Very ingenious design! I echo the desirability of a harder, denser base, as my experience with wooden stamping anvils has been unimpressive. However, wood is hard to beat for ease of fabrication, so it may be a reasonable tradeoff unless you really get into production mode.
I don't stamp enough caps to make this a tempting project to copy, but I'm very aware of the difficulty of getting straight rows of properly-spaced characters when eyeballing it. Some of my caps look like I might have stamped them back in my drinking days...
> My prototype design of a survey disk stamping jig that I finished yesterday.
That's very cool. But what is the timeline requirement for such disks? Wouldn't it be easier to just lay out the disk in CAD, send a DXF to your local CNC milling guy to mill them precisely as required?
We recently had to identify multiple, subtly different steel "left" and "right" parts for a project and began stamping them when our CNC guy announces that the mill software has text capabilities built in. Took perhaps 5 minutes to machine two dozen 3/16" high letters in steel. Brass would probably be faster.
Just a thought.
I have those metal lettering sets that you hammer onto metal discs. Problem I have using them is if the first strike don't produce a clean letter then repeated strikes will just blur the letter & render the letter unreadable.
How do you guys make a clean strike the 1st time?
> I have those metal lettering sets that you hammer onto metal discs. Problem I have using them is if the first strike don't produce a clean letter then repeated strikes will just blur the letter & render the letter unreadable.
>
> How do you guys make a clean strike the 1st time?
Practice helps, of course, but the fact is that I don't always get a good impression on the first whack. When that happens I reposition the die by feel -- you can tell when it slips into the partial impression -- and hit it again. I very rarely get a blurred character.
If you can make enough of an indentation on the first blow, then the die will fall back into the same indentation for a harder blow. I've had to stamp some cast bronze disks that required about 4 or 5 solid blows to make them look good.
Use a good anvil or stamping block, hold you die with pliers and use a big hammer. I have had the best luck with vice grips to hold the die. I very seldom hit my finger when I use pliers or vice grip pliers. A miss hit can cause you to look for the die for several minutes though
Try to get the stamp as perpendicular to the surface as possible. This is a little more challenging on domed caps. I use a framing hammer. Like Jim said, if it didn't completely stamp then put it back in the letter and twist it a little back and forth so you know it's in by feel.
Sometimes, especially if I don't have a good hard surface to stamp on, it is easier to lightly tap tap tap slightly tilting the letter back and forth, side to side, to get the ends of the letter stamped. If you lightly tap the letter doesn't seem to skip around. If you give it a solid whack then you need to recheck the letter is in before hitting it again.
> That would be perfect for our commemorative paper weight disks that we present to retirees. We cut the stem off a bronze cap and put their name a dates of service, then polish and laquor it.
Wouldn't the retirees prefer it if you liquored them?
> How do you guys make a clean strike the 1st time?
I'd second or third what others have said. You don't try to cut the number or letter in one strike. You make an initial, somewhat lighter, strike to set the die, which means that the object is to make an indentation in the surface to align the die for the second strike. Then, on the second strike you can put some snap into the hammer blow for the full-depth impression.
"local CNC milling guy"
Please elaborate...
We generally get caps with some stamping already done frorm the supplier, but so much of stenciling is site specific that it's best done in the field.
You don't want to return to a site to stamp a section corner if you can do it while you are there, and you don't want to prestamp them and have to grind it off when the corner isn't found, or you need to do something special with it.
You may find that the section corner location needs a witness corner or a reference marker and the corner itself can't be set. Then you have a stamped cap you can't use, or one you have to do so much "fixing" to that it's easier to stamp a new one. Or you may find there is one already there that you can just accept. I have many caps that end up being grinded off to get restamped, it's not very efficient.
Something like subdivision corners have the pls# already on it, then the lot # are stamped into them using the vice in the shop, if you have hundreds you don't want to take much time doing them
> Something like subdivision corners have the pls# already on it, then the lot # are stamped into them using the vice in the shop ...
Do you set any sort of limits on the level of vice in the shop or just accept whatever shows up for work?
no limits, lol
> "local CNC milling guy"
>
> Please elaborate...
Your best, local machine shop. Most nowadays have at the very least, a three axis CNC milling machine, which would do these caps (even with some crown). But if, as MightyMoe says, this is something most likely done on the spot, in the field, then this idea would not work. If you developed a relationship though, with a local machine shop, and they had the jig to hold the things in the vice and you stocked him with blanks, it might be pretty easy to fax or email the actual text needed for any given job, and have it done fairly quickly.
This text took about 4 minutes to set up and mill:
As a last thought, since most here use CAD of some sort, how about having the text for any given corners come right off the drawing file (like a "live" bill of materials does in a mechanical drawing), and into a CAD drawing of the monument. The dxf file for this goes right into the CNC machine with no risk of typos, incorrect corners etc. (unless of course the plat itself is wrong), in which case you got bigger fish to fry.:-O
Closest place that can do this is about 2-1/2 hours away from me...