Quick question on making templates

Hey guys!

Finally had a chance to swing by an awards shop and ask about getting some old / scrap plastic for making templates for my pantograph. Got the hoped for "Here's our scrap bin, help yourself" response.

So, I know to upsize my pattern (since it will be reduced in operation) and use a #54 round graver, but what's the best way to bevel the edges of the template for locking it into place? Do I even need to bevel the edges? Also what's the recommended way to cut this type of plastic? Score and snap or fine toothed saw?

Thanks in advance!

Steve, you're on your own about beveling the edges.
Some plastic and brass needs it and others don't.
One thing I can offer some help on in hand cutting templates in plastic.
If you use a round or diamond graver to cut with you will get a much cleaner track and right angle corners if you relieve down the face of the graver.
Take a separating or cut off disc in your rotary and cut a slot down the gravers face from the top nearly to the point.
Then install a small carbide ball or flame bur in your rotary tool and widen the slot out.
Do a little finishing of the face relief with a small round power or hand stone, it need not be perfectly polished.
This relieved graver goes through the plastic much better. Finish the bottom lift just like any other graver.
If you are using thin clear plastic for templates lay it over your printed copy and be sure to keep your head directly over the area you are cutting to avoid distortion, but I'm sure you know this.
PETG clear sheet is the best for this IMO. SOME of the window plastic sold by Home Depo and Lowe's also works.
Best of luck with it, let me know if you need any help with this.
John B.

I don't bevel anything. I just C Clamp them to the table with small clamps.

John, sounds like you end up with darn near a wood chisel? Sounds like it would work well. I've just used a round bottom graver I made many years ago and it seems to cut well for me but all I cut is Lexan so perhaps that works better than other materials and doesn't give me a fit.

Rex

Yep Rex, that's about right. Much like a miniture wood chisel except the upper relief doesn't go back as far down the shaft.
Give it a try sometime. It works easier and faster for me even in Lexan, PETG and Lucite.
Best, John B.

Gonna have to give it a try. Lord knows I make enough masters for the NASCAR trophy!
Thanks,
Rex

Thanks guys!

I'll have to test the stuff I have to see if it'll slide into the slots without beveling or if it's easier just to clamp it to the table.

John B.

I can see how that face groove would help in the plastic riding up / over the graver - it's likely not going to bend the way metal does and, in fact, probably will act more like wood.

kc: very easy to bevel without the bevelling machine. take a coarse, double-cut mill file. hold the top temp edge at roughly 45 degrees, and take a few strokes along the file. repeat along the bottom edge. don't take too much at a time, eventually your piece will smoothly slide into your copy carrier. this way you conserve plastic, you need no c clamps, and the regular copy stops will lock the temp in place in the carrier. another trick-- take a soft lead pencil and blacken the groove. this graphite coating in the groove will allow a smoother travel for your stylus.
any further questions, feel free 724-328-4951 till 1 am eastern daily

Hi Steve, Let the machine tell you how much to up-size. Lock the piece to be engraved in the machine. Center the machine so the styles you use for tracing the design and the diamond point that engraves are lined up. Be sure the piece is centered. Move the styles to the left till the diamond point is at the right extreme. Put a pencil mark where the styles is. Move the styles to the right till the diamond point is at the right extreme. Mark where the stylus is. The distance between the two pencil marks is the size of your template. Oops I forgot to set the size, it should be about the middle of your size range.

Hope this helps, I've been doing some tracing from my sketches. I found to cover the shaky hand the size should small and the art work large.

Jim

Thanks for the tips guys!

Jim I knew to check the corners for picking my spot / size going from the templates to the piece but hadn't thought about going the other way when making a template. Like many great ideas it's obvious once you know it.