All Things Wireless & Letterpress

All Things Wireless & Letterpress

Monday, March 27, 2017

DIY Low Profile Gauge Pins for Boxcar Bases.

Those of you who run standard or deep relief bases know that standard gauge pins, such as the Megill adjustables, cannot be used because there isn't enough clearance.  They get crushed.  Most printers either cut their own guides from chip board or thicker card stock.  Some use Henry Adjustable guides which are, essentially, double sided foam adhesives, like Tiger Tape or Carpet Tape.  

They all work, of course, but the devil is in the resetting and adjustment of these guides which have one thing in common: they are adhesive.  Some how they are either taped down or glued down or in some way adhesed.  To adjust, the adhesive must be worked loose which tears into the tympan paper, creating a rough surface and reducing the ability of the adhesive to adhere for the second, third, and fourth time.  Using the same tympan paper for multiple jobs becomes rather challenging due to the upbraided surface of the tympan cover.

The Henry's work great, btw. I still have mine. But being a foam pad, the stock does not glide smoothly, as with traditional gauge pins.  Some talc can take care of that, for a while. After a while during long runs, I discovered the stock being fed managed to find it's way between the foam tape and the tympan sheet, so I would have to stop the press and push the guides down.  What was happening was the adhesive was giving way, slowly but surely.

Traditional gauge pins can be used off the base area.  For this reason, some printers either get a smaller base, or they keep their pins in an off base area safe zone quite a distance at the bottom of the platen, and set up their print area accordingly.  And that's good.  Sometimes, for short guys like me, it's a pretty stiff reach for hand feeding.  Great for the Windmill folks, or the Automatic Kluge folks, but to us manual folks, we like to hand feed . . .  not bottom feed. 

After enjoying some of these frustrations for a few months, I thought I might try to adapt my own low profile gauge pins.  This post is the result of what I came up with.

The Idea

What gave me the idea were my spare Megill standard gauge pin guides.  I had far more than I needed!  They are made from brass so they are easy to cut and to bend.  They had no inherent 'budge', save for their native springiness. As I looked at the smaller sliding tongue, I began thinking "what if . . . ", and a low profile gauge pin took shape in my mind as I reached for my flat nibbed snipes.

I began with the sliding brass Megill sliding tongue itself.  I needed to do something to make it grip the tympan when inserted, and hold, not permitting the fed stock to slide under.

Using flat nosed snipes, I straightened out the slide grips of the brass Megill tongues. This is step one.  Flatten the sides.

Notice that little tab thing in the center of the "T"?  That will come in handy later.  For now, all we need is a straight brass "T".

Next, I used wire clippers to cut the "T" bar edges as shown.  Note the angle.  This is purposeful, to create two gripping points when slid into the tympan paper.

The two sides of the "T" are now bent down.  Note where the bend is.  Also, care is taken to ensure the bend is perpendicular to the main shaft body.

Here is another close-up showing the generally low profile of this pin.  Can you see that even if contact where to be made, the flat of the pin is flexible and will give way.  The sides are spread apart enabling them to flex further outward in case of a miscalculation of depth is experienced although, using a standard relief base, I have yet to make contact with the pins.

The last step is to cut and file or hone the back end of the shaft to a point.  This is what is going to be inserted into the tympan sheet, exactly like the Megill singles, securing the pin and enabling adjustment by sliding the whole pin itself back and forth..  These pins adjust like most Megill pins, actually, save for their larger "single-slice" mounted adjustables.  The 'stab' point should be sharp indeed..  I used a smallish metal file to make a sort of pointed blade.  Once adjusted in place, they can be taped, although sometimes I found they held good even without taping or using sealing wax.  (do any of you all still use sealing wax?)

Here is a mounted low profile pin, the very one shown in the photos above.  Ideally, the entry point should be a few millimeters back from that edge line... to provide some slip-way should the need to adjust present itself.  Best to use an Xacto Knife with a pointed blade to create the entry and exit holes for these kinds of pins.  Makes it easier to slide the tongue in and out.  I do that for the standard Megill pins, too.

This is a 90lb card held in place.  That little lip across the "tee" zone that I pointed out early just covers the edge of the paper, but is surprisingly effective for holding on to the card during the printing process. You can see that there is still enough room for thicker calipers of stock.  I was able to set thicknesses of up to 2.5mm effectively

A parting shot of the low profile gauge pin.  So far I have completed three print orders using these pins, all with a good results.  Once taped down, they do not budge.  Not a single mark on the Boxcar Base.  

Do they feed exactly as a standard type Megill gauge pin?  Yes and no.  The regular gauge pins provide a long, flat edge which the stock rests, and can slide easier.  These provide a stop, not a smooth edge.  So the slide and drop technique of feeding is no better than the Henry adjustables or any other paper or foam edge.  So, there is NO improvement there.

My goal, however, was to A: provide some sort adjustable stop with a low profile so as not to jeopardize the pin, the stock or the base, and B:  provide a stop that would not permit stock to slip under or beyond it.  Once these pins are in place, the pointed edge digs into the tympan sheet like cleats

So, they are certainly not perfect, but for me, they are simple, inexpensive, and most of all, re-usable.  

There are those, apparently, who oppose my use of these brass tongues in this manner.  One gave me a mini-course on the use of the sliding tongue on the Megill adjustable gauge pin, I thiank you for the short talk.  It was a great refresher.  I've used them for about 45 years, but sometimes it's good to be reminded.  I do not believe I am not destroying a valuable resource.  There are oodles of these, they were sold separately by the pack, most shops I know that use gauge pins have them quite in excess.

Recently, Ally, printer at 9th Letter Press came to visit. She tried out these pins, and they held firm for the entire run. They do take a little "getting the feel".   We did about four hours of printing on the Open Kluge, double rolling.  each cycle.   The stock slid into place well.  We did have to pay attention to the feeding pressure on the bottom pins because there is no flat surface.  If you push too hard you can dimple the edge!  We had to develop a fairly light touch.  Once established, you can feed these pins to your heart's content with no edge anomalies whatever.

Here is a shot of one of the cards coming off the platen.  Looks like it's just laying there with nothing holding it, doesn't it?

To be sure, on occasion I did lose a couple cards which landed in the "basket" behind the Kluge, that also happens on every other gauge guide, quad or pin I've ever used at one point or other. 

Another observation: they stayed put!!   In all, I'd say "mission accomplished"!

That's it for today's blog entry.  Thanks for joining me.

gary // Paper Wren Press.

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