Center Band Circles: Part Deux - The Jig Is Up

[Wmcullen]

I’m not sure if this process is right or wrong; unique or common. But it works for me and I want to share in case it's interesting.​

09: Center Band Circles: Part Deux
The Jig Is Up
last post: 08: Exploring Proximity with Dots

A few weeks ago I posted about a jig I built to drill holes at regular intervals around a wood Center Band.
I appreciate everyone’s feedback and wanted to share an update with some improvements.
Also, a few people asked how they could get one and I have a couple of options listed at the end of the post.

The Upgrades

1. a 30 degree guide to compliment the original 45 degree guide
2. stool/holder assembly more stable
3. adapters for 7mm holes
4. a caddy to keep track of all the pieces and assist with glue-ups.

30 and 45 degree attachments
The original 45 degree increment was fine but I thought having more dots at greater frequency would look better. I added a 30 degree attachment which works well with smaller dots.

With two separate attachments and lanes I can drill holes every 30, 45, 60, 90, and 120 degrees.

degrees​	which attachment to use/how	# holes per 360°​
30°​	30° attachment	12​
45°​	45° attachment	8​
60°​	30° attachment- every 2nd hole	6​
90°​	45° attachment- every 2nd hole	4​
120°​	30° attachment- every 4th hole	3​

Support Stool and Holder Assembly
These pieces are critical to getting good results. The holder was shortened and reshaped. It is easier to hold stable while drilling.

7mm Adapters
The system assumes your center bands are drilled with a 1/4” hole.
To use with 7mm blanks I made adapters that snap between the jig pieces and wood blank.

Tip: I’d recommend attaching only to wood. Brass tubes could damage the plastic holder assembly.
The caddy
Having a way to hold the wood while gluing was helpful so I built this functionality into a caddy.
If you have a spare mandrel or 1/4” rod this is an easy way to free up a hand while gluing.

Summary
The new jig is easier to use than the last one. With it I achieve what I’ll call “rustic precision” meaning it is not perfect but close enough to look “handmade with care.”

This is my latest pen which I used to test the new jig. I'm pleased with the way it turned out and enjoyed the process of making it.

How can you get one?
If you have access to a 3d printer, I’m attaching the geometry file (CenterJigV2.zip).
I’m not looking to sell these.
I am going to print a few extras and will mail them out to the first folks who ask for them. I may not be able to make many. Depending on requests, I may ask you to pay for shipping or make a voluntary donation to a charity... I'm still thinking this through. Once I have a few printed I will place a post in the IAP Marketplace->Trades, Gifts and Wants subheading with details.
- Cullen

 

[Penchant 4]

Very clever idea and engineering. Is the file you are offering something that could be sent to one of the on line 3D printing services. Not having a 3D printer, nor being very familiar with the process is the reason for the question.

 

[Roly]

I'd buy one tomorrow but I think the postage could be a bit prohibitive so I will see what I can get done down under. Very nice and informative

 

[howsitwork]

What a good idea.

Thanks for sharing it so freely.

stay safe

 

[FGarbrecht]

Very clever idea and engineering. Is the file you are offering something that could be sent to one of the on line 3D printing services. Not having a 3D printer, nor being very familiar with the process is the reason for the question.

It's an obj file which can be used to generate the stl (e.g. Fusion360 can convert it to stl for free) which is then used in a slicer application to generate gcode to run the 3d printer. I'd imagine any 3d printing service can just use the obj file.

 

[tomtedesco]

It's an obj file which can be used to generate the stl (e.g. Fusion360 can convert it to stl for free) which is then used in a slicer application to generate gcode to run the 3d printer. I'd imagine any 3d printing service can just use the obj file.

I have no idea what you said here.

 

[jttheclockman]

I do not want to take away from this thread but would like to add an option. I do my dots a couple different ways. One is with a router on a platform that I made for my lathe. The other is with a device that is not expensive and very easy to use. It does use collets so there is that expense but if doing alot of segmented pens with dots of all sizes and varied locations this divice can work well. Of course there are other ways to do dots if you leave the blank square or with flats you can always build a jig to use your drill press. The device I mentioned is used in conjunction with a drill press and can be indexed to just about any value divisible evenly. It is a 5C Spin Indexer. If you want to see one here is a link. Many different companies out there that make them.

https://www.shars.com/products/workholding/collet-fixtures/5c-spin-index-fixture

 

[Wmcullen]

Thanks all for the great feedback!

5C Spin Indexer. https://www.shars.com/products/workholding/collet-fixtures/5c-spin-index-fixture

John: this machined system looks like it would have the endurance that these diy plastic printed parts lack. Thanks for sharing!

It's an obj file which can be used to generate the stl (e.g. Fusion360 can convert it to stl for free) which is then used in a slicer application to generate gcode to run the 3d printer. I'd imagine any 3d printing service can just use the obj file.

Navigating the 3d printing world can be really confusing and I deeply appreciate Fred's help answering these questions.
He wrote me that some UPS stores (in the US at least) are starting to offer a 3d printing services.

Best,
Cullen

 

[FGarbrecht]

I have no idea what you said here.

LOL. An object file (.obj) is a file type generated by a 3d design program that completely describes the object being designed. The obj file can be converted into an stl file (using software). An stl file is also a data file that describes a 3d object, but in a form that is recognized by a 'slicer' program, which then generates a gcode file that basically tells the printer how to make the object from the original data description. It does stuff like specify printer bed and nozzle temperatures, plastic extrusion speeds, and controls the stepper motors that push plastic into the heated nozzle and that move the print nozzle and bed relative to each other in 3 axes (x,y,z).

 

[tomtedesco]

LOL. An object file (.obj) is a file type generated by a 3d design program that completely describes the object being designed. The obj file can be converted into an stl file (using software). An stl file is also a data file that describes a 3d object, but in a form that is recognized by a 'slicer' program, which then generates a gcode file that basically tells the printer how to make the object from the original data description. It does stuff like specify printer bed and nozzle temperatures, plastic extrusion speeds, and controls the stepper motors that push plastic into the heated nozzle and that move the print nozzle and bed relative to each other in 3 axes (x,y,z).

Thank you.

 

[civilwartalk]

I recently discovered this tool:

Center Finder with 3/8" Diameter x 1-1/2" Long Shank

DetailsSpecial Indicator Locates Drill Chucks Exactly on CenterNever drill off-center holes again...use our Center Finder to quickly and easily position your drill press chuck directly above the exact center of a round workpiece. Indicator amplifies the slightest misalignment so you can adjust...

www.micromark.com

This of course doesn’t account for the gearing used to turn the stock between drills, and likely will require radically different methodology, but may accomplish much the same thing.

Since I don’t have access to a 3d printer, I’m going to try it out!

 

[Wmcullen]

This looks like one of those handy/inexpensive/simple gadgets that could become a "regularly used tool." Thanks for sharing!

 

[Paul in OKC]

I do not want to take away from this thread but would like to add an option. I do my dots a couple different ways. One is with a router on a platform that I made for my lathe. The other is with a device that is not expensive and very easy to use. It does use collets so there is that expense but if doing alot of segmented pens with dots of all sizes and varied locations this divice can work well. Of course there are other ways to do dots if you leave the blank square or with flats you can always build a jig to use your drill press. The device I mentioned is used in conjunction with a drill press and can be indexed to just about any value divisible evenly. It is a 5C Spin Indexer. If you want to see one here is a link. Many different companies out there that make them.

https://www.shars.com/products/workholding/collet-fixtures/5c-spin-index-fixture

Hey, I got one of those!

 

[jttheclockman]

Hey, I got one of those!

That is good. They do work well. I did a pen where I used it for 1/16" dots. Not ready to show these pens yet because I am still trying to get a bunch together so I can show all at once. Hopefully in a few weeks. Ran into some down time in the shop that was unexpected so just getting back there. I tried doing the pattern with my router but being it is hand operated and not on a fixed tool like on a metal lathe there were problems doing that small of a hole. So I went with the 5C.