Looking for tiny U-channel

[ataradov]

I'm trying to find tiny U-channel. I need the inside opening to be ~1.6 mm to accept a typical PCB. The sides must be tall enough to grip and hold the PCB, bun not obscure significant parts of it, so no more than 1 mm. The wall thickness - does not matter that much, I imagine that being rolled from sheet metal.  Material is probably going to be steel given the requirements, but any metal would do.

Ability to get in bulk is great, but I'm fine with ripping it out of something cheap for the prototype. I only need a few inches.

The closest I could think of is hardware on umbrellas. But it is not easy to find, since Amazon pictures don't show the hardware close enough and local stores don't tend to carry umbrellas in California

I want to make a low profile PCB holder/vice of sorts, but I need the actual holders to be as non-intrusive as possible.

It probably does not need to be U-channel, it probably can be just an angle. But I'm not sure an angle this tiny would be structurally sound.

Ideas are welcome.

[Alex Eisenhut]

Does it need to be metal? I'd look for plastic grommet strips.

https://www.alliedelec.com/view/search/?keyword=nylon+caterpillar+grommet+strips

Otherwise you're looking for an extruded channel, although I don't know if they go that small.

https://eagle-aluminum.com/products/channels/

[ataradov]

It has to survive soldering temperatures, so plastics are probably out.

Extruded aluminum is too bulky and I don't think commonly available stuff is that small.

I was thinking more of folded sheet metal like in the picture. Lightweight, simple and rigid enough. No idea if it is available as a standalone product though.

[ConKbot]

1439-1330-ND seems reasonable, kind of has flange you could bolt to vice jaws. Datasheet is a little sparse on details though

[ataradov]

This is still too heavy duty. I need this for a vice for soldering under the microscope.The holder must be as much out of the way as possible. The goal is to have the vice body outside of the field of view, so it could be bulky, but it will not obstruct the view.

I don't think any sort of extrusion would work, they all just too bulky. The maximum length it needs to support is 100 mm or even less.

[Someone]

Commercial PCB holding vice/fixtures use tiny little extrusions. But plastics aren't impossible:
https://www.bivar.com/product/DC-250/

Usual question, do you want
small quality? just machine something from bulk
huge quantity? get a die made for extrusion

[ataradov]

"pcb card guides" is a good search term that yields some results. But still, all I see is too bulky.  I need to hold 10 x 20 mm PCBs. Those guides will cover them entirely them.

I guess I'll hunt for umbrellas.

[mclute0]

Maybe try Bakelite, you can buy sheets on amazon and machine on it all you want. All the old Weller soldering guns were made from it as were most vacuum tube sockets. There are companies that will make it into whatever part you want. You can buy it from China too.

[JohnGi]

Miniature brass sections sold for making model girder bridges etc.

Example

https://www.chronos.ltd.uk/product-category/round-square-tube-sheet-metal-ptfe-nylon/albion-alloys-precision-metals/albion-alloys-brass-channel/

As you're in US try somewhere like www.micromark.com

[jc101]

This kind of thing any good?

https://www.waveroomplus.com/WaveRoom-Plus-TF-3-Titanium-Edge-Finger-Mask_p_2361.html

There are wave solder strips, used to hold/protect the edge of the PCB, but might be workable?

[Ian.M]

You should be able to get small brass box and angle section strips from any good modelmaking supplier.  1/16" square section tube is fairly commonly available and would be a good start towards holding a PCB that small.

Notch the ends of the tube to grip the PCB end-on, and glue the other end in fractionally undersize holes in your vice jaws using a high temperature adhesive.  Alternatively, braze or silver solder the tube stubs to your vice mechanism.

[beanflying]

Apart from getting someone to bend you a custom look at K&S as you are in the USA. Tower Hobbies and most of the R/C mail order guys will carry most of the range. They also carry Brass is a few different sections in small size square or channel https://ksmetals.com/collections/aluminum/products/als014-3-32

[Conrad Hoffman]

Cut a piece of aluminum slightly thicker than your PCB and some size that will fit in your vise. Cut a strip of heavy brass shim stock to the desired width. Clamp the shim and the aluminum in your vise such that the narrow edge of the aluminum is in the center of the brass strip. Using a flat blade to start, then small hammer, wood blocks or whatever, fold the edges of the brass against the aluminum plate. Voila, U-channel. Since the project is small, you don't need terribly thick brass to be strong enough, maybe 0.010" at worst. 0.005" might be good enough. It's a compromise between strength and being able to easily bend it. The brass is nice because you can then solder up a whole frame or whatever you want. If you need to go really shallow, so it makes bending difficult, make it a bit deeper and file it down to the desired depth.

[Marco]

Why not just take square stock nylon or phenolic and mill slots?

[MarkF]

It has to survive soldering temperatures, so plastics are probably out.

Assuming you are just hand soldering, I don't see that the edges would get too hot for plastic.
Maybe, 3D print jaw covers with a slot for your vise?


Probably not what you had in mind but I'm going to toss it out there:
- A single blade kerf from a table saw in a piece of hard wood would be about the right thickness.

I use a small set of wooden clamps without a slot to hold my PCBs while soldering. 
You could take a set apart and cut a slot or get the pieces and cut your own wood jaws to suit.
Or rabbet the top edge on each side to the depth of a PCB.

[Alex Eisenhut]

Just buy some brass shim stock of a few mils thickness and fold it with a metal ruler?

[JDubU]

Cut a piece of aluminum slightly thicker than your PCB and some size that will fit in your vise. Cut a strip of heavy brass shim stock to the desired width. Clamp the shim and the aluminum in your vise such that the narrow edge of the aluminum is in the center of the brass strip. Using a flat blade to start, then small hammer, wood blocks or whatever, fold the edges of the brass against the aluminum plate. Voila, U-channel. Since the project is small, you don't need terribly thick brass to be strong enough, maybe 0.010" at worst. 0.005" might be good enough. It's a compromise between strength and being able to easily bend it. The brass is nice because you can then solder up a whole frame or whatever you want. If you need to go really shallow, so it makes bending difficult, make it a bit deeper and file it down to the desired depth.

Instead of the aluminum form, why not just use a spare 1.6mm PCB?

[themadhippy]

couple of bits of wood with a slot cut in the side,and 2 bits of threaded rod to clamp it together

[LaserSteve]

K&S Hobby  or McMaster Carr

You may also find it in model airplane or model race car carbon fiber extrusions.

S.

[JDubU]

Glue three pieces of scrap 1.6mm PCB's together as a sandwich with the center piece offset inward from the edges of the two outer pieces to form a channel.  Cut off the length/width that you don't want.

[ataradov]

Model stuff is a bit closer. I'll research that.

Any machining is out, I don't have the equipment and I don't want to bother custom ordering stuff.

Wood and plastics are out. Soldering also involved heated air.

I don't want to have a conventional PCB vice, there are lots of them and I don't like any of them. The idea here is to have the actual vice away from the view and have those channels to be extended jaws that are as small as possible.  At this time I don't care how the actual body is made. It might be just a custom 3D printed clamp to hold those things as a set distance.

[JDubU]

Something like this?

https://ksmetals.com/collections/brass/products/brchan-1-8x1-8

[langwadt]

Model stuff is a bit closer. I'll research that.

Any machining is out, I don't have the equipment and I don't want to bother custom ordering stuff.

Wood and plastics are out. Soldering also involved heated air.

I don't want to have a conventional PCB vice, there are lots of them and I don't like any of them. The idea here is to have the actual vice away from the view and have those channels to be extended jaws that are as small as possible.  At this time I don't care how the actual body is made. It might be just a custom 3D printed clamp to hold those things as a set distance.

bit hard to guess the exact measurements but

https://www.ebay.com/itm/174288271580
https://www.ebay.com/itm/360884811825

[ataradov]

Something like this?

Not really. This is too huge. 1/8" square results in ~2.5 mm internal channel. This is too much.

Model railroad tracks may end up closer to what I need. I'm currently figuring out how they are sized.

[ConKbot]

.  I need to hold 10 x 20 mm PCBs.

Look into watchmakers vices then

https://www.amazon.com/Hand-Free-Universal-Holder-HOL-173-00/dp/B0058EDVXQ/ref=asc_df_B0058EDVXQ/
Remove it from the base and cut off the stem to get something that fits under a microscope and just sits on a bench.