Pencil Review: Rotring 800, Rotring 600, Pentel GrapghGear 1000, Uni Kuru Toga Roulette

    

      Yeah, I know. Weird, right? I know it’s not what you’d expect, but hey… I felt inspired.

    For those that don’t know me,   I have a bit of a pencil fetish, and also I haven’t seen a review of these from an engineer, so I figured I might just as well. And just as a mention, no, I don’t use the pencils for “art” purposes. I can’t draw a picture to save my life, but what I do draw with the pencils are mainly schematics, make some annotations or draw up mechanical stuff.

    But, before I start, I’ll make the disclaimer that these pens were bought with my own money. I’m not affiliated with any company selling these pencils. It’s just me, trying to put down my thoughts, likes and dislikes about these four models that I have.

And now, let’s get down to it.

    The pencils (from left to right) are:the Uni Kuru Toga Roulette (also 0.5mm), the well-known Rotring 800 (0.5mm lead), the Rotring 600 (0.7mm) Black, though I'd normally expect it to be longer than any other pen... cough cough...  and the Pentel Graphgear 1000 (0.9mm).

    First off is the Rotrings. Now I should just start by saying that both pencils are my favorite. The design is  simple and elegant but has a very technical aspect to it. The whole body is made from nickel plated brass so they have quite some heft to'em.

And you can feel this when you pick one up. For some people this might be a turn-off, but personally, this is one of the reasons I like it. 

Despite the weight, they're well balanced and don't feel tip-heavy. The 800 model features a retractable tip so you take it with you to  work…to show it off to your fellow engineers and make then jealous.

Aesthetics-wise, the contrast between the bare brass accents and the  dull nickel finish on the 800 is very nice and, considering the money you pay for it (65 Euros), the guys at Rotring really paid attention to the details. When you retract the tip, you can actually leave the  lead sticking out a bit and it still won’t protrude out, something  that Pentel didn’t really get right.

The 600 one is also very pleasant looking, sporting a lead indicator and a black satin finish. This feels more rugged and bumpier and also makes it a pain to take proper photos of it.

    When you look at the Pentel, you’re met by a generous grip with rubber inserts and an overall nice looking design. Then as you go up, to the clip  …… NO!... Just No!  

     There’s a gaping hole right under it, like someone  had his way with a dremel tool. And that exposed plastic mechanism inside…..

 Ok, I’d have no problem with this, it still looks kind of nice, but considering the ~20 Euro price on it, I’d have expected a different kind of locking mechanism that doesn’t let you peek under its skirt.

     It  is heavier towards the tip, which depending on your preference, it may not be a good thing (I like it though)

    Fancy-pantsy stuff aside, the pen itself is really sturdy and nicely built The body is all metal and just like the Rotring, it looks like it can survive a small nuclear blast. The model I have takes 0.9 or 1mm lead, but regardless of the size, the problem is the same….  you have the lead sticking out and you retract the Pentel’s tip… but there’s still going to be some lead poking out. Which, let’s face, it’s not the end of the world, unless your OCD kicks in. And then you have to pull out the  tip again, depress the lead release thingy, push the lead back in, then retract the tip again....sigh...

  And speaking of OCD, whenever I’m using it, if I rotate the pencil too much in my hand, the big metal clip hits on my thumb and becomes somewhat of a nuisance. Therefore, I can’t really rotate the pencil as much, so the lead gets lob-sided really  fast.

  But still, between these and  the knurled  grip and the lead hardness indicator, it remains a fine instrument which I love to use, despite the shortcomings (most of which are psychological).

   The Uni pencil is the latest in my collection and also the cheapest… something like 17 euros including shipping. And unlike the Rotring and Pentel, it came with extra  lead and erasers So thumbs up for Uni.

    Design-wise, the grip is metal with fine knurling on it, while the rest of the body is plastic, making for a nice overall look and feel. Personally, I’d have liked all of it to be metal, but you take what you can.

   The tip doesn’t retract like on the other two but that again, it’s already got a gimmick of its own: it rotates the lead  a bit, every time you touch the paper, ensuring the wear on the tip isn’t lob-sided

  And it actually works quite well. At least for doing schematics and drawing small and medium length lines.

  It takes a surprisingly light pressure to make the mechanism actuate and from the little use it’s  had, I think it’s a real nice piece of engineering. 
   I’m curious about is how sturdy and durable the mechanism is, but only time will answer that question. The tip doesn’t flop around because of this. It’s firm when in contact with the paper and I can’t feel the actual movement of the lead, which is what you’d expect

  Of course, no review would be complete without some true engineering work and some final opinions regarding the pens

     Now, something that pops up  almost always is tip movement. Most people say some pens  have a tip that does the conga, while others say theirs is stiff as a coffin nail. Truth is, I'm curious what that actually means, in engineering terms. How much is too much movement? 
  Also, when you have something that's 0.7mm in diameter and 20 or 30 mm long, that's surely going to flex, no matter what. And some retractable tip pencils tend to have a real issue with this.

  So, I got out my trusty gauge and set to find out.
  The set-up consists of this big hunk of square milled aluminium bracket to which I so professionally held down my pencils to measure the tip movement. Yeah, we don't need no stinkin'  granite plate and toolmaker's vise.

   I took some care to only  put slight pressure on the tip, so as to get the measurement only for the free movement and not put additional pressure that would actually bend the tip. I succeeded, somewhat, but for a manual set-up like this, you can't really expect too muhch out of it.

And now, the results  I got

• The Rotring 600, without the old in-out tip, registered 0.05 to 0.07 mm of movement
• The 800 on the other hand, with the retractable tip, got something like 0.08 to 0.1 mm
• The Pentel, the most beefy of the bunch tip-wise, got a 0.05 to 0.08 mm. Honestly, I would've expected even less movement, though most of it.
• As for the Uni Kuru Toga, the one that started this idea in the first place, the tip  moves something like 0.15mm. 

    Like I said the method I tried out isn't fool-proof so take these numbers with a grain of salt. Also this is side-to-side movement. So when you're putting pressure on the pen, the travel is basically halved. 

   And even though the Uni Kuru Toga has the largest movement, I can't say it is something that you feel when writing or drawing.

   Now for some fun facts that came out of using these pencils for a while.
  The Pentel, which is the less used of the lot, due to it being a 1mm lead, is OK, but kind of awkward to hold. Also, that big hole in it kind of putts me off sometimes.
The Rotrings are great for everything, from drafting to  writing and feel nice in the hand. The black version  of the 600 that I have has  some sharper knurlings and you can see that in most pictures online. 
   Probably due to the black coating or treatment it has. But still, it's on par with the 800.
 Between these two, the 600 has a very satisfying  "click" to it and the lead hardness indicator on it makes it stand out. That, and the black  paint job. The 800 's mechanishm isn't that "clicky" to be honest, but the fit and finish.. well that more than makes up for it.

    The Kuru Toga's hybrid style, part plastic and part metal gives it a nice look, but just knowing it's not completely metallic, kinda gets my nerd-juices in a tight spot. Still, I've used it and can say that as far as drafting goes, the roulette mechanism works, but for writing.. the pencil lead is gone in a flash. Full discolsure: I have bad handwriting and I mostly use cursive, so the mechanisn isn't really being put to good use here.

    The knurlings on it are awesome and give it a unique look  and for better or for worse, it's something I can tolerate having on my desk within arm's reach. Oh, and I think it's worth mentioning that the factory HB lead that comes with this one is a bit on the soft side, compared to regular HB from Rotring or Faber Castelle. 
And speaking of soft, the eraser is also like this.... so now I know why it came with so many spare erasers.  

      As a final word, there's also some Rotring Rapidographs ISO that I recently bought and reconditioned. so expect some nice pcs for thse in the future. Oh, and I also got an old drafting (draughting?) kit......aaand a Leroy lettering kit... some of you know where this is going...

Read More

Picoscope 3000 Series Review....or maybe not

  First off, let me start by saying that this is not really  a full review, but more accurately a first impression after I got to play around with one of these things. 

And because it's a PC scope, the impressions are not so much about the physical aspect of the scope as it is about it's user interface. And, boy, do I have some comments to make here...

"High Performance USB Bla bla bla...."

  The culprit....sorry, I mean the product I had the... opportunity? to play with is a Picoscope 3406D MSO PC oscilloscope.

This little thriller comes with 4 analog channels and 16 digital channels, a 1 GS/s real time sampling (even though the software lets you select all the way up to 2GS/s, but I don't know if that really does anything or it's there just for  the fun of it), USB 3.0 and more features than you can poke a stick at.

Yeah, right. 

And let me make an analogy here: suppose you go to the  local car dealership and go around the show floor, only looking at the specs where it says "Horsepower", paying absolutely no attention to, let's say, how comfortable the interior of the car is, or how well it drives on the street, or... I think you get the point. 

When you do find the one with the most horsepower, you give the dealer all you hard earned money, two small coins, a bottle cap and a paperclip you happen to have in your pocket, making sure you quickly but the latter two back in you pocket, as fast as discretely as possible.

After  you drive home, happy about you new purchase, you will be hit by the worse case of buyer's remorse, ever, because, you will have realized that you just bought the most ugly, uncomfortable, unusable car in history. See where I'm going with this?

So, yes, the hardware specs for the Picoscope 3000 series are very nice, and maybe the scope would deliver on them.....who knows... because I was too preoccupied with getting the software interface of  this thing to actually  work and with scouring through the menus to find basic stuff  like a cursor,  getting the waveforms to actually fit in the center of the screen, and so on. And for these kinds of scope, where all you have is the interface to it, no buttons or knobs, how it looks and feels makes all the difference.

Yes folks, it's bad. The Picoscope software interface is horrific. In the year 2016, when more and more really nice PC scopes are coming on the market, the interface is really frustrating and awkward to use. This, combined with the fact that it looks like something from 10 years ago, really makes you wonder why on earth someone would go and buy this product, as opposed to any other scope of the same caliber. 

First of all, when you start the application, as a first time user you will be met by the most mild-mannered and spartan GUI yet. Also, notice the selected 2 GS/s rate. YEAH baby, now we're talking 

At first glance, you'll notice that it has all the things a normal scope should have....like time-base and Volts/div settings...and trigger settings. Sweet!

On to the fun stuff

Now, for any engineer that has ever used a scope for more than 5 minutes, you will soon realize that for some measurements, you need some way to measure the time interval between event A and event B in time. Nothing more simple, just press the "Cursor" button an a scope's front end.

Well, this detail seems to have escaped the guys that designed this interface. After a frustrating hour of searching all the menus, all the nooks and crannies this interface has and calling another one of my colleagues to the rescue, nu luck. No "Cursor" tab, or menu, or anything like that. Only a daft looking green  little circle tucked away in the lower right corner, that has the amazing property of displaying "0°" on it, no matter where you move it on the waveform.

Again, this is from the perspective of a first time user. It shouldn't be rocket science to use one of these devices and I do apologize if some people that have read the user manual for the GUI know where everything is, that still does not make it any easier to operate.

This thing is also boasting all kind of communication protocols decoding, which is very handy. Except that, with 4 analog channels and 6 digital lines, all 6 with CAN protocol decoding on them, the GUI gets sluggish sometimes. And that happened on a i7 core machine with about 8 Gigs of RAM on it.
Also, that "real time sampling" thing....in the scenario I used it, no way was that real time. But who am I to complain.
Also, there was a very peculiar thing I stumbled upon....the traces would not zero properly, i.e. they had a a butt load of offset, one of them about 100 V. But, the guys from Picoscope thought of this ahead, and put in an auto-zeroing button for each channel

Too bad each time I zeroed channels B, C or D, the application crashed.
 A nice thing is that this thing always has the last 32 frames on hand, so you can review them  at any time, to see any missed signal behavior (see the "32 of 32" in the upper middle of the photo). Nice feature this is. But unfortunately, from all the button pushing, my application decided to go all Alzheimer on me and by the time I managed to set up my signal capture profile, both analog and digital (it only took abut 2 or 3 hours, what would have taken me 1 minute on any other mixed signal scope), the GUI only had the current frame on memory, and nowhere could I find something referring to the buffer size or history or the like. So, yeah, all we had to go on was a trigger on a certain event an hoped that all went well.

The Bottom Line

If this software was a pre-beta, OK, I would excuse a few mistakes in the code, here and there. But it's not. The version I downloaded was the latest one. It even said "stable" in the comments next to the version name, in Picoscope's Downloads page, so it had to be good. (F.Y.I. This version also crashed when I hit the "Zero" button for channels B C or D)

 I wonder why the latest version didn't work......

Anyway, a LOT of improvement is necessary here. The guys at Picoscope need to step up their game and actually build a GUI that works. I'll even lend them my scope and see how that works, since obviously none of them ever touched a scope before, otherwise they would have known to put all the common and important stuff where it can easily be accessed, front and center.

So, what's next?

Well, I've been doing a lot of work an my own personal projects lately, and built some nice gear. Of course I'm going to share them, pictures, schematics and all. Also, there's some power supply stuff going on that I want to share.

Also, I've been thinking about building my own LCR meter. After reading and doing some hard core research on the matter, I came up with a configuration  that I hope will work.

So, more interesting design posts to come.

Have fun and keep playing

Read More

How I make my PCBs: Toner transfer and PCB etching technique

      I know there's a ton of blogs and articles on the matter of DIY PCB making, and for every hundred articles, there's a hundred different ways to do it. 

So here, I'll just present you the way I do my PCBs. It's pretty simple and cost effective, not to mention I get good results...most of the time.

Things needed:

• A4 Laminator (I use a Peach PL718)
• Glossy A4 paper (150 gramms)
• Ferric chloride
• A large glass bowl 
• An even larger plastic  dish (for hot water)
• Isopropanol alcohool
• Plastic gloves
• 800 grit  sandpaper (if needed)
• Laser Printer

   And now, how I use the above mentioned items. Well, first, it's important to have a flat  laminator. Meaning that the paper, or in this case the PCB should go in and come out  flat and not at an angle, because, for obvious reasons, the fiberglass material isn't all too "bendy".

This is a recent board I did. It's about 300 mm in length, so heat dissipation can become an issue.

   The paper I use is glossy 150 grams A4 paper. It can be of higher weight, maybe up to 250 grams, but the most important thing here is that the paper must be glossy. That will allow for all the toner to stick to the PCB and give you a nice solid transfer, that will not flake off when you remove the paper. Regular A4 paper just won't do. I've tried it, and the result is crap. The toner transferred to the PCB will be easily rubbed off with your fingers, if you use the regular paper.

   So, needless to say, the next step is to use you PCB software to make your board design, the you print it out on a laser printer, on the mentioned type of paper. The type of toner is somewhat important, but most will give you a very decent result. Just do not forget to set your printer to print o heavy paper. This will have the effect of depositing a thicker amount of toner, which is exactly what you need.

   If the PCB has been lying around for a long time, in open air, it might have an oxide layer on it that will prevent the toner adhering. So I take some 800 grit sandpaper and give the copper a gentle rub. If you don't have any lying around, you could use some steel wool.
Then, wash the board under a stream of water then with some tissues soaked in isopropanol, give it another cleaning to get rid of the fine  dust.

   Next is setting things up for the toner transfer. As a common practice, I stick the paper to the PCB with a little Kapton tape so it doesn't wonder off when it goes through the laminator. I don't recommend using scotch tape or masking tape because the scotch tape will melt and ruin your day and the masking tape is too thick and any toner that is under that area will not be pressed down by the rollers of the laminator. Also, make sure the Kapton tape is in an area where there is no toner underneath, because of the same reason I mentioned for the masking tape.

I make about 10 to 20 passes on the laminator, depending on the board size and level of details of the tracks (spacing and track width). I basically just go with my gut instinct, but a rule of thumb for me, is after the board gets up to temperature (the temperature where I need a glove to handle the board), I do about 6 or 7 more passes, then that's it.

   After it's cooled for a bit, I put the PCB with the stuck-on paper in some warm water and let it sit for 5 minutes. Then I peel most the paper off and the rest rub it off with my fingers or use a toothbrush. If  the toner or the paper are not OK, this is where it shows. If you  use the toothbrush, or just you fingers, no toner should flake off, even if you give it a firm rub. If it does, then either try another type of (glossy) paper or try with another laser printer.

Don;t panic if yours looks like this under water. It's supposed to look like this. This has been staying in the water for  a few minutes

   All you need to do now is etch away the copper. I use a "bain Marie" for this part. I put the ferric chloride in a glass bowl (this should be large enough to accommodate the PCB but not too large, because it will cause you to use too much etchant) and then I place this in a larger plastic dish full of hot water. Warm ferric chloride will work much faster than if you leave it at room temperature.

Also, if you leave it to just sit, it will take a fairly long time for the whole copper to etch away, that's why I hold the glass bows in the water and constantly move it side to side (the idea is to keep the liquid moving in the glass dish).
In about 10 minutes, a   5cm x 5cm board should be ready. Don't forget to wear some plastic or latex gloves, because the etchant stains. And do this in a ventilated place, as the process will release Chlorine fumes. And Yes!, Chlorine is bad for you! - that's why they put it in water, to kill every living thing in there.

    After you can't see any more copper except the one covered by the toner, remove the board, wash the etchant off under  a stream of water (again, careful here, because the ferric chloride stains you skin and anything else it touches ). 

After you admire you masterpiece and brag to anyone in the house at that moment, use a stainless steel sponge or steel wool to remove the toner off the copper. Again, do this under a stream of warm water.

At the end you should be left with a nice, fresh PCB, ready for tinning and drilling some holes (if it's for Through-hole). I've tried this method for track widths down to 0.4 mm and it works great. You could push it down to 0.3 without any issue, but that depends on your luck and skill. Too much temperature and too much pressure may cause the narrower tracks to flatten out and actually get wider.

Again, this is how I do things. It's worked so far, even for some SMD boards, but if you design a board with really fine pin pitch, I'd recommend the UV exposure method.

It's OK if things don;t work out first go. As you can see below:

This is an example why the printer and toner a very important. Here, the printer did not deposit enough toner on the paper, even though the settings were for heavy paper. So it's all about experimenting, to find the right printer that works for you, or the right settings on a printer you already have.

This is the second go, and the result is much better:

    The tracks did not flake off this time. Also, I had some 0.4mm tracks going extremely close             to some pads (upper right corner)...those turned out great.

So the conclusion is, experiment, find what works for you, then stick with it.
Also, you might find that for through-hole boards that have thick traces, one process might apply, but for SMD boards, you might go with a UV exposure method maybe.

Read More