for 3D Printing on Sat, May 16

May 03 2020

NYC Makes PPE

May 01 2020

More Face Shields for Milwaukee

Last week we reported delivering 2,199 face shields to Milwaukee area hospitals and clinics. That number was high due to a backlog the week before, so we were doing a lot of catching up last week, and we started this week all caught up (and a little ahead) so this week’s delivery number of 1,612 doesn’t seem as impressive, but in total since we started producing face shields, we’ve delivered 4,396.

For the clear front part of the face shield we’re still working with a few companies to cut those for us, but Markus has been working on a clicker press so we can also make them on our own. He has the die mostly ready to go thanks to Apple Die. With the giant roll of PET plastic we got this week we should be able to put quite a dent in the 30,300 injection molded frames we have. Yes, that’s 30,300 injection molded frames. We… have… a… lot.

Because we have a lot, and can (fairly easily) produce more, we’ve had some requests from outside Wisconsin for some. We’re deciding how to deal with those, but know that our primary mission has been to keep medical professional in the Milwaukee area safe when they are at work caring for our family, friends, and co-workers.

Once again if you are in need of
face shields, please request them!

Also, major thanks are due to Netzer Plastics in Medford. We could not have reached these numbers without them. Their injection molding capabilities (and awesome robot) have helped us help keep people safe. (Their web site is still “under construction” because they’ve been busy making frames for us, but if you need some injection molding done, talk to them.)

We’ll keep going with production… Our GoFundMe campaign just crossed $19,000 so we’re doing okay for covering expenses, and at least a one or two requests were not fulfilled due to some organizations being supplied PPE from other sources. We don’t know if we’re out of the woods yet, or if things will get worse, but we will help while we are able to. Keep checking back for more updates!

Want to help?
https://charity.gofundme.com/o/en/campaign/ppe-for-milwaukee

April 26 2020

Freier Software Abend am Mittwoch, 29. April: Freie Software für Remote Working

Der nächste Freie Software Abend wird wieder online stattfinden, dieses mal mit einem Erfahrungsaustausch zum Thema "Freie Software für Remote Working".
Reposted byantihec antihec

April 24 2020

Another Week, Another 2,199 PPE

It’s been quite a week! It was just seven days ago when we said We are almost ready to make a lot of face shields! because Compumold was able to get our injection mold done in less than a week and do it at a reduced cost for our efforts. Thanks again to the crew at Compumold!

Once the mold was done it went to Netzer Plastics in Medford where they were able to start injection molding immediately. Within a day we had 1,700 injection molded face shield frames.

But that was just a start! Netzer Plastics injection molded all week, we kept sending people to pick up gaylords full of frames, and we’ve now got 17,000 injection molded 3DVerkstan face shield frames at Milwaukee Makerspace. (Erik who designed it even took notice.)

17,000 is a large number. That’s a lot of frames! But wait… we’ve got more numbers…

Our GoFundMe campaign PPE for Milwaukee is at $18,797 as of this post. Which is good, because we spent a lot of money on the injection mold, and a lot of money on plastic. Milwaukee Makerspace is an all-volunteer non-profit organization, so no funds to go pay anyone, everything is going towards materials, and any needed tooling. I don’t have a number for volunteer hours, but it’s easily into the hundreds…

There’s one more number… 2,199. That’s the number of face shields we’ve delivered this week. We’ve worked through about half of the requests that have come in through the request form, and looking at the requests we still need to fulfill, a lot of them are for 100 and 200. Hopefully we’ll surpass our 2,199 delivery number by next week’s total.

Finally, beyond all these numbers, and talk about plastic, and other things… the reason we are doing all this is for the people. Medical workers in need of protection. Here are a few of the recipients of our efforts.





Want to help?
https://charity.gofundme.com/o/en/campaign/ppe-for-milwaukee

Reposted byfinkregh finkregh

April 20 2020

Injection molded frames have arrived!

Jon Hughett arrives at Milwaukee Makerspace Sunday night with over a thousand molded frames from Netzer Plastics in Medford.

Ten thousand. Ten thousand frames in three days.

TEN THOUSAND FRAMES MOLDED IN THREE DAYS.

Holy smoke, you guys. 

We are going to be able to help so many people. 

This is all moving so fast. 

On Wednesday, the mold was ready. The people at Compumold in Phillips worked late every day and over Easter/Passover weekend to finish the mold in less than half the time it usually takes to make one. They understood that our mission is to save lives and they wanted to be part of it.

On Wednesday, Jeff Netzer at Netzer Plastics in Medford drove to Phillips to get the mold and made some samples.

On Thursday, Markus Schneider drove to Medford to look at the samples. 

They were good.

Jeff started cranking out the frames. At the rate of 2,750 a day.

Frames come off the conveyor at Netzer Plastics.

On Friday, Markus drove to Medford again and picked up a box of frames.

Our first batch of molded frames. They don’t have to be rinsed or washed in an alcohol bath, which speeds the process dramatically.

Jeff kept cranking them out.

On Sunday, Jon drove to Medford to pick up half a Gaylord of frames. (That’s all that could fit into his van.)

Markus retrieves the box of frames from Jon’s van on Sunday night.

And today – Monday – there are more frames waiting.

Jeff says he will keep making frames as long as he has the plastic.

And we will keep helping medical workers with shields as long as we can.

April 16 2020

We are almost ready to make a lot of face shields!

The employees at Compumold worked through the weekend and some people stayed late to make sure they completed the mold as soon as possible. They delivered it to us more than a week ahead of schedule. This is a steel mold, which is more complicated to make than an aluminum one, so this turnaround has been extremely fast.

Our mold is ready!

The mold for injection molding of the frames for the face shields is ready.

Why does this matter, you ask?

Because with injection molding, we are going to be able put a lot more shields onto the faces of our medical workers in the Milwaukee area as they fight coronavirus. We are going to be able to save more lives.

We have been cutting the frames one by one on Tom Gondek’s CNC router, which is not a bad way to do things, but it’s slow. And each one of these frames has to be washed two times, once in water, once in alcohol. By hand. Which is also slow.

Frames after the initial washing at Tom’s shop.

As of April 15, we have requests for almost 4,000 face shields in the queue.

We can produce about 200-500 frames per day with the CNC router.

But with our new process – with injection molding – we will be able to quadruple production, making up to 2,000 frames per day.

And the frames made by injection molding do not need to be cleaned even once, so the overall process will be a lot faster.

I spent yesterday afternoon with Alden and Chris cleaning frames. It’s a tedious, slow process.

You dip the frames, two at a time, into a bath of alcohol water. (Which, BTW, makes your hands really cold.)

You let them sit on one side for five seconds, then you turn them and let them sit on the other side for five seconds.

Then you lift them out, let them drain, carry them to a drying rack (of which we have limited capacity), and hang them. They have to be completely dry for packaging.

Chris is cleaning frames. But this is not an efficient process.

This is not the best way to ship a lot of shields. Not when you have a backlog of 4,000.

Jeff, our injection molder, has already picked up the mold in Phillips and taken it back to his machines in Medford. He will have samples for us today.

Stay tuned!

Reposted byfinkregh finkregh

April 15 2020

Simple hack for a quiet morning

I usually see big, wacky, catchy projects on blogs like these.  Well I’m here to remind you that small, commonplace, everyday hacks are just as important, especially during times of stress. Making or modifying something to make your life easier can be every bit as rewarding as making a giant installation or rolling art project.

 

Our cat gets a quarter-cup of food every morning.  I have a half-cup scoop reclaimed from a box of protein powder.

You’ve heard the joke before, about a partially filled glass? The optimist says it’s half full, the pessimist says it’s half empty, the engineer says it’s twice as big as it needs to be.

I’m an engineer.

 

Here we see a perfectly unassuming 90cc scoop. 

Scoop before alteration

Scoop before alteration

I know it’s 90cc’s because it says so.

90cc

90cc

We need a 45cc scoop. We do not have a 45cc scoop. They sell these, as it’s basically a ¼ cup, but I am disinclined to spend money, plus certain world events are extending shipping times and making a run to the store problematic.

 

Modification time!

 

I found an appropriate measuring device, in this case a tablespoon (yes my tablespoons have metric on them, however approximate). 

Tablespoon 15ml

Tablespoon 15ml

I measured 3 tablespoons of water, or about 45cc (cc and ml are basically the same thing), and traced the water level to give me the desired height of the cup.

Water line marked

Water line marked

To make sure the handle didn’t get too floppy, I also drew in these supports on the side.

Lines for handle support

Lines for handle support

Then it was just a matter of using a pair of scissors to trim off the excess.  It would have been way better to use a smaller pair of craft shears, but big ol’ kitchen shears is what I had handy, so that’s what I used.

Snip snip

Snip snip

If you start off cutting a notch out, you can get the big scissors parallel to the cut.

Notching

Notch cutting

Make sure to cut above the line! That is, leave a little extra so you can finish it off nice.  You can always take off a bit more, but adding it back on is a whole ‘nother level of complication you don’t need.

Cut above the line

Cut above the line

Leave enough extra for finishing

Leave enough extra for finishing

With the shape roughed out, grab a piece of sandpaper, or a nail file, or, in my case, an actual general purpose file. It’s what I had lying around.

hand file

Hand file

Use the scissors to trim down any big protrusions or bumps, then use the file/sandpaper to bring it down to the final shape. If you have a finer grit, you can use it to give a nicer finish, but I just kinda burnished it with the handle a bit. Good enough to scoop cat food with! (Warning: filing plastic will make a mess, and that mess will include micro-plastics to one degree or another. If that’s something that bothers you, do this outside, or over a trashcan. Wear whatever PPE you feel you need, assuming you haven’t already donated it all to your local hospital. I did it on the back stairs with a strong breeze blowing so I didn’t breathe in any of the dust.)

Finished 45cc scoop

Finished 45cc scoop

Tada! A 45cc (ish) scoop! No more guessing on the cat food, just one scoop and good! 

 

Took longer to write this post than it did to make the thing, but I felt it was important to remind you, making is about the little things too.

 

Stay sane in there people!

April 13 2020

Shields and Masks – Week One(ish)

We’ve got a progress report on our MMS Face Shield project. As you may know we started cutting face shield visors about a week ago in an effort to fill the gap in the supply of PPE going to hospitals and health care clinics in the Milwaukee area. Our total as of Friday was about 2,000 face shields cut on the CNC routers we have access to at ABC Woodworking.

We’re cutting more each day, and plan to add an additional two spindles to the primary CNC router’s gantry so it can cut three at one time. Meanwhile our friends at KAPCO Metal Stamping are able to stamp out 20,000 of the clear front shield parts to go with the frames.

Our GoFundMe campaign has raised over $12,000 so far, and we should be doing injection molding of the frames in less than two weeks. That will do two things: dramatically speed up the process of creating face shields, and lower the price of material per shield. (We are estimating close to 1/10 the cost of plastic used in the injection molded version.) With the ability to increase volume, we hope to expand beyond front line medical workers if their needs are met, and examine providing face shields to essential workers as well and investigating reaching outside the Milwaukee area. (We’ve already gotten requests from friends in other states as well.)

Now, if the face shield market gets completely saturated and we don’t need as many (which is a good thing!) we’ll be looking at what else we can do. Speaking of diversifying, we’ve also got a group of members who are sewing masks. Dan and Hapto put together 130 mask kits to distribute to members (in a non-contact fashion) and over 80 masks have been produced so far. There’s a lot of great sewn mask making efforts in our area, but it’s great to see our members jumping in as well.

One last update: Much of what we are doing started in the Open Source COVID19 Medical Supplies group, and while we haven’t been as active as we’ve wanted to (due to making face shields) there is now a local effort, the Open Source COVID19 Medical Supplies – Milwaukee group which a few of our members are involved in. Hopefully they’ll be able to steer us towards the best practices and efforts of the larger group. (And if you can help, please join in!)

We’ll do out best to keep you up to date with progress on this project as we move forward. As we’ve said among the group, we can’t wait to put ourselves of out the face shield making business, but as long as there’s a need to keep people safe that isn’t being fulfill, we’ll keep doing it.

Want to help?
https://charity.gofundme.com/o/en/campaign/ppe-for-milwaukee

Reposted byfinkregh finkregh

April 09 2020

(Online) Arduino: Sensors and Input/Output on Sun, Apr 19

April 07 2020

First Shields are Out!

We’ve delivered face shields! Medical professionals are now using these in the field, and we’re happy to see this photo they sent us.

We’re working on ways to speed up production, still exploring new partners to help out, and doing our best to keep our spirits high… and this helps a lot.

April 06 2020

Face Shield Files Available

We’re still learning and refining things, but we’ve had a number of people ask about the files… so here are the files!

https://github.com/raster/MMS-Face-Shield

They are on GitHub, you can download them, you can fork them, you can share them with others. Since we started with the 3DVerkstan design we are also using a Creative Commons BY-SA license. Please respect that, we want to grow the world of Open Source Medical Supplies.

If you have improvements or suggestions or feedback, we’d love to hear it. Email covid19help [at] milwaukeemakerspace.org

We’ve already had people suggest some improvements, or ask why we are doing things a specific way, so we’re hoping we can all develop better practices through dialog. Also, expect the GitHub repo to change/improve as we learn more. (There’s a cleaning guide for the shields coming soon!)

Any changes to the files should maintain the peg spacing so that shields fit properly into the pegs (at least on our end) as we’re getting thousands of those stamped out right now, and it’s sort of a standard at this point…

Again, share these, try these, use these… Let’s keep fighting COVID-19 and doing all we can to help medical professionals keep themselves (and us) safe!

Reposted byfinkregh finkregh

Ham Radio Mobile Install

Preamble

I am a simple girl. I like little cars. I like sporty cars. I like putting my foot down and zoomy happening. I also happen to like mobile radio operation. This poses a number of packaging challenges; for some reason, no one is building small, sporty cars with ham radio operation in mind.

About a month ago, I totaled my car. RIP Matilda; she died valiantly protecting us, and rides on to Valhalla. Matilda was a 204 Mazda3 s Grand Touring with the tech package, and around 136,000 miles. (HATCH LYFE)

Matilda, with bonus appearance of the trailer for my boat, Aly Kat. Note the HV-7A antenna on a K400S mount on the hatch.

Matilda, with bonus appearance of the trailer for my boat, Aly Kat. Note the HV-7A antenna on a K400S mount on the hatch.

Matilda, on her final journey to Valhalla. Note the ATAS-120A on the same lip mount.

Matilda, on her final journey to Valhalla. Note the ATAS-120A on the same lip mount.

So I figured that, with my new car Minerva (a 2019 Mazda3 Sport hatch, with around 1200 miles), I would take the opportunity to ditch the mildly-inconvenient Diamond K400S hatch mount I was using for my Diamond HV-7A antenna (and recently my Yaesu ATAS-120A antenna), and put two brand-new Breedlove 195 SO239 ball mounts onto the car.

New car, Minerva. Note there are no antennae yet.

New car, Minerva. Note there are no antennae yet.

But of course I also like my cars to be clean and functional inside, so I needed to spend a lot more time than I did on Matilda with the radio install now that I have two mobile units. Also, I wanted big plates on the mounts so I did not can-opener the body steel…

Power

First and foremost, I needed a lot of power. The Yaesu FT-8900R daily rig draws up to 15A full-bore, and the Yaesu FT-857D all-band/all-modes rig draws 22A full-bore. In addition, I want to run my trailer light harness (LED lights on the car means I need a transistor box and a battery feed to run the trailer), and since Mazda for some unknown reason has something against accessory ports (seriously there is one gorramed port in the whole car), a 20A drop on PowerPole in the trunk is a good idea.

I had wired Matilda with some specialty AWG8 that was scrap from work, but I was not able to salvage much of that from her and plus I am under quarantine. However, I had a little left on the spool of AWG6 THHN from running a 50A 240VAC run to my garage. Score!

The remains of a spool of AWG6 THHN from Anixter, I used for a 50A 240VAC run to my garage.

The remains of a spool of AWG6 THHN from Anixter, I used for a 50A 240VAC run to my garage.

I bought some lugs and a crimper from Amazon to suit my sub-panel and the distribution block on the battery (Mazda is super helpful here!). The distribution block has several M6 studs with built-in high-current fuses. The panel and the wire are rated for around 80A in this use case, and conveniently there is an 80A fuse spare.

Battery with distribution block. The two bottom-most studs are both spare and fused at 80A.

Battery with distribution block. The two bottom-most studs are both spare and fused at 80A.

With any project like this, getting through the firewall in a safe, clean, and watertight way is a challenge. I used a gasketed cable gland through a conveniently blank spot. I say convenient…I did have to remove the air filter box, the battery, the ECM, the battery tray, and much of the ECM harness to access the area from the engine bay, and had to slice through the carpet and soundproofing mat in the cab. But it went well and now I have a watertight penetration.

View of gland and cable inside cab. This is directly behind the instrument panel cluster.

View of gland and cable inside cab. This is directly behind the instrument panel cluster.

View of gland and cable in engine bay. This is directly behind the battery and ECM.

View of gland and cable in engine bay. This is directly behind the battery and ECM.

In the driver’s side rear quarterpanel, I lucked out. There is a wide-open area with a horizontal frame member forming a shelf, with plenty of space for my sub-panel and FT-8900R. I did have to relocate the “ELECTRICAL SUPPLY MODULE” off its bracket and forward, under the rear seatbelt reel, but I am confident this is OK.

Driver's side of hatch, with the LED for the cargo area. Behind this carpet is an astonishingly large free space...and soon a subpanel and radio...

Driver’s side of hatch, with the LED for the cargo area. Behind this carpet is an astonishingly large free space…and soon a subpanel and radio…

Driver's side rear quarterpanel. The right-most black box is the OEM "ELECTRICAL SUPPLY MODULE", relocated under the seatbelt reel. The subpanel is a cheap unit found at O'Reilly or similar.

Driver’s side rear quarterpanel. The right-most black box is the OEM “ELECTRICAL SUPPLY MODULE”, relocated under the seatbelt reel. The subpanel is a cheap unit found at O’Reilly or similar.

Once the engine bay was reassembled, the feed was labeled and landed on the stud.

Engine bay, reassembled, with AWG6 feed to subpanel labeled and landed on 80A stud.

Engine bay, reassembled, with AWG6 feed to subpanel labeled and landed on 80A stud.

FT-8900R Installation

Now that I had power, I wanted to install my FT-8900R. This is an FM-only quad-band (70cm, 2m, 6m, 10m) dual-VFO/dual-receiver radio that is excellent at repeater work in the local area, matched with the HV-7A antenna.

The FT-8900R is a ridiculously compact radio, and gets even smaller with the head detached on the separation kit. With the mobile mounting bracket, the whole radio fits flush behind the carpeting on the diagonal frame rail over the shelf. Three #8×1/2″ sheet metal screws hold the bracket in place.

FT-8900R mounted on diagonal frame rail over shelf and subpanel. White flying connector is for cargo area LED; flying PowerPole is 20A auxiliary for cargo area. Ziptied PowerPole over OEM module is feed for FT-857D on the other side of the car; the one under the FT-8900R is for that radio.

FT-8900R mounted on diagonal frame rail over shelf and subpanel. White flying connector is for cargo area LED; flying PowerPole is 20A auxiliary for cargo area. Ziptied PowerPole over OEM module is feed for FT-857D on the other side of the car; the one under the FT-8900R is for that radio.

I eyeballed the placement of the Breedlove mount so the ball was centered between the fuel door and the combo light, then marked out the holes. Pucker factor 100% drilling holes in brand-new body panels. A quick deburr inside and out, and it was time to pull the panels together…whereupon I had an issue. The inside frame members were too close to the outside panels for me to reach the holes. Fortunately, I also really like rope (get your minds out of the gutter; I am a sailor and taught Pioneering merit badge for years through my BSA career). I threaded some light line through the holes and grabbed it inside the car, then tied it through the backing plate with a slipknot. Careful feeding of plate and knot into the interstitial space and I could pull the whole plate flush and aligned with the outer holes.

A clever fishing expedition, pulling the backing plate of the Breedlove mount against the inside of the body panel so I can get the two plates aligned with each other and the body panel.

A clever fishing expedition, pulling the backing plate of the Breedlove mount against the inside of the body panel so I can get the two plates aligned with each other and the body panel.

Fishing the LMR-240 through the ball and inner shaft, into the cargo area.

Fishing the LMR-240 through the ball and inner shaft, into the cargo area.

All that time in the Scouts really paid off; a traditional whipping bites well enough on the coax to act as a non-damaging pull.

All that time in the Scouts really paid off; a traditional whipping bites well enough on the coax to act as a non-damaging pull.

Completed mount with HV-7A standing proud and plumb.

Completed mount with HV-7A standing proud and plumb.

Completed installation, with coax labeled and terminated. The  backing plate for the mount is approximately behind the triangular gap formed by the FT-8900R and the OEM module. All access was through a narrow slit aft of the inner frame member, shown with a large knockout and the Breedlove grounding wire.

Completed installation, with coax labeled and terminated. The backing plate for the mount is approximately behind the triangular gap formed by the FT-8900R and the OEM module. All access was through a narrow slit aft of the inner frame member, shown with a large knockout and the Breedlove grounding wire.

With everything installed and confirmed working, I ran the separation cable into the passenger area, a programming cable extension into the cargo area, and an external speaker cable into the cargo area, and buttoned everything up.

Driver's side rear quarterpanel, now with radio and subpanel installed. Note the 20A PowerPole drop tucked under the cargo area LED, and the 1-2 switch for external speaker (soon to be replaced with an actual mixer). Not shown (because framing!) programming cable extension.

Driver’s side rear quarterpanel, now with radio and subpanel installed. Note the 20A PowerPole drop tucked under the cargo area LED, and the 1-2 switch for external speaker (soon to be replaced with an actual mixer). Not shown (because framing!) programming cable extension.

FT-857D

Next up, the FT-857D. This is an all-band (something like 1MHz through 700MHz) all-mode (AM, FM, upper sideband, lower sideband, packet and digital modes) dual-VFO/single-receiver radio that is excellent at longer-range things and packet digital work, matched with the motorized tunable ATAS-120A antenna.

The FT-857D is nowhere near as compact as the FT-8900R, even with the separation kit. With the mobile mounting bracket, the radio does bow out the carpeting when mounted horizontally on the shelf inside the passenger side rear quarterpanel. Two #8-32 bolts and Nylock nuts hold the bracket in place.

Passenger side rear quarterpanel has a similar shelf arrangement as the driver's side, but no OEM module to deal with.

Passenger side rear quarterpanel has a similar shelf arrangement as the driver’s side, but no OEM module to deal with.

FT-857D mounted, with bonus appearance of soundproofing plug for interstitial space.

FT-857D mounted, with bonus appearance of soundproofing plug for interstitial space.

Mounting the antenna was much the same as for the FT-8900R, but I actually measured the mount position so it matched.

Five mounting holes for the Breedlove mount. The central one is 5/8" and accepts the brass inner shaft for the cable; the outer ones are 11/32" for the mounting bolts.

Five mounting holes for the Breedlove mount. The central one is 5/8″ and accepts the brass inner shaft for the cable; the outer ones are 11/32″ for the mounting bolts.

ATAS-120A mounted proud and plumb

ATAS-120A mounted proud and plumb

When everything was tested, I could not get any reception on KEC63 (this station broadcasts from the National Weather Service in White Lake on a frequency of 165.55MHz...). Which, you know, bad.

So I cut the connector off and redid it. Everything good the second round; I think I got some of the braid into the center conductor the first time around.

In-process round two of PL-259 connector for the ATAS-120A.

In-process round two of PL-259 connector for the ATAS-120A.

Completed (and working!) PL-259 connector.

Completed (and working!) PL-259 connector.

Once everything tested out OK I mounted the CF-706 duplexer, ran the separation cables into the passenger area and an external speaker cable into the cargo area, and buttoned everything up. (No programming cable extension yet; it is in the mail still, along with a Bluetooth adapter from KC8UFV).

Completed installation. Note how little space behind the radio there is for cabling. Also note the CF-706 duplexer mounted above the radio on the diagonal frame rail.

Completed installation. Note how little space behind the radio there is for cabling. Also note the CF-706 duplexer mounted above the radio on the diagonal frame rail.

Just the barest hint of a curve in the vent panel over the FT-857D. Otherwise, buttoned up just fine.

Just the barest hint of a curve in the vent panel over the FT-857D. Otherwise, buttoned up just fine.

Interfaces

Inside the passenger area, it was time to figure out where the heck I was going to put two microphones and two heads. In Matilda, I had the FT-8900R head mounted under the dashboard near the door knee panel, and that worked well. It fit right over the hood release lever and below the random little storage compartment Mazda bequeathed the 2019 with.

FT-8900R head shown under dashboard, just above the hood release lever.

FT-8900R head shown under dashboard, just above the hood release lever.

The cabling for that and the microphone for the FT-857D were pulled through the driver’s side door sills and up behind the inside OEM fuse panel. The FT-857D mic is the lesser-used one and got a clip on the left side of the steering wheel; the FT-8900R is the daily radio and got a clip on the right side next to the pushbutton start.

Overhead shot showing both mics nestled around the steering column.

Overhead shot showing both mics nestled around the steering column.

FT-8900R mic on right side of steering column, next to pushbutton ignition.

FT-8900R mic on right side of steering column, next to pushbutton ignition.

FT-857D mic on left side of steering column.

FT-857D mic on left side of steering column.

Now, where to put the FT-857D head? On Matilda, I mounted it front and center on the dash, just under the infotainment screen and vents. However, Minerva’s dash is laid out differently, the cupholders are up there in the way, and absolutely everything is covered in leather that I am loathe to drill holes in.

So I put the head in the much-expanded center console storage area. Some DualLock holds it to the wall, it is set low enough the console cover slides over cleanly, and just a little plastic notching and the cable runs cleanly under the trim panel, down the side of the console, and under the carpet under the driver’s seat to the door sills, where it joins its sister cabling back to the rear quarterpanels.

FT-857D head mounting inside center console storage bin. Note the one and only accessory port in the car, and the cable neatly going under the trim panel...

FT-857D head mounting inside center console storage bin. Note the one and only accessory port in the car, and the cable neatly going under the trim panel…

...which then runs down under the panel to the floor, to go under the driver's seat...

…which then runs down under the panel to the floor, to go under the driver’s seat…

...and under the carpet under the seat to the door sill, where it heads back to the rear quarterpanels.

…and under the carpet under the seat to the door sill, where it heads back to the rear quarterpanels.

Speaker

With the radios hidden behind much of the soundproofing in the rear of the car, they really need an external speaker. On Matilda, I had this “hidden” behind the infotainment screen. However, again, Minerva’s dash is all leather and laid out differently, so that option is just bad.

However, there is kind of a useless open storage area under the HVAC controls, forward of the cupholders. Some (OK, a lot) disassembly of the center console later, and I had the whole cupholder/storage/valence module out. A few holes drilled into the valence for the bracket, and another careful cable notch in the edge, and the whole thing reassembled into place. The cable runs through the console to meet up with the FT-857D head separation cable, and then back to the rear quarterpanels to meet the 1-2 switch (and eventually the mixer).

Center console with some disassembly.

Center console with some disassembly.

Bracket mounted on valence.

Bracket mounted on valence.

Cupholder module assembled with speaker installed.

Cupholder module assembled with speaker installed.

Cupholder reinstalled, working the valence with speaker into place.

Cupholder reinstalled, working the valence with speaker into place.

Everything back into place, now to reassemble the console.

Everything back into place, now to reassemble the console.

Everything complete, cupholder door closed.

Everything complete, cupholder door closed.

And yes, of course the door opens and there is plenty of space for drinks.

And yes, of course the door opens and there is plenty of space for drinks.

Remaining Tasks

No project is ever finished. Next up for this one:

  1. Pack the mounts with dielectric waterproof grease (I do not trust some of the metal-on-metal seals in the mounts and I like automatic car washes)
  2. Find an SWR meter and retune the HV-7A for its new situation
  3. Install the mixer in place of the 1-2 switch
  4. Install the programming cable extension and Bluetooth adapter for the FT-857D
  5. Install the connector caps for car washes
Cargo area fully buttoned up, showing both antennae.

Cargo area fully buttoned up, showing both antennae.

KE8HOJ mobile, 73 and clear!

April 05 2020

Face Shield Materials & Process

When the push to make face shields started we saw a lot of makerspaces and individuals fire up the 3D printers as tons of designs started showing up online. If you’ve got a 3D printer, by all means, help out by making things… they aren’t the fastest method, but they are nice in that it’s “hit print and walk away” to some degree. And filament? There are a lot of rolls of filament available. (Got access to 10 or 20 or 50 machines in a print farm? Get them running!)

We then saw other people start using laser cutters, which tend to be a lot faster than 3D printers, and PETG was the material of choice, until it ran out. We know a guy who used all the PETG he could source locally, then drove 16 hours to buy more, and at this point there are people who just cannot buy PETG to feed into their laser cutters. (If you can find PETG, keep going, fire those lasers!)

So we opted to use 1/4″ sheets of HDPE (high-density polyethylene) as our visor material. It machines really well and on a large CNC they go pretty fast. You might be familiar with HDPE if you own a plastic cutting board. It’s great because it can be easily cleaned and disinfected, unlike things that are 3D printed.

We’ve got two CNC machines running at a shop one of our members runs. (Milwaukee Makerspace is not open, we are not using the CNC machines there.) We are running with very few people, working a safe distance from each other. The process involves two replaceable spoilboards so you can prep one by screwing down the material, loading it onto the CNC and running it while you spend time unscrewing the cut material from the other one.

The other part of the face shield is the front part, the shield that is in front of your face. Clear semi-rigid vinyl was available so we got that. It cannot be laser cut (well, sort of) so we looked into getting a steel rule die made so we could cut them easily and quickly. In our quest to get a die made we talked to KAPCO Metal Stamping and they offered to just stamp them out for us. Amazing! We don’t have a clicker press and while some friends offered use of their equipment for automated loading and cutting, KAPCO can do a huge volume quickly and safely.

As long as the supply of HDPE and clear vinyl holds out, we’ll keep going with this process. If we can’t source those materials we’ll move on to something else. It’s probably a good idea to start making a list of other materials that could work, or alternative processes for making.

Older posts are this way If this message doesn't go away, click anywhere on the page to continue loading posts.
Could not load more posts
Maybe Soup is currently being updated? I'll try again automatically in a few seconds...
Just a second, loading more posts...
You've reached the end.
(PRO)
No Soup for you

Don't be the product, buy the product!

close
YES, I want to SOUP ●UP for ...