thank You 4D

 

4D, I was taught that the 4- basic dimensions are: X, Y, Z & Time, do you concur?

I like the way you think and solve problems. You also have a tremendous gift of self-critique to improve on your initial designs.

Otis Guillebeau (inventor) from Auburn, Georgia

 

Thanks Otis.

As for dimensions it depends on who you ask. I had a college studio professor who balked at me when I claimed my project for him had a 4th dimension (of time). The office space I designed (a 1st floor bank in a multi-floored building) could be reconfigured during the evening non-business hours to keep upper floor visitors and tenants out of the bank spaces, but permit easy access to banking resources during banking hours. He eventually accepted my 4th.

On a CNC we may have X,Y,Z and A (rotary) for 4, as well as X,Y,Z,A and B for 5 where A and B are two more dynamic dimensions of bit movement/orientation during a cut. You could consider the variety of router bits used a unique dimension. Change the bit and you change the outcome.

String theorists might insist there are 10, 11, or 26 dimensions.

I try and stick to 4 where time is the 4th. Of my own designs many have more than one configuration their 3 dimensions can change to or through. A chair that folds up for flat storage has a 4th dimension. It can't be folded AND unfolded at the same moment, so each state exists at different times. A coffee table of 4 parts that can be re-arranged to change the height of the top has a 4th dimension. A tv-tray stand that can turn inside out to present a flat or a sloped top (for tablet/laptop use) has a 4th dimension. Etc..

The open frame design of Probotix' CNCs permits re-configuring it for complex cuts as your needs change over time. Keeping the 3 axis of movement the same, but adding new orientations for clamping work beneath them lets one take advantage of their 4th dimension potential.

4D

 

4D thanks for posting this file. I have one rail section of my CNC Shark pushed back so I can mount a jig I made to cut guitar headstocks for inlays. It adjusts for any angle in the neck.

I might try to use a modified version of this on one of my other machines.

 

I've got a CNC Shark too Mike. Love to see a photo of your jig and how you mounted it on your Shark. With the plastic bottom and center Y axis threaded rod I gave up on vertical/angled mounting for anything more than small/short parts. Main reason I bought my Probotix Meteor.

4D

 

I have my machine mounted to torsion beams so I can level it easily and I have made several modifications to the bed and machine. My shop is on a steel frame sitting on a bed of rocks and this land use to be farm land and is still settling so my shop moves every time it rains ... or doesn't rain.

This is the jig I made. It mounts below the machine in a slotted block so it can be quickly adjusted to change the angle by loosening the knob and sliding the block in or out. The arms can be adjusted with a screw driver if needed. At the top it has t-bolts that slide into the rails and tightens down with knobs. The guitar neck clamps to the upper arm and I use a tilt box to level up the head stock. Then zero on the head stock and cut the pocket for the inlay. Then un-clamp the neck and hand it to the owner as he hands me the money.

 

Very clever Mike. Thanks for posting the photo and explaining how it works. We have had a few students who made string instruments as their shop project, but I defer them to another professor who actually plays guitar and has made a few of his own related instruments.

4D

 

I've since made a larger version of my jig in anticipation of needing it for student projects this semester. Quick photo here. I cut all the parts (but the top bar) from a roughly 2' x 4' piece of 18mm (3/4"ish) plywood. The top bar that bolts to the front frame member is 1/2" plywood (could have been hardwood) with two end pins joining into the vertical connection bracket.

4D

 

The jig in the above photo is getting frequent use this semester. Most of the time it is just to hold a part vertical for cutting tenons or finger (box) joints or the occasional dovetail row. As it can be set level with the bed it also gets used to solve flat clamping challenges that the t-track on the back half of the bed fails at. We had a 3-legged stool project at the beginning of the semester and many students wanted a way to attach legs at an angle other than 90 degree to the seat of their design. With the seat panel clamped upside down on the jig I adjust it to match the angle they want their legs to attach at. Some used a tapered hole at an angle to attach their legs. Some used an array of small tenons cut from the end grain of their legs to penetrate the seat. This jig (and earlier versions) lets us solve many furniture design/assemble challenges that would be difficult if not impossible to solve using any other tool in the shop.

4D

 

I see that my pattern file has been downloaded 270 times (270 views?). If that is right I'd love to see photos from anyone else who has made their own jig based on my design. Thanks in advance!

4D

 

Well the jig in the above photos survived another semester and saw plenty of use. The last two weeks I've helped students cut pockets for legs on the sides of her end table project at 20 degrees from vertical, helped a student cut tiny finger joints for her hexagonal themed kitchen spice and utensil rack at 30 degrees from horizontal, 30 or so sets of 90 degree finger joints both plain and very fancy. I had only one official class to teach so I offered to help any student who wanted to do some 3D carving or rotary axis work. Ended up with several takers.

As it is now I have yet to find anything I need to improve about this adjustable angle jig. We move into a new shop space in the fall and I plan to re-work the t-track bed on our Meteor, replace a failed limit switch on our Nebula, and maybe convince a new department head to buy me a comet and spindle upgrades for the dedicated CNC room in the shop.

4D