Does anybody know anything about “Pad Printing” and could either give a good description of it, and its various considerations, or else could point to a good online reference or book that I could read more about how its done? I’m primarily interested in learning about its basic principles, problems/issues to be aware of, and how to construct a simple pad printer for use at home.
I’ve also considered alternate technologies such as ink jet printing (starting from a sacrificed ink jet printer) but I’m not sure how well this would work. Certainly that idea has some merits if certain issues could be worked out such as controlling the ink deposit a short distance away from the print head (enough to allow feature clearance).
I don’t want to do decals if I can help it, though that might be the most realistic way to go. I’ve got literally hundreds of cars to do, mostly hoppers and boxcars, and most undecorated still in kit form. So I’m trying to figure out how to set up a small personal-use assembly line to do it.
Pad printing is not really something you can do at home. It took me a couple months to learn the process in a factory. It involves a ratther complex machine. an engraving plate etching, a large assortment of printing heads and fixtures.
Pad printing is something that requires special training, machinery and dies. It is not for the do-it-yourselfer unless you’re so wealthy that you can afford to spend hundreds or thousands of dollars per copy produced.
A better method would be silk screen printing. You set the type or artwork with the ink jet. You make a neg. You expose the neg to the treated silk screen, develop and print as many as you want.
Just Google Silk screen supplies and see what you can learn.
Best of all you can do white printing as well as muliti color printing with multiple screens. Very fine screens are available to print reporting marks, etc.
I am producing 60 baggage and RPO cars. Decaling them would be too expensive if I could even buy them. By setting up a printing frame the car sides can be registered with small blocks to obtain precise location on every copy.
This won’t work if you have grab irons or other obstructions on the surface so set up an 8 x 10 page full and print them on decal paper.
Yes, I considered screen printing but I don’t think that’s an option due to the irregularity of the surfaces and I don’t want to decal hundreds of cars by hand. So in researching options, the one that really stands out is pad printing. I’ve had a hazy, general idea of how its done, but had not found good information until today. One of the respondants to this post provided some pretty good links. That also helped me find some videos and to contact a pad-printing company for more information.
After reading through the various articles and stuff it seems reasonable to me that there could be a home-built assembly rig to do some sort of pad printing on a small scale. The issues, as I understand them now, are primarily how to get the plate (the ‘cliche’), obtaining the right type of pad for printing, and the inks. The remaining aspects would seem to be constructing a suitable rig to ink the cliche and move the pad over it to pick up the image, and then roll / stamp it in the right spot on the car.
I’ve already thought out the solution to some of this. The rest I need more info from the pad printing company regarding costs, what’s available, etc. I also wouldn’t mind knowing more-- from any source?-- about the hardness of the cliche needed, amount of time required to properly ink it, etc. More of the process details. It doesn’t matter to me if its a mostly manual process as long as its repeatable and less tedious than decaling.
Another thing I’m thinking about, while I’m waiting for input from elsewhere, is whether or not the material used in those foam “stamping” pads that kids us
Did you consider having the cars pad-printed for you? Companies such as Bowser do this for special runs such as model railroad club cars. You will still have to decal on the car numbers, but you can minimize this by having the first couple numbers pad-printed, and the remaining digits decaled on. Business being what it is these days, maybe they’ll be willing to give you a good price to get the work.
Note that even the professional companies will have mis-hits until they get the registration straight, and that’s with their fancy equipment, so I don’t think you’ll find the process easy to accomplish with home built equipment.
That’s one of the things I contacted the pad printing about, to find out how much they would charge.
I understand what you’re saying but I don’t think there’s any reason that a home-made rig has to be any less capable than a pro rig-- it just wouldn’t be suitable for professional-level jobs. Its certainly possible to build accurate home-brew equipment even though it may take require more setup to use, take more time to operate, be more difficult to operate, not be as efficient or automated-- or even as you suggest, as accurate. But as long as its good enough and produces reasonable output, that is the essential goal, and one that I think is probably achievable. My goal isn’t to put the professionals out of business, rather to just make something that would work “good enough” to use at home. Two different levels of engineering.
As an example, I can’t imagine that anybody could produce a template as accurate as a commercially-produces Fast Tracks jig… and yet somehow, people manage to build reliable and accurate home-made turnouts all the same.
Seems like a whole lot of energy/time/costs/trials/rejects/etc. to me. Have some custom decals made and do the cars in batches, lay them all out on a table, do one, move on to the next one, etc. Several (or many) such work sessions would produce cars with proper lettering and very little waste or experimenting. Farm the decaling out to a local club. Minimal investment in time and money, no messing around indefinitely trying to get pad printing to work properly, no special inks or processes, no cars with problems.
I’d be happy to be proved wrong, but unless you intend to do pad printing commercially for others, I think you’ll find the expense is way too high for the equipment to just to do it for a few cars of your own at home. If you shop around you can get custom made decals that per set don’t cost much more than over-the-counter commercial decals, or software to do your own decals.
I suspect it’s kinda like the difference between burning your own CD’s on a computer, and pressing your own LP’s. One is feasible as a home project, the other isn’t.
Also it looks like manual Pad Printers can be had off of ebay for about $250-350 bucks. Plus the cost of supplies I’m sure. Assuming decals are in the $2-3 bucks each range, then the cost to do 100-150 cars would be about the same. After that it would get cheaper.
Does anybody know how you go about making the cliche (printing plate) ??
Here’s another pad printing video to spark the imagination. This looks like it could be accomplished with a simple XYZ table, some industrial steppers / controller with maybe “G-code” protocol. The interesting thing about this video is the cliche (plate) and ink & ink cups are handled separately. This looks like it could be buildable in the $500-1000 dollar range. Which admittedly is on the high side for a hobby project, but on the other hand, you could probably use the addressable XYZ setup for other stuff too.
Let’s try that one again. A decal page is about a dollar a page, likely a tad less for an 8.5 by 11, dpeending on the hobby shop and the sale. I don;t know the ballpark for ink, but it can;t be up to 2 bucks. Also, lay out as much of the decal as you can into one piece, so your not decaling 6 times for six rows, but once, so long as it;s not white font. In hO scale, I’ve got almost 60 decals soley for car numbers on an 8.5/5.5 sheet. Assuming then that you add in a logo, you still end up at 60 to 70 decals a page at 8.5/11, or 1-2 bucks for 70 cars. At worst, you spend ten bucks for somewhaere around 200 cars.
And not to rain on an idea, I applaud trying to break a mold, but the only reason I can see pad printing as being more effective is whites. You can’t print whites. But for a cost difference of about 25 fold, I’d go find another solution.
EDIT:I neclected setting solutions. To do the dec als, you;d need maybe 8 bucks in Microsol and and 4 in Glosscote ( you can get in a spraycan if you don;t want to hassle with an airbrush, and you’d likely want the Gloss with the pads anyway. And that’s total, not per page. Morwe might bbe needed depending on how much is used, but we still aren’t over $30 to make your own decals.
Not to be bellicose, but I’m not sure where you’re getting that $1 buck a sheet price…? My experience is that decals run $2-5 bucks a set…? For each car I have to do two long sides and two short sides (sides and ends). That’s reporting marks, car number, railroad name, logo, build date, and all the rest.
That actually might be a reasonable partial solution in this case. I could probably silk screen the sides as easily as I could pad print them. Its the ends that are going to be the real problem.