Pantograph machines were the early way of doing pattern tracing. Deckel is a well know manufacturer. Here's an example of one machine:
http://www.sterlingmachinery.com/
They do allow you to do scaling (make a larger tracing pattern at a fixed ratio) so you can improve the resolution of the actual machined surface. These use regular milling heads with standard cutters (square end mills, ball end mills etc).
Most of the engraving machines are much lighter duty, made to "scratch the surface" for lettering on plaques etc.
CNC (CNC=Computer Numerical Control)obsoleted the pantagraph for the most part. There was not need now to make patterns as it was all done in the initial programming. Most machine shops have at least 2 axis CNC's for most work. Many have 3 axis or more. 3 axis would be needed for stems if you want the letter depth to be constant as you are cutting on a curve.
In either case, you're either paying for the programming time (several hours of shop time) or else pattern time for the pantograph. After that, you can make dozens of parts. Doing replica parts for the famous Italian marques would seem like a nice little niche business for the small machinist.
I've wondered if chemical etching isn't an economical choice for chainrings and stems. It won't have nice square corners at the bottom but once painted, it would look very nice and it's easy to do at home. Food for thought anyway.
Gary Watts Vancouver, Washington
-----Original Message----- From: classicrendezvous-bounces@bikelist.org [mailto:classicrendezvous-bounces@bikelist.org] On Behalf Of Mark Buswell|SisuHome Sent: Friday, October 06, 2006 2:47 PM To: CR Subject: Re: [CR]Re: panto-ing
Thanks Alan.
I have considered contacting some engravers here in the city (San Francisco). While there are many, I need to find someone that can engrave deeply (instead of just etching the surface) and someone that
can do the cuts in one pass. It looks like that's how original panto'ing was done. I believe the machine used is called a CNC mill (?).
Thanks for the tip. Mark Buswell San Francisco, CA United States
On Oct 6, 2006, at 1:22 PM, worthy2@earthlink.net wrote:
>
>
>> Has anyone ever had a stem pantographed by an engraver or machinist?
>>
>> I'm looking to have a black anodized Cinelli 1R stem pantographed
>> with the Rossin logos and 3 stripes. Attention to detail is a must
>> since it is essentially going to be a replica. I'm wary of bringing
>> it to just anyone. If anyone has had experience with this, let me
>> know. I know the stem has got to be out there but dang it, 2 years of
>> looking and haven't seen one.
>>
>> I live in the Bay Area, San Francisco to be exact, so a local person
>> would be ideal.
> Mark, I had a brief job in a SF trophy shop that used a
> pantographing engraving machine (and idiot operator) to engrave
> anything that came through the door. That trophy shop is long gone,
> but I'm sure there's a survivor somewhere in the Bay Area. We had a
> cyclist come in once with a crankset and pay for some engraving
> that the idiot screwed up, ruining the customer's crank, but that
> was fairly common in this shop. I'd suggest you supply the master
> guide, in the form of a zinc die that is made up-size (say 200%)
> from your camera-ready art or Illustrator file, from a diemaker
> like Apex in San Carlos, for example. Supply that to the
> pantographer with exact area-to-be-engraved taped off and
> percentage written right on it (50%)...it'll be almost idiot proof.
> Good Luck,
> Alan Goldsworthy
> San Francisco, CA, USA
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