Standoffs

Sorry for another dumb question, but I was curious about standoffs.

I tried a couple of standoffs I had picked up from Radio Shack and I noticed that the bolts are a little bit too big for the Shruti PCBs and definitely too big for the LCD.

I was curious what people were using for the standoffs and if they had a good source for standoffs?

Thanks.

Which standoffs were they? Don’t you mean that the standoff itself was a little too thick? I can’t remember what type of screws come with that pack.

4-40 screws will definitely fit in the holes on the PCB. 2-56 screws should fit in the LCD PCB because they’re about 2.2mm in diameter and the LCD’s holes are 2.5 mm, according to the data sheet. The height of the standoff is up to you and your design.

The place you want to go is www.mcmaster.com .

The screws were what I was referring to.

I’m not sure myself what the radio shack sizes were exactly. They list the height of the posts as 11/16", but nothing else.

I’ll check McMaster and see what they have. Thanks for the help.

4-40 is too big for the LCD so 2-56 is what you will need. The pots used in the shurti are the same as the x0xb0x so a 15/32" long standoff will be the right height

I’m a little confused about standoffs/spacers myself. I’m based in the UK so I’m heading out to my local Maplin tomorrow to pick up tools and parts, but from the website the only relevant-looking stuff I can find are these:

http://www.maplin.co.uk/Module.aspx?ModuleNo=219941
http://www.maplin.co.uk/Module.aspx?moduleno=29864

Am I right in thinking that the second link is somewhat useless because a 3mm thread is too small for the PCBs and too big for the LCD? And that the first link with the snap-on things might be suitable for the PCBs but will be unsuitable for the LCD (as well as having the added disadvantage of being fugly by sticking out of the outside of the case)? Anyone know where I can pick up the right parts from a UK supplier (ideally something I don’t have to mail-order, since the postage will be way more expensive than the components!), and what to ask for?

ElectroDruid:

Those are all wrong. You want something called, “female threaded hex standoffs/spacers”.
Here’s an example of what I used for one of the pcb’s (which may prove to be too tall when I get my case): http://www.mcmaster.com/#91780a427/=6skrmh
…and the LCD: http://www.mcmaster.com/#91780a103/=6sl549

Again, these are just examples; you may want your LCD to stick out of the front panel or be flush with it (mine is not). I can’t tell you how high you should have the pcb off the ground, either.
All I can say is that you should have an idea of how you intend to house your Shruti, before ordering standoffs. For instance, I was going to mount the inputs/outputs on the rear panel, not using the hardware on the PCB, so I didn’t care how tall they were. I just ordered some more of the ones I was going to use on the control PCB. Subsequently, I had to raise my design a lot to allow for this (but I could have just bought different standoffs).

I couldn’t find this stuff in any hardware store, not even the 2-56 screws, so buy them when you place your order! (I did eventually find some of those screws at one of the last Radio Shacks to have one of those component drawers.)
Yeah, it’ll cost more than you want to play for such tiny things, but you just can’t them in stores, it seems.

These things still seem to be like hen’s teeth to try to get anywhere in the UK. Even ordering online, pretty much every site says that it has to deliver stock from the USA, with £15 worth of postage or whatever, which is pretty ridiculous. I’m thinking that might be because I’ve been looking specifically for the 4-40 that’s been recommended here, but it looks like maybe that’s some nonstandard USA-only imperial type measurement and I want something standard in metric to stand a better chance of somewhere in Europe stocking them. What’s the equivalent? M2.5?

I don’t think I can even find any spacers that are 2-56 or equivalent. Am I better off just buying some screws of suitable width and length and just screwing the LCD directly to the case without standoffs?

:http://www.reichelt.de/?ACTION=3;ARTICLE=7120;GROUPID=;SID=28KlE5NKwQARwAAAxu1g0195e62f0e7edb89db1b002f91c638921

the pic’s a link to the page.

those 15mm long guys with 3mm thread (sorry for the metric) are just 11cent at reichelt.
ordering from outside germany requires 150€ minimum order, but if you just need those hex standoffs or whatever i can order them for you.

they have them in different length, also a 4mm variant (DI4 xMM)

I need some of those too! and I’m in Italy so ordering from Reichelt is a problem. Why do you say I need 15mm standoffs? According to my calculations they should be exacly 10mm… for the buttons to stick out just a couple of mm (using 3mm thick frontplate).

i don’t say you need 15mm, they’re just a random example. they have 10mm too (just substitute the numbers in the item nbr). actually you can also cut excessive length with an ordinary metal saw if your needs don’t match the standard.

@rosch - If you can order parts without the 150€ minimum order and if you don’t mind sending them on, that would be amazing. I’d be more than happy to pay for them and for the postage. What would be the best way to contact you to let you know what I’d like to get, where to send it, and to arrange payment?

well if there is going to be a collective order thing count me in!

When I did my x0xb0x this was a huge issue and I got soaked buying not quite right standoffs in Canada in lots costing upwards of $100, just like the euopean prices mentioned above, all because McMaster wont ship out of the us in small orders even in a free trade zone. I hate 15/32 sizes because 1/32 either way is easy to find but not 15/32.

you can get away without spacers using loads of normal washers and long bolts. thats what i did.