4th Axis usefulness?

[EdThorne]

I'm trying to convince myself that I can't live withourt this device. I don't see any posts of great spindles that people are making. Maybe I am just missing the posts. I already have a great collection of gadgets that I don't use including the probe. I have Aspire 8 and wish to make 3d rotary parts. Anyone tried making a doll's head? How about carving a person in 3d or a car?
Your thoughts are much appreciated.
Ed

[Ronwoodson2]

Ed.
I raised both the headstock and tail stock a half inch by attaching them to an aluminum base.
This allows cutting up to 4 inches in diameter. I have done several pencil cups and bowls with 3d designs
and various carvings, and text, around the outside. Most of the pencil cups were hollowed out with a standard
lathe, but can be done with the Shark (mine is a Mako).
The attached pics are of a 4 inch by 2.5 inch bowl with 3d designs, all done on the Mako.

I am working on raising my head and tail stocks by another inch. This would allow me to cut up to 6 inch diameter, which
the Mako will do. I still have an issue with this, and Joe at but I think it will work.

[Ronwoodson2]

Another picture

[Ronwoodson2]

And another

[NewAgent45]

Ron: Nice work!

Ed:

I'm not sure if you saw Bob's Super Simple 4th Axis. We had some success with this with minimal cost to build.

There are 15 pages in this string of posts.
http://www.cncsharktalk.com/viewtopic.php?f=12&t=1521

I posted some videos in some posts on page 13 showing Bob's concept.

With this device I am carving the model "unwrapped". For the Pepper Grinder profile I created the grinder base profile using Google Sketchup. I Carve the 3D models (3) on cylindrical portion of the profile. I did the pepper grinder profile work using a trial version of Sketchup. The trial version is a full version that reverts to the free version after 30 days. Now I have to ante-up!

I also made some adapters to mount and acrylic cylinders on the device and carve 3D models on the cylinder. The trick is to distort the model in y to match one revolution.

Have a great day!

... Rod

[4DThinker]

We have two machines with a rotary axis attachment in the university shop I teach in. Took a year to find a student project that needed to be cut on one rotary. Few will use the lathes we have these days. I've started making/collecting examples to keep around to give them some ideas. Like any new machine/add-on they are worthless if you have nothing you can use them for. I suspect I'll get a project or part each semester that can best be cut on the rotary axis, but doubt we'll ever have one running constantly unless I assign a project to use them. Still, the one cut we made last year was a perfect excuse for the Rotary we have. No other way to make the cut he needed.

[EdThorne]

Very nice work, Ron. Thank you for posting your pics.

Rod, I have seen Bob's Siimple 4th Axis. It's a great approach and will probably do most things that I might wish to try. Thank you for the reminder.

Thank you 4d. That's a good answer. I should wait until I have something worth making.

I already have the probe that I used only a couple of times for testing. I also have a collection of cutters that I never use and a nice drag tool that sits in its box waiting for a project. No need to add more tools until I need them. Think I will try Bob's simple approach until I need something better.

Thanks to all of you for your feedback and help. Great suggestions!

[NewAgent45]

Ed,

I found the gear design including the fit in the system was crucial for this accessory. I slotted my gantry mounting arms to allow for adjustment. I'm not that good with gears and got some help from Fixitmike on the gears. I used Fixitmikes procedure for designing the gears. The gear gadget is not adequate for making these gears. You can get his procedure from this post on the Vectric Forum. Be sure to get Mikes latest version. For me this was a challenge. Using his procedure your gears will have a "full radius root" contour.

http://forum.vectric.com/viewtopic.php? ... ar#p160842

I included some documentation on my gears in the post referenced earlier.

If I ever decide to raise my gantry I figure all I need to do is make a pinion gear with a larger pitch diameter and same pitch as the rack. This would allow you to make larger objects. Raising the gantry 2 inches would allow you to work with materials up to about 8" dia. You would still be limited by the length of the bit.

I should mention my machine has some upgrades including the Billet Aluminum router clamp and the Aluminum gantry support plate. I built the 4th Axis accessory before upgrading the gantry. We have seen improvement in all operations since the upgrade including 4th Axis.

Enjoy the project!

.......... Rod

[EdThorne]

Thank you Rod. That's a great program but will take awhile to understand. I'm not used to the terminology. I'll try.
Ed

[NewAgent45]

Ed,

After building the 4th Axis accessory I started by doing real simple stuff like mounting a piece of square stock and turning it round. In my setup one revolution equals 10.6 inches Y. The 10.6 y is constant for any diameter for my setup. Of course it is only going to turn to that point or maybe slightly beyond. So you just draw a rectangle X (length of stock you want to turn) x Y (10.7 inches) Then all you need to do is create a pocket toolpath with the correct depth and pass depth. Simple and works every time.

The next thing I did is cut a spiral. All you need to do is draw diagonal lines with in the same rectangle make sure the top of each line matches up with the bottom of the next. If you want a 1 inch per turn pitch you just space the lines 1 inch apart. The selecting the diagonal lines and create a profile path. I was successful with this the very first time. I used 10.7 inches in this example which would mean the piece would 0.1 inch past one revolution. In reality you can dial in the "overcut" based on your tool diameter. See the attached a video of my spiral cut test. I hope simplifies how this accessory works.

https://www.youtube.com/watch?v=wegBE3HyaVk

Enjoy!

.......... Rod