Homebrew PCBs

Wow! The list grew quickly from the start. The majority of the latest
burst of members mention direct inkjet resist as their reason for
joining. I have no doubt that James Newton posting Volkan and Stefan's
results on Massmind had something to do with that.

I had not looked at the numbers lately, last time I checked (last
year?) we were at around 1500 members. As of today, over 3000 strong!

Good thing most are lurkers. ;') History shows us that a lurker may
suddenly pop up with some critical bit of information.

I love this list!

I am going to be adding Leon Heller and Bob Hyland as moderators.
They'll help me screen new applicants and messages from new members,
and help clean up any spam or off topic junk in the files, photos,
links, and database. And calendar, too, apparently. I'd never have
thought someone would use the calendar to post abusive messages!

Steve Greenfield
listowner Homebrew_PCBs

On Mon, 21 Aug 2006 21:45:00 +0200, Steve <alienrelics@...> wrote:

> Wow! The list grew quickly from the start. The majority of the latest
> burst of members mention direct inkjet resist as their reason for
> joining. I have no doubt that James Newton posting Volkan and Stefan's
> results on Massmind had something to do with that.
> I had not looked at the numbers lately, last time I checked (last
> year?) we were at around 1500 members. As of today, over 3000 strong!


Wow, it was 2000 when i checked not so long ago!

Why is there so little going on with inkjet?
I was kinda hoping for more results.

I want to and have to make many more boards, but the oven is delaying me.  
I thought i could finish that before making more boards. I tried to design  
the control circuit today, but quite frankly i'm not happy about it. The  
first one or two components i needed i didn't have, and they cost about  
5eur (a temperature sensor like lm335 and a precision reference with low  
temperature drift). With things going like that i will be much better off  
buying an industrial controller for about 20eur.
It's only a handful of components i would need to buy, but probably still  
cost at least 20eur. And then the thing is neiter designed nor built, so  
i'm really leaning towards an industrial controller that would just need  
to be hooked up.

BTW i also tried taking the thermostat out of that old oven after shooing  
the mice away, but the deadband is like 60C and not adjustable. Useless.

Anyway, i guess i'll just use the clothes iron upside-down some more until  
i have a controller.
Got some propylene glycol at the chemicals shop recently, will report what  
it does if used like brake fluid.

Another thing, i noticed a slight height difference left/right of the head  
rails, so the head gap is not constant. This does not matter for most  
boards, but i bought a dial gauge anyway to adjust it precisely.

ST

> stefan_t wrote:
>
> <Snip stuff about inkjets and curing ovens>
>
> one or two components i needed i didn't have,
> and they cost about 5eur (a temperature sensor
> like lm335 and a precision reference with low  
> temperature drift). With things going like
> that i will be much better off buying an
> industrial controller for about 20eur.

Not going to argue about use of industrial
controllers against self built stuff (I always
say why buy it for 10$ when you can build it
yourself for only 100$)

However - Unless its some magic type of LM335
(or LMx35 variant) then it is not going to like
the 200+ degrees inside an oven.  I think the
normal LM-whatever tematrature sensors top out
at 125 degrees.

I think if you wanted to measure the temp in
the oven then a thermocouple might be a good
move.  If you want to interface to analog
electronics and didn't want to design your own
cold junction compensation then an AD595 could
be used (expensive and old).  If you wanted to
interface to an MCU then the MAX6675 would be
a good choice. (direct temprature out on an SPI
bus)

On Tue, 22 Aug 2006 01:53:27 +0200, Andrew <andrewm1973@...> wrote:

>
> However - Unless its some magic type of LM335
> (or LMx35 variant) then it is not going to like
> the 200+ degrees inside an oven.  I think the
> normal LM-whatever tematrature sensors top out
> at 125 degrees.


Yes, yes, of course thermocouple inside the oven.
But the LMxxx would be needed as a cold junction compensation, ad595 too  
hard to get.

ST

Stefan,

I have not been entirely idle! I only got my C84 a few days ago and
work-life and home-life have conspired to only give me a small amount
of progress to report. Thus far I only have the refillable ink carts
installed and the black and cyan nozzles printing well. The yellow and
magenta seem to be jammed, but since every cart has the same
yellow-black mixture I don't really care.


Anyway I have a bit more detail on my blog:
http://roycepipkins.blogspot.com/ . I intend to try to keep a somewhat
decent log of my efforts to reproduce your results.

Regards,
Royce


--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@...> wrote:

> Why is there so little going on with inkjet?
> I was kinda hoping for more results.

> > Me wrote:
> >
> > However - Unless its some magic type of LM335
> > (or LMx35 variant) then it is not going to like
> > the 200+ degrees inside an oven.  I think the
> > normal LM-whatever tematrature sensors top out
> > at 125 degrees.
> 
> ST wrote:
>
> Yes, yes, of course thermocouple inside the oven.
> But the LMxxx would be needed as a cold junction
> compensation, ad595 too hard to get.

Opps - sorry - you are doing your own cold junction
stuff.

I will just shut up now.

Keep up the good work :D

Stefan,
This chap just used a Glass NTC thermistor!
http://www.ustr.net/smt/oven.htm
HTH
Regards
John C

> -----Original Message-----
> From: Stefan Trethan [mailto:stefan_trethan@...]
> Sent: 22 August 2006 10:15
> To: Homebrew_PCBs@yahoogroups.com
> Subject: Re: [Homebrew_PCBs] How not to control ovens - was - The list
> is huge! Really huge!
> 
> 
> On Tue, 22 Aug 2006 01:53:27 +0200, Andrew 
> <andrewm1973@...> wrote:
> 
> >
> > However - Unless its some magic type of LM335
> > (or LMx35 variant) then it is not going to like
> > the 200+ degrees inside an oven.  I think the
> > normal LM-whatever tematrature sensors top out
> > at 125 degrees.
> 
> 
> Yes, yes, of course thermocouple inside the oven.
> But the LMxxx would be needed as a cold junction 
> compensation, ad595 too  
> hard to get.
> 
> ST
> 
> 
> Be sure to visit the group home and check for new Links, 
> Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
> 
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ 
> Yahoo! Groups Links
> 
> 
> 
>  
> 
> 
> 
>

On Tue, 22 Aug 2006 04:24:43 +0200, John Craddock  
<John.Craddock@...> wrote:

> Stefan,
> This chap just used a Glass NTC thermistor!
> http://www.ustr.net/smt/oven.htm
> HTH
> Regards
> John C


Yes, but i would like some form of actual temperature display and only a  
thermocouple produces a nice almost linear output.
One would need a micro with a conversion table for a thermistor...


ST

> Why is there so little going on with inkjet?
> I was kinda hoping for more results.

Sorry Stefan.  I was hoping to be well on my way with the ink jet 
stuff too - perhaps even beating you to having ink jet printed 
boards.  However, too many things were/are up in the air for me right 
now and I can't keep them all straight. I decided a while ago (month 
or two) that I need to finish up some projects before moving onto some 
new ones.  I must finish my machine, or at least get it moving in all 
axis and changing tools. I must get the DRO project designed and 
working as that is needed for many other things I am doing.

Once I get those two biggies out of the way and if nothing else in 
the "Poop occurs" category happens, I will be back on the conversion 
of the R220 printer.

When we bought that ink together, I really figured I would have been 
able to do the ink jet process within a week or so of getting the ink -
 GRRRRRRRRRRRR.  Too many things to do, so little time to do it all.

> -----Message d'origine-----
> De : Homebrew_PCBs@yahoogroups.com 
> [mailto:Homebrew_PCBs@yahoogroups.com] De la part de lcdpublishing
> Envoyé : août 22 2006 08:43
> À : Homebrew_PCBs@yahoogroups.com
> Objet : [Homebrew_PCBs] Re: How not to control ovens - was - 
> The list is huge! Really huge!
> 
> Sorry Stefan.  I was hoping to be well on my way with the ink jet 
> stuff too - perhaps even beating you to having ink jet printed 
> boards.  However, too many things were/are up in the air for me right 
> now and I can't keep them all straight. I decided a while ago (month 
> or two) that I need to finish up some projects before moving 
> onto some 
> new ones.  ...


Same thing here.  I am devouting my time to my main project for the time
being.  For a while I was spitting out many PCBs, but now that I've finished
the electronics phase, I am in no hurry for another circuit (I can always
slap one together with toner transfer if need be).

Now I'm up to my eyeballs in VB/ACCESS and its intricacies.  Once things
settle down and I have some free time then I'll get back into the inkjet
project.  I figure once I ship it out to patent and send a few demos to
testers I'll have time to get back into this.

Robert
:)