Engraving pantograph

[mklotz]

I made this miniature pantograph to engrave name plates and such, primarily for the models I make but also for other practical purposes.

It's a simple, fixed 2:1 reduction ratio mounted on a bearing so it can be swung up out of the way to inspect the progress of the engraving and mount/dismount workpieces easily. It carries a clamp that can grasp the handpieces of flexible cable tools such as the Foredom and Dremel.

The characters are traced from a Rapidograph (TM) template. (Remember those? Back in the dark ages of drafting they were all the rage.)

Here's a picture of the pantograph flipped back on its bearing to show the workpiece clamped in place.

The stylus used to track the letters in the template has a tiny, turned-down tip sized to match the grooves in the template. The other end of the stylus has a different diameter tip to match a different font on the template. A brass cover for the other end protects the stylus tip and functions as a handle used to guide the stylus.

And here's an example of the type of text produced.

Bronze or hard brass are the best materials for engraving. For an engraving tool I use either a very tiny spherical bur or grind my own pyramidal point tools on 1/8" drill rod.

I should mention that there is a drawback to using the Rapidograph template as a guide. The template has to be relocated a variable distance for each letter while the engraving bur always moves the same distance to the next letter.

In practice, I solve this problem by ruling lines on a piece of sheet metal taped to the base under the template. This provides a reference for where to place the next template letter. Sheet metal is used in place of a paper guide because the rather tiny tip on the stylus tends to catch and tear paper while it glides smoothly over metal.

[DIYer]

Thanks mklotz! We've added your Pantograph to our Miscellaneous category,
as well as to your builder page: mklotz's Homemade Tools. Your receipt:

Pantograph by mklotz

tags: pantograph, engraver

[Paul Jones]

Marv,

This is a marvelous and ingenious device you made and something I have always wanted to make.

The use of the Rapidograph (TM) templates is the ingenious part. I still have my Rapidograph (TM) templates, pens and pens bodies for beam compasses from the good old days of vellum and ink drawings in grad school. I have been following your other postings using the flexible cable Foredom tools and decided it is time to seriously consider buying one. I am impressed with you designs and thank you for showing this. You should consider using the HMT Tool Plans section and probably do very well with the interest in your plans.
Thank you,
Paul Jones

[mklotz]

I can't recommend the Foredom enough. It's an excellent tool, well designed and extremely well made. Expensive, yes, but you get what you pay for. The end play in the handpiece bearings is much less than in the Dremel flex shaft tool. Of course, that makes all the difference in producing attractive, consistent engravings.

BONUS HINT:

It's best to keep any flex shaft as close to straight as possible in use to reduce friction and the chance of overheating. Most folks hang the tool from a vertical hanger next to their dominant hand. Many hangers are available and most of them suffer from being too wimpy and flexible (the Foredom one may be an exception; haven't tried it).

I took a gas pipe bar clamp and drilled and threaded the tip for two hooks. Being adjustable, it mounts to any thickness bench and is perfectly rigid. I hang the Foredom motor from one of the hooks and the router speed controller I use with it from the other. (See below for more on this.)

Foredom and others sell a benchtop mount for their units. The motor is held horizontally and can rotate about a vertical axis. I would avoid it. Who wants a flexible shaft and the power cord lashing about on the bench top while you work? If I want to knock tools on the floor I can do a better job with my own two hands.


Here are two articles describing the Foredom hanger mentioned above in more detail...

http://www.homemadetools.net/forum/f...h-hanger-49170

http://www.homemadetools.net/forum/f...138#post100837

[Charron63]

RioGrande.com sells a flex shaft kit for 100$ thats complete and has the horse power to not bog on long taskings.

[aalv2003]

Hi Mklotz. Thank you for sharing! These tool is exactly I need. Could you show (pictures or drawing or at least explanation) on how you machining the screws and arms to mount the bearings?
Thank you very much in advance.
Alberto.

[mklotz]

Hi Mklotz. Thank you for sharing! These tool is exactly I need. Could you show (pictures or drawing or at least explanation) on how you machining the screws and arms to mount the bearings?
Thank you very much in advance.
Alberto.

I don't have any plans but there is information on the web about building a similar one...

Pantograph Engraver : 8 Steps (with Pictures)

There may be other information available; do a search and see what you can find.

My device was built using materials available in my shop. Plans for it would be superfluous since there is virtually nothing in the design that could not be altered to fit materials available in the builder's shop.

[aalv2003]

OK Marv. Thank you. Im watching your link. As you say Im planing to make some similar from scratch too. No plans needed, but you know, sometimes the crucial parts are tricky then is a good option watching how a previous version was constructed. I think the mounting of the bearings (machining housings) and their shaft (machining screws) are crucial, these reason Im looking for info.
Thank you very much again.
I will show my trying.

[mklotz]

I think the mounting of the bearings (machining housings) and their shaft (machining screws) are crucial, these reason Im looking for info.
Thank you very much again.
I will show my trying.

The bearings on the pantograph arms are nothing more than shoulder screws running in reamed, close-fitting holes in the arms themselves. Bearing wear is a non-issue on something that receives such little use.

The bearing that allows the pantograph to be flipped up out of the way to inspect the work is just a piece of drill rod again running in a reamed hole. This flip-up feature is convenient but not essential. It can easily be sacrificed in the interests of simplicity or rigidity.

Try for a close fit on the bearings. A loose fit will allow vibrations from the Foredom/Dremel to "muddy" the engraving.

An essential tool when making bearings like this is a set of over/under reamers. Think about adding some to your tool arsenal if you don't already have them.

The shoulder bolts I used were the same as the one pictured here...

http://www.homemadetools.net/forum/m...435#post101577

IMS, the shoulder is 1/4 or 5/16" diameter and the thread is 10-32. Of course, the exact size doesn't matter; any reasonable size you have available will do just as well.

[philipUsesWood&Brass]

The use of the Flex-Shaft is so Vital in almost all styles of Machine work. My Mentor had a Flex-Shaft BENCH, with FIVE Flex-Shafts plugged into a Rotary Switch, ~Then~ a single Floor Foot Pedal.

After a while I finally asked him the development of this, and his Reply I will remember Forever.

"The Time to Change Out from one Bit to another PAYS for the Cost of the Additional Foredoms. I also KNOW exactly in which order they are hanging (On the Pipe as you suggested).

(EDITED IN) His Time over a Year is how he thought!

philip, who got called to do a Food Run for his daughter.