Pen attachment for 1/2" spindle

Does the “ultrafine” fit in the collet? Dug one out of the Eggbot box, it’s tapered, 0.4"/11mm in the middle so some tape could make it fit nicely in 1/2" collet.

Sharpies use their own measurement system. Fine is very wide, ultrafine is on the wide side of fine, etc.

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If the body is the same size as the sharpie mini, then yes. There is a bras tube that is slightly flared at the bottom to accommodate the pen. The tube is then supposed to fit in the collet. Inside the tube is another bras tube that shims the pen to prevent wobble, and a “counter weight” that fits inside that to contact the pen.

I imagine that I could take a couple mils off of the diameter of the outside tube to make it fit, but I won’t be doing any modifications before I hear back from the company. And really, there shouldn’t be a need to modify it.

The only thing I can think of is that the Ridgid collet is a complete tube at the mouth, so there is no give to allow something even slightly oversized to fit where other collets sometimes have expansion slots all the way to the opening end. This still shouldn’t matter if it’s sized properly. And something intended for cnc tooling should be built to tight tolerances.

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How long is the ‘ultra fine’ Sharpie? I couldn’t find any short enough to be reasonable in a router collet adapter, tried cutting a couple in half to be similar in length to the mini-Sharpie. A very messy process…

Is it a weight, or a spring? I wonder whether a weight would work at the Maslow’s mounting angle? A spring surely would.

It is a weight, but it doesn’t really maintain pressure on the pen, since the pen is friction fit into the tube. Not really sure what the weight is for. The point on the sharpies is pretty fine, assuming you don’t mash it (which for me usually takes about 2 seconds)

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If you wanted to use a pencil all you need to do is drill a hole in the center of a 1/2" dowel to fit the pencil snug. You could even put a spring in the end to push the pencil out. To keep the pencil from sliding out of the dowel I was thinking of threading in a bolt or set screw and flattening the pencil where the bolt is so that you would get some travel. If it is not necessary for the spring you could just drill the hole for a snug fit.

I have no idea if a pencil trace is dark enough for marking.

depending on what you are marking, a pencil would be a fine choice. For rough ply it might not work (the lead would likely break). Good idea! I would still like to have a sharpie marker, and may have to fall back on a DIY solution if this purchased solution can’t be made to work. I was hoping to save time (not money!) since my available tinker time is low. If nothing else, I can be the guinea pig so that everyone else can figure out if they want to purchase this thing

I plan on taking a log from firewood pile and turning on the lathe to fit in the router base. Then drilling out the end to accommodate a spring and maker. I’ll put a piece on the end to keep the shape from popping out. I will also notch out on the side so it can be controlled by the z axis.

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Anyone know the exact diameter of the rigid router. I haven’t bought it yet.

It’s just off from most routers, I think it’s 3.5 inches when most are 3". Matthias Wandel did a video on creating a router lift and used one, and griped quite a bit when he found the size was just slightly off of what’s normal.

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I went out tonight and turned the blank for it. I used a piece from my firewood. I’m going to finish it once I get the router to confirm the fit. I’ll taper the end to give it a pencil type look.

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So, I heard from Russ at Widget Works, and he and I talked for quite a while. I was very impressed with their customer service and their commitment to making their product work for me. In the end, it seems that the collet of the Ridgid and the tube of the pen are just too tight in tolerance. Russ agreed that taking a small amount off the tube might work, and committed to working with me to find a solution or to refund my money. Somewhere I have some optical abrasive pads for polishing the ends of fiber optics, with grits ranging in the micron to tens of microns, so I figured I’d pull those out and try to slowly reduce the diameter of the tube until it fits. 5 mil should come off pretty quickly, and I can always jump up to something like 1000 grit if needed.

This was also a concern of Russ’, as he verified that the counterweight is meant to provide a small amount of restoring force to the pen in a vertical orientation. He suggested that replacing the weight with a piece of soft foam might accomplish the same thing in the Maslow’s vertical orientation. I think that failing that, a spring from a ballpoint pen could probably be adapted.

As it is, I plan to give the CNC pen another try once I can find some time to shave it down a little. I am cautiously optimistic at this point. Unfortunately, I probably won’t have time to play with it for the next week or two (and then the new ring kits will be coming out and I’ll be on to getting that set up when I have time… etc etc.). I’ll let you all know when I do.

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That’s good news, and impressive customer support. Keep us posted.

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This is the idea. Just need to figure out the tension on the pen and how to keep it from jumping out.

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This is so cool! Does it move up and down within the router base OK?

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I used an alignment pen but I’m having problems with the shape of the pen. I will work on it more this week.

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Alright, so after talking to Russ and ensuring that he’d support trying to take a small amount off the OD, and since my daughter is home sick today so I can’t go to work, I went ahead to try to chuck up the pen again. After a quick hit with some fine abrasive pads with the pen holder chucked into my drill, it fits the collet just fine now. I am hoping to have some time today to test it out and see if I can get some marks on my backer board.

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I finally have a solution after testing many different ideas. This is what have I have learned. The best solution is to make a pen holder that replaces the router. The 1/2 in clearance on the router does not give enough room to put a marker in with enough room to slide.
The pen holder is best if the pen can pass through it and the stop and spring system is placed on top. I turned a piece of wood to fit inside the base. In my example, I used a pencil with a notch on the top for the rubber band to stay in place. I hammered a small brad to keep the pencil from coming out. The pen holder has a notch that the z axis can pull the pen off the material. Here are pictures.

IMG_20180221_172004|375x500

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I finally have a solution after testing many different ideas. This is what have I have learned. The best solution is to make a pen holder that replaces the router. The 1/2 in clearance on the router does not give enough room to put a marker in with enough room to slide.
The pen holder is best if the pen can pass through it and the stop and spring system is placed on top. I turned a piece of wood to fit inside the base. In my example, I used a pencil with a notch on the top for the rubber band to stay in place. I hammered a small brad to keep the pencil from coming out. The pen holder has a notch that the z axis can pull the pen off the material.

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Beautiful build! I wonder if I could make something similar by cutting a bunch of plywood circles and stacking them because I don’t have a wood lathe

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