Darwin Master BOM

I merged all the separate BOM's into a central one on google docs. the developers should have access to it. email me if you dont. i also removed privileges on the olds ones, so we dont accidentally get version mismatches. you can find it here:

[spreadsheets0.google.com]

the only thing that needs done now is to change the embeds on the documentation. if anyone wants to tackle that, i'd love it!

> Is there any way to give non-developers read-only
> access, or at the very least export an XML or
> something of the data within it? A central BOM
> would be useful to me for the website I'm working
> on. Thanks!
>
> -Kyle

absolutely! thats actually one of the major reasons that google spreadsheets is such an attractive solution. they do some really rad things. first off, check out the BOM area on the wiki, i added links to major output formats for the BOM. you can also get CSV, TXT, and RSS data for each individual sheet on the spreadsheet with custom urls.

[reprap.org]

secondly, google offers some very interesting API's to interface directly and programmatically with the data. it looks to be a very solid API that has many potential uses. here is their page explaining it for PHP:

[code.google.com]

finally, the BOM is still a work in progress. there are a few HTML tables in the wiki that need moved over, and some of the pages need formatting to make them easy to work with via a computing language. regardless, this is a good first step.

one more thing, google does JSON output for spreadsheets! for doing web mashups, this is my favorite, and an absolute joy to work with. it takes all the work out of data interchange. spend more time doing cool stuff, less (zero) time parsing the data.

[code.google.com]

Zach,

I can view the spreadsheet fine, but not, apparently, change it. Initial reaction: I like it!

Why are so many columns apparently formatted to 2 decimal places. Items like Ref, Qty and so forth are (I would think!) always going to be non-negative integers, and if so, the sheet would be easier to read if they were formatted as such, IMO. I'd fix it, if I could edit it :-)

I have a couple of questions about two specific components from Mouser:

Q1. Why are we using a high-temp (max 125C) capacitor for C1, which has only a 16V voltage rating, when other nearby caps C2-C5 are normal (max 85C) temp rated but 50V voltage rating? If my PowerComm board ever reaches anywhere close to 85C, never mind 125C, surely something will be badly wrong (!). Therefore, my instinct is that I'd prefer the extra voltage "headroom" of using a 140-XRL50V100-RC (or even a 140-XRL25V100-RC if 25V is considered enough voltage headroom). Am I overlooking anything here?

Q2. On the UCB, are the little H1 heatsinks 532-530613B00 definitely known to be beefy enough to keep an L298N cool in our application? They just seem a bit on the small side based on my initial visual inspection. I've not done any detailed reading of data sheets to check ratings etc. on them, nor have I tried to compute max watts they are expected to dissipate and therefore what temp they are likely to reach.

Thanks,

Jonathan

Hi Zach,

Was gonna start embedding the sheets, but have a sugggestion...

It would be kind of neat if the suppliers were on the same sheet as the
parts list, that way any edits don't get lost between sheets, plus it's a
bit confusing flicking between sheets to find out where to get the part. Or
is there a reason I'm missing?

Just wanted to get it nailed before embedding...

eD

--On 14 June 2007 17:48 +1200 RepRap Forum Mailer wrote:

> Author: jmarsden
> Username: jmarsden (pool-71-103-170-244.lsanca.dsl-w.verizon.net)
> Subject: Re: Darwin Master BOM
> Forum: Developers
> Link: [forums.reprap.org]
> Approved: Yes
>
> Zach,
>
> I can view the spreadsheet fine, but not, apparently, change it. Initial
> reaction: I like it!
>
> Why are so many columns apparently formatted to 2 decimal places. Items
> like Ref, Qty and so forth are (I would think!) always going to be
> non-negative integers, and if so, the sheet would be easier to read if
> they were formatted as such, IMO. I'd fix it, if I could edit it :-)
>
> I have a couple of questions about two specific components from Mouser:
>
> Q1. Why are we using a high-temp (max 125C) capacitor for C1, which has
> only a 16V voltage rating, when other nearby caps C2-C5 are normal (max
> 85C) temp rated but 50V voltage rating? If my PowerComm board ever
> reaches anywhere close to 85C, never mind 125C, surely something will be
> badly wrong (!). Therefore, my instinct is that I'd prefer the extra
> voltage "headroom" of using a 140-XRL50V100-RC (or even a
> 140-XRL25V100-RC if 25V is considered enough voltage headroom). Am I
> overlooking anything here?
>
> Q2. On the UCB, are the little H1 heatsinks 532-530613B00 definitely
> known to be beefy enough to keep an L298N cool in our application? They
> just seem a bit on the small side based on my initial visual inspection.
> I've not done any detailed reading of data sheets to check ratings etc.
> on them, nor have I tried to compute max watts they are expected to
> dissipate and therefore what temp they are likely to reach.
>
> Thanks,
>
> Jonathan
> _______________________________________________
> Developers mailing list
> Developers@reprap.org
> [reprap.org]




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> I can view the spreadsheet fine, but not,
> apparently, change it. Initial reaction: I like
> it!

thanks! i invited the 'reprap spreadsheet' google account. if you'd like your account directly invited, please email me w/ your username.

> Why are so many columns apparently formatted to 2
> decimal places. Items like Ref, Qty and so forth
> are (I would think!) always going to be
> non-negative integers, and if so, the sheet would
> be easier to read if they were formatted as such,
> IMO. I'd fix it, if I could edit it :-)

possibly copy/paste errors, probably just havent been formatted correctly.

> I have a couple of questions about two specific
> components from Mouser:
>
> Q1. Why are we using a high-temp (max 125C)
> capacitor for C1, which has only a 16V voltage
> rating, when other nearby caps C2-C5 are normal
> (max 85C) temp rated but 50V voltage rating? If
> my PowerComm board ever reaches anywhere close to
> 85C, never mind 125C, surely something will be
> badly wrong (!). Therefore, my instinct is that
> I'd prefer the extra voltage "headroom" of using a
> 140-XRL50V100-RC (or even a 140-XRL25V100-RC if
> 25V is considered enough voltage headroom). Am I
> overlooking anything here?

i sourced the parts and it was my first foray into the jungle that is the Mouser catalog. thank you for pointing this out, as it should definitely be corrected if i chose the wrong part, or theres a better part out there.

> Q2. On the UCB, are the little H1 heatsinks
> 532-530613B00 definitely known to be beefy enough
> to keep an L298N cool in our application? They
> just seem a bit on the small side based on my
> initial visual inspection. I've not done any
> detailed reading of data sheets to check ratings
> etc. on them, nor have I tried to compute max
> watts they are expected to dissipate and therefore
> what temp they are likely to reach.

dunno. they were passed to me, and i ran with it. i put in an order for heatsinks, so hopefully they will arrive soon and i can actually physically test them.

Zach,

OK, thanks. My Google userid is the email address of mine that you already know,

I'm not enough of an electronics guru to really be *sure* about the value of trading away the higher temp rating for a higher voltage rating on C1 ... I thought *you* were an expert on this stuff :-) Let's hope someone with more electronics background than either of us comments on that. I was "brave" and ordered the 140-XRL50V100-RC part for C1 on my PowerComm board, in place of the listed part, so when I actually populate it, we'll have an idea of whether that "works" or not. It's an extra US$0.03 over the listed part, but I don't think that will break the bank! My guess: I suspect it doesn't really matter either way.

I have one of the H1 heatsinks here, untested until I try it, and I don't have any steppers to load up the LM298 with. I doubt a stepper tester board will be enough of a load to need a serious heatsink :-) I think Eric M. used this same part in Lamarck, so he may have some useful real-world input on this one already. His June 10 entry on the builder's blog suggests he may have a heat issue in the stepper electronics. Eric wrote:

> "I was actually able to get it to start extruding a minimug, but I ran into a
> few issues - mostly communications errors after one of the axes' motors had been
> running a while. I suspect it is heat related, so I will concentrate on making
> the heat sinks more efficient tomorrow."

Jonathan

> I thought *you* were an expert on this stuff :-)

god, i wish. i'd actually love it if someone who is a guru would appear that is interested in taking over maintenance of the electronics areas. the only reason its me right now is because it needed done, and nobody was doing it. any takers?


> I doubt a stepper tester
> board will be enough of a load to need a serious
> heatsink :-)

heh, nope... its just some LED's, no big load there.

okay, i started to work on the wiki BOM area. I added links for each BOM, as well as to a variety of formats that google provides. Please check it out and let me know if any links dont point to the right place:

[reprap.org]

Things left to do:

1. *done* Combine BOM / suppliers for the board lists (powercomms, etc)
2. *done* update embed codes to point to the correct google docs
3. *done* double check electronics BOM's to make sure they are ready for mouser BOM importer
4. *done* update electronics boms with new parts from recent electronics posts
5. *done* import / integrate other BOM's from the wiki to google.
6. *done* create BOM for stepper tester / opto endstops (needs population)
7. *done* double check everything

if anyone would like to help, just drop me a line and i can get you setup. otherwise it will probably get done by monday.

Edited 3 time(s). Last edit at 06/16/2007 09:25PM by Zach Hoeken.

jmarsden wrote:

> I have a couple of questions about two specific components from Mouser:
>
> Q1. Why are we using a high-temp (max 125C) capacitor for C1, which has only a 16V voltage rating, when other nearby caps C2-C5 are normal (max 85C) temp rated but 50V voltage rating? If my PowerComm board ever reaches anywhere close to 85C, never mind 125C, surely something will be badly wrong (!). Therefore, my instinct is that I'd prefer the extra voltage "headroom" of using a 140-XRL50V100-RC (or even a 140-XRL25V100-RC if 25V is considered enough voltage headroom). Am I overlooking anything here?
>

No you aren't. I haven't seen that before. I suspect somebody ordered
a capacitor, it turned up, and it happened to have that rating so it got
into the BOM. There is no reason for it. It is barely worth specifying
the max temp for the capacitors because it's more likely to confuse
people than help them. If the BOM says 85 and somebody happens to find
a 125 in a shop, they may be confused enough not to buy it. If it says
anything, perhaps it should give ranges, such as ">= 85C" rather than a
specific value.

> Q2. On the UCB, are the little H1 heatsinks 532-530613B00 definitely known to be beefy enough to keep an L298N cool in our application? They just seem a bit on the small side based on my initial visual inspection. I've not done any detailed reading of data sheets to check ratings etc. on them, nor have I tried to compute max watts they are expected to dissipate and therefore what temp they are likely to reach.

I can't help there. I don't have any of those heatsinks and I haven't
read the specs either. I don't know who selected them, sorry. Anybody?

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On Fri, 2007-06-15 at 01:27 +1200, RepRap Forum Mailer wrote:
> dunno. they were passed to me, and i ran with it. i put in an order
> for heatsinks, so hopefully they will arrive soon and i can actually
> physically test them.

I'm kinda limited on the heatsinks I can buy, so I just bought the
biggest pressed sheet one that would fit in above the diodes. Actually,
I bought a couple of big ones and cut them in half...

Vik :v)

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[reprap.org]

update:

finished #1, suppliers have been merged into the boards for universal and powercomms.
finished #2 as well.

also, i added new sheets for each of the other major system components in preparation for moving the rest of the BOMs into the spreadsheet.

Edited 1 time(s). Last edit at 06/15/2007 05:24PM by Zach Hoeken.

phew! after the mild frustration earlier today with kicad and the universal boards, i decided i needed to work on something i know i'm good at... and that is mucking w/ the wiki and the google spreadsheets.

i basically got all the things done that i set out to do this weekend. pretty much anything and everything is now nicely integrated with the google spreadsheets, everything is ready for the mouser BOM, and all the boards have BOM's made up. it could still use some work on formatting and cross linking, but at least now everything is there and accounted for. i think the only thing i'm missing is the heatsink for the L298N, which i'll try and dig up now.

yay!

>> Q2. On the UCB, are the little H1 heatsinks
>> 532-530613B00 definitely known to be beefy enough
>> to keep an L298N cool in our application? They
>> just seem a bit on the small side based on my
>> initial visual inspection. I've not done any
>> detailed reading of data sheets to check ratings
>> etc. on them, nor have I tried to compute max
>> watts they are expected to dissipate and therefore
>> what temp they are likely to reach.
>
> dunno. they were passed to me, and i ran with it. i put in an order for heatsinks, so hopefully they will arrive soon and i can actually physically test them.

If they do 10 deg C per watt or better they should be OK.

There's an annoying thing about Mouser here: their data sheet links seem
to try to fire up Adobe, rather than simply resolving to .pdf files
(which is what they are, I presume). So, if you use - say - xpdf, they
don't work.

Anyone want to send them an e-mail asking them to just put the data
sheets up as links to pdf files? RS and Farnell do it, so there can't
be irresolvable copyright issues.

--

Best wishes

Adrian

Dr Adrian Bowyer
[staff.bath.ac.uk]
[reprap.org]
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RepRap Forum Mailer wrote:

> I'm not enough of an electronics guru to really be *sure* about the
> value of trading away the higher temp rating for a higher voltage
> rating on C1 ... I thought *you* were an expert on this stuff :-)
> Let's hope someone with more electronics background than either of us
> comments on that. I was "brave" and ordered the 140-XRL50V100-RC
> part for C1 on my PowerComm board, in place of the listed part, so
> when I actually populate it, we'll have an idea of whether that
> "works" or not. It's an extra US$0.03 over the listed part, but I
> don't think that will break the bank! My guess: I suspect it doesn't
> really matter either way.

C1 needs to be 25v; C2 16v. These ratings are minima - extra will not
hurt, though they'll be physically bigger. C1 is actually subjected to
12v in practice, which gives a good safety margin. C2 sees 5v, so ditto.

The temp ratings are irrelevant, unless you want to operate your RepRap
in Death Valley on a very hot day... :-)

--

Best wishes

Adrian

Dr Adrian Bowyer
[staff.bath.ac.uk]
[reprap.org]
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Adrian Bowyer wrote:

> If they do 10 deg C per watt or better they should be OK.

Looks like 16.7 (Thermal Resistance == dec C / Watt, right?) ... so they are indeed too small! Data sheet is at [www.aavidthermalloy.com] unless I did something silly.

> There's an annoying thing about Mouser here: their
> data sheet links seem to try to fire up Adobe,
> rather than simply resolving to .pdf files
> (which is what they are, I presume). So, if you
> use - say - xpdf, they don't work.

I can download most Mouser datasheets directly, them using wget, as PDFs. Look at the one for the 16F628A as an example -- works fine. They are appearing with a Content-Type of "application/pdf", so any normal web browsing setup with a PDF viewer that is used for that Content-Type should work fine.

The one for these heatsinks (linked to above) is a redirect to a cgi-bin script at the www.aavidthermalloy.com web site, which is returning text/html not a PDF at all. But that is probably not Mouser's fault?

Are you sure this issue isn't a peculiarity of the machine you are browsing from? If you give me a specific datasheet from Mouser that doesn't work with xpdf but does work using Adobe Reader, I'll explore what is going on and report what I find.

> Anyone want to send them an e-mail asking them to
> just put the data sheets up as links to pdf files?

Not until I can duplicate the issue :-)

Jonathan

RepRap Forum Mailer wrote:
> Author: jmarsden Username: jmarsden

> I can download most Mouser datasheets directly, them using wget, as
> PDFs. Look at the one for the 16F628A as an example -- works fine.
> They are appearing with a Content-Type of "application/pdf", so any
> normal web browsing setup with a PDF viewer that is used for that
> Content-Type should work fine.
>
> The one for these heatsinks (linked to above) is a redirect to a
> cgi-bin script at the www.aavidthermalloy.com web site, which is
> returning text/html not a PDF at all. But that is probably not
> Mouser's fault?

That link works for me, and so do links to ordinary .pdf files, so
you're right - not Mouser's fault. Don't know why some Mouser links
don't work for me - probably not important.

--

Best wishes

Adrian

Dr Adrian Bowyer
[staff.bath.ac.uk]
[reprap.org]
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if you'd be willing to do the math and figure out exactly which heatsink is required for the L298N and the TIP110, I would be very appreciative. Just post the mouser part numbers in a new thread or something.

RepRap Forum Mailer wrote:

> if you'd be willing to do the math and figure out exactly which heatsink is required for the L298N and the TIP110, I would be very appreciative. Just post the mouser part numbers in a new thread or something.

I think 532-566010B03400G will work for the L298N. It's 11 C per watt
rather than 10, but that's not a problem. And I think it's designed for
multiwatt casings, which is what the L298N has. But I'm still having
trouble with the Mouser data sheets, so someone ought to check, or buy
one for $1.27 and try it...

I don't put heatsinks on the TIP110s. They're fully saturated when
they're on, so the voltage drop across them should only be about 0.4v.
You've got to put a lot of A through that to generate significant W.

But has anyone found they get warm?

--

Best wishes

Adrian

Dr Adrian Bowyer
[staff.bath.ac.uk]
[reprap.org]
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"I don't put heatsinks on the TIP110s. They're fully saturated when
they're on, so the voltage drop across them should only be about 0.4v.
You've got to put a lot of A through that to generate significant W.

But has anyone found they get warm?"

I can't speak to the TIP110's, but the BD681's which we specified in earlier design iterations of the extruder boards certainly do. I had a bunch of them in my stocks since I purchased early on and being Scots-Irish used one of them to run the extruder barrel heater on Tommelise. They get quite hot without a heat sink when I run them in the vicinity of 2 amps.

Edited 1 time(s). Last edit at 06/19/2007 10:26AM by Forrest Higgs.

that sounds good enough for me =)

i updated the new heatsink, and i'll remove the heatsinks from the BOM for the extruder. i guess if it turns out we do need them, then we can add them in later.

Quoting RepRap Forum Mailer :

> I can't speak to the TIP110's, but the BD681's which we specified in
> earlier design iterations of the extruder boards certainly do.

OK - they're both NPN power Darlingtons so they should be
indistinguishable in this regard. I suspect the difference is that
you're driving it full blast, whereas I'm using the PWM in Simon's
extruder code, so I'm going at a duty cycle of about 50%.

This means we ought to put a H/S on - there's nothing to stop someone
upping the PWM to 100%, and so it'll be needed for safety.

Mouser 567-290-1AB should fill the bill.

Best wishes

Adrian

Dr Adrian Bowyer
[staff.bath.ac.uk]
[reprap.org]
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> OK - they're both NPN power Darlingtons so they
> should be
> indistinguishable in this regard. I suspect the
> difference is that
> you're driving it full blast, whereas I'm using
> the PWM in Simon's
> extruder code, so I'm going at a duty cycle of
> about 50%.

Yes, I think so. The only difference between the two that I could see was that the BD681 seems to have a somewhat higher peak amperage than the TIP110, viz, the TIP110 peaks out at 4 amps and the BD681 peaks at 6. I seem to be able to do whatever I want at a max of 2-2.5 amps and the majority of my work with HDPE down at about 1.5-1.75 amps.

BOM updated.