I was at my local building supply store to see what I could use to make a cheap holder for a Sharpie. It would be useful to use the CNC to trace lines on paper (for example, to make a big banner) or for whatever other application where you would want to draw with a marker.
I think I found the simplest and maybe even the cheapest option for about $12 CAD. All you need is:
A piece of 1/2" PEX tubing (OD is 5/8")
a 1/2" NPT end cap, I used a brass cap that I already had but you can buy a PVC cap if you prefer. Note that the 1/2" NPT cap is not actually 1/2". The OD itself is more like 1".
A compression spring. Not sure what stiffness. I just used what I had.
MOEN tub spout adapter kit (part M1498).
an o-ring or electrical tape. For the o-ring, I’m not sure what size. I used what I had but it looks like it is 1/2" OD and 1/16" thickness.
The Sharpie fits snuggly in the PEX but since it’s tapered, I used the o-ring on the narrow end. Use tape if you don’t have an o-ring
The Moen adapter has an o-ring on the inside of the gray bushing. That needs to be removed for the pex to slide freely. And the little set screw needs to be screwed in and is used as a captive screw to keep the pex tube from siding out.
Once I get my Altmill, I’ll figure out how best to mount it.
I am also able to use this holder with a 2.5mm mechanical pencil. The brand I purchased off Amazon is NicPro, which has an OD of 13 mm (or maybe it’s 12.7mm). But instead of inserting it in a PEX tube, I used a copper tube and a bit of electrical tape. I also cut off the little pocket clip, which I never use anyways. These mechanical pencils come with coloured leads and in various hardnesses.
It looks as if the MOEN adapter is only available in Canada.
Telescoping brass tubes you say? My brother used to be a professional model maker and he gave me a bin full of brass and plastic tubes. You have no idea how many times I used them to makes or fix stuff. A pen refill is a good idea and I’ll see if I have a tube that will fit
I’ll throw my old version in here. Originally put this on thingiverse almost a decade ago!
Edit: Since then, and after building and helping to build several small drawing robots, I’ve come to prefer gravity driven pens over the spring loaded. I’ve always had less issues with using weight to hold them down rather than a spring as they tend to follow variations in the surface height easier.
Sorry for the tardy reply, but here’s where I got my plan from:
All the sizes, dimensions, and the specific refills that fit.
I will say, I had trouble soldering it together.. if done right you can get it to work with the AutoZero touch plate, which I have, but it’s not 100% fool proof. Whenever I need to do this. I auto zero with any other 1/4" bit, then swap it out and eyeball Z. Sometimes Z works.
