I've been trying to make a holder for a mechanical pencil for my mill. I wanted to check for anomalies of a drawing on a flat piece of material. It's hard to see what's actually going on in mid-air!

I've tried ball point pens (unpredictable results regarding ink flow)
I've tried pencils (lead rubs away prior to finishing drawing at stationary z-axis)
I've tried ultra-fine tipped markers (tip collapses and are too long to fit in center spindle without cutting; hence messy)

So, I got the idea to make it spring loaded but I don't have the correct drill bit size needed to bore for the mechanical pencil or it's internals to slide in a holder.

I've search the net again and found Ken Jenkins plotter pen idea (which is almost identical to my trials and efforts), but the site shows "Last changed October 1, 2003".

http://kj.cloudcitydigital.com/pages/CNCplotterpen.html

I sent an email to the link listed on the page above, but it got kicked back as no longer available.


ANYONE making one of these for sale?


I've search the net and found lots of patents but no one selling a pencil holder.


And Yes! I have searched these forums already, LOL!

Vogavt............

Had the same problem- I took an old centre punch apart (they are spring loaded) and stuck the inside of a bic pen where the pointy bit was. That seemed to work although I ended up making it a bit more solid by using that putty metal stuff.

Hope this helps!

I looked at the center punch too. Finally got an understanding of what "double-spring loaded" meant. LOL!

Anyway, I hadn't thought about using the metal putty as a filler. Great idea.

Did you have to do any boring, reaming or drilling? How did you get the extraneous movement out of the pen/pencil tip?

Nah, I bodged it in the true tradition of the Scottish engineer lol-

I took the pen apart and taped the brown bit that holds the ball bearing to the punch pin. I then used the metal putty to lock the pin to the punch housing so it couldn't rotate and some more to make the pen tip secure... obviously your X and Y will be a bit off centre cos it's on the side of the punch pin, but that wasn't too important to me :)