Parts List

Hi Zach

Parts list for PowerComms attached with Farnell UK Numbers

They are not verified in that I did not order every item as I had some parts in stock. However I think they are all OK. Be warned some Farnell items have minimum quantities but if you order a lower quantity they automatically up the quantity.

The 4700uf cap I did buy and it is not a perfect fit but OK with a little pin bending.

I noticed C5 has a bigger pin spacing than all the other 1uf caps.

I also placed the LED the wrong way first time as I misunderstood the silk screen and thought there was a flat on the side to the middle of the PCB


Regards

Ian

CommBoardParts_Farnell.xls

I placed a futurlec order for one of everything I could find on Friday. Our lists match up pretty well.

I added a heat sink for the power transistor that looks pretty close to the mouser one, 4-pin female header, jumper block, and 9-pin D-sub connector.

I changed your MAX232EPE to a MAX232CPE which has a more restricted temperature range (0-70C) and is a little cheaper. Realized I ordered 5mm LEDs instead of 3mm ones, oops.

I have a feeling we could get away with using PCBT2 for the universal board power connector. It's 5mm pitch instead of the required 5.08mm pitch. Didn't add this, though.

The big cap from futurlec is 25V instead of 50V. Is that going to be a problem?

A few of the items, like resistors and crimp pins, come in packs of 10. It probably doesn't matter since there's no automatic BOM import, I guess we can count on the human doing the right thing.

Cool. It will be interesting to see how fast they turn your order around -- Futurlec seems to have a bit of a reputation for slow shipping.

Can you either add your additional Futurlec part #s to the spreadsheet, or let me know what they are, so I can add them? Thanks.

There were so many MAX232 variants I stopped searching when I found one with the right packaging! The cheaper CPE one should be fine, of course. Bigger LEDs should be fine, too, I think, as they aren't crammed up against other components. PCBT2 is worth trying, I doubt we care about 0.08 mm pin spacing difference, the holes in the board should be able to accommodate that small a change!

I wondered about the 25V vs 50V rating on the capacitors, too, but since most people will be powering it from an already regulated supply (12V output from a PC PSU), I can't see a problem. If you were doing something interesting like powering your RepRap from a waterwheel in your local stream, you might want to be a bit more careful with stuff like that (rainstorm causes stream to flow extra fast one day, voltage goes way up?)! But I suspect in that case you'd be charging a couple of old car batteries or something anyway, which would help keep the output voltage reasonably sane.

Jonathan

jmarsden Wrote:
-------------------------------------------------------
> Cool. It will be interesting to see how fast they
> turn your order around -- Futurlec seems to have a
> bit of a reputation for slow shipping.

They're certainly not fast. My last order was placed on 3/18 (sun), shipped on 3/22, arrived in VA on 3/29. This time I figured I'd pay the extra $5 for "express" shipping, so we'll see how they do with that. At nearly half the price of mouser/digikey type places, I'm willing to cut them quite a bit of slack.

> Can you either add your additional Futurlec part
> #s to the spreadsheet, or let me know what they
> are, so I can add them? Thanks.

Done.

> Bigger LEDs should be fine, too, I think,
> as they aren't crammed up against other
> components.

They do fine. It looks like they were the size originally specified -- that's what mouser sent when I ordered from the BOM a month or so ago.

>> Bigger LEDs should be fine, too, I think, as they
>> aren't crammed up against other components.

> They do fine. It looks like they were the size originally
> specified -- that's what mouser sent when I ordered from
> the BOM a month or so ago.

Ah, so it was really *my* "oops" specifying 3mm ones! We should be consistent. I'll edit the Futurlec part numbers into 5mm LEDs.

Jonathan

jmarsden Wrote:
------------------------------------------------------->
> Ah, so it was really *my* "oops" specifying 3mm
> ones! We should be consistent. I'll edit the
> Futurlec part numbers into 5mm LEDs.

No, no.... sorry for the confusion. The current mouser part specified in the BOM is 3mm, so your original LED was correct. It seems that one of the old versions of the BOM I ordered from a few months ago specified it as 5mm. I just looked at the current assembly instructions and it's definitely a 3mm LED in the pictures.

OK, fixed. BTW, when you modify the spreadsheet and are happy with the changes, you need to "republish" it so that the BOM Generator sees your changes. Took me a few minutes head-scratching to understand why your changes were there and visible in the spreadsheet, but the BOM Generator didn't see them at all :-)

I'm about to order parts from Futurlec for my Y and Z axis StepperControllers, 3 endstop boards and one Stepper Tester board. I'll do it the slow shipping way and see what happens.

Looks like we're now "missing" just 2 parts at Futurlec compared to Mouser, the H21LOI opto gadget from Fairchild, and another heatsink. Mouser parts are 512-H21LOI and 532-566010B03400G .

Jonathan

jmarsden Wrote:
-------------------------------------------------------
> BTW, when you modify the spreadsheet
> and are happy with the changes, you need to
> "republish" it

Ah, thanks. I knew there must be some secret to it.

> Looks like we're now "missing" just 2 parts at
> Futurlec compared to Mouser, the H21LOI opto
> gadget from Fairchild, and another heatsink.
> Mouser parts are 512-H21LOI and 532-566010B03400G

I ordered one of the small extruded aluminum TO-220 heat sinks to put on the L298, we'll see how well that works. It looks like we don't need a heat sink at all, so I think I might get away with it.

We're probably out of luck on the opto-interrupter. They don't have any, and it seems like vendors who just carry a few usually stock the 4-pin varieties instead of the 5-pin ones we use.

Still, pretty good coverage for a discount store.