Yet another resistance decade box

[smgvbest]

I like it, Sandra. What's the minimum length possible (i.e., would the case bump into the switches first or the binding posts)?

I'm have to figure it out for sure.
6 decades with end caps is ~42mm,  with my design I need at minimum 10mm total clear so figure 6 decades at 52mm width.
the 16x8 need about 29mm depth for the PCB then add rear jacks and some clearance. so I'm sticking with the 60mm deep and that may be cutting it close.

So here's a question
what is the preference for the jacks?
do most envision plugging bannana plugs in or test probes or bare wire?

I could make the rear a separate panel to allow for different options in the design (which thinking about it I think I will)

for me personally I'm probably going with these so my initial design will be based on them
http://www.digikey.com/product-detail/en/mueller-electric-co/BU-31610-2/314-1267-ND/4692920

[Back2Volts]

I think the gray ones are prettier
http://www.ebay.com/itm/391269356283

I think those are the ones I call white.   That seller does not ship to US       We must give bad feedback when they ship the wrong thing 

[all_repair]

I think the gray ones are prettier
http://www.ebay.com/itm/391269356283

I ordered direct from Taobao china.  I came across a similar one but dare not order as it is 2mm shorter.  The one I came across has the signs, + and -, of the button painted red.

[Fortran]

Time for another update: 

I have now ordered more resistors, and they should arrive by the end of next week.
The ones I ordered the last time where out of stock, so I had to change the price a little.

6 PCB's = 1.50 USD (or 0.25 each) Edit: ** Out of stock **
1% resistors kit = 2 USD Edit: ** Out of stock **
0.1% resistors kit = 16 USD  Edit: ** Out of stock **
Shipping worldwide = 3 USD

[Back2Volts]

I like it, Sandra. What's the minimum length possible (i.e., would the case bump into the switches first or the binding posts)?

I'm have to figure it out for sure.
6 decades with end caps is ~42mm,  with my design I need at minimum 10mm total clear so figure 6 decades at 52mm width.
the 16x8 need about 29mm depth for the PCB then add rear jacks and some clearance. so I'm sticking with the 60mm deep and that may be cutting it close.

So here's a question
what is the preference for the jacks?
do most envision plugging bannana plugs in or test probes or bare wire?

I could make the rear a separate panel to allow for different options in the design (which thinking about it I think I will)

for me personally I'm probably going with these so my initial design will be based on them
http://www.digikey.com/product-detail/en/mueller-electric-co/BU-31610-2/314-1267-ND/4692920

I have been thinking about the case for the last week or so.   I have come up with a few thoughts:

- The box has to be as small as possible so it can be close to the breadboard (or whatever) and not be an annoyance.
- Connections have to be as short as possible (some uses may require it).
- Connection binding has to be as small as possible.  If jacks, that would point to 2mm units. 
- Digits have to be visible to operator while in use.
- Utility takes precedence over stylistic shapes.

With that in mind,  I am afraid I will have to design my own...    I am not trying to convince anyone.   I have put some (retirement) hours browsing eBay, Alixpress, Mouser, Digikey... 

So, if I think I would be placing the unit(s) behind the breadboard, with digits facing me, then the connections would have to be as close to the front as possible.   

If using jacks, because of their dimensions, they would be 2mm ones, and to minimize case size, they would have to be placed in the front face, left or right of the switch block.   But 2mm jacks are not that common on my bench, and a good jack may cost more than the rest of the box.  So, do I really need jacks?   

I have mulled over if just a couple of good silicone wires coming out of the from wall (mini grommets?) would be enough, but I think some times I may need longer or shorter ones.   

All the above is taking me to think that the best solution for me is to build some custom bolt based binding posts.   May be M3 Allen head, fork lug and washer on the inside; flat nut and acorn nut outside to receive wire with fork slug.   Both bindings vertically aligned can take around 12mm to 15mm of horizontal space in the front wall. 

The switch block, with 6xswitches + 2xbookends, has a total width of 42mm, plus 2x1mm lips.   The height is 16mm plus 2x1mm lips. The switch depth with the new boards is short of 30mm plus the lip which will stay outside. 

A box with inside dimensions of 60mm x 30mm x 16mm should do it.   Top and bottom overlapping except where the switch block is, where they move back to account for the lip.   Top and bottom tied with 3mm screws on the inside and nuts on top.

May be I can draw something tomorrow.

 

[julian1]

I have now ordered more resistors, and they should arrive by the end of next week.

Ordered 2x kits!

[PeterZ]

I'm going to order the larger switches and design an MBB pcb for them, too. Since it will be larger, maybe a version for through hole resistors (higher wattage?) would be a good idea?
Anyway, glad to see my simple hack is getting popular!
Make sure you post some pics of your finished decade boxes.

[gblades]

So here's a question
what is the preference for the jacks?
do most envision plugging bannana plugs in or test probes or bare wire?

I would probably go for terminal posts on the back so I have a choice of bare wires or banana plugs.

For use when prototyping on breadboard it would be nice if the top and bottom had guides to hold a piece of strip board where a couple of bits of 2.54mm socket strip could be soldered. There could be a small rectangle hole in the front next to the switches where this could stick out to be flush with the front.
When you are prototyping on breadboard you could then just plug your normal jumper wires directly into the socket and the whole unit would be as close as you wanted to the prototype and visible. For other uses you still have the option to use the terminal posts at the back.

[gblades]

There is a company very local to me who does 3D printing so if you have a finished design but can't print it yet I would be happy to get a test done and post photos etc... Here are the details of the printer they have :-
http://aaisp.net/printing-3d.html

They charge £0.30 per gram which I have no idea what the normal rate is. Any idea how much the case would weigh? I am guessing very little.

[bitseeker]

what is the preference for the jacks?
do most envision plugging bannana plugs in or test probes or bare wire?

Binding posts are pretty flexible when it comes to connection variety. That's what are on my IET decade boxes.

The RBox Mini only uses two posts and places them on the side of the enclosure, if I recall correctly.

I could make the rear a separate panel to allow for different options in the design (which thinking about it I think I will)

Yeah, folks can choose which panel they want to print.

for me personally I'm probably going with these so my initial design will be based on them
http://www.digikey.com/product-detail/en/mueller-electric-co/BU-31610-2/314-1267-ND/4692920

Would jacks require more internal space (i.e., larger enclosure)?

[ez24]

How about something like this

http://www.ebay.com/itm/Keystone-5010-Test-Point-PC-multi-purpose-Red-lot-of-96-pieces-/142033934902?hash=item2111e1da36:g:KqMAAOSwc1FXahMX

and use alligator clip end wires

[Back2Volts]

for me personally I'm probably going with these so my initial design will be based on them
http://www.digikey.com/product-detail/en/mueller-electric-co/BU-31610-2/314-1267-ND/4692920

Would jacks require more internal space (i.e., larger enclosure)?

This is the data sheet for the above jacks:  http://muellerelectric.com/wp-content/uploads/DS-BU-31610-2.pdf   

One of those jacks is about as long (depth) as the switches with the new boards; just a millimeter shorter than the switches and almost three times the width of one of the switches.   So, yes, if 4mm binding posts are used, the size of the box increases significantly.

It all depends on what one values more:   To have the flexibility to use any kind of 4mm connectivity no matter how bulk it becomes or to compromise with dedicated wire/lead solution for the benefit of smaller footprint.

FWIW I just came back from the local hardware store with some 6-32 screws(~3mm), nuts, washers and knurled nuts.   May be I will post a picture.  I am looking for the smallest footprint possible.   I will splurge in a two position 2.54 female header for straight breadboard use.   I can always snap a 4mm  crocodile clamp on the knurled nuts.

I have a piece of 2mm clear acrylic somewhere in the garage, but have no fancy tools to deal with it other than the 10" table saw, which is very much like a cannon for the flimsy sheet.   Still scratching my head as to how to approach the building.

[Back2Volts]

How about something like this

http://www.ebay.com/itm/Keystone-5010-Test-Point-PC-multi-purpose-Red-lot-of-96-pieces-/142033934902?hash=item2111e1da36:g:KqMAAOSwc1FXahMX

and use alligator clip end wires

At was looking at similar test points yesterday.   They sure are small.   It would be a compact solution.   A custom wire with a one of those small wire clamps and whatever, pin, jack or clamp on the other end.

[ez24]

Ebay  ?

\\http://www.ebay.com/itm/20pcs-brass-Banana-Socket-Jack-Binding-Post-FOR-4mm-BANANA-Plug-/151247841828?hash=item233712ea24:g:gDYAAOxy0NtTF7hM

[smgvbest]

Made a few updates,  still basically the same but the front and back panels are now replaceable so different combinations can be done.

This box isn't going to make everyone happy.  this is as flexible as possible and stable. 
it's stack-able so you could have multiple decades boxes all handy.
will accommodate up to a 10 decades including end-caps
5mmx2mm magnets on bottom and those match up to the screws on top (5mmx2mm because I have a bunch  )

The depth accommodates most binding posts and I'm using 8mm (.313in) holes which seem to be common)

Still waiting on hotend for me printer
FWIW, it's estimate is 75G of material to print.

[Back2Volts]

Ebay  ?

http://www.ebay.com/itm/20pcs-brass-Banana-Socket-Jack-Binding-Post-FOR-4mm-BANANA-Plug-/151247841828?hash=item233712ea24:g:gDYAAOxy0NtTF7hM

Those could possible be mounted on a side with relatively less increase of the box size because it seems a large part of the piece is on the outside.

[bitseeker]

Made a few updates,  still basically the same but the front and back panels are now replaceable so different combinations can be done.

Cool. One adjustment to the front-panel label: "MOhm" instead of "mOhm". Lowercase 'm' is milli- vs. capital 'M' being mega-.

This box isn't going to make everyone happy.  this is as flexible as possible and stable.

Nothing makes everyone happy. This is good and can be further modified by someone to suit their individual needs.

[ez24]

Is someone making a case for these switches for sale?   Or is the talk just about personal cases?

[gblades]

My switches arrived today and I soldered and assembled them. The pcb's are a perfect snug fit.

[smgvbest]

Cool. One adjustment to the front-panel label: "MOhm" instead of "mOhm". Lowercase 'm' is milli- vs. capital 'M' being mega-.

Thanks for the catch,   fixed it

Quick edit
Here's case with a 6 decade (as ordered from Fortran.

Another edit:
here are 2 stl files, 
1. for a 6 decade with endcaps
1. for a 10 decade with endcaps

Had to zip them as the site doesn't permit stl files

if anyone wants to do a test fit that has a 3d printer let me know how they fit
since its a test a 30% or less infill would be recommended to save filament and time.
hopefully my hotend will be here Saturday or Monday

[Alex Nikitin]

Yesterday I've received the switches and built two 4 decade assemblies (100 Ohm steps) for my alignment cassettes recording setup - to adjust the bias voltage and recording current accurately. I've used MELF 0.1% 15ppm (Vishay MMA series) resistors, as I've found these very stable and consistent.

Cheers

Alex

[Alex Nikitin]

Ordering more boards!

Just paid for 3x 6 pcbs only.

Thank you.

Cheers

Alex

[rudika79]

Money sent for 12 boards

Rudolf

[smgvbest]

Binding posts are pretty flexible when it comes to connection variety. That's what are on my IET decade boxes.
Would jacks require more internal space (i.e., larger enclosure)?

didn't reply to those questions
I'm not using binding posts in mine but the space inside the box would easy allow for them
there's all kinds of binding posts/banana jacks I choose some longer ones on purpose to allow for most fitting options.

[smgvbest]

Just orders more PCB's and a 1% resistor kit.   already have others I need