Custom instrument labels

Those ones worry me from the EMI point of view. We're using Keystone 612 angle brackets to connect the board to the box in 6 places. Slightly fiddly but really nice electrically.

We're using these ones to provide the usual 1/4-20 mounting hole.

There's a matching hole in the board so that too-long screws won't kill it.

Cheers

Phil Hobbs

How does that work? Holes in the side of the box?

We use PEM threaded spacers, pressed into the bottom of the box, or pressed into the bottom of the PCB.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

n 6 places. Slightly fiddly but really nice electrically.

might be less fiddly with something like these:

-Lasse

Thanks. Because the box is so strong, I'm sort of relying on the screws in plain holes to allow a bit of squirming around during assembly. We might be able to rout out a little flexure in the board itself that would let us us e those without cracking the solder. Wouldn't cost any more, and might be a win.

Cheers

Phil Hobbs

Do you think non-conductive slots between the screws (between face plates and extrusion) might cause issues? It's hard to fill them with EMI gaskets or whatever if the facing materials only conduct at the screws.

As you say, you'll have to drill the holes afterward but that should be no problem, and then the tolerance would then be okay for sure for inserts or threaded holes.

I never liked the feel of screws in aluminum thread (nor putting in expensive helicoils to fix them when they strip), but there is probably some combination of thread pitch and screw size and and material that will work nicely. At least North American screws are relatively coarse thread compared to the overly fine metric standards.

Unfortunately they usually use a fairly mushy alloy of aluminum such as 6063 to make the extrusions easy. I guess you get to specify the heat treat and temper too.

--sp

--
Best regards,  
Spehro Pefhany 
Amazon link for AoE 3rd Edition:            http://tinyurl.com/ntrpwu8

is about 3

to a

Thanks. I don't have a colour laser printer, though, and the box has a blac k powder coating, so the label has to be opaque. So maybe inkjet printed la bels with a plastic cover would work for the first few.

I have a few sample kits coming so that I can see how the labels look on to p of the rough powder coat, and how well they stick.

Fun.

Cheers

Phil Hobbs

I don't expect EMI problems. The end plates will have 4 screws each and the top/bottom plates will each have 4 or maybe 6.

The top plates of the Hammond boxes barely get grounded in the four corners. The end-plate screws sort of crunch into the top cover a bit. That's ugly.

We drill and tap extruded heat sinks, and the Hammond boxes, for good ole USA size screws (4-40 and 6-32 mostly) and that works fine. Stainless screws don't gall into aluminum, generally.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

For small-volume stuff including first-runs, we have used Scotchmark (adhesive backed) through a decent laser printer (fuser temp is important - too low and the toner doesn't adhere especially well).

Hand cut.

If especially fussy about durability of the printed image, clear spray

- but some of those discolour to a yellowish tinge after a time.

We use these:

Papilio model CWVF8511G - Inkjet Contouring White Waterproof Vinyl and Papilio waterproof over-lamintate

Both are available from Amazon or papilio.com

--

Best Regards, 

ChesterW 
+++ 
Dr Chester Wildey 
Founder MRRA Inc. 
Electronic and Optoelectronic Instruments 
MRI Motion, fNIRS Brain Scanners, Counterfeit and Covert Marker Detection 
Fort Worth, Texas, USA 
www.mrrainc.com 
wildey at mrrainc dot com

Interesting, thanks. I've ordered some, and we'll try it out.

Cheers

Phil Hobbs

-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058

hobbs at electrooptical dot net

Yup. Those small drill bits that do countersunk holes in one go are stiff enough to survive the side loads due to drilling through the board slots. I doubt that a normal drill bit would work.

That, or else finger stock or wavy washers or something, would be a bit less fiddly but would need more tooling, which costs money and floor space.

I'm remodelling my lab space a bit to turn the storage room into an optomechanics area, so I'll probably get a Sherline for modding the boxes. The hunchbacks should learn how to use machine tools, and that's an easy way to start.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 
845-480-2058 

hobbs at electrooptical dot net 
http://electrooptical.net

We have a Sherline and it was a good investment. It's great for plastic and light aluminum machining. We added a cutting fluid pump and a collecting tray, which increases cutting speed but isn't really necessary.

I don't know if we still use it. We got a Tormach, a much beefier gadget.

Since Engineering buys toys, it's only fair that we let Manufacturing get a toy now and then.

Every kid should learn how to machine metal and solder and work wood and do basic electrical stuff.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

Take the transparency after it comes from the black only laser printer and spray paint over the printing with white/red/purple/whatever before gluing it.

Hul

Phil Hobbs wrote:

Thanks.

That's a bit more of a science project than I'm up for on this one, what with the unknown compatibility of laser film, paint, and adhesive, and the seemingly strong likelihood of delamination and consequent ugliness.

Beautiful Layout Hunchback is doing full-colour artwork. (Our logo is medium olive green on light yellow green, for instance.)

So the inkjet options are attractive for the first few units at least.

Cheers

Phil Hobbs

When/if it comes time to order real printed labels, specify the sensitive colors (such as logo) in terms of Pantone colors. Also if you're doing the artwork for silk screening make sure you do the appropriate expansions etc. so that registration is not critical, keeping the order of printing in mind. You don't want a slit due to slight misregistration to show through allowing highly contrasting background to show through. Or pay someone to do it from the conceptual RGB/CMYK design. Do everything possible in vector format (eg. Adobe Illustrator aka Frustrator or its open-source clones).

Personally I think if you can make messy stuff like die-cut labels and enclosures go away for a halfway affordable price, it's worth doing.

I have made many (probably thousands) of silk screened graphic overlays by hand (screening each layer) and cutting with a steel rule die or other methods once it's done. Messy business and not particularly cheap except if you just need a few. The materials and setup alone are expensive (check the minimum order for 3M permanent adhesive in a roll), and more (maybe double) if you want nice UV cured materials with low VOCs for a nice work environment.

--sp

--
Best regards,  
Spehro Pefhany 
Amazon link for AoE 3rd Edition:            http://tinyurl.com/ntrpwu8

is expensive but available in any quantity.

labels fit into a slight recess in the top of the box and on one of the end s.

B. Grin... The relative price of things is sometimes hard to reconcile. The other day I noticed that a 2" piece of buss wire costs the same as

1% 1/4W TH resistors.

George H.

When I need little wire jumpers for breadboards, I cut the leads off

1/4 watt resistors. I use the oddball values from the lab bin, like 11K, that nobody else seems to use.

Bus wire is outrageous. Ebay has art-type tinned copper wire, cheap, but it's hard-drawn, not so good for electronics.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

k m d l " e e

I wonder if you could use Scotchcal?? Years ago I used it for a custom face on a VU meter with the company logo. I silk screened a bunch at a time. They w orked great. Much faster than screening each meter face.

I don't sell final products, but boards. One board I made was very small and I left a small area with white silkscreen for a serial number. I would hand number these boards with a very fine point sharpie. This was hard for me as I have a bit of a tremor which has gotten worse over the years. I eventually turned the testing over to the fab house and they have a label maker which they plop on the only IC on the board big enough for it, the FPGA. Just the basics, SN, model name and revision number. The company name and logo are on the board in the art work, small, but visible.

--

Rick C