Introduction: CNC Plate Marker/Engraver - Homemade Attachment
Automation is a bit fascinating to me and I am active on several cnc forums. Recently, adding a plate marker to machines has been the hot thing to do. (Those of you not familiar with plate marking, it is essentially drawing/engraving on a sheet of material, be it steel, aluminum ect, with a quality built pneumatic engraver) Me, being who I am, upon seeing these amazing attachments wanted one to add onto my small home-shop cnc table. That is until I saw the lowest priced setup weighing in at over $2k.
So again, me being who I am, said aloud, "pfffttt, I can make one of those with matching quality for waaaay less than that." And, then I set off to do so.
I had posted this process on an extremely popular forum and was emailed by the owner of a manufacturer of these systems (made the mistake of posting in that manufacturers sub-forum) and asked to delete the thread because he did not want the simplicity of this process exposed. He said it would drive away sales if people were making their own tools. I am a huge fan of innovation and it hurt me to see this asked of me. I believe that while more and more people begin using plate markers (or whatever is relevant), the drive to find the "next best thing" will intensify and the industry will prosper due to advancements made. However, it was his forum and I respected his wishes and deleted, what I felt was, a wealth of information. It is now time to share. While I do not expect that anyone can do this as cheaply as I have, while competing with the quality of tools I have used (in fact, I challenge it) and maintaining the boundaries of the law (stealing is cheating), I do hope that I can open some eyes to resourcefulness
Now, through my explanation I will reference purchasing used tools. I must disclaim before going any further that if you are in the "used" tool market, I beg you to PLEASE do you research before making a purchase from an individual. Some important things to consider are:
- How old is the tool
- Who is the manufacturer
- Where was the tool made (this can tell you worlds about the quality)
- How many people have owned the tool
- Is the seller a responsible person (was the tool maintained properly? oiled if called for, kept clean and free from abuse and excessive/unintended wear)
- Why is the tool being sold (it's hard to justify selling a useful tool, as it should still be making money if it is in useable condition)
- Is the person you are buying from trustworthy (nothing worse than buying a stolen tool, having to return it and not getting your cash back)
- Lastly, be sure to look into common defects with the tool (as this could point to the reason it is being sold in the first place.)
I watched a few more videos to see exactly what was happening during the marking process and observed: The tool is held above the plate while traveling between marking/drawing points. This is to keep the engraver from marking across the entire plate and making the whole thing look... Well... Dumb. I observed, next, that the engravers are also turned off during this lifted travel. I can assume that this is to cut out unnecessary sound. (pneumatic engravers cause quite a racket) And then I noticed that... Well, that was all I noticed about the process o_0 Nothing to it! Beyond the mounting bracket this two-thousand dollar process was not much more than a relay and a 5-way air solenoid!
The next step was to watch more videos and make sure that what I was seeing was correct, and it was. Then it's onto a parts list.
- Pneumatic Engraver - I was fortunate enough to come across a gently used Chicago Pneumatic brand engraver for $50. These sell for just over $400 new. I bought mine from an old tool-maker who didn't use it enough to justify the space it was taking up in his box and couldn't remember how much he had paid for it. With that being said, my $50 offer sounded pretty good to him, for a "shaking pen." I do know that this guy takes great care of his tools, to an extreme. So +1 for me!
- A 5-way solenoid - I picked this up a few years ago for free-dollars when the company I was working for ordered an extra by accident. The manager new that I was collecting components for a pneumatic can crusher at the time, and asked if I would like to save him some paper work and just take it off his hands. 0_0 ! Yup! (gotta love managerial logic... Giving something away for free > 5 minutes of re-boxing an item along with a reason-for-return slip to get refunded $350.) I wound up with a top of the line SMC brand 5-way that would later be used to control the up/down motion and air-to-engraver. +1 again!
- Air Cylinders - These are needed to accept the air that will control up/down. A couple years ago I was just browsing eBay and came across a seller who had listed "as new" small-bore 1" stroke air cylinders for $5/each. I thought to myself, "One day I'll find something for those..... Right? ... SURE!" I grabbed 5 of them to sit on the shelf.
- Mounting bracket - I need a way to hold my setup to my tool (typically plasma torch) holder. I had a scrap piece of 1/4" steel in my "shop" (shhhhh It's really just my garage) I drew up a bracket that would clear any obstacles that the makeup of the machine would present and plasma cut it out, broke (bent) it and called that job done-zo. +3 because I'm cool like that and don't charge myself for my own time and the scrap was paid for so that part was free to me, sans some nuts and bolts.
- Single Pole Double Throw Relay - I actually use (as you will see in the video) a DPDT and just use one of the poles on each side of the throw. While it would be convenient to use a 12v relay I happened to have a 24v close to me while I was building so it got picked. I'm not sure what I paid for this but I'll just say, if you're on this site and you don't have a box of relays sitting around, maybe you don't need to be on this site. :)
- Power Supply - You need a power supply to trigger your relay. I keep an Omron brand 24v supply tucked in my tool box so that I have 24v whenever I need it. iirc, it was around $30. But it has done it's work for me previously and had, in a logical way, paid for itself already. Free to me for this job. I win again! (Gotta love financial justifications)
- Wire - Uh... Yeah, you'll need some wire.
- Air fittings and tubing - After making the decision that I wanted to use push-to-connect fittings and stick with one sized tubing to plumb this job, it was mandatory to do a little reading about the different applications that each fitting and tubing type are designed for. I opted to use plastic petroleum resistant fittings and tubing, to avoid and air-line oil deteriorating my components. I purchased these items from MSC Direct, and piggy-backed it with an order at my "real job" to avoid shipping fees. Air fittings and tubing is outrageously expensive and I believe the cost for these items was pushing on the high end of $70.
And that's all, component wise. I'm being quite liberal with my math here but:
$50 for the engraver
$10 for some eBayed air cylinders
$70+ change For air line and fittings
+ wire and little pieces/parts, nuts bolts
And there you have it, a functional cnc controlled plate marker for a grand total of between $130-$150
Well, this part took much longer to type than I had expected, now it's 4:10am and I have to be at work @ 6! Yikes!
I'll post up a quick overview of my setup that should cover everything I explained so that you can put words to something visual and get a better understanding of what I was describing. I have a couple vids on my yt channel covering this, that I have taken over the last month or so. Feel free to check 'em out at: youtube.com/bossfabrication
Oh yeah, I almost forgot to tell what I will do if I win the ShopBot... I would like to find enough work for a table that big so that I can, ditch my tiny cnc table, take some time off from my "real job" expand my garage hobby into a business and make Boss Fabrication ( that's what I call my garage. lol ) a reality. We are talking about one of those nice 5-axis machines, right? Isn't that what's up for grabs here? ;)