Build report times two

[Mark Hammer]

I packed a bag of parts and a board to bring to my in-laws for our annual holiday visit, and last night I put together a Ross phaser using the Tonepad layout.  Francisco, it worked flawlessly first time I fired it up with no troubleshooting required.

I am pleased to report that not only does this unit have a nice sweep which is obviously of the "hypertriangular" variety (sweeps slower as it goes to the bottom of its range and then picks up speed as it goes to the top of its range) , but the phase-filter mod sounds terrific.  In fact, because of the greater variation in resonance and the different LFO waveform I think it sounds even better than the Small Stone in that mode.  At highest resonance it has a very pronounced wah-wah sound, and at slightly slower sweeps it produces a nice swell effect.

I did the mod using the pair of 3300pf caps found in the lower left-hand corner of the board (looking at the illustration of the component side at Tonepad).  The resistor to lift for vibrato effects (which also yields strongest phasefilter effect) is the 27k resistor just below the dual op-amp.

The second happy report is that the board was made using glossy photopaper for laser printer/photocopier.  I needed to touch it up a wee bit with a pen, but 95% of itwas every bit as good as PnP.  Given that I paid 20 cents a sheet for the paper, that is a really nice holiday treat for me since post-shipping/duty PnP would probably run me about $3 a sheet.  Thesurprise to prepare yourself for is that instead of seeing the more familiar blue surface on the copper board where the toner adheres, you see the white emulsion of the photo paper lifted off.

I probably still have to get used to adjusting the heat and pressure on the irn to get truly clean pattern transfer, but I used it for the Ropez  which is a tight layout and it came out fine on the first go-around.

So, two thumbs up, and a satisfying holiday.

Now, Francisco, if you could redo the Ropez layout for 8 stages with a quartet of 13600s that would be fantastic!!

[M.D.]

Sounds cool I have the ross phaser schm.and would love to build it but I dont have the components :cry: lol,but speaking about the art work I just got a new all in one lexmark x75 and I'm a bit scared how my photo meathods will turn out, like I said last time my hp did an outstanding job,hmm sorry to cut into your post mark.

P.S. would you be able to give me some pointers on that ross if I get stuck?

Mike. :twisted:

[ExpAnonColin]

Mark-
I seem to have missed this glossy photopaper in place of PnP bit.  Is there a thread or site I could look at to do this?

-Colin

[Mark Hammer]

I couldn't tell you where to look but it was certainly brought up somewhere in the last few weeks.

The gist of it is this.  PnP operates by having an emulsion on the sheet that bonds/fuses with the toner in a laser-based printing device (laser printer or photocopier).  The toner, in turn, bonds nicely to copper board when heat is applied. More importantly, the blue emulsion on the acetate PnP sheet *DOESN'T* bond to the copper all that well.  The end result is that when you apply heat properly, let it cool properly (and these days that can be as simple as pressing the board against a window), and peel it off, those parts of the PnP sheet with no toner on it come "unstuck" from the copper board/surface really easily while those parts with toner stay put, yielding the resist pattern.

Although glossy photo paper is not designed to do anything like that specifically, the fact of the matter is that it *DOES*, because it has an emulsion sitting on top of the paper backing.  Black toner on the surface of the paper will bond/fuse to the copper when heat is applied, and the emulsion layer of the photo paper without any toner on it won't.  

Note that this is a question of TONER and *not* INK.  Use photo paper with an inkjet printer and the principle will not apply, since what all of this depends on is the properties of toner against copper and not just the glossy photo paper itself.  I bought some glossy inkjet paper and it was a complete bust.

One of the primary differences between PnP sheets and glossy photo paper is that PnP comes on a thin acetate sheet with a fairly thin emulsion.  In contrast, glossy photo paper is thicker, the emulsion is thicker, and it does not conduct heat as uniformly as PnP.  What this means is that although you can use photo paper as a means to attach a resist pattern to a board, the image will generally be crisper and have cleaner edges with PnP because it has so much going in its favour.  The long and the short of it is that I would wholeheartedly endorse photo paper for some board layouts but not for others.  For instance, if you have a layout where one or more traces run *between* IC pads, go straight to PnP and skip the heartache.  The overwhelming majority of layouts posted in this community, though, will likely work fine (although the pads could stand to be just a tiny bit larger, Francisco).

Because most folks use glossy paper for their own photos and most folks do not have colour laser copiers, I suspect you'll find that stores which carry even a huge assortment of photo paper will have tons of inkjet photo paper and either not carry such paper for laser printers or only have it available in commercial/institutional quantities ($100 packs of laser paper anyone?).  The good news is that places where you can bring in photos and ask them to blow it up to 8-1/2 x 11" on glossy paper WILL carry glossy laser paper.  They may well be seriously perplexed when someone asks them to transfer a black and white image onto glossy photo paper, but they will be able to do it.  If they can sell you some sheets to use on your own laser printer or even a 10-cent public photocopier, even better, but since the paper stock they use can vary from thin to thick, it may be smarter just to pay the money and have them do the copying.  You have no guarantees that the paper feeder in the printer you plan to use can accommodate that thickness but obviously the copier place's printer will.

What I do is cut out the patterns from different PDFs I print out and make a composite of multiple layouts on a single sheet.  If there is a particular circuit I want to make sooner, I'll stick two copies of it on the same sheet just in case I screw up one.  Since these don't always print out maximum darkness, you can crank up the contrast/darkness on the photocopier.  Remember that the more toner the stronger the bond with the copper.

I made the mistake of buffing one board with fine (320 grit, I think) emery paper.  Bad move.  I should have buffed it with steel wool.  With PnP, I don't think that non-mirror-like surface gets in the way of good pattern transfer.  Because you are dealing with paper, though, the copper surface needs to be as smooth as possible to compensate for the unevenness of the paper medium.  Visible scratches from too coarse a buffing/cleaning agent provide poorer grip for the toner.

I used a standard clothes iron, set up for cotton or wool (no steam, obviously).  Much like PnP, you will see a very very slight bas relief pattern emerge as the toner adheres to the copper board (i.e., you can see the pattern on the back of the sheet in 3-d).  I found that the iron picked up a little bit of residue and that can cause it to catch or snag.  Not good for the paper and not great for clothes (which can also mean not great for relationships! :lol: ).  A bit of extra fine steel wool for buffing can help that.

There, I think that summarizes most of what you need to know.  My eternal thanks to the pioneers who suggested use of glossy photo paper in the first place.

[Chris R]

Yeah.. PhotoPaper rocks.. i've never tried PnP .. but this is soo cheap.  

I've been using this method.. well since we were at the old forum.. 6 months at least.

just print the schem on the glossy side of the photo paper (like you were using PnP)

Then iron on the printed picture.. to the copper (make sure the printed/glossy side is towards the copper).  I use my cotton setting ;p  and iron for about 5 minutes 1 minute i rub the iron back and forth.. then the next 1 minute i just let the iron sit on top.. and repeat till the 5 minutes are up.

Next let the board soak in cold water for 15-20 minutes.. and then try pulling the photo paper off.  If your having trouble pulling the paper off then let it soak a little while longer.

And the traces can always be touched up w/ a sharpie.

This method works great for me.. in fact i just made a couple MXR Envelope Filter boards from tonepad (Thanks FP)

C

*Edit* oh yeah.. i don't remember who.. but someone long ago figured out that the Jet Print brand Glossy worked the best.

[Chico]

With regard to photopaper, I have tried this method and have had pretty good success.  However, the type of photopaper dramatically affects the results.  For example, HP photopaper worked to near perfection.  The traces were clean and crisp.  My biggest complaint with HP paper is that it is a royal pain to get the paper off.  I had to soak it for hours to soften it up enough to remove it.  Also, dont rub too hard to get the paper off, or you can damage the traces.

Epson paper worked terribly.  The paper released after reasonable soaking, but the traces were inconsistent and pitted.

Jet Print Photo paper Multiproject Gloss Finish worked vastly superior to any other photopaper, and is really cheap.  IF you go this route, I would highly recommend this paper.

One other problem with the photopaper generally, is that unlike PNP, the toner is your only etch mask.  Thus you run a greater risk of etch inconsistencies such as overetch.  As I understand it, PNP is nothing more than a toner reactive foil on a carrier sheet.  The toner forms the etch mask, but the  toner reactive foil serves as a second etch barrier to protect the toner from breaking down during etching.  Therefore, you can be a little less precise in your etch technique.

This weekend, I just experimented with a paper from Pulsar called TTS.

This paper cost 14.95 for a pack of 10 (about the price of PNP).   Where you are looking for simplicity and consistency, this is the way to go.  I printed using a HP laserjet onto the paper.  Cleaned the circuit board using Scotchbrite, cut out the pattern, and ran the board and pattern two passes thru a GBC Heatseal H200 laminator (that I also purchased from Pulsar).  Quench with water, and the paper litterally falls off.  No extended soaking required.  The precision is exceptional.  Pulsar also sells a roll of foil that is green (again it was 14.95) It behaves a lot like PNP blue, but it is green.  I cut a piece of green, placed it over the toner covered board, passed it thru the laminator, and the toner was applied.  After the board cools, the foil peels right off.

The laminator and TTS paper was relatively expensive, but from layout on my computer to printout to ready to etch is less than 5 minutes, including the time to clean the board.

Also, Pulsar recommends a technique they call direct rub etching.  Their basic theory is that microscopic etch particles adhere to the surface of the board, which slows down etching (something like this).  So you can etch faster if you "rub" the particles off periodically.

I took a kitchen scrub brush with a long handle, dropped the board (with green foil) into a small platic tub, heated Radio Shack Ferric Chloride, and periodically rubbed the board with the sponge.  The board etched in about 2-3 minutes.

Evidently, the green foil serves as a strong resist and can prevent even abrasive rubs from pulling the toner mask from the board.

Needless to say, from layout on my computer to firing up my drill to drill the holes in the board was less than 15 minutes including a few breaks and a sandwich.  Thats pretty cool.

Sorry to digress.  If you want to use photopaper, try the Jet Print first.